GE To Turn World's Biggest Civilian Plutonium Stockpile Into Electricity 241
First time accepted submitter ambermichelle writes "GE Hitachi Nuclear Energy has proposed to the U.K. government to build an advanced nuclear reactor that would consume the country's stockpile of radioactive plutonium. The technology called PRISM, or Power Reactor Innovative Small Module, would use the plutonium to generate low-carbon electricity. The U.K. has the world's largest civilian stockpile of plutonium. The size of the stockpile is 87 tons and growing. Nuclear reactors unlock energy by splitting atoms of the material stored in fuel rods. This process is called fission. For fission to be effective, neutrons – the nuclear particles that do the splitting and keep the reaction going – must maintain the right speed. Conventional reactors use water to cool and slow down neutrons, keeping fission effective. But water-cooled reactors leave some 95 percent of the fuel's potential energy untapped."
Re:Water-cooled reactors are only 5% efficient? (Score:2, Interesting)
It's not the thermodynamical efficiency. The usual water cooled
reactors use slow neutrons (water slows the initially fast neutrons from
fission to slower speeds). These reactors can only extract a fraction of available
energy from the fuel. Liquid metal cooled reactors use heavy metal
atoms (sodium, eutectic lead/bismuth) as primary coolant which does not slow
neutrons. The fast neutrons are used in fast breeder reactors, which can burn
the fuel more thoroughly or create new fuel (U-239/Pu) as they run.
CANDU (Score:4, Interesting)
But water-cooled reactors leave some 95 percent of the fuel's potential energy untapped.
Light water reactors, sure. But heavy water reactors are a whole different kettle of fish. CANDU can already burn anything from natural uranium through plutonium. Hot stuff you just dilute down.
No need to invent some new crazy reactor, just burn it at Bruce or Pickering.
Re:New power source? (Score:5, Interesting)
You should really read up on the "Integral Fast Reactor" - the S-PRISM this article is about is evolved from the technology developed in the IFR project.
The main potential safety weakness of an IFR is the possibility of sodium leaks leading to a sodium fire (I'm not sure how they manage this risk; it certainly seems like a potentially nasty problem, but I'm sure they've taken some sort of measures to try to prevent that from happening; I hope they are effective).
But, Sodium fires aside, the type of problems you had an Chernobyl, TMI, and Fukushima-Daiichi simply cannot happen in an IFR-style reactor. You can't get supercriticality/runaway fiisson like happened at Chernobyl; you can't get a meltdown; you don't have to worry about steam pressure overwhelming the containment (because water is not used as the coolant, so hence no steam), and you can't get a hydrogen explosion (again, no water in the reactor).
You might get a hydrogen explosion if, somehow, water started mixing with the sodium, as sodium and water will combine to form sodium hydroxide and hydrogen gas, but if they can keep water out of the reactor, then no hydrogen explosions.
So far as I know, there have only been a few sodium fires amongst all the world's sodium cooled reactors over the last 60 years - the most famous one was in Japan back in the late 90's or early 00's, and while that scared the public, it wasn't actually a disaster - just a relatively minor industrial accident in the end. I've never heard of a sodium fire at a nuclear plant becoming a major problem, so I don't think the risk of sodium fires is actually a big, unmanageable 'ticking time bomb', but again, I'm no expert.
Still, I think the technology looks *very* interesting. Let's face it, we have a nuclear waste problem, and either IFR or another type of fast reactor (such as a molten salt fast reactor) are basically the only way to solve that problem. Let's stop fighting the solution to the nuclear waste problem. It truly is the only realistic solution - burn off that 100,000 year "plutonium problem".
Geeky density fun (Score:5, Interesting)
87 x 10^6 gm / 19.816 gm/cm^3 = 4.39 x 10^6 cm^3 = 4.39 m^3.
4.39 cubic meters is a single cube 1.637 meters on a side (or a little more than 5 feet/side, for us backward Yanks). More or less the size of a smallish SUV, yes?
Of course their Pu isn't, one hopes, stored all in one solid cube, which would probably exceed critical mass by some large factor. But still, it's not a massive physical quantity of material you're talking about here.
Re:New power source? (Score:5, Interesting)
Area under water behind a dam is uninhabitable and unarable, same goes with solar. Wind is just uninhabitable. If you count the amount of land required by them and compare to land made "uninhabitable" by nuclear, average over power generated, nuclear is a clear winner.
The radiation levels in Chernobyl Zone are lower than natural background radiation in some areas around the globe. Year of living in Ramsar in Iran exceeds nuclear industry limits during emergencies! Calling them "uninhabitable" for 1000 years is a bit of an overstatement... Unarable for food production, maybe, but then you can use those areas for production of automotive fuel.
Oh, and don't forget the amount of land made unarable and uninhabitable by heavy metal poisoning from regular industry, just look at mercury pollution in USA.
Re:New power source? (Score:0, Interesting)
Care to comment on Thorium MSR's?
Or are Gen IV reactors not producing weapons grade fissile material still forbidden from being discussed publicly amongst the Nuc. Eng. community, or suggested as an implemented design?
Re:New power source? (Score:4, Interesting)
I was wondering why GE was trying to get a new reactor design built in the UK instead of its home country, the US. Then I realised why: our government is the only one that will pay for it. The Conservatives view the government as a way to fund commercial enterprises, to build stuff that no bank would back but which with most of the cost paid for out of taxation are a potential gold mine for the owner. That is the way we build nuclear plants here, the tax payer funds it and takes on most of the risk and clean-up cost while the commercial owner creams off a nice profit during the operational lifetime.
Unfortunately the government always gets ripped off when building anything and the companies running our nuclear facilities seem to be incompetent and unwilling to invest in safety. The plant TFA mentions, Sellafield, is notoriously accident prone, so I'm not sure it is a good idea to give them any more ways to screw up.
Thanks but no thanks GE, get back to us when you have built a working one paid for out of your own pocket.
Not quite like that (Score:5, Interesting)
Here's a clue - liquid sodium is used for technical and not safety reasons.
Whoever is selling you on some snake-oil "sodium is safe" marketing line is not being honest to you and you are making yourself look naive and poorly informed by repeating it.
Two things, first it only consumes a small portion of nuclear waste and produces a larger volume of a different type of waste - which I'm sure you already know. Second, the established civilian nuclear energy producers have been the ones fighting the solutions to the nuclear waste problem on the basis of cost. I atteneded a seminar on Synrock over twenty years ago and it's only recently that it has been adopted anywhere due to governments pressuring reactor operators to do something with their waste.