Britain's on the brink of a small-scale nuclear reactor revolution For the first time ever in April, the UK's data centres and clouds ran on electricity generated without burning coal. The National Grid celebrated the news on Twitter with the promise of more coal-free days to come. As coal-fired power plants wind down and with talk of blackouts in the air, nuclear is back on the table after …
It doesn't get around the NIMBY problem. Some folks will hate anything (ignoring the folks who automatically hate everything) and the usual fix for nuclear installations is to convince local government what a boon the installation will be, possibly via bribes such as infrastructure promises.
For SMRs, the size of the payoff can be correspondingly smaller than for something like Hinkley Point. Since SMRs are likely to be doing combined heat and power, the deal on offer will probably be based around cut-price piped hot water for domestic and industrial use.
The flip side is that SMRs still need lots of cooling water. The likes of Hinkley Point need to be on the coast with deep water close inshore or on major rivers, for SMR we could go smaller. I wonder what the Norfolk Broads would look like when lit up by Cherenkov radiation?
"The flip side is that SMRs still need lots of cooling water. "
Water-moderated ones do, because of the low temperatures they run at and their very low thermodynamic efficiency.(*)
Molten salt reactors run a LOT hotter(**), are a LOT smaller (not needing to be pressurised and not needing the associated pressure vessel and containment vessel) and as such they can dump directly to atmosphere via cooling towers (which could possibly be large enough to run a vortex and generate more power from the waste heat) and as a nice side effect they can't leak radioactive steam/water or cause radioactive hydrogen explosions.
The OTHER nice side effect is that if you use molten salt fuel (LFTR) designs you can load follow almost as quckly as gas or hydro plants without the risk of neutron poisoning as the pesky Xenon can be drawn off and stored until it breaks down or reinjected later, avoiding any prompt-critical excursions.
Alvin Weinberg should be hailed as a Hero of Humanity, after inventing the water moderated reactor for nuclear submarines he became gravely concerned by the safety issues of sizing them up to GW scale (especially the pressures!) and developed molten salt systems as a safer alternative in the 1960s - The USA ran a molten salt plant at Oak Ridge between 1962 and 1968 but Nixon killed it in 1972. Oh, what could have been.
(*) They're also intrinsically unsafe as they rely on high pressure, high temperature water being in contact with radioactive materials. Steam explosions are a fact of life and the fact that nuclear plants are 300,000 times safer than coal ones is down to careful management and paranoid design standards. It's still better not to mix water and fissionables.
(**) Water-moderated reactors top out about 450C. Most molten salt ones are just getting started at that temperature and are designed to run at 600-900C, with fission reactions self-limiting about 1100C (which is about the temperature of the inside of a conventional fuel rod) and the molten salt itself boiling at 1300-1600C depending on the exact chemistry used. The extra heat on the hot side means that conventional cooling towers can be used instead of relying on dumping heat to water, which in turn means the power station can be located away from shorelines (tsunami risk) and rivers (which tend to follow faultlines). Yes, you can dump heat to water for greater efficiency, but the greater safety margin afforded by not doing so(**) is worth considering.
AGR plants (UK's main design) can also run bloody hot and don't really need water cooling but they have their own sets of problems such as radioactive gas containment when things go pear-shaped. This isn't helped by not being designed to handle a full temperature excursion to 1100C
(***) And not having to derate your output in hot weather in order to preserve the local wildlife. This is a fundamental weakness of any plant using rivers or shallow seawater areas for cooling.
Another way you can load follow is to have another tank of just molten salt. That way you can run the nuclear island at continuous full power and sell most of that energy. Moltex Energy's 'GridReserve' may interest you: http://www.moltexenergy.com/learnmore/Moltex_Renewables.pdf
"Water-moderated ones do, because of the low temperatures they run at and their very low thermodynamic efficiency"
not entirely accurate the way you put it. total plant efficiency is generally a function of the steam temperature going into the turbines, and the rejection temperature of the condenser.
You can run PWRs at very high temperatures, but the steam plant itself limits the total capability. I would imagine that a 1200 psi steam plant (with gas-fired superheaters) is "typical". The reactor would run in the 550 degree F range for that kind of pressure. Not a problem, really. Steam itself, in many ways, determines what the max efficiency will be for a power plant. If you could drive the turbines directly with molten salt, that would be different. but you can't. You still need steam (for a practical solution, at any rate).
Water, as convenient as it is, just has physics properties that limit your overall efficiency. You can't have steam above a certain temperature (its phase is indefinite, actually, neither liquid nor gas) and you can't have heat rejection below a certain temperature (i.e. ICE formation).
https://en.wikipedia.org/wiki/File:HS-Wasserdampf_engl.png
That makes me wonder actually... there are plenty of metals that are solid way above salt's melting point (otherwise containing it would be difficult), so isn't there any way to produce a practical system for turning its energy into electricity? The stuff must still convect after all, and I bet there are pumps somewhere within the system.
"You can run PWRs at very high temperatures, but the steam plant itself limits the total capability."
You _can_ run PWRs at very high temperatures and pressures, but it's not a good idea to do so.
Water's half-jokingly known as the universal solvent. Once you get it up to 400C + 20 atmospheres and add boric acid it has a nasty habit of eating pipework AND weak welds on nuclear fuel rods. There are a number of photos on the net of such examples.
The US nuclear industry has has a number of near misses caused by corrosion. Water is simply not safe enough to be in direct contact with nuclear materials. When things do go wrong it usually escapes and carries radioactives off into the environment. (And don't get me started on molten sodium... One word: Monju)
If you have a steam explosion on the tertiary loop, it's a steam explosion. No radioactives, no big deal.
Yeah, monju (extract from Wikipedia):
An accident in December 1995, in which a sodium leak caused a major fire, forced a shutdown. A subsequent scandal involving a cover-up of the scope of the accident delayed its restart until May 6, 2010, with renewed criticality reached on May 8, 2010.[4] In August 2010 another accident, involving dropped machinery, shut down the reactor again. As of June 2011, the reactor has only generated electricity for one hour since its first testing two decades prior.[5] As of the end of 2010, total funds spent on the reactor amounted to ¥1.08 trillion. An estimated ¥160-170 billion would be needed to continue to operate the reactor for another 10 years.[6]
As of 2014, the plant had cost 1 trillion yen ($9.8 billion).[7]
A final decision on the project (e.g. to decommission or extend funding) was due by end 2016,[8] and a decision to close the facility was made in December 2016.[9][10]
... Intense vibration caused a thermowell inside a pipe carrying sodium coolant to break,...'
a
Troublesome , those vibrating pipes. Reminds one of that reactor in California...
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Anybody know why the plan isn't to install lots of tiny reactors at the grounds of the existing large nuclear power stations?
Grid losses, and heat. Government want the SMR build close to demand centres (cities) so that they reduce transmissions losses of around 2-3%. Overall grid losses are lower, but the existing nukes have very long distance transmission routes because they were built in the middle of nowhere. And there's a plan to use the heat from nuclear power to drive district heating systems - about two thirds of the energy potential in nuclear fuel is waste heat, and you could recover about half of that heat if you could dump it into a heat network. It's technically feasible, but even by Hinkley standards it would be hugely expensive.
The number of Towns and Cities that have declared themselves to be 'Nuclear Free Zones' (not including medical uses though) is quite large.
So it is a non starter despite making perfect sense.
Personally, I think even these SMR's are too big. I'd like to see 40ft container sized reactors. That way, they don't need to be decom'd on site or even refueled on site, just put the thing on a railway wagon and take it to Windscale/Sellafield.
Then site half a dozen or more where there used to be a coal fired plant as it has the grid connections.
People with complain about the security of the radioactive bits but if the container is made to safely shut down the terrorsts would have a hard time letting it escape before the place was bombed. Naturally, the critical bits would be hardened.
But I'll shut up and take my meds. Farr too much common sense for one day.
"I'd like to see 40ft container sized reactors."
Genuine question - what size are the reactors on subs? How are they cooled?
I really don't know that much about this area but it seems to me that if we can make a sub with a reactor we could make a sub that is JUST reactors (and propulsion) - we can connect offshore windfarms to the grid why not offshore reactors? or at the bottom of a lake?
Genuine question - what size are the reactors on subs? How are they cooled?
a) All systems included, about the volume of two or three 40 foot containers. But that's for a submarine reactor of 30 MW, which in a civil context is about 15 MW of electrical output.
b) You know all that cold seawater on the outside? Incidentally, the thermal trace of a sub is a problem when you're aiming for a stealthy, invisible vessel, and the designers want to minimise it, but unfortunately there's nowhere else to dump the surplus heat.
"Incidentally, the thermal trace of a sub is a problem when you're aiming for a stealthy, invisible vessel, and the designers want to minimise it, but unfortunately there's nowhere else to dump the surplus heat."
This is why the newer diesel-electric class boats such as Australia's Shortfin-Baracuda Collins-class replacements are making some navies nervous. They don't (quite) have the endurance of nuke boats but they're a lot harder to detect and they can stay underwater for a few weeks at a time.
"And I think they use a far higher level of enrichment un subs - around 20% instead of 3-5% 235Uranium."
that little? come now, use your imagination. The higher the enrichment, the smaller the reactor size (due to smaller critical mass/geometry being possible). there's a LOT more going on than that, of course, engineering-wise [you want to make that a "lifetime of the boat" core, by pre-loading every bit of fuel you expect to need in 30+ years, right?] but 20% enrichment is a WAY small number. Just sayin'.
what size are the reactors on subs
it depends on the sub. most reactor specs are classified. Some are published in 'Jane's Fighting Ships' etc. but they're not official. Suffice it to say, they are much larger than you think, megawatt-wise.
Back in the 1980's I was on a 688 (Los Angeles) class sub that used a core that was originally designed for a destroyer, and was adapted for a sub. They actually had to do a post-manufacturing modification to the main engines (steam turbines) for it to use 100% reactor power. And it went fast enough for 'back then', enough that they had seat belts on key watchstations for "rig for high speed".
Now, add 30 years of technological development to that timeline, and speculate. You're probably close.
Needless to say, 30MW is probably close to what the Nautilus had when it first launched in the mid 50's.
but yeah I can't truly confirm any of that. it's classified.
On carriers, the Enterprise originally had 8 reactors. I think the newest carries have only 2, and they're pretty big (more total steam than the Enterprise's 8 reactors). That gives you a perspective on how the nuclear tech has advanced over the years.
Submarine reactors are generally much smaller in output than you would need to power a town. They are built with special constraints that make them uneconomic for commercial use (which is incidentally why commercial ships don't use nuclear power). That is ok for the navy because they have a defence budget to pay for them. And as to cooling, submarines have an ample supply of seawater.
All heat engines (Coal, Nuclear) reject nearly 2/3 of their total energy. So a 300MWe plant will be rejecting nearly 600MW of heat per hour.... Laws of Thermodynamics can't be beat... This is why a Natural Gas fired plant is more efficient, but still reliant on fossil fuels... Natural Gas directly drives the turbine generator.
Natural gas generators can get close to 60% efficiency because they're a 2 step process.
1: Gas turbine engine and attached generators
2: Bog standard steam plant driven from the turbine's waste heat.
That's why they're called cogeneration systems. Standalone peaking plants are called OCGT (open cycle Gas turbines) and hideously inefficient, although cogen plants can provide some peaking capacity on the turbine side.
Super critical steam turbines can hit efficiencies of over 48%. So not much difference with CCGTs maxing at about 60%. Utterly irrelevant though, has to be considered with the fuel and the energy density of nuclear fuel can't be beaten.
https://www.xkcd.com/1162/
BTW, gas turbines are heat engines too.
(Pointless discussion but I saw an excuse to link to XKCD)
"So a 300MWe plant will be rejecting nearly 600MW of heat per hour.... Laws of Thermodynamics can't be beat..."
The trick is to find uses for the "waste" heat - hence the push for district heating (and cooling!(*)) systems driven from them.(**)
(*) https://entropyproduction.blogspot.co.uk/2005/10/solar-thermal-cooling.html - yes it says solar but any suitable heat source will do. Solarfrost.com have been working on these kinds of systems for 20 years.
(**) In some countries the district heating is used to warm greenhouses and extend the growing season as well as defrost critical roads. It's not just something for housing.
In places where it gets icy you can also put pipes under the streets and sidewalks using the waste heat tl keep them clear of snow and ice.
Holland, Michigan has been doing this in it's downtown for many years and their "Snowmelt" system has been a great success... and western Michigan winters are not to be taken lightly!
"Natural Gas directly drives the turbine generator"
Thats's why I've always wondered aloud, surely these fancy solutions for generating steam to drive turbines can't be the best way forward?
Tidal generation seems one of the most sensible to my mind, although that approach will always incur transmission losses due to the remote locations you have to build such installations.
If gas turbines can be largely powered by methane/etc produced by local organic digesters, then a lot of the 'new CO2' problem can be mitigated. It also therefore creates a recycling solution for organic waste as well as electricity.
"that approach will always incur transmission losses due to the remote locations you have to build such installations."
Frequently heard, but not all that significant.
In the UK at least, the majority of the transmission and distribution losses are in the low voltage side of things, e.g. the last mile between the end user customer and their nearest substation. That part of the loss (the "distribution" loss is unchanged whether the power to the substation comes from five miles away or five hundred miles away (the "transmission" side of things).
There are issues with the UK transmission network but they're more about capacity and connectivity than they are about losses (lots of generation in the North, lots of demand in the South), though obviously the aspects are linked somewhat.
Rooftop PV does change the "last mile" losses picture somewhat - there is no distribution loss when there is no distribution supply e.g. sunny midday, lots of people with PV - but it brings its own challenges when penetration in any given locality downstream of a substation becomes significant, e.g. curtailment of rooftop PV on sunny days. Not insurmountable by any means, but mitigation would need investment, and 'invest' isn't a word that't currently well understood by UK utilities.
Probably because there is a lot of fat on a £18 billion contract with the inevitable overruns and renegotiations that will expand the budget and keep thousands of civil servants employed for decades along with offering consultancy roles for ex-ministers and civil servants along with their families and friends.
Whereas £1.2 billion offers far less opportunity to hide cronyism and therefore is considered far less attractive by senior civil servants and ministers.
These factors are far more important than any advice from technical experts brought in to evaluate such schemes.
"No deaths, no strange glows at night and no two headed sharks."
LOL almost perfectly safely?! It was one of only two International Nuclear Events Scale level 7 events ever recorded! The other being Chernobyl.
So you must have missed the 34 that died during the evacuation, and the hundreds that will eventually die from radiation exposure? http://www2.ans.org/misc/FukushimaSpecialSession-Caracappa.pdf
Not to mention the massive leaks of radioactive material into the groundwater, sea and air!
TheVogon, no doubting nuclear on here bud, there are contracts at stake (I assume).
Besides some of that stuff will be gone in such a short time, much of it well depleted in a few thousand years and if you think us humans have a good chance at existing for long enough to see it properly cleaned up you are a more positive thinker than me.
The bags that Fukushima cleanup waste was scraped up into, and stored locally have a life of a few years and have been holding it for a few years no so they have chimneys in the stacks to take away the heat from decomposition to avoid the whole thing going up and dispersing all that lovely radio active crap into the air again.
But there I go being negative on nuclear, it just won't do.
By the way how is the Hanford Vitrification plant coming along? and where is that site going to be safe? I mean that's only about 79 tons of plutonium waste there (?), must be easy enough to drill a hole or something and drop it in see I'm getting into "this is not an issue" mindset myself right now.
I'm still sort of skeptical about the validity of that rating, as that's a logarithmic measure-of-magnitude scale, and it just doesn't seem to qualify for some of the tickboxes...
I mean, it didn't send a plume of vapourised reactor contents floating several thousand miles across a large part of the northern hemisphere for one thing. The water pollution is actually fairly slight, and although it's been measured and tracked with ease, that's because radiation detectors are very sensitive devices on the whole. No-one on the site died during the initial incident, no-one received such large doses that they died within a matter of days if not hours, and they didn't have to immediately forcibly bus the entire local population out of the area for fear of them succumbing to radiation sickness before the year was out.
We saw this drama unfolding over a matter of days after all... no actual release of solid nuclear material or fuel occurred, only irradiated cooling water and maybe a few gaseous decay products. The evacuations are mainly on a just-in-case basis. All the melted fuel is solidified somewhere in the ground underneath the plant, so it doesn't need a janky concrete cube to be hastily thrown up around it.
The plant isn't even necessarily unsalvageable, though hopefully they won't be fool enough to try... (he says, having a funny feeling he saw a news story about the second reactor having been put back into service already).
Some byproducts did escape, some people have had significant but not immediately lethal or crippling exposure - the effects of which will take time to show - and there has been significant local disruption as a civil protection measure. But it's not on a "hundreds if not thousands of deaths and immediate ruin of an area the size of Greater London which might last for millennia" scale.
"LOL almost perfectly safely?! It was one of only two International Nuclear Events Scale level 7 events ever recorded! The other being Chernobyl."
The japanese declared it as a 7 but it never came even close to that.
If you look at https://en.wikipedia.org/wiki/International_Nuclear_Event_Scale and the actual effects it was a 4 or 5 at most, but panicmongering set in.
Yep Fukusihima lost primary cooling , secondary cooling, and tertiary cooling, went into meltdown and the core stayed put in the containment .
If they hadn't been so worried about venting a bit of radioactive gas, it wouldn't have popped its roof off either.
It they hadn't been so worried about waste disposal there wouldn't have been 20 years of fuel rods stored in old tanks either.
A minor and trivial accident turned into a 'disaster' by the press, the greens and the anti-nuclear propagandists.
Fukushima's only design flaw involved the (non-nuclear) emergency generators, which were flooded out by the Tsunami. If electrical power could've been restored within 48 hours, none of the bad things would've happened. The Tsunami wiped out the entire town as well. The containment vessels that were there helped keep the problem down to a minimum.
And all of the FUD about radiation from Fukushima showing up in california is just nonsense. background radiation levels from Mr. Sun would keep it below detectable levels. Seriously, it's a BIG planet!
/me got LESS radiation living within 100 feet of an operating nuclear reactor on board a U.S. submarine than on the surface of the earth, and I know this because we recorded our radiation dosage. I got 80mrem per year [whatever new-fangled measurement THAT is] from Mr. Sun, and about 60 from Mr. Reactor.
Most of the radiation you get is from the Sun. You're in greater danger if you fly a lot or get a root canal, than from any failed nuclear reactor on the planet, including Fukushima and Chernobyl, so long as you're not "right there" at ground zero.
"Build like there will be a super landslide in Norway"
FWIW the next Storegga Slide will probably occur on the Leptav Sea continental shelf - and probably be larger.
In the other direction, the main risk comes from the Canary islands. It's worth noting as all the UK's west-coast/irish sea nuclear plants are in the firing line when that breaks.
No it wasn't, and any sensible regulatory authority would have shut down Fukushima temporarily or permanently before the incident happened, due to e.g. well understood and demonstrably inadequate defences against sea water ingress in the event of a realistic tsunami.
See e,g,
http://carnegieendowment.org/2012/03/06/why-fukushima-was-preventable-pub-47361
"[...]
Had the plant’s owner, Tokyo Electric Power Company (TEPCO), and Japan’s regulator, the Nuclear and Industrial Safety Agency (NISA), followed international best practices and standards, it is conceivable that they would have predicted the possibility of the plant being struck by a massive tsunami. The plant would have withstood the tsunami had its design previously been upgraded in accordance with state-of-the-art safety approaches.
The methods used by TEPCO and NISA to assess the risk from tsunamis lagged behind international standards in at least three important respects:
* Insufficient attention was paid to evidence of large tsunamis inundating the region surrounding the plant about once every thousand years.
* Computer modeling of the tsunami threat was inadequate. Most importantly, preliminary simulations conducted in 2008 that suggested the tsunami risk to the plant had been seriously underestimated were not followed up and were only reported to NISA on March 7, 2011.
* NISA failed to review simulations conducted by TEPCO and to foster the development of appropriate computer modeling tools.
At the time of the accident, critical safety systems in nuclear power plants in some countries, especially in European states, were—as a matter of course—much better protected than in Japan. Following a flooding incident at Blayais Nuclear Power Plant in France in 1999, European countries significantly enhanced their plants’ defenses against extreme external events. Japanese operators were aware of this experience, and TEPCO could and should have upgraded Fukushima Daiichi.
Steps that could have prevented a major accident in the event that the plant was inundated by a massive tsunami, such as the one that struck the plant in March 2011, include:
* Protecting emergency power supplies, including diesel generators and batteries, by moving them to higher ground or by placing them in watertight bunkers;
* Establishing watertight connections between emergency power supplies and key safety systems; and
* Enhancing the protection of seawater pumps (which were used to transfer heat from the plant to the ocean and to cool diesel generators) and/or constructing a backup means to dissipate heat.
Though there is no single reason for TEPCO and NISA’s failure to follow international best practices and standards, a number of potential underlying causes can be identified. NISA lacked independence from both the government agencies responsible for promoting nuclear power and also from industry. In the Japanese nuclear industry, there has been a focus on seismic safety to the exclusion of other possible risks. Bureaucratic and professional stovepiping made nuclear officials unwilling to take advice from experts outside of the field. Those nuclear professionals also may have failed to effectively utilize local knowledge. And, perhaps most importantly, many believed that a severe accident was simply impossible.
[continues]"
It's not rocket science, but until the nuclear industry in general gets rid of its long standing head in the sand problem, there will understandably be people against it - even well-informed people.
The Tsunami triggered the disaster; however, it was the basic design of the reactor itself that caused the problem: when the tsunami struck it flooded the generators that operated the pumps that were used to carry the heat away from the reactor core. This caused the cores to go into meltdown because the reactor design itself was not failsafe. A failsafe nuclear design is one in which the consequence of removing power is to cause the reactor rods to withdraw and the fission to cease. An additional problem at Fukushima was that it was not possible to connect auxiliary power from outside because it transpired that the connectors were themselves incompatible.
Fission ceased at the Fukushima reactors pretty much as soon as the earthquake was detected onshore. The problem was residual heat from the decay of short-lived radioactive fission products in the fuel rods -- when running at full power reactors 2 and 3 generated about 2500MW of heat (reactor 1 was a bit smaller and produced less heat and electricity). After fission ceased the heat output from radioactive decay was about 50MW. When the cooling systems shut down due to loss of external power the cores overheated from that decay energy, not from fission.
A good rule of thumb in the metal foundry business is that 1MW will melt 1 tonne of steel if it is well-insulated so 50MW is a considerable amount of heat energy.
"decay energy IS fission, just not as we know it, Jim, (chain reaction)"
There's more to it than that.
Uranium oxide - like most ceramics - is a LOUSY thermal conductor.
In PWRs the centre of fuel rods (which is where most of the fission takes place) usually sits around the doppler limiting temperature of 1100C whilst the outside is cooled to 400-450C by water. You could stop all fission and simple thermodynamics will ensure you have substantial quantities of heat needing to be dumped until the rods reach equilbrium. Secondary fission is minor in comparison.
Think of it as a 50MW heat source and thermal block surrounded by _very_ good insulation and then a water jacket, where you're extracting heat from the water. It takes quite a while to get rid of all the residual heat when you turn the source off.
...it was not possible to connect auxiliary power from outside because it transpired that the connectors were themselves incompatible.
How can that be? We have an emergency, we need to get power into this place. Er, our plug doesn't fit.
Um, gee. A nation with some of the most amazing engineers and electricians in the world and not one of them could figure out a way to either a) swap out the connectors or b) jury-rig something that would do as a temporary measure? They'd rather risk a meltdown than solder/weld a few wires into place?
What am I missing with this story?
Fission did cease, the rods were properly in place. The shutdown went just fine. No problems.
The problem was that even a shutdown reactor still has latent heat that needs to be removed.
Which by the way, is the SAME reason that CPU fans continue to run after the CPU is halted. The latent heat STILL has to be removed, or damage to the core will occur.
The PROBLEM was that the pumps doing the cooling had their power source flooded.
"The PROBLEM was [...]" @oldcoder
That's part of the picture.
The failure you describe, and those other failures described here by other people, are individual problems, each of which could have been managed differently and likely resulted in a different outcome. But for whatever reason, the "right" approaches were ignored in too many places.
We are where we are. We didn't get there because one single technical thing went a bit wrong, we got there because *lots* of technical things went very wrong, many of them in ways which had been predicted before the big day. But not enough was done to fix them even after issues and impacts were identified.
Swiss cheese. Head in the sand.
You appear to have no knowledge of anything
The reactor did shut down
As it was designed to.
The decay heat is what was needed to be dealt with. A working reactors is fizzing and popping with lots of short lived isotopes that cause it to get hot even when the main chain reaction is stopped.
That is what you need emergency cooling for.
Otherwise the core melts.
As it did,
Which is why you have secondary containment to shield it.
Which it did.
which is why outside of the containment vessel, the radioactivity was pretty low.
And would have been lower still if they had flooded the thing with seawater and let the hydrogen escape, instead of trying to trap everything ..
> "Insufficient attention was paid to evidence of large tsunamis inundating the region surrounding the plant about once every thousand years."
Correct but to defend against such a large tsunami, the protective barrier would have needed to be at least 50ft high.
The biggest issue was the loss of backup power generation to cool the reactors. Since the diesels were in the flooded basement, nothing could be done to prevent meltdown. Had the diesel backup generators been on the roof, the plant could have been saved.
"to defend against a [1000 year] tsunami, the protective barrier would have needed to be at least 50ft high."
Remember the Boxing Day tsunami in 2004 (seven years before Fukushima got hit)? Lots of disruption and casualties and maybe a quarter of a million fatalities, with a wall of water up to 100 feet high.
So maybe a 50 foot barrier (or some other way of achieving the same robustness) wouldn't have been a bad idea at Fukushima? Lots of that kind of analysis went on in the years following 2004, what did it show for Fukushima?
Afaik the specific analysis concluded that, based on the updated understanding, there was a very significant (50%?) probability of Fukushima's sea defences being overtopped in the planned remaining lifetime of the power station (a decade or so?), which would cause the loss of not just backup generators but also critical electrical switchgear, both of which had been inappropriately located (or inappropriately protected). How does that sound?
Does it sound like reason to make some significant changes to plant protection? Does it sound like reason to shut the plant down permanently if the changes could not be profitably implemented? Does it sound like reason to stick head in sand and do nothing?
"Had the diesel backup generators been on the roof, the plant could have been saved."
There's that, and there's various other aspects which could have been done differently, some quite low cost, each of which might have helped make the setup safer. Defence in depth, maybe. Or the "Swiss cheese" model, as many safety-aware folks call it:
https://en.wikipedia.org/wiki/Swiss_cheese_model
"The reactors proved robust seismically, but vulnerable to the tsunami. Power, from grid or backup generators, was available to run the Residual Heat Removal (RHR) system cooling pumps at eight of the eleven units, and despite some problems they achieved 'cold shutdown' within about four days. The other three, at Fukushima Daiichi, lost power at 3.42 pm, almost an hour after the quake, when the entire site was flooded by the 15-metre tsunami. This disabled 12 of 13 back-up generators on site and also the heat exchangers for dumping reactor waste heat and decay heat to the sea. The three units lost the ability to maintain proper reactor cooling and water circulation functions. Electrical switchgear was also disabled. [...] A hardened emergency response centre on site was unable to be used in grappling with the situation, due to radioactive contamination."
[...]
"The tsunami countermeasures could also have been reviewed in accordance with IAEA guidelines which required taking into account high tsunami levels, but [Japanese regulatory authorities] continued to allow the Fukushima plant to operate without sufficient countermeasures such as moving the backup generators up the hill, sealing the lower part of the buildings, and having some back-up for seawater pumps, despite clear warnings."
from
http://www.world-nuclear.org/information-library/safety-and-security/safety-of-plants/fukushima-accident.aspx
It was also already known that TEPCO had a history of neglecting things like the periodic tests of the backup power generators. Simple cost effective stuff like that, which can make a big difference on the day you need things to work - as lots of people in and around the real IT industry used to know.
Let's not try to defend the indefensible. This safety stuff is not rocket science. It's not fixable by the industry sticking its head in the sand either.
" Protecting emergency power supplies, including diesel generators and batteries, by moving them to higher ground or by placing them in watertight bunkers"
This in particular was pointed out _DURING CONSTRUCTION_ by GE engineers, who demanded that the generators be moved to higher ground for safety reasons.
The Japanese management smiled, nodded and completely ignored the demands.
During the crisis, they refused outside help until it was much too late (the USA had emergency generating equipment ready to go from Okinawa, but couldn't move until authorised. It could have been onsite before the batteries gave out) - in a series of cockups reminiscent of Japan Airlines flight 123.
The meltdowns were 100% avertable right up to about 6 hours before they happened. It took a goodly amount of hubris and spectacular series of management screwups in the years leading up to and the hours after the tsunami to allow them to happen. It's worth noting that quite a few other plants along that coastline were hit and _none_ were damaged, because they'd taken note of the safety issues and sorted them. Having caused 1500+ deaths in the ensuing panic evacuations, TEPCO manglement should be stripped of their pensions and permanently barred from ever doing business again.
Only 50 feet high, that's nothing. The one in Lituya Bay in 1958 destroyed vegetation 1700 feet above the normal water level (and someone was in a boat on the water and lived to tell about it!) I don't think you can assume anything stays dry near a lake, especially one with the particular geography of Lituya Bay.
The problem with Fukushima wasn't that they didn't have the generators high enough, it was that they didn't enclose them so they could be underwater for the duration of a tsunami event and keep running. An underwater slide in the wrong place could create a tsunami larger than in Japan's recorded history, and putting them at a "safe height" above the highest tsunami in recorded history just means they are vulnerable to a record tsunami.
"Wasn't Fukushima a "fail-safe" design?"
Nope. There's very few reactors operating commercially that are considered fail safe by even old standards. By modern standards.. Even the modern reactor designs aren't fail safe per se.
In the wake of Fukushima the Swiss have voted to phase out their nuclear energy. That should protect them against tsunamis.
Yeah but it won't protect them from France charging them through the roof for power they generate cheaply via... nuclear power.
That's a matter for the statisticians, I think. I can't remember if there were any reports of direct casualties, but there's a lot of staff who have almost certainly received much higher doses than was originally admitted to. Including most likely the firefighters, even those in the helicopters. That's something that takes a long time to show in the population.
Of course, the tsunami itself was far more deadly, so it's a matter of comparitive harm I suppose.
Even so, like Grenfell, it could easily, and should have been much safer than it actually was. Both of them have a thread of "how could anyone so bloody stupid have been put in charge of something so crucial and fundamental?". Let's hope no-one's put polyethylene cladding on a reactor yet.
....also, I guess the judgement sort of hinges on whether you want to get into a discussion of how many people you have to move from within a roughly 30-mile hemispherical exclusion zone on a long-term basis before that is equal to one life lost in terms of stress and disruption to people's lives. Given that it's Japan, I wouldn't be at all surprised to hear of at least a half dozen suicides that could be directly linked to being evac'd from the Fukushima area.
" I guess the judgement sort of hinges on whether you want to get into a discussion of how many people you have to move from within a roughly 30-mile hemispherical exclusion zone on a long-term basis before that is equal to one life lost in terms of stress and disruption to people's lives."
Especially when not moving those people would have exposed them to extra radiation equivalent to 2 chest xrays per year (by way of comparison that's about the same as a single 4-5 hour passenger jetliner flight above 25k feet)
Most of the hysteria associated with nooo-cle----arrrrrgh accidents has no basis in fact and is informed by B-grade science fiction movies.
Fukushima wasn't fail safe in the sense of more modern reactor designs. As I understand it, the problem with a lot of older reactor designs is that they require power for cooling, If you lose power, which is what happened at Fukushima, you lose cooling, and then you have a problem. Fail safe designs have passive safety features that do not require power to operate. You lose power, and the reactor shuts down. That's what is meant by a failsafe design.
From an NHK program I saw on the Fukushima accident, the reactor operators were turning the passive cooling system on and off as they believed that it couldn't be left on for some reason. The passive system was off when the control facility lost power and nobody knew how to tell if it was on or off and believed that it was on. Tepco had training problems as well as location and design problems. One perfect storm and it was all over.
Read up on Molten Salt reactors; Intrinsically safe. IE: if it all goes horribly wrong switch everything off. The salt will "freeze" when it approaches room temperature; As a bonus they are not High pressure reactors so no massive pressure vessel containment. In fact you can run them at a slightly negative pressure which helps contain any unintended emissions.
Very cool looking tech. What the nukeE's call walk-away safe.
Read up on Molten Salt reactors; Intrinsically safe. IE: if it all goes horribly wrong switch everything off. The salt will "freeze" when it approaches room temperature; As a bonus they are not High pressure reactors so no massive pressure vessel containment. In fact you can run them at a slightly negative pressure which helps contain any unintended emissions.
This technology is going to take so long to develop the cash might as well go on fusion research. It's the classic electric cars versus hydrogen problem. If the money isn't misdiverted to pie in the sky solutions to simple problems we'll get a proper solution earlier. Fusion is a proper solution (not to say that ITER et al are the correct path to that proper solution).
Any time water is used to cool reactors you have the problem of generating hydrogen and oxygen in the fail condition. This isn't how reactors should be built - and I say this as somebody who is pro nuclear.
The AGRs were a sensible path in reactor technology, shame we tried to build them all at once rather than building a technology demonstrator plant to iron out constriction issues first. In the end Thatcher killed the long term project of course.
"This technology is going to take so long to develop the cash might as well go on fusion research. "
Except that unlike fusion systems, the USA ran a working Molten Salt reactor between 1964 and 1968, the identified problem mainly being corrosion and certain metals plating out at cold spots. Research got killed by Nixon in 1972 for political reasons - primarily being no jobs for the boys in southern california, but compounded by the fact that the MSRs were virtually impossible to weaponise so the military was against it.
https://en.wikipedia.org/wiki/Molten-Salt_Reactor_Experiment
The Advanced Gas-cooled Reactor (AGR) was an evolutionary upgrade from the semi-militarised Magnox design and had a lot going for it such as efficiency since it runs hotter than a PWR. Unfortunately that benefit would only make it a commercial success if the fuel was rare and expensive, which it turned out not to be (the spot price for yellowcake, the product of uranium mines on May 5 2017 was about $50 a kilo).
The bad news is that our existing fleet of AGRs is life-limited because of growing flaws in the carbon moderator blocks in the core, caused by neutron fracturing of the graphite crystal structures. The cracks are not a problem now but they will get worse meaning there's no chance of extending the operation of these reactors past 40 to 45 years. In contrast many PWRs built in the 1970s and 1980s are getting their operating licences extended to 60 years and more, subject to some relatively cheap upgrades and parts replacements since they were seriously overbuilt in the first place.
""And what was the actual (not FUD) result of Fukushima?"
3 reactors meltdowns and a level 7 nuclear disaster."
And further, fully documented, proof (as if any more were needed) that regardless of how safe nuclear power is, many of the people in charge of it are simply still not trustworthy.
I say this somewhat reluctantly, as a physicist turned engineer with extensive experience in helping the people who build critical systems, hoping against hope that one day the nuclear industry might get its act together, preferably before the lights go out. It's already been a bloody long time coming, I wouldn't want to bet on it ever happening, would you?
Olkiluoto 3 was originally scheduled to open in 2009. It's not there yet, but it's keeping the lawyers busy.
https://nuclear-news.net/2017/05/19/areva-and-edf-pin-their-hopes-on-delayed-super-costly-olkiluoto-3-nuclear-project/
"Wasn't Fukushima a "fail-safe" design?"
Interestingly, it was meant to be, but the politics and traditions of Japanese culture resulted in nobody being able to point out the design flaws without appearing to diminish their superiors' authority. Hence the sea wall was too low and the diesel back up generator was placed too low.
"Wasn't Fukushima a "fail-safe" design?"
No, not by a long shot, not even in someone's imagination.(**) Those kinds of features(*) only became mandatory after TMI and that plant significantly predates the TMI accident. It was running more than decade past its design end of life for starters.
(*) A failsafe nuke plant can scram and cooldown indefinitely without needing external power _at all_
(moderating rods self insert under gravity when the power goes off instead of needing to be levered into place, thermosyphon system for continuous cooling circulation) - Fukushima had none of that - and that's without even going into the need for redundant feed locations into the control rooms that didn't exist at most plants before TMI (one of the things that came out of TMI was that the redundant control systems which did exist all exited/entered the control room via the same hole/cableways and as such constituted a single point of failure in case of a fire. That particular change requirement was also propagated to other technology thermal plants.)
(**) And the japanese can be quite imaginative in their failures. Look up Monju sometime. How do you dispose of several tons of slightly radioactive sodium in your basement?
Not really, no. There was only the one method of generating backup power, no emergency batteries, no protected hardline to bring a minimal amount of power in from the grid to run the pumps, and no passive method of circulating cooling water to keep built-up decay heat from melting the fuel if all the power went out. Not even a small auxiliary turbine that could use steam produced by that selfsame heat to directly turn a mechanical pump, turbocharger style.
And even if you consider "has external diesel generators" as a suitable failsafe, then the design may have been fine but its placement was absolutely boneheaded. Fuel tanks on top of the gensets instead of the other way round, no snorkels on the air intakes, etc. Despite it being at sea level, in a particularly earthquake-vulnerable area of a country more or less directly over a continental faultline and often beset with tsunamis.
Add to that seemingly no proper contingency plan for preventing fuel meltdown in the case of total water circulation failure (which could have happened for various other reasons anyway), e.g. physically separating the core somehow to prevent central heat buildup, or connecting external pumps, and a parent company whose main approach to dose monitoring and site safety was "write down any old shit, and if that doesn't work, run away", and you have something that only really avoided taking the #1 spot ahead of Chernobyl by luck rather than judgement.
Not to mention the weird choice of where to put the longer-term waste storage pools (right at the top of the building, where water needs a lot of energy to be pumped to and anything that leaks will piss all over the lower levels) and the lack of suitable hydrogen venting should they also start to cook off... and no proper secondary containment for the molten core and waste water should there actually be a meltdown (would, say, a protective pool of cold water built underneath and never normally used for anything not have been worth a little extra time and money to install? with enough spare capacity to hold whatever falls out of the reactor, and able to rapidly cool the individual blobs of the former core as it leaked out of the primary flask? Or at least some extra layers of concrete foundation, textured such to break up the material that might fall through? Anything that would have prevented it settling into a big ol' solidified puddle of radioactive awfulness, and stopped the reactor water leaching away into the soil?)
(Now in comparison, most smaller reactor designs can be considered inherently safe simply because of the small amount of material they contain - for one thing, not enough to make a bomb from, so there's a limit to how much havoc can be caused... these things tend to scale up exponentially, and indeed that's why they're not really as efficient in terms of ground area per megawatt.
But if they're also more modern designs internally like fluidised/pebble bed, thorium, the aforementioned molten salt, etc, then that adds an extra layer of protection that would also help a larger model, if only the people building the large models were at all bothered about building anything other than the same old shit that we know to be inherently dangerous...)
I've long believed that ALL nuclear facilities should be placed underground.
It's only a matter of time before an accident occurs involving an errant aircraft.
The roof must be designed to withstand significant impact. You might want to up that to give some protection from enemy action in war.
Bonus points if you also cover the turbine hall and essential switching. With very large stations built on the well proven "bigger is always better and cheaper" and the" lets put the eggs in as few baskets as possible" principles - where have we heard that before - loosing only one station at the wrong time could be critical.
Small district heating schemes - I'll buy that. It worked well in Pimlico with the waste heat from the coal fired Bankside station on the Thames piped under the river.
What about agriculture / market gardening? Around Sizewell in Suffolk the ground is sandy. Generally produces alternate crops of pigs and arable. Cover some of it with glasshouses, heated by the cooling water, ventilated and lit by the leccy. Alternative option - multistory hydroponics. Already being done commercially in the states. Just need the leccy.
"It's only a matter of time before an accident occurs involving an errant aircraft."
All nuclear reactors in the UK have their own no-fly zone, and they're reinforced to withstand a collision from a full sized passenger aircraft on the reactor (just another reason why nuclear is expensive).
>A full sized passenger aircraft from 50 years ago is a 747, everything since then is smaller and lighter.
Simply not true....the A380 (which has 40% more floor space than a 747-8 - itself very much heavier than the early 747-100) is currently the largest passenger aircraft in regular service, though not the largest ever flown.
"All nuclear reactors in the UK have their own no-fly zone"
Most of the UK is a no-bombing zone too, on paper.
How well's that been working ijn the last few decades?
See, there's a difference between what's permissible and what actually happens.
>"The roof must be designed to withstand significant impact."
Like this? :-
https://www.youtube.com/watch?v=25vlt7swhCM
PS. Don't tell Greenpeace. They spent lots of money on fearmongering TV advert campaigns about "what if an aircraft hit?!" and they get incredibly hysterical when confronted with evidence that people actually considered these issues long before they were born.
>PS. Don't tell Greenpeace. They spent lots of money on fearmongering TV advert campaigns about "what if an aircraft hit?!" ....that people actually considered these issues long before they were born.
Can't speak for Greenpeace, but they'd probably point out that's a small fighter jet (designed to be as light as possible) not a huge passenger/cargo aircraft designed to fly as heavy as possible. Increase the weight 10-fold and the impact energy increases 100-fold. It's a credible test of a military scenario at the time, not the threats we face today.
"The locomotive tests outmassed and out "grunted" any aircraft you could think of."
Would that be the UK locomotive tests where the engine was mechanically disconnected from the locomotive frame, thereby reducing the impact effects? The locomotive frame hits the fuel container, and is rapidly stopped, but the engine itself then briefly continues to slide along inside the locomotive and its energy is dissipated relatively slowly, reducing the effect on the fuel container.
Conceptually similar to crumple zones in a car - dissipate the energy more slowly rather than all at once.
Now, why might they have done that?
And then there's the small matter of the effects of the fuel carried on board a passenger jet, vs the fuel on a rail locomotive.
>The locomotive tests outmassed and out "grunted" any aircraft you could think of.
Doubtful - the effect of speed is exponential and they weren't carry several kilo tonnes of aviation fuel. I wasn't aware they'd tested a containment wall using a locomotive - sure you're not thinking of waste fuel containers?
When it really matters they hollow out a mountain.
Putting nuclear stations underground doesn't solve any issue that can't be fixed with good design. Only difference would be they're harder to get to if there really was a bad accident.
Nuclear power doesn't have many issues, it's disposal that needs sorting out. This shouldn't be a thing until that is dealt with. I've long been a proponent of deep borehole disposal but it's not ready for commercial use yet and we shouldn't be rushing ahead with new power stations beyond what it will take to prevent blackouts without it.
"it's disposal that needs sorting out. "
That's the rub. Right now with uranium-fuelled systems we're throwing away at least 80% of the mined metal enriching it to 3% from the natural 0.5% or less(*) and then throwing away 97-98% of the energy content of the fuel at the other end when it's "spent"(**)
It's a bit like picking an entire apple orchard, keeping one tree's worth of apples, making cider with it, drinking one glass and binning the rest.
(*) "Depleted uranium" is favoured by the military as it burns nicely inside tanks, but it's a nasty environmental toxin, worse than lead. It's also an essential component of hydrogen bombs, being what you make the cases of the things out of to get the multi-megaton yield
(**) The military love the used stuff too, extracting plutonium from it to make bombs.
The USA regards the energy expenditure of enriching uranium for the civil nuclear program as a classified military secret, but the power feeds into the facilities where they do it give a clue that it's extremely high. (power feeds into the centrifuges are also the giveaway for Iran's enrichment program)
All this stuff can be "burned down" happily in a LFTR-type reactor, resulting in that 97% output waste becoming less than 1% (the entire waste output of a 900MW nuclear power plant over a 60 year lifespan is enough to fill a single olympic size pool), as well as eating all the "depleted" stuff too.
It's technically possible to make weapons out of LFTR technology, but the various isotopes are so thoroughly mixed up that you'd need a _very_ large set of centrifuges to do it and some of those isotopes are so hot that you don't want to be anywhere near them(***), which should dissuade most terrorists from trying (being dead before they reach the boundary fence is a good persuader) and the power requirements of refining from the fuel are so noticeable that any country trying would be spotted quickly - especially after what India managed to pull with CANDU technology.
(***) Hot as in "fatal radiation dose in seconds"
Uranium tech is a dead end anyway - it's rare, expensive to refine and sources are limited. Thorium is the better long-term solution and as it happens we have megatons of the stuff already mined and ready for the technology. That's why so much effort is being put into making LFTRs commercially viable.
Ummm, so much wrong, a Gish Gallop of wrong repeatedly wronged. I congratulate you, I've not seen so much sequential nuclear tech wrong since I accidentally listened to a couple of minutes of Helen Caldicott on a Youtube video.
No-one has built a LFTR ever so saying definitively what they can do is a bit of a stretch. There's a lot of Youtube videos, Powerpoint presentations and grad student TED Talks about them but no actual operational experience. The molten-salt reactor at Oak Ridge National Laboratories failed in many ways and it never ran with thorium (it used uranium). "Thorium" fuelled reactors actually burn uranium, the thorium is bred up into U-233 before being fissioned to produce energy and radioactive waste. Thorium by itself is not fissionable.
Uranium is commonplace, not rare. It's simple to refine. Sources are not limited. It is incredibly cheap to buy on the open world market and a number of large mineable deposits are not being exploited because the market is effectively saturated. Uranium as a metal is not particularly toxic, in part because the common forms are very insoluble and can't enter the bloodstream or digestive system easily. The damage, if it does cause any, is limited to some effects on the renal system. It's not evil poisonous stuff like beryllium or cadmium or arsenic or lead or a dozen other elemental toxins with low LD50 and bad neurochemical effects.
No nation extracts plutonium from civil nuclear reactor fuel[1] -- it's hopelessly contaminated with Pu-240. All of the nations with nuclear weapons made their stocks of nearly-pure Pu-239 is specialised reactors in places like Windscale and Hanford. All of those nations have more weapons-grade Pu than they will ever need, indeed it costs them to securely store the surplus after the number of weapons held was vastly reduced in the 1960s (Britain had over five hundred nukes at one time, today it has about 140 or so). Any power reactor built after the early 1970s had nothing to do with making extra nuclear material for weapons. There were a couple of designs that could be co-opted to make weapons-grade material, the British Magnox and the Russian RMBK-4 but I don't think they ever actually did since there were proper weapons-grade breeder reactors available to both nations.
[1] It's possible North Korea tried reprocessing spent commercial reactor fuel in the early days of its nuclear weapons development. The first few tests did not work out for them, you may recall.
Afternoon, pedant alert here. District heating in pimlico was provided by Battersea Power Station, rather than Bankside. The scheme actually still exists (PDHU), but doesn't use waste heat from the power station, for fairly obvious reasons. They did think about district heating from Bankside, but not until the late 60's early 70's. For extra pedant points, Bankside would have been oil fired by then rather than the coal that you said. The oil crisis did for the scheme, and ultimately Bankside itself. District heating is, by the way, a fantastic idea.
Actual fact.
In 8 decades of reactor operations no one has.
That said the one thing that the world does not seem to be running out of a supply of is misguided loons and fanatics so probably the way to go.
"In 8 decades of reactor operations not one has occured."
Careful please.
Isn't this the "no incidents in X decades" attitude which is allowing some (maybe many, maybe most) of the PHBs in the safety-critical players in the aircraft industry to say "how many accidents has the industry had? why do we need all these safety margins, all this resilience, all this FMEA, all this weird software (Ada!), all this testing? No other electroncs/computer designer bothers with it."
The same complacent attitude to an improving safety record in the UK rail industry which in due course led to a string of incidents and accidents (and more) in the rail industry?
Some of those aircraft industry players also have connections in the SMR business. Historically some of them have avoided software-controlled submarine reactors, for entirely understandable reasons. Is that likely to continue when it's a commercial civil (not taxpayer-funded military) product?
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The essential problem is cooling. Coal fired power plant chimneys obviously blow out a lot of CO2 smoke, but what is less obvious about a coal-fired plant is that the chimney takes away a massive amount of waste heat. Nuclear power plants typically have huge cooling towers precisely because they have no chimney. Putting them underground would create impossible cooling problems.
SMR's are the way to go but using Thorium and Molten salt (FLibe) ideally as burner types. Cos using conventional PWR type reactors only increase the vast amounts of plutonium and actinides we already have already but a Flibe burner will dispose of them. Leaving a tiny proportion of the waste behind which can be fuelled in another burner and the rest like CS-137 will decay way in 300 years.
Over 100, probably 150 tons of waste Plutonium and growing in the UK along with the other transuranics should be fissioned as energy rather than the mad folly of trying to store it for tens of thousands of years by vitrifying it into glass..
I remember watching a documentary on Windscale/Sellafield, and back in t'day they just dumped the spend rods in to a swimming pool that was on site.
The correct term is 'cooling pond', and they're still there. It's not a swimming pool because if you tried to swim in it, you'd die - not from the radiation which is very well attenuated by water, but from the bullet wounds.
"I remember watching a documentary on Windscale/Sellafield, and back in t'day they just dumped the spend rods in to a swimming pool that was on site."
Was that the one on BBC4 last month? they did a whole night about nuclear - still on iPlayer I believe and well worth a watch.
They went into detail about the outdoor ponds that they dumped everything in - basically the number one concern was producing enough material for the h bomb so nut much thought was put into the mess left behind - which they are cleaning up now.
>Was that the one on BBC4 last month? they did a whole night about nuclear - still on iPlayer I believe and well worth a watch.
Definitely - Cockcroft's Follies are an interesting warning from history (aside from the terrifying amount of waste that remains).
The follies are a nice example of how 'nay sayers' on nuclear safety are treated too - even a Nobel prize winner was ridiculed. The death toll in 1957's reactor fire would have been huge without them (only ~1000 mortalities are attributed - thyroid cancer etc which sounds a lot, but I guess coal power killed countless more in the same period)
If fuel rods in a spent fuel storage pool are emitting neutrons then you've got problems (and Star Trek physics going on to boot).
Spent fuel rods outside a reactor are "hot" because of the radioactive decay of fission products (Cs134 and Cs137, Sr90 etc.) producing alpha and beta particles and gamma radiation. Fission has stopped since there is no chain reaction going on so no large amount of neutrons should be present.
Yes, water is a very good absorber of particles and radiation and it also acts to cool the fuel rods, preventing them from overheating and breaking apart.
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Somewhere along the line I read that the reason why Uranium 235 fission reactors got the nod in the 1950s was because the military of the time considered plutonium (handy if you've got bombs to build) production high priority. Which seems reasonable enough given the recent history of the time.
So, yes, in context plutonium was very useful indeed.
Quite right - at least in the UK.
The first two Magnox plants at Calder Hall and Chapelcross were essentially built to supply plutonium to the military. They were publicised as providing power to the grid, but their contribution was very small. The Magnox design was especially suited to plutonium since fuel elements could be removed from the core after a very short burn of 90 days or so which ensured there would be a high ratio of 'useful' 239Pu to 240Pu in the spent fuel. 240Pu is not wanted in weapons since it occasionally spits out a neutron which can cause predetonation of the bomb during implosion.
The later, much large Magnox stations were civilian and IIRC all of their spent fuel was put through a civilian reprocessing cycle.
Yes of course the Pu isn't in the mix per se - but the current chemistry we used for reprocessing is almost as flawed as the silly designs of reactors everyone made largely in the quest for the bomb.
The Purex process produces chemical by-products which are even more toxic than what comes in.
Before the work does eventually go fusion one day and not in my lifetime we need to deal with the mess that's been left behind and chemically and efficiency wise its using FliBe salt. Not water or air soluble and a very stable compound at normal temperatures and when hot a much better efficiency match for a gas or even supercritical CO2 turbines than the current steam. The CO2 turbines are a fraction of the size too.
Even stored it will leak tritium - but tritium with a half life of 12 years decays to Helium-3 which is certainly going to an extremely valuable resource powering fusion reactors. Why mine the moon for it?
Renewable energy means that the *fuel* is renewable. That claim is true for wind and solar.
It does not mean that the *installation* is renewable. If you want to compare that, the article needs to go into how renewable the nuclear installation is. At least an old wind turbine is not a radioactive hazard for centuries to come, like a nuclear installation
"At least an old wind turbine is not a radioactive hazard for centuries to come, like a nuclear installation"
No but the environmental damage of having to landfill all those defunct solar panels and wind turbines is almost as bad. What about the chemicals in old solar panels? We need to get away from the idea that we really have any environmentally friendly electricity production methods. Some methods are not as bad - some worse. All are bad to some degree, though. What we really need - if we care bout the planet - is less people.
"Not if we eat them."
...which raises its OWN set of problems:
http://www.npr.org/sections/thesalt/2016/09/06/482952588/when-people-ate-people-a-strange-disease-emerged
(Plus, there's so much FAT in them, unless you're willing to pay more for the grass-fed, all-organic stuff!)
No but the environmental damage of having to landfill all those defunct solar panels and wind turbines is almost as bad.
Plus the pollution during their manufacture, and the pollution/environmental damage in making the sites for them (which can be reused I guess), plus the damage done during the extraction of the ores etc that went into making them. And the same for the backup generators for when the wind turbines stop turning.
Must check the math again, but I suspect that it will show that wind is still a serious net polluter.
Maybe wind and solar ARE net polluters (I still remain to be convinced), but they are still better than the alternatives.
How so?
UK : Electricity use is at its peak during still winter nights. Yet on still winter nights you have neither solar nor wind. Your entire grid must be from other sources. That means that a large portion of the resources spent on solar and wind is wasted.
Solar: UK isn't in one of the greatest areas for sunlight. You don't get huge amounts of sunlight.
Wind: When a wind turbine stops spinning, you must have another turbine already up to speed to replace the power you get from wind. Given the small size of the UK, there are chances that most or all wind plants will stop at roughly the same time ("stop" here means not producing power, even if it is moving). For every wind turbine you build you need the equivalent power from another source. You also have a hell of a lot of environmental damage in building the site for wind turbines, and a lot of resources consumed in their manufacture and shipping. They tend to have a very short life of only a few years before needing to be replaced (though the site itself could be re-used). The resources used in making wind turbines mean much more coal is burnt than if said turbines were never going to be built. It also only makes money due to the subsidies involved.
Wind is one of the most anti-environment scams out there.
Compare with most forms of nuke - nuke is much cleaner than wind. And as I've said a little while ago, I used to be very anti-nuke and very pro-wind till someone suggested I really look at the math. Do so yourself, and you will not want to promote wind again. (of course, improvements in manufacturing may've made wind turbines more efficient but I doubt it)
'Renewable energy means that the *fuel* is renewable. That claim is true for wind and solar.'
No it isn't. The sun runs out of fuel and the earth moon system decays and entropy wins....
Most 'renewables' is making use of energy otherwise wasted during conversion, albeit from large fuels sources over significant timescales.
Reminder to read this fine article at IEEE Spectrum:
Also:
It took financial backing from the Chinese government to land.
Ah, Sinotriumph coming.
Coal-free day
I never found out whether that was a stunt (i.e. due to random downward fluctuation and the grid able to run on renewables for a limited time for once, or maybe more gas turbines coming online) or something sustainable.
Coal-free day.
It is indeed a stunt. It's a con to allow you to think if we just had more windmills and more subsidies to support them then we could be entirely coal free. This is false. Intermittent, low energy-density sources such as wind and solar cannot feasibly meet the baseload requirements of a modern industrial society.
The irony is that we have plenty of wind-free days and that is never reported. We have solar-free periods every night! That is never reported either.
Drax was converted from burning coal to subsidised wood-pellets at great expense. These are shipped from the US at great expense. The CO2 emissions for this are ignored because of the false belief that new forests reclaim the carbon. In Germany there is outrage that old forests are being slaughtered to fuel power stations that are supposedly Green.
We need to exploit all the shale-gas we can and build more super-critical coal fired power stations.
Cheap energy allows our modern civilisation. Renewable (really replaceable) energy cannot ever be cheap, it will downgrade everyone's living standards to the point of disaster.
"Intermittent, low energy-density sources such as wind and solar cannot feasibly meet the baseload requirements of a modern industrial society."
Depends on the scale and the willingness to "Think Different". Details matter.
E.g. in Europe (never mind the UK on its own) weather systems can be bigger than the area of interest, so it is entirely probable that much of Europe will have periods of several consecutive days where there is no worthwhile wind-generated electricity. Dealing with that is not impossible in engineering terms, but it takes money, and it needs joined up thinking by politicians and markets (which is almost impossible).
On the other hand, the USA is bigger than weather systems. It is simply not possible for the whole of the USA to be becalmed at one time. So, invest a fortune in wind generation in widely separated parts of the USA, and a fortune in long distance transmission across the USA, such that regions with wind can supply sufficient electricity to regions without wind, and the job is done.
There's a relatively well known well argued paper or two to this effect from a few years ago, unfortunately I can't remember the details - suggestions welcome.
Depends on the scale and the willingness to "Think Different". Details matter.
If you flooded every single valley in the UK to form dams which you could run hydro power off of (which might encounter some political opposition from people living in those valleys) then you still wouldn't have anywhere near enough storage capacity, and it would be utterly economically unviable even if you accepted that any industry would flee to sane countries in response to prices rising faster than rockets heading to orbit, dropping power requirements considerably.
Pretending anything else after the studies on the idea have been done is an absurdity on a par with suggesting that the world is still flat, as is ignoring the undeniable fact that electricity prices have increased by a percentage that has no relation to the percentage of green usable electricity delivered unless you commit the same sort of accounting tricks used to get to zero coal use in a month.
Ah yes, chopping down trees to shred and feed into coal plants makes those coal plants "biomass plants" instead of coal plants. Even if the trees are co-fired with biomass then it's still "green energy" and saving the environment! Produced twice the amount of power today as wind as well!
"If you flooded every single valley in the UK to form dams which you could run hydro power off of (which might encounter some political opposition from people living in those valleys) then you still wouldn't have anywhere near enough storage capacity,"
Absolutely correct. As I wrote earlier, details matter. So does being able to distinguish what's written (I did write "wind power alone could run the USA without storage [1] but the same doesn't work in Europe let alone the UK, for unavoidable scientific reasons") and what's not written (e.g. pumped storage can supply the UK).
If I'd written anything about biomass I'd have agreed with you, btw. As currently implemented in the UK it's yet another distraction, primarily for the benefit of the UK's corporate subsidy farmers.
For some more words, and more importantly some more *details*, including facts and numbers, of how practical it is for the UK to supply all its own renewable energy, try this 20 minute video from Professor David Mackay, RIP):
https://www.ted.com/talks/david_mackay_a_reality_check_on_renewables
"How much land mass would renewables need to power a nation like the UK? An entire country's worth. In this pragmatic talk, David MacKay tours the basic mathematics that show worrying limitations on our sustainable energy options ... and explains why we should pursue them anyway."
"David MacKay is a professor of Natural Philosophy in the Physics department at the University of Cambridge and chief scientific adviser to the UK Department of Energy and Climate Change. He received a degree in Experimental and Theoretical Physics from Trinity College and a PhD. in Computation and Neural Systems as a Fulbright Scholar at Caltech. In 1992, MacKay was made the Royal Society Smithson Research Fellow at Darwin College at University of Cambridge and was elected a Fellow of the Royal Society in May 2009. He has also taught at the African Institute for Mathematical Sciences in Cape Town. In 2003, his book Information Theory, Inference, and Learning Algorithms was published and, in 2008, he self-published Sustainable Energy — Without the Hot Air. Both books are fully available for free online."
Not perfect (what is), but strongly recommended.
So, invest a fortune in wind generation in widely separated parts of the USA, and a fortune in long distance transmission across the USA, such that regions with wind can supply sufficient electricity to regions without wind, and the job is done.
Theoretically possible but... What is the net cost (carbon/pollution/environmental damage/raw resources used including oil and other non-renewables including rarer metals etc) in such a scheme? Even if the turbines have a decent lifespan (my understanding of wind turbines is they don't last very long although how much has to be replaced is another matter - eg the gearbox is a relatively small part although replacing it still require a lot of heavy lifting!), could such a scheme actually save on energy/pollution/etc? Forget completely about economic cost (would probably be considered to be prohibitive even if the scheme would work), what would be the environmental impact?
You could perhaps build hydro schemes where possible, and nuke where hydro can't be done. Wind could be used to pull water from downstream back upstream, which would potentially lessen the land needed for the lake. Hydro has a huge environmental impact but we have ~100yr old installations here in NZ, a lifespan that well outdoes current wind technology.
"You could perhaps build hydro schemes where possible, and nuke where hydro can't be done. "
Once you have MSRs down pat, you don't _NEED_ solar, or windmills or hydro.
The environmental impact of hydro is a lot greater than people realise, apart from the death tollls when dams fail there's a substantial methane component from drowned biomass.
NZ is in an arguably unique position, being in the roaring forties and having the southern alps to build dams in - but even there the easy wind has already been pretty much tapped out and hydro went from being 80% of the energy source in the country in the 1970s to 20% in the 1990s. Clyde dam is an example of prioritising energy over safety and a decently large quake is going to be a big wakeup call.
Most of the rest of the world simply doesn't have the kind of terrain and low population that NZ has.
"The economical maximum for carrying electricity is about 1500 miles"
Citation welcome. Readers will note that the USA is very very very roughly 3000 miles left to right, and a USA-scale network of interconnected regional grids wouldn't necessarily need anything like a single full length link from left hand to right hand or top end to bottom end.
That said, limits can be dictated by engineering, and then there's economic limits too.
Whether something is economical or not often depends on what the alternative is, unless there is an underlying physical limit such as energy return on energy invested (EROEI), which e.g. makes some fossil fuel recovery tactics uneconomic.
In the engineering side of the electricity transmission picture, there are typically conversion losses and transmission losses (both of which have a cost in money as well as energy terms).
HVDC reduces the transmission losses vs HVAC. UK<>France HVDC is decades old, UK<>Norway HVDC is finally being built, a decade after it was technologically possible. Only the transmission losses depend on distance, the conversion losses (for a given power transfer) are largely independent of distance.
Modern high power semiconductors in the conversion equipment have reduced losses and improved controllability vs their various predecessors.
Superconducting HVDC reduces the transmission losses to zero (but increases the up front cost and also has the cooling cost to pay for, in energy and money). Modern high temperature superconductors can reduce the cooling costs vs original low temperature semiconductors.
The over-capacity wind with long distance transmission idea is unlikely to be a winner, but economically and in engineering terms it could work (at least as well as, say, Olkiluoto has worked so far).
I'll be happy to hear why there's an insurmountable 1500mile limit.
"Citation welcome."
My old engineering textbooks are long gone, but the practical maximum for transmission lines (AC or DC) is around 1 million volts. Beyond this they just arc over too much (500kV ones will arc over too if there's a fire nearby putting smoke near the lines.)
Between this and practical limits on line diameters dictated by the mass of the wire strung between poles and tensile strengths of steel a 700 mile segment is going to lose about 50% at full load. 1500 mile segments (and longer) exist but they're primarily used as interconnectors for topping up power in one direction or another rather than feeds carrying hundreds of GW (the costs are cheaper than peaking plants etc)
You're right about the size of the USA, but you'll find the longest practical transmission distance anywhere in the USA is about 400 miles with longer hauls used as above.
The reason it matters is when people start raving on about paving deserts with solar panels or XYZ with windmills and then using the energy to feed a continent (usually the Sahara and Europe). Apart from the political implications (there's more demand to the south than the north), the transmission line project would lose 75% or more of the generated power AND be the single largest engineering project ever undertaken in human history (the solar panels would be a bigger one but never mind).
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"I wonder what it's like at 8-9 am on Christmas morning when all the Turkeys go in the oven?"
Gridwatch has the answer (it also used to be available direct from the official source that Gridwatch uses but I can't find that at the moment).
Top left hand corner of Gridwatch main page, to the right of where it says "Download data sets (CSVs)", ckick on "Download" button, and (in principle) select the data items and the time range you want to download. I can't quite get it to select the right date range at the moment, but it has worked in the past and still works for some strange selection of date ranges (?).
Have a lot of fun.
I never found out whether that was a stunt
No not a stunt, just an artifact from slinging a huge load of wind and solar assets at the grid, and having operating and payment arrangements such that these assets become "must run", and indeed even get paid if there's insufficient demand or grid constraints.
Today's a minimal coal day (see for yourself, search on the terms templar and gridwatch), but as I write, the reality is that nuclear is running at full chat around 8 GW, the Dutch and French interconnectors are importing the better part of 2 GW, Drax is burning the forests of Louisiana to make 2 GW, and the biggy is gas turbines are humming away to the tune of 16.5 GW. Wind is producing a miserable 1.39 GW, merely serving to push coal off the grid at the moment, and thus require "Capacity Market" subsidies to keep it available.
Going back to your point about SMR, I've had some limited professional involvement, and I think your view on costs is correct - that by the time you've got something buildable, the cost per GW will be astronomical. However, this won't stop the mad fools of the British government. With their obsession about saving the planet by cutting CO2 emissions, they hope to decarbonise not just electricity and transport, but heating. And what they (wrongly) believe is a possible solution, is to have cities linked to large and astronomically expensive district heating systems, using the surplus heat from small, local nuclear reactors - these SMR. You might think that's utterly, utterly mad, but this is laid out in the government policy documents (eg Chart 18, p46, The Future of Heating, DECC, 2013). Obviously there's no heat demand around Trawsfynydd, Hinkley Point or Sizewell, so the bureaucrats plan to take the nuclear reactors to where there is heat demand.
The cost of solar PV built so far in the UK averages about £150 MWh across the portfolio. Hinkley has a contract for £92 MWh, but at 2012 prices, so uplifted by CPI we're already at £104/MWh, and by the time it is operational (I guess) in 2032 it'll also be up to about £150/MWh. These SMR will need the same sort of price (even if simpler than an EPR, they lack the economies of scale). Which means the average commodity element of electricity bills will roughly triple by 2030. Add to that all the money being frittered on energy storage and network reinforcement for all the crappy renewables, and the plans for another seven nuclear reactors, of about four different designs and people in the UK won't be able to afford to have electricity. And they won;t be able to afford heat, either, because the cost of district heating is about £10k per connected property.
You couldn't make a worse mess of energy policy if you actually set out to do things wrong intentionally.
Scrap the Climate Change Act. CO2 is not a pollutant.
15% of the world's record food production last year can be directly attributed to increased CO2 allowing plants to thrive. This is a good thing.
Global temps have been static for nearly 20 years.
The climate change scam is busted.
There may be a link between increased atmospheric CO2 and increased plant thriving. However, using that argument to say "The climate change scam is busted." is like saying the Mr Hitler was a good egg really because he instituted a great road-building programme.
How silly.
The climate scam is busted because it is absurd to restrict the amount of CO2 we add to the atmosphere. It is absurd because:
1) It has little to no effect on climate. The change in temps in the early 20th century is almost identical to the change in temps at the end of that century. This cannot be so if CO2 is the control-knob. Man-made CO2 is not involved in early 20th C temps. This is the attribution problem that CO2 fans cannot resolve.
2) Warm is good for civilisation, cold is disastrous.
3) Restricting CO2 will mean we are purposefully and expensively trying to reduce crop-yields. Most people don't like starving.
4) Cheap energy == modern civilisation != Expensive windmills
>It has little to no effect on climate.
Lie #1. Really, this has been solid science for over a century
> Warm is good for civilisation, cold is disastrous
Lie #2. It's relatively easy to keep warm in a cold climate. It's pretty difficult to keep cool in a hot climate.
>Restricting CO2 will mean we are purposefully and expensively trying to reduce crop-yields.
Lie #3. No-one is suggesting removing CO2 below base levels.
>Cheap energy == modern civilisation
Just a half-truth. Yes, we've built modern civilisation on cheap energy - which is now destroying modern civilisation. Not very bright.
"Yes, we've built modern civilisation on cheap energy - which is now destroying modern civilisation. Not very bright."
The issue that I see is that developing countries need cheap energy to keep developing - and if "we" don't give them nuclear power, LFTRs, etc then they'll easily burn as much coal/wood/oil as we've stopped burning. Preventing them from doing so is not an option unless you fancy an all out war between the global haves and the have-nots which will make Egypt vs the Sea People look like a friendly match between Arsenal and Spurs.
"if "we" don't give them nuclear power, LFTRs, etc then they'll easily burn as much coal/wood/oil as we've stopped burning. Preventing them from doing so is not an option unless you fancy an all out war between the global haves and the have-nots"
This was part of the philosophy behind Desertec (RIP). Readers unfamiliar with the concept might want to look it up, but basically the suggestion was to generate solar electricity in (e.g.) North Africa and transmit it to Europe. There are obvious geopolitical issues to address in that scenario - e.g. making sure that the people whose land is used for the generation have a share of the scheme's benefits, so that it's in *everybody's* interest for the scheme to succeed.
https://en.wikipedia.org/wiki/Desertec
2) Warm is good for civilisation, cold is disastrous.
As long as you don't live anywhere near the coast[1]. Or in an area where changes in weather patterns[2] mean you no longer get much rainfall (check how much civilisation in the Sahara!). Or in an area where the rivers dry up because of higher temperatures.
In short - that statement is even less reasoned than the rest of your blinkered posts.
[1] Hard to be civilised when your pleasant coastal town is now largely underwater. As are your fertile croplands..
[2] Because weather events are driven by temperature differences in the atmosphere. More heat==more energy. More energy==changes in weather patterns.
"[2] mean you no longer get much rainfall (check how much civilisation in the Sahara!). "
This is one area of great concern for climate scientists. The effect on ~3 billion people of the asian Monsoon failing or significantly changing its pattern is something that should give pause for thought.
Increased CO2 has had a definite effect on ocean chemistry, with a 30% change in acidity levels in the last 200 years. This is starting to affect shell-forming animals and not in a good way.
You can discount global warming all you want, but one of the very real geological effects recorded for CO2 spikes has been anoxic oceanic events - look one up to see why these are bad.
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Satellite and radiosonde data sets (The most accurate we have) show no warming for this period.
News which must come as great comfort and relief to the polar-dwelling animals that have been watching their habitat slowly recede into the sea as the ice caps melt.
The Antarctic ice-mass is increasing. It is at near record highs.
Polar bear numbers are increasing.
I thought the North Pole was supposed to be ice-free in 2015? What happened?
Please look into it some more. You will be aghast when you see how science has been abused by the climate change religion.
'The Antarctic ice-mass is increasing. It is at near record highs.'
That is not inconsistent with a warming planet. Warmer air and a weaker vortex allows moist air to blow over East Antarctica and fall as snow.
The Zwally study you are probably referencing (https://www.nasa.gov/feature/goddard/nasa-study-mass-gains-of-antarctic-ice-sheet-greater-than-losses) has issues highlighted by the author which are often lost in the noise. Zwally's data only covers part of Antarctica and it only goes up to 2008. Zwally found that ice was accumulating in East Antarctica as predicted, but Zwally also pointed out that loss of ice in the West and the Peninsula was accelerating and would outstrip accumulation within the next two decades.
Zwally's study also conflicts with other NASA data from the GRACE satellite which measures the mass of Antarctica. That shows a clear trend of mass loss at a rate of 125Gta. So far, Zwally is an outlier in the data which suggests Antarctica is net losing mass.
https://climate.nasa.gov/vital-signs/land-ice/
'Polar bear numbers are increasing.'
Possibly, but it's probably due to the cessation of hunting of polar bears rather than purely natural causes. Even the people who study polar bears admit there are huge uncertainties over their numbers and the health of populations:
http://pbsg.npolar.no/en/status/population-map.html
http://www.sej.org/publications/alaska-and-hawaii/magic-number-a-sketchy-fact-about-polar-bears-keeps-goingand-going-an
'Polar bear numbers are increasing.'
Possibly true, but then polar bear numbers have been below the carrying capacity of their habitat for decades, due to hunting. As hunting has mostly ceased it would not be that surprising if numbers were now increasing. As Mike says it is also very difficult to estimate the size of polar bear populations as they spend most of their time at sea and range over vast distances. There is also an argument that polar bear numbers are less dependent on summer sea ice than previously thought- some populations live onshore during the summer and those that do go on the ice during the summer are still probably mostly dependent on fat reserves built up during the spring.
Just because there are more polar bears it does not follow that Arctic temperatures aren't increasing or that the extent summer sea ice is decreasing. Polar bears (and bears generally) are remarkably adaptable animals and I think their outlook is fairly good even with global warming. However I would like the generations that follow to be able to see polar bears hunting seals on sea ice like I have rather than raiding the municipal rubbish dump for scraps.
"The Antarctic ice-mass is increasing. It is at near record highs."
Antarctic Ice extent is at record lows: http://nsidc.org/arcticseaicenews/files/2017/05/Figure6.png
Global ice extent is also at records lows:
https://sites.google.com/site/arctischepinguin/home/sea-ice-extent-area/grf/nsidc_global_extent.png?attredirects=0
"Polar bear numbers are increasing."
There is no evidence to support that. We know that several populations are declining. We also know that global warming is reducing their habitat. See http://www.independent.co.uk/environment/polar-bears-arctic-global-warming-40-years-iucn-sea-ice-a7459531.html
"Polar bear numbers are increasing."There is no evidence to support that.
Can you guys go back out to the other room and get your stories straight? While this is only a very small example it is a key one in this very thread. Up above we have one man-made climate change supporter admitting that it appears that polar bear numbers are increasing based on the available evidence (though he does suggest it is hard to be sure, which I fully understand), and here we have one saying there's "no evidence", contradicting the other.
This is one of the many issues others have with "MMCC" - we see those promoting it cannot agree on things themselves except "global warming" . "Yes, Antartic sea ice is increasing in some areas" "No it's not, it's consistently getting less in all areas".
Get your stories straight, present a united front, and we might start to believe you. Continue to post data that conflicts with each other, and why should we believe you?
(In case any one doesn't know, I am someone who believes that climates can change considerably, that man probably isn't largely responsible but we should do our best to preserve resources and protect the environment - hence why I dislike wind (wastes resources and destroys the environment), love nuke and hydro (the latter does a lot of environmental damage short-term but can last considerably long term), would probably kill anyone I met wanting to build new coal, accept gas (not that bad until we get better stuff running) and do what I can to save resources and replenish the earth myself, ie pretty much a greenie but the only time I foam at the mouth is when I am cleaning my teeth)
"I thought the North Pole was supposed to be ice-free in 2015? What happened?"
Go listen to the most recent More or Less broadcast on the BBC. Tim Harford will explain to you 1) what "ice free" actually means 2) how that claim for 2015 came to be reported 3) why it's all more complicated than that and 4) the effect of removing ice layer from the seas
Actually it is you with the weak position. Satellite measurements are not the most accurate since satellites do not directly measure atmospheric temperature, rather they measure microwave radiation emitted by oxygen in a range of wavelengths which are then converted to temperature using various statistical methods.
There are multiple microwave temperature datasets obtained by multiple satellites with differing sensors and using multiple statistical methods upon which differing corrections have been applied. However, once the datasets are correlated the consensus is that there has been an overall warming of the troposphere since the mid-20th Century and a cooling of the lower stratosphere due to ozone depletion and an increase in water vapour due to higher temperatures in the underlying troposphere.
This satellite interpretation is supported by radiosonde data which is especially accurate for the Northern Hemisphere outside of the tropics. However, uncertainties in the correlation and lack of radiosonde data for the tropics and Southern Hemisphere mean that the rate of temperature change is uncertain. The best estimate is the lower troposphere is warming 0.12 - 0.135C per decade compared to 0.161C per decade for the surface.
Here are some links:
http://www.remss.com/measurements/upper-air-temperature
https://www.ipcc.ch/pdf/assessment-report/ar5/wg1/WG1AR5_Chapter02_FINAL.pdf
http://science.sciencemag.org/content/309/5740/1548
https://www.gfdl.noaa.gov/bibliography/related_files/tmlw0602.pdf
Tropospheric data here - go knock yourself out, but don't forget to write down your method:
https://www.ncdc.noaa.gov/data-access/weather-balloon/radiosonde-atmospheric-temperature-products-accessing-climate
Actually it is you with the weak position. Satellite measurements are not the most accurate since satellites do not directly measure atmospheric temperature, rather they.....
If I could just observe, when satellite measurements support the received official wisdom of climate change, they are breathlessly quoted as proof of the matter. Funnily enough, if they don't support that position, then they can be explained away.
Climate change is happening, I accept that. But the correlation against CO2 is probably similar to the correlation with toothpaste consumption. Unlike the majority of the population and most climate change enthusiasts, I have actually studied climate science at degree level. And I'm unconvinced by the simplistic CO2=climate change. You'd better mark me down as some racist Brexiteer climate change denying Daily Fail reading, 4x4 driving, reactionary idiot.
'If I could just observe, when satellite measurements support the received official wisdom of climate change, they are breathlessly quoted as proof of the matter. Funnily enough, if they don't support that position, then they can be explained away.'
I think the issue is that where research is republished especially for a popular audience, satellite = high tech = better has been assumed. What isn't explained is how satellites infer temperatures and that there are known issues with their records - some of which have only been discovered since the discrepancies in the satellite record have become obvious. What we should be saying is that the satellite record, although imprecise, gives us a truly global coverage which hasn't been the case so far.
'Climate change is happening, I accept that. But the correlation against CO2 is probably similar to the correlation with toothpaste consumption. Unlike the majority of the population and most climate change enthusiasts, I have actually studied climate science at degree level. And I'm unconvinced by the simplistic CO2=climate change.'
At a very simple level CO2 is causative on temperature change - John Tyndall and Svante Arrhenius proved that in the 19th Century. The exact percentage of temperature change due to CO2 as opposed to other factors is the current question. But the weight of evidence is such that people proposing other methods are struggling to find suitable mechanisms for warming the planet whilst finding some way in which increased CO2 concentrations in the atmosphere don't do what they do in the lab. (And yes, climate change was a good part of my post-grad degree, so I've laboured through more forcing papers than is good for anyone's soul).
'You'd better mark me down as some racist Brexiteer climate change denying Daily Fail reading, 4x4 driving, reactionary idiot.'
Why on Earth would I want to do that? Twitter is there if I want to be horrible online.
Have an upvote for having a decent argument.
>If I could just observe, when satellite measurements support the received official wisdom of climate change, they are breathlessly quoted as proof of the matter. Funnily enough, if they don't support that position, then they can be explained away.
Funnily enough, the people who interpret these data know what they're talking about. You don't. That's why we're ignoring you.
"Scrap the Climate Change Act. CO2 is not a pollutant"
I can only assume you are trolling. Either that or you just got out of a Delorian. No one can be that poorly informed surely?
That a) the planet is significantly warming over a timescale of decades, and b) human emissions of green house gases - primarily CO2 - is at least a significant cause has been in zero scientific doubt for about 2 decades now.
"Global temps have been static for nearly 20 years."
Erm, no. https://s.w-x.co/jma-mar2016-graph.jpg
"The climate change scam is busted."
Either your brain or your bs filter is busted.
Erm, no. https://s.w-x.co/jma-mar2016-graph.jpg
Given the regularity with which you spread, well let's just say "severe misinformation" regarding MS products, especially the links you tend to provide, don't you think the best thing you could do to support the "AGW" argument is to stay out of it? Or at least post as AC?
Given your record, I would assume anything you link to is false, without wasting my time to visit.
I can only assume you are trolling.
Well, 90% trolling. Unless 90% is a problem for AGW, in which case it's 20% and I'll figure out how to explain away the original 90% as being perfectly fine and not false data at all, and the existence of the false data further proves AGW!!!!
I mean last time I checked, there were apparently no concepts or demonstrators for that kind of power plant. If this was actually a way towards the future, you'd expect some little demo reactors being built to find out what problems you get when scaling it up. It's just common engineering practice.
How proven a technology do you want?
From memory, the reactors on subs are about 20-40 MW, although I suspect that's MWth, not MWe (meaning that the useful electrical output is about half of that) . If you have to build ten units for a 300 MWe plant, then it will be hopelessly expensive. For an individual power station you need no more than four reactors (and ideally less), so for a 300 MW power station, you've got to increase the unit output several multiples over a submarine reactor, from what is already a military grade cost-no-object design. That won't be quite as easy as some people seem to think.
Then you've got context. In a submarine there's a whole ocean of heat sink, but for a land based plant you need to add cooling (and likely heat recovery) plant, you need the system to be acceptably safe against terrorism and foreseeable accidents (eg, build them near cities, means build them near airports), and you'll have the cumbersome safety regulations for civil plant.
So, the OP was correct: There's no working example, no reference site, and all we've got is marketing graphics. Going back some years, before the Germans raised the white flag on nuclear matters, they came up with a different SMR concept, the PBMR, and they had a proof of concept plant built and working (IIRC). When the Green party carried out their evil wish to rid Germany of nuclear power, that technology was sold to South Africa, who really didn't have the resources, technology, or will to develop it, although the ghost still lives. Personally, I think PBMR had/has a lot of promise for simple, safe, relatively low cost nuclear power, but I suspect that the British government will as usual pick a winner, and then wonder why it all fails abysmally.
The two German pebble-bed reactors both broke and one released noticeable amounts of radioactive material into the atmosphere. They still don't know exactly how to safely decommission them (Google THTR-300 and AVR for details) so they're mothballed until the radioactivity dies down a bit more.
The Chinese have been operating a small high-temperature pebble-bed reactor for a while now, the HTR-10 (it generates 10MW of electricity). They're building a bigger version which is sort-of modular, a 105MW reactor that will work in pairs to drive a 210MW turbine. The vague plan is to site a dozen or so of these together to make one complete generating plant but they want to see how the scaled-up version works before they start mass production.
As for submarine and other propulstion reactors, the modern cost-no-object designs used in the US Ford class carriers and British Astute subs run on bomb-grade uranium enriched to 90%. Having this sort of stuff sitting around in civilian hands in regular power reactors is a bit of a proliferation risk. The US and other nations have been working to replace existing highly-enriched (but still nowhere near bomb-grade) cores in some research reactors with low-enrichment fuel cores.
" they came up with a different SMR concept, the PBMR, and they had a proof of concept plant built and working (IIRC). "
Pebblebeds are still being developed. The german ones had some safety issues which you'd kind of expect being an experimental setup and got shut down as a result.
A bit longer than that:
@hammarbtyp
Not simple enough for him I suspect. So I'll use my nifty bronze commentard badge to simplify it to the point where he'll at least be able to get to the article by clicking instead of having to cut and paste.
I doubt he'll be able to understand it, but at least he'll now be able to get to the page without straining his intellect too much.
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Er, no they have not. You are quoting NASA but are referencing a wordpress article. Try looking at the actual NASA data and you will see an increase year on year since mid-1900s.
https://data.giss.nasa.gov/gistemp/graphs/
Don't let the facts get in the way....!
Cherry picked data with a large axis from an antiwarmist site? The original graphed data is here: GISS NASA website. This shows a rise of ~1C The lump in the 1940s may be due to the increased production and devastation of WWll?
That''s why separating the yet-to-demonstrated-as-commercially-viable fusion from the commercially-viably-if-heavily-subsidised fission is important. Fission is "nuclear power" with its toxic legacy of negative PR. It's what causes stars to explode. Fusion is the "wholesome", "harmless" process which makes the sun's shine. The difference is that between a shark and a dolphin. Yes, they both swim in the water (or manipulate the nuclei) and they both have fins, but that's about all they have in common with each other.
But fusion won't make wind farm builders and their lobbyists in Brussels rich, will it? It'll put them out of business. And cheap, clean, always-on electricity is the LAST thing the green movement wants, because if we have that then why do we need them to bang on about AGW?
But fusion won't make wind farm builders and their lobbyists in Brussels rich, will it?
I work in this sector, have good connections with my employers policy, lobbying, PR teams. The reality is that industry is following policy, not shaping it. EU policy is formed primarily by the broad red-green political alliances in Brussels who are fully committed to the climate change cause. The influence of commercial lobbyists in this sector is weak, but it doesn't really matter - the policy is set, and the political classes are happily committed to it. The commercial sector follows the money, and in this case, the money is all about pushing the fashionable "renewables", and the great thing for the British government is that most of the costs of this are completely hidden in your electricity bill. As a broad estimate, about 50% of your entire energy bills are consumed by the various costs of UK government decarbonisation policies - ECO, RO, CfDs, RHI, FIT, and then the huge costs added to electricity distribution costs by having to cope with all the renewable toys. And that's before the twats of Westminster start "decarbonising" heat and transport.
The Green movement in the EU has fought tooth and nail against nuclear for decades. It wants expensive windmills
If only they would fess up and stop claiming to want to protect the environment! Promoting very filthy wind over (relatively) clean nuke shows that either they don't know their science or they really are anti-environment. Either way, the more they get their way the more the earth is screwed.
Security is rather important and means we probably won't be seeing any reactors in the middle of a roundabout anytime soon. I could see how having one of these reactors next to a large consumer of power with preexisting security like aluminium smelters would work though.
I could see how having one of these reactors next to a large consumer of power with preexisting security like aluminium smelters would work though.
This assumes that we have such large consumers of power, and ignores the commercial "counter-party risk". As an example, Wylfa nuclear power station was built next to an aluminium smelter, which has now closed, meaning that in the now highly unlikely event that Horizon build Wylfa B, we'll have a 3 GW power station built as far away as possible from any population centre, with local energy demands essentially streetlighting for Pontypandy.
The British government having forced the vast majority of heavy industry offshore over the past forty years, we simply don't even have suitable industrial clusters to match with a big nuclear power station.
"The British government having forced the vast majority of heavy industry offshore over the past forty years,"
O'really.
Does the name Weinstock mean anything to you? In the 1960s, his empire at GEC owned the capability to build all the important bits in the electricity supply chain, from heavy stuff like steam turbines, alternators, transformers, and switchgear in the power station, via transmission and distribution all the way to domestic appliances at home, and lots more too (including fighter aircraft and digital telephone exchanges and the odd computer or automation controller).
A bit like (but largely unrelated to) GE of the USA.
It wasn't UK Government(s) that made GEC vanish. A major factor was Emperor Weinstock's insistence on keeping almost all GEC's cash in the bank rather than investing a bit of it for the future - on people, processes, products, and technologies. "If I need something new, I'll buy it in" seemed to be the motto - until they were so far behind that joint ventures and bought in technology no longer worked.
"we simply don't even have suitable industrial clusters to match with a big nuclear power station."
Don't Sheffield Forgemasters still exist? Coincidentally or otherwise, Weinstock never got his hands on them, and they do still exist despite the City (and their Westminster puppet's) reluctance to invest in companies that literally do metal-bashing. Beyond them, er well yes you're probably right.
The various boards of directors ran most of the GEC and ex-GEC companies down and sold them off for a mess of pottage.
You're forgetting the Civil Nuclear Constabulary, one of the few national police forces in the country (the others being the British Transport Police, and the Ministry of Defence Police) - it's also an almost fully armed force with all of it's officers being firearms trained and almost all armed every shift.
They train all the time for the scenarios you describe and they currently don't need military assistance as their security is first rate.
"137 years of measurements"
This is what concerns me about climate change discussions. Set against the period of the post-glacial it's about 1% and yet all the arguments hang on this.
There are very good arguments against unnecessary consumption of fossil fuels: they have multiple alternative uses as raw materials and when they're gone they're gone. There have been no good arguments against shoving them up power-station chimneys for the last half-century or more. It's largely down to the self-styled green movement that we're continuing to do this.
'This is what concerns me about climate change discussions. Set against the period of the post-glacial it's about 1% and yet all the arguments hang on this.'
That's why there are proxies for further back in the record such as oxygen isotope measurements in sediments, air bubbles in ice and organic carbonates.
"That's why there are proxies for further back in the record"
And what are the error bars on such proxies?
The trouble with all this argument is that the period for which we have good global measurements (give or take arguments about integrating them) is very short so we're really arguing about noise which includes such things as the effects of volcanic veils - and do we know yet what caused the cold & wet period in Western Europe starting in 1315? In any case anyone who thinks that constant climate and constant sea-levels are the norm is living in a fools paradise. They have changed and they will change whatever we do.
OTOH we should really be concerned about conserving scarce resources. It's wantonly using up those that our descendants will be cursing us for.
The big bogey men with nuclear power generation are decommissioning costs and dealing with the left-over radioactive waste. Just look at all the nuclear debris lying around Sellafield at the moment.
Either we need a commercially viable way to clean up the waste, or, even better, not generate any radioactive waste at all.
Well it used to be (Windscale).
About 90-95% of the UK's nuclear waste is down to the nuclear weapons programmes of the 1960s. You can see that in published NDA documents. Windscale (and before that Calder Hall) was never a commercial prospect, it was always about making weapons grade fission materials. Any power output was purely incidental. And unfortunately, in the pell-mell panic to make more and more nuclear weapons, all common sense was ignored, leading to accidents, vast amounts of high grade waste, and lots of contamination.
due to the so called 'green' people who see the word "Nuclear" and go into a complete meltdown.
And then theres the sort that see the exhaust from a gas station , compare it to the clouds of steam coming from a coal station, and decide coal is polluting the world....
>due to the so called 'green' people who see the word "Nuclear" and go into a complete meltdown.
Bollocks. For several decades, there have been no restraints on building nuclear in this country. They haven't been built because they're an economic disaster - no-one was prepared to foot the bill (since government stopped doing that). You only need to look at the gyrations around getting Hinckley C started, to know that.
Isnt this in response to our own policies to cut our own power generation? The determination that not releasing Co2 is more important than having the lights on but appealing to the fantasist in all of us by erecting monuments to the wind gods. Although I do think labour actually did think those wind farms actually worked.
Instead of trying to fix a problem we have created why not remove the problem and produce energy. Problem solved. The increasing costs of energy are due to this crazy push for a futuristic technology we dont have to provide a utopian outcome we cant reach. Lets walk before we can run.
Press release out today on consultation for the new Wylfa station on Anglesey (Wylfa 1 was switched off in 2015)
Output 2.7GW, cost £10 billion. 'Enough for 5 million homes' 850 full-time jobs once commissioned.
Questions: how much of the salaries from those 850 jobs end up locally? How many of the 850 will even live locally?
5 million homes - but there are only 1.4 million in all of Wales! We could get rid of all the wind farms - although did I hear a whisper of 'single point of failure'? Personally I think that is one of the biggest risks from very large Nukes. Small ones will mitigate that risk, whatever other issues there are.
Perhaps time to scrap this idea and commission 10 SMRs scattered around the country - we have some very nice old underground mines that could be ideal locations.
"commission 10 SMRs scattered around the country - we have some very nice old underground mines that could be ideal locations
Trawsfynydd has been suggested as an SMR site, it seems well qualified [1]
"How many of the 850 will even live locally (to Wylfa)?"
Unknowable, but the Wylfa consortium is already scaling down its employment and accomodation plans, even for the construction phase, by increased use of shared facilities between the two proposed units (?). Hopefully the newly-shared facilities aren't of a safety-related or safety-critical nature. Plans for offsite accomodation appear to have been quietly abandoned in the last few weeks [2]
[1] https://www.theengineer.co.uk/north-wales-site-has-potential-for-uks-first-small-modular-reactor/
(13 March 2017)
[2] http://www.itv.com/news/wales/2017-05-24/latest-plans-for-wylfa-newydd-on-anglesey-unveiled/
Interesting article in the Indie today - India has cancelled plans for 14GW of coal, as the wholesale price of solar is now 25% below coal.
Auction price for a 500MW solar deal recently was $38/MW - eat your heart out Hinckley!
Okay, we have a different climate to India, but interesting...
Okay, we have a different climate to India, but interesting...
But this is true anywhere that you have a lot of reliable sunshine, and the power demand peaks during the day. Solar is a great fit with the power demands in lower latitudes (say anywhere between the equator and 44 degrees) - although worth noting that if you've got a monsoon season, there will be several months of very low direct sunshine, and that needs to be given some thought.
The UK situation is that we have poor azimuth on the sun because we sit on the top edge of the temperate latitudes, our power demand peaks in winter, and maximum demand is correlated with low wind speeds after dark. Which means that even if UK solar power came down to $38/ MW, it wouldn't help us one jot - we'd still need all the fossil and nuclear plant we've got, and if we built more PV then we'd have to pay bigger subsidies to keep the CCGT's available for when we do need power, because PV and wind reduce the running hours of thermal plant, and absent subsidy it wouldn't be economic to keep it open.
The reason oil companies fund climate change propaganda is obvious.
And what are the reasons of the propaganda supplied by the environment-hating pushers of "wind power"?
The reason you want to believe it is probably because it hurts your nationalistic pride.
My posting history will show that I don't have any "nationalistic pride". In fact given our previous shonkey pm and our current criminal government, "deep shame" doesn't even come close.
That there is a problem in the world that can only be solved by international cooperation.
Lots of problems could use some international co-operation. Sadly the people we most need on board are those who will most want to do it their own way, to the detriment of the rest of the world.
But tell me. Would you support nuclear and hydro, with gas as a backup for emergencies? Or would you rather wind and solar, with coal/imported wood chip providing the brunt of the generation for the UK?
"The reason oil companies fund climate change propaganda is obvious."
They mostly stopped being oil companies decades ago. They're energy companies.
If nuclear was cheaper than oil (in terms of cost benefit ratio), they'd be in it boots'n'all, but if they can keep the cost side low then they'll stick with oil.
If they can keep those cost side of oil low by FUD against everything else then they will.
Science has always been politicised, from the moment that Giordano Bruno was burned to death for proposing the plurality of worlds. In those days, politics was pretty much for or against the Pope and his view of reality.
But here's a thought.
Why are the 19th century buildings for the old science departments in Cambridge so impressive? Because the scientists of the day were seen by rich landowners as the means of making them even richer. Geology was driven by the desire to find where to excavate in order to find coal or iron ore, the new sources of wealth, or where best to dig a canal or, later, to site a railway. Canals and railways were pretty damn political; the equivalent of the Watts or Monckton of the day was Dionysius Lardner telling people nobody could travel at more than 30mph at the behest of the road and canal interests [historical note - he lost the argument.] Fossil research, crystallography, mineralogy were all funded by the profit motive. Scientists were dragged in to tell people these new fangled railways were safe. It was a PR coup when Queen Victoria went on a train.
So now look at today. Politicians would love to believe that climate change is a hoax and business as usual can continue. Any group of climatologists who could cast serious doubt on the consensus would be enriched by the oil companies. And if they won the argument it would be Nobel prizes and heads of departments at large universities with seats on the board at BP, Exxon and Gazprom. There is all to play for. But they don't. Why? Too pure minded? Who would care if everybody else opposed them so long as they knew they could prove their case? So what conclusion can we draw from this?
"
Politicians would love to believe that climate change is a hoax and business as usual can continue
"
That is the very opposite of the truth. MMGW is the bogey-man that is fuelling punitive taxation, funding all the wild schemes that ultimately filter back to swell government coffers and justify disproportionate increases in energy costs.
An obvious one here is motorway service stations. That way there might be a chance of charging all those electric cars.
Now that's a bloody good idea! So few people give a thought to the demands electric cars would place on the grid should they become more common (there was a report here in NZ yesterday (IIRC) that there would be no more petrol cars by 2025 - just a few years away - because they'd all be replaced by electric. I pointed out to the person who told me about the report that it's going to take another 3 years before he has fibre at his house despite the government-mandated "roll out", how quickly does he think the national power grid would be upgraded to allow for each house to charge 2 cars let alone places like apartment blocks, or the neighbours across the road who have 4 cars used daily in their 5-person household, or the neighbours down the hill who have 3 flats, 2@2 occupants each with a car they use daily, and no off-street parking?
With clean electricity electric cars are a nice, clean and green item. Where coal and oil power stations are having to be fired up to subsidise the grid to cater to these cars, they're not at all clean or green. I've heard talk that some of our mothballed coal and oil stations will need to come back online due to increasing demand a part of which (likely really a small part) is electric cars.
once the fast recharge problem is cracked,
Easy fix for that. STOP SUBSIDISING THE FUCKING THINGS! Why should someone rich enough to buy one of them get "free charging" at various spots built by the local council? Why should the poorer people be paying (through rates) for these pricks to be able to drive their latest wankmobile? Cut the subsidised charging spots, make them pay for their own power at an appropriate rate, and you'll soon see things change!
Icon : Gimmie a blowtorch and one of those fuckers who boasts about being able to charge his latest $60,000 toy for free while the rest of us struggle just to get 2 meals a day!
I thought the Russians were already building a new generation of lead-cooled small reactors, partly using old warheads as fuel?
One of their solutions to safety and cooling seems to be to put reactors on barges and float them offshore with the cables coming onshore. No risk of running out of water. A smallish lead cooled reactor is rather nice in theory because if anything goes wrong the lead damps things down and absorbs the neutrons and a lot of the short half life radiation - and its boiling point is rather high, at over 2000K.
Does anybody know more about this who can comment?
Russia has built a series of fast metal-cooled reactors, the BN-family over the past fifty years or so. The current new kid on the block is the sodium-cooled BN-800 which started up a couple of years ago. It is capable of burning spent fuel, destroying waste isotopes from reprocessing, using up weapons-grade plutonium etc. but it's still experimental with new kinds of solid-metal fuel structures needing developing and testing before it can do all the things it's supposed to be able to do. It's very much experimental, they're not going to be building lots of them in a hurry. Instead they're churning out VVER-1200 pressurised-water reactors very similar to the ones that failed at Fukushima. They claim the new pressure vessels for the VVER-series reactors can be licenced to operate for a century in service due to new manufacturing and testing techniques, and pretty much everything else in a reactor can be replaced during scheduled servicing and upgrade operations.
As for the barge-mounted reactor concept they're building a couple of these to be used in northern waters to provide power to remote communities. They're using existing KLT-40S ship reactors, the sort that power their big nuclear icebreakers. They're small conventional PWR designs, not thorium or travelling-wave or anything the PowerPoint Cowboys have a hard on for. The main use for these barge-mounted reactors will be to make oil and gas exploration in the Arctic a bit easier by powering the onshore facilities, ports etc. The Chinese are also investigating this idea, in part to power the offshore islands/unsinkable aircraft carriers they're building in the Spratlys.
Lead-bismuth cooled reactors were a design used in some Soviet nuclear subs. I understand they were not a technical success with some problems in controlling the reaction in various operating modes -- ship and sub reactor output levels get swung from low-power to high-power a lot and that makes for tricky nuclear chemistry in some situations (Xe-135 poisoning of the fission process, for example).
"The current new kid on the block is the sodium-cooled BN-800 which started up a couple of years ago."
Yeah, because liquid sodium is an intrinsically safe cooling material, even if the loop that happens to get exposed to air doesn't happen to be radioactive, and putting out a fire involving 30 tonnes of sodium that happened to find its way into the basement is easy. (Monju)
There needs to be a checklist of "SHALL NOT" for nuclear reactors and "be able to catch fire" high up on it.
The americans and russians never managed to stop their sodium rigs from catching fire and not to be outdone, the Japanese built Monju. The plant is now being dismantled.
I don't care that "modern technology means it will never leak", the fact that "if it does leak, it WILL burn, it's nearly impossible to put out, and it WILL burn a big hole in the loop causing the rest of the coolant to leak out, giving you an even bigger fire" means that even that "one in a million chance" is one too many.
Lead cooled sounds safe enough but the russians found out the hard way on one submarine that if you let it solidify you can't get to the fuel rods.
If you want to swing your power levels (load follow) then you can't use fuel rods. The Xenon needs to be able to be vented off because apart from the neutron poisoning aspect the sheer pressure of its presence inside the rods breaks the fuel pellets down to a fine powder. That's where MSRs win.
Alvin Weinberg looked at what commerce was doing with his lovely little submarine reactor (powered by uranium because that's what they had available at the time thanks to the weapons program), threw up his hands in horror at the safety issues and came up with an intrinsically safe design. His reward was to be fired and driven out of the industry. Would you run a car using cordite as the fuel?
... is that the owners will take it as a challenge.
Every major nuclear accident - Windscale, TMI, Chernobyl, Fukushima, you name it - came about despite precautions, because administrators saw that all was working well and decided to cut corners. The more failsafe the design, the more they'll cut.
There's no way to avoid it. You need to invent a reactor that literally can't do anything dangerous, no matter how much it's abused, because sooner or later it will be abused to that level.
"Every major nuclear accident - Windscale, TMI, Chernobyl, Fukushima, you name it - came about despite precautions, because administrators saw that all was working well and decided to cut corners. The more failsafe the design, the more they'll cut."
[Citation needed].
IIRC Windscale happened because someone thought it a good idea to have a reactor which basically worked like a coal fire, with a through air flow. Then the radioactive bits got hot and the carbon caught fire...it was a terrible design with no safety at all except the filters over the exhaust which were there because the administrators didn't manage to prevent them on cost grounds. Windscale was the exact opposite of your argument; an insanely poor design which did as little harm as it did because someone made it safer.
Fukushima and Chernobyl arose because of design errors that were made before the reactors were constructed.
You need to look at the publicly available safety reviews for new generation reactors to realise that things are done in a completely different way nowadays.
"IIRC Windscale happened because someone thought it a good idea to have a reactor which basically worked like a coal fire, with a through air flow. Then the radioactive bits got hot and the carbon caught fire"
More or less. But remember that Windscale's _sole_ purpose was to produce plutonium to make nuclear weapons. The military (all militaries) has repeatedly played fast and loose with safety protocols when it's suited them to do so.
Bear _that_ in mind when you realise that the water moderated reactors we know and love are "modernised" and "safened" versions of an experimental nuclear reactor primarily designed as proof of concept - and whose inventor subsequently sat down and _built_ a new _intrinsically safe_ design with safety designed in at every stage of the process to ensure that operator abuse couldn't result in an accident of the kinds we've seen over the years and which didn't rely on bomb fuel to operate it.
Hmmm... does anyone know if these are aiming for a failsafe system, in the original sense of the word?
One thing that remains worrying about nuclear reactors (and I approve of nuclear energy) is that the designs all pretty much posit active control and safety. You'd instead want a system that can't sustain a reaction, much less a thermal runaway, when it fails.
For example, a car, if it loses power, can in most cases be expected to cruise to a stop. An airplane can somewhat be glided to safety (fly by wire and hydraulics loss aside). A helicopter on the other hand is a bitch to land safely and that's pretty much inherent in their design.
Problem seems to be that our current reactors are like helicopters, not cars. They have multiple redundancies sitting on top of a design that requires active control and cooling to keep it in a safe envelope. You'd want to be able to say "no more control => no more fuel/reaction => shutdown". That's a very different aspect than how much staff you need. And it's also unrelated to making it 100% safe in case bad guys fly an aircraft into it or there is a massive earthquake. Or tons of other metrics like nuclear waste production. It might still spew some crap around and make a limited mess, but it shouldn't increase its heat production on the way there. All it is concerned about is minimizing the consequences of worst-case scenarios which is really something that needs doing, IMHO.
That's not what we had, at all, with Fukushima or Chernobyl. And I find mooted similarities in design with submarine reactors hardly reassuring in that context. But, yes, nuclear energy has enough PR and financial challenges that going back to the drawing board may not happen in the West.
"I find mooted similarities in design with submarine reactors hardly reassuring in that context."
Ditto.
ALL the submarine reactors are based on the same basic Gen1 Weinberg principles - and they all use Uranium, which means you're spending an insane amount of energy and throwing away 90% of the fuel before it even sees the inside of a nuclear reactor - worse still, that fuel is a weapons proliferation risk.
More importantly, submarine reactors are _small_ and have virtually _infinite_ cooling capacity available (the sea's just outside the hull). If your design isn't capable of rejecting all its waste heat to air then sooner or later you're going to have a problem.
This article describes the Nukes under Erdogan control in Turkey. The bootnotes has a 65 article
series on Nuclear Education on the development, miniaturization and recent use nuclear
weapons and energy. Beyond college indoctrination, a must read for thoughtful debate.
China is going all out on LFTR research and with that will emerge a whole sheaf of patents. The US was nice enough to give them all of the research papers from the development project at ORNL. There appears to be a tremendous number of advantages in LFTR reactors and they deserve to be studied further.
Wind and solar are fine, but the existing power grids are not built to handle the varying loads and South Australia found out the hard way that relying heavily on wind without a complete analysis of the grid can cause big problems. At least some baseline power from a non-variable source can act as a regulator and sync source.
I see solar PV as a perfect point of use technology and wind as the input for something like a pumped storage installation or being used to generate Ammonia. Ammonia production consumes a large percentage of electrical power in agricultural areas and it can be used as a motor fuel too.
China is going all out on LFTR research and with that will emerge a whole sheaf of patents.
Really? Just how are they going "all out" on LFTR research? Do they have a reactor under construction? Do they have a firm finalised design for such a reactor? Do they have planning permission to build such a reactor, or funding to build it or a site to construct it on or anything in fact?
No, they don't. They are not going "all out" any more than the LFTR TED Talkers and the Powerpoint Rangers in the US and elsewhere are actually anywhere near realising their dream in terms of working hardware and operational experience. Sorry to disappoint.
Yes, they plan to have a proof of concept reactor up and running with the next 2 years. Building more fossil fuel burning plants is no longer viable given the pollution they are having to deal with.
China doesn't need planning permission. I can't remember the lead scientists name off hand, but his father was a Premier so a lot of "red" tape (ha ha) is automatically cut through.
Other people's lack of information never disappoints me.
Yes, they plan to have a proof of concept reactor up and running with the next 2 years.
Where in China? Who's building it, who's funding it? What's the design, power output, fuel mix etc.?
I follow news about nuclear power projects with a great deal of interest and there's nothing about any actual funded and approved construction projects for a LFTR in China or anywhere else for that matter. There's some funding for academic studies on how an LFTR might be built, operated and eventually decommissioned but they are usually on the grad student and Ph. D. study level based on computer models and simulations with no hardware involved. There's certainly a lot of press reports and popular-magazine articles about LFTR but nothing concrete, so to speak in the real world.
The one experimental reactor actually being built in China at the moment is a 105MWe "modular" pebble-bed design (Google for "Shidaowan HTR-PM"). It will use some thorium in the pebbles eventually but it will be fuelled purely by enriched uranium to start with. It's definitely not a molten-salt design.
The only viable Molten Salt Reactor designs are the ones which contain the fuel salt and have a coolant salt (Molex's fuel in tubes design and China's fuel in pebbles design achieve this).
If Kirk Sorrenson's LFTR sprung a leak, it would be fuel salt that is leaking, which would not solidify due to the fission products in the salt, but would instead boil off, spreading cesium and creating a massive cleanup/decontamination bill. If Moltex's reactor springs a leak it is non or low radioactive coolant salt that is leaking, which will freeze and be cleaned up by a dustpan and brush. Yes if I said that in front of Kirk he'd probably slap me as the Molten Salt Reactor Experiment ran of 6 years without any leaks, but I don't find that too reassuring.
In the event of a catastrophic failure (e.g. a terrorist bomb inside the reactor somehow) the much larger volume coolant salt would dilute the fuel salt to the point where it could air cool without dangerous fission product salts boiling off. You'd wait several weeks for the fission products to 'burn themselves up' before performing a clean up.
Moltex's fuel in tubes design is superior to China's pebble design as Xenon gas can be allowed to bubble off, allowing the fuel to be left in the core indefinitely as the fission reaction is not blocked by the Xenon. Also the dangerous fission gases cesium and iodine are converted into stable salts.
Moltex's concept really is a very clever design and is just waiting on a political backer to fund it.
" it would be fuel salt that is leaking, which would not solidify due to the fission products in the salt, but would instead boil off,"
it would be fuel salt that is leaking, which would not solidify due to the fission products in the salt, but would instead boil off,
FLIBE boils at about 1500-1600C.
Fission reactions are self-limiting at 1150-1200C (which is about the same temperature as the centre of a conventional fuel rod) thanks to doppler limiting
How exactly would this stuff "boil off"?
Moltex' design is a hybrid which would allow conventional light water designs to be built using MSR pipes instead of ceramic fuel rods.
The Chinese first concept is using a pebblebed because that's been done before (germany) and they're working along the lines of verifying each step before moving to the next one. The Pebblebed MSR should be operational in the next 2-3 year and the experimental fuel salt designs are expected to follow about 5 years later.
Alvin Weinberg built and ran the Oak RIdge experiment between 1958 and 1968. He certainly didn't big-bang everything from day one and a lot of the planned work on breeding was blocked when Nixon realised it would compete with the SoCal mob.
""it would be fuel salt that is leaking, which would not solidify due to the fission products in the salt, but would instead boil off"
FLIBE boils at about 1500-1600C.
Fission reactions are self-limiting at 1150-1200C (which is about the same temperature as the centre of a conventional fuel rod) thanks to doppler limiting
How exactly would this stuff "boil off"?"
You are correct that fission reactions are self-limiting at 1150-1200C due to the salt expanding (negative temperature coefficient). However about 7% of the heat produced comes from the decay of the already fissioned radioisotope products in fuel. This heat still needs to go somewhere, and Ian Scott's calculations show that air cooling and conduction into steel or concrete below a leak of fuel salt would not be enough to prevent the temperature of the fuel salt rising to the point where the cesium chloride would reach its boiling point and distill out of the molten salt.
"Wind and solar are fine, "
No they're not. Not by a long shot.
If you look at _actual_ installations and _actual_ outputs and scale them up to what's _actually_ possible (even discarding safety limits to allow for windmill blades going over a mile if they break off) and carpet the countryside in windmills and PV, you'll _just_ be able to match the existing electrical generation fleet.
And that's without even going into the issue that large windmills are eating gearboxes at a prodigious rate, such that pretty much the only way to make money off them - even with subsidies - is to be paid not to run them. Or the issue of the hydrofluric acid mess unfolding in China from manufacture of solar panels (putting the potable water of several tens of millions of people at risk)
Forget paving the Sahara. Firstly it's not ours and secondly the practical limit on electrical transmission systems before losses become excessive is about 1500 miles, unless someone's come up with some magic pixie dust that make ultra-low-loss Megavolt transmission lines practical (higher than that and they start arcing to ground) with the limit dropping to a few tens of miles for underwater links.
Chad, Morocco and others might be able to use it as a good power source but not Europe.
Now factor in that electricity accounts for 35-40% of carbon emission, with virtually all the rest being taken up in industrial processes (mainly heat), domestic heating (gas/oil) and transportation. Electrify those and you need to increase your generation capacity by a factor of _AT LEAST_ 6 to keep up, if not 8
Now factor in the developing world. You can't leave them out or their carbon emissions will simply rise to match what we reduce by, as they work to advance their economies.
To be serious about reducing carbon emissions and avoid an anoxic oceanic event, we need to have embarked on a crash nuclear building program a decade ago, but the problem with THAT is that there's nowhere near enough uranium available "off the shelf" to start the things and only enough reserves to run them for about 150-200 years at the scale required. Compare and contrast with _known_ thorium reserves at the scale required being about 200,000 years' worth and hundreds of thousands of tons available right now (it's a nuisance waste byproduct of rare earth mining and difficulty disposing of it is why most of the rare earth mines in the USA closed down)
Yes you need uranium or other fissiles to start a thorium reactor but think of it as a starter motor and once the thorium reactor is running you can syphon out enough fissiles to start a new one relatively easily.
The country which can build and distribute LFTR designs to the developing world over the next 2 decades is the one which will call the economic shots for the next 2-3 centuries.
Yes you need uranium or other fissiles to start a thorium reactor but think of it as a starter motor and once the thorium reactor is running you can syphon out enough fissiles to start a new one relatively easily.
Thorium (Th-232) is not fissile. It needs to be bred up into U-233 in a very hot dense breeder reactor to produce lots of neutrons in a small volume to breed more U-233 and to fission that U-233 to release energy and breed and fission more U-233. Molten-salt reactor designs complicate an already difficult engineering challenge for breeding fuel by moving the incredibly radioactive fuel stream around the reactor in pipes that corrode and leak very easily.
There are so many things wrong with this article it is hard to know where to begin
"Mini reactors are nothing new – they have been installed in nuclear submarines since the 1950s, and Rolls-Royce produced them for the Royal Navy for a decade."
While completely accurate it leads the reader to the exact wrong conclusion. Are these reactors being proposed as a model for SMRs? Why no, they are crazy expensive and no utility would dream of using them for generating electricity.
In fact, the claim that SMRs are cheap is also unfounded, because none of the small reactors anywhere in the world have been. Modular reactors, like the AP1000, ran so far over budget that they bankrupted the world's largest reactor maker Westinghouse. Is it possible SMRs will be cost effective? Sure, but so far no one has been able to build even a prototype which makes us believe it is at all likely.
Nor have they really solved the waste, proliferation, terrorism and severe climate disruption safety problems.
It is just another in the long line of nuclear scams which include the nuclear airplane, reprocessing, fusion power, breeder reactors and the denial of the link between civil and military nuclear programs.
The nuclear aircraft was a cover for LFTR development. Politicians bought the idea of an aircraft powered by a nuclear reactor even though people with brains had already figured out that it wasn't workable and a stupid concept to start with. In the world of government funded research, you tell whatever whoppers you need to so you receive the funding you need.
Small reactors don't make sense as they have the same parasitic costs (lawsuits, etc) as a much larger reactor. Construction costs can be less then 50% of the project so why go small? There is no choice for a naval ship and no need to show a profit either.
The German pebble-bed reactors (AVR, THTR-300) built in the 1970s both broke and leaked radioactive crud into the environment. The Chinese have been running their HTR-10, a small prototype helium-cooled pebble-bed reactor for about ten years on and off and they've finished building the first HTR-PM, a small (105MWe) "modular" pebble-bed reactor which is, in theory, capable of being built in quantity to generate useful amounts of electricity. As of April this year they were starting to load the HTR-PM with moderator pellets, with fuel pellets to follow later. I believe it's supposed to be operational by the end of this year but it will be going through a test and experimental operation process before they decide to build more.
The Chinese first concept is using a pebblebed because that's been done before (germany) and they're working along the lines of verifying each step before moving to the next one. The Pebblebed MSR should be operational in the next 2-3 year and the experimental fuel salt designs are expected to follow about 5 years later.
Can you point me to any links about this MSR pebble-bed reactor you keep on saying the Chinese are working on? Ditto for the fuel-salt MSR some people have been saying they're building right now (and they've been saying this for a long time now...).
I track the Chinese nuclear build efforts with some diligence although I tend to concentrate on actual projects with funding, sites, permissions etc. rather than vague plans and academic exercises. The only pebble-bed designs they are spending serious efforts on are helium-cooled (the experimental HTR-10 and the "production" HTR-PM). As far as I know they're not planning or funding any kind of MSR never mind having a finalised design for one, getting permission to build one, locating a site to build it on etc.
Small modular reactors are not new. They've largely been ignored by the 'States since they pioneered the technologies but are now being built, also here in Canada, and -we hope soon- everywhere - there will be rapid growth of this technology, and manufactured locally as this article suggests for the UK. Safe nuclear power will be necessary to supplement renewables if we want Home Sapiens and our supporting cast of animals and plants to survive our unhappy fossil fuel age. This article doesn't say as much (I can't seem to scroll back), but if they use the IMSR technology we are talking about burning up nuclear waste from the older plants too! Clean, safe, necessary.
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