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from the fast-enough-for-government-work dept.
The Buffalo News reports progress on the West Valley Demonstration Project. After years of converting liquid nuclear waste to glass, the buildings are now being taken down, very carefully.
http://buffalonews.com/2018/01/09/slow-and-steady-west-valleys-decommissioning-is-on-track/
West Valley was the nation’s only commercial nuclear reprocessing plant. The waste was created when the site was operated by Nuclear Fuel Services between 1966 and 1972.
[...] The building where the most highly radioactive materials at the West Valley Demonstration Project were once handled is being torn down.
The vitrification plant is where 600,000 gallons of liquid nuclear waste were turned into glass cylinders in the late 1990s and early 2000s. The cylinders were then packaged in fives and welded into steel canisters before being stored under 21-inch thick concrete casks and relocated to another spot on site.
In mid-September, contractors started peeling away the outside of the steel and sheet metal exterior of the building and the roof. That work wrapped up in early November, said West Valley officials.
“The (contractor) is making great progress with the safe completion of the first phase of this facility’s demolition,” said Bryan Bower, project director for the U.S. Department of Energy. “This accomplishment allows our team to continue its work in the completion of site demolition activities.”
The linked article includes several photos, inside and outside the plant.
(Score: -1, Troll) by Anonymous Coward on Thursday January 11 2018, @07:56AM (10 children)
By reprocessing you mean fast breeders, so reactors that can be used to make weapons grade material
(Score: -1, Troll) by Anonymous Coward on Thursday January 11 2018, @08:01AM (9 children)
Also reactors that could theoretically reach critical mass and blow up, Carter was not wrong, the idea that if you just keep doing things that are know insane and destructive it will somehow get better is wrong.
sorry for responding to myself, just needed to add
(Score: 3, Insightful) by Anonymous Coward on Thursday January 11 2018, @08:35AM (4 children)
No. I mean reprocessing: the act of extracting fissionable elements from spent fuel rods (or any other "used up" thing) to make new fuel rods.
The typical input comes from an ordinary commercial power plant. You can certainly feed in stuff from weird sources: unwanted weapons, Navy nuclear ships, breeder reactors, university research reactors, medical isotope production reactors, etc.
The typical primary output is fuel rods for an ordinary commercial power plant. Obviously, you also get waste, neatly separated by chemical.
Normally you can't make weapons from reprocessing. The reason is that the isotope mix is all wrong. The uranium presumably came from a reactor that was fueled with stuff that wasn't weapons-grade, so you'd need to feed that into the separate enrichment process to upgrade it. The uranium presumably sat in the reactor until the fuel rods were inefficient for commercial use, meaning that any plutonium present has been hopelessly tainted with isotopes that are far too radioactive to make a warhead. Such plutonium gives off lots of heat, which would damage the bomb casing and electronics and everything else.
Fast breeders are great. So what if they, like other reactors, could be operated with an unusually short-duration fuel usage cycle for creating weapons? This doesn't mean that we have to do that. We can just use them for commercial power. That said, Russia has more nuclear weapons than we do, so we ought to do something about that.
You're misusing a term, just like in that stupid China Syndrome movie. All nuclear reactors are critical at all times when they operate.
They are unable to undergo a nuclear explosion because the fuel is not enriched enough (is 5% instead of at least 25%) and because there is nothing to explosively slam it all together. The worst you could get is essentially a boiler explosion, with superheated water flashing to steam. We saw this in Fukushima. Incidentally, that one was made worse because the spent fuel rods hadn't been taken away to be reprocessed. They were sitting above the reactor, where they could be tossed around by a steam explosion. Oh yeah, here in the USA we have spent fuel rods sitting around at every nuclear plant because we too aren't reprocessing.
Carter was wrong. Keeping spent fuel rods around is insane and destructive. Bad shit happens if they get tossed around due to a steam explosion. It's also insane and destructive to waste 95% of our fuel. We really ought to reprocess that.
(Score: -1, Offtopic) by Anonymous Coward on Thursday January 11 2018, @12:23PM
don't americans have a replacement for "percent"?
i mean they have their own length, volume and weight.
they have a replacement for everything else these days... maybe "perhex"?
(Score: 2, Interesting) by mrkaos on Friday January 12 2018, @12:03AM (2 children)
Only if you have the right reactor technology, otherwise you end up with more plutonium that you started with because of the element you add to use the plutonium you've got. They are not called breeder reactors for nothing. No one wants a plutonium economy.
My ism, it's full of beliefs.
(Score: 0) by Anonymous Coward on Friday January 12 2018, @12:28AM
Plutonium is a damn fine reactor fuel. It is usually part of a fuel called MOX, mixed oxides, which also contains uranium.
We burned that for years, under a deal to use up old Russian warheads in our commercial reactors. The warheads got reprocessed in Russia, then shipped over to the USA for power generation. We ended that just a couple years ago, having used up the entire available supply.
Lots of nuclear stuff is "not economically viable" on purpose. We regulate it to death. It takes balls to say "NO" to just one more regulation -- think of the children -- and that is how you kill an industry. Some people childishly think an economy can operate on rainbows and dreams, so just make that icky industrial stuff go away.
(Score: 2) by Aiwendil on Friday January 12 2018, @10:26AM
As already pointed out - we do actually want a plutonium economy.
But beyond that, first up MOX (extract the U and Pu from the spent fuel and blend it in with fresh fuel - this is the common reprocessing) is a very good way to recycle, not to mention the new russian REMIX (remove the gasses from the fuel and blend in enriched fuel (some 15-19% enrichment in the top-ups) which allows you to only have three full cores worth of fuel for the entire reactor lifetime, increases the amount of depleted uranium produces but drastically reduces the amount of spent fuel). But you could just run the fuel in a better reactor as the DUPIC-process shows (basically you cut the fuel from PWR to size to fit in a CANDU reactor fuel bundle and run the spent fuel as-is, four PWRs can fuel a CANDU completly).
A bit here.. DUPIC has been demonstrated in S.Korea and in China, REMIX is something the russians are starting to use right now, and MOX is something many countries has been doing for quite some time (mainly produced in France which is the main user of it, Japan also uses it but all their MOX is produced in France due to lack of domestic facitilites (one is almost done)).
Also - not all breeders produce plutonium, for instance a Th-232 bundle will breed more fissile fuel in the form of U-233 (after a few steps of decay). And if you're not impatient you also get U-235 out of "conventional" breeders (Pu-239 has a halflife of 24k years, and decays to U-235), but that is just wasting energy since Pu-239 is a nicer driver than U-235).
Being a "breeder" just means you have a breed/conversion ratio above 1 (ie, you produce more fissile material than you use), but pretty much all reactors breed to some extent a normal LWR is at about 0.6 and a PHWR (CANDU et al) is at 0.8 and a few upcomming designs aims for between 0.9 and slightly below 1.0 (notably the VVER-1700 (VVER-SCWR)).
Oh yeah, also, all common power reactors can be modified to run as breeders so it isn't as exotic as people think (in a CANDU it mainly is a matter of picking the right fuel mix and fuel-shuffling pattern).
And the reason why reprocessing isn't economically viable is that uranium is dirt cheap, it is at something like 50usd/kg, reprocessing doesn't make economic sense until you start to hit about 150-200usd/kg (the uranium prices has been up to that level a few times - it increases the cost of nuclear by about 0.02c/kWh), for reference most uranium mines need at least about 70usd/kg to make economic sense.
But yeah, in the mid-term (2 to 60k years (ten half-lifes of Pu-240)) you'd end up with more Pu but less Pu-239 and Pu-238. That is unless you start to use the Pu in a Th-232 or ADS (accelerator driven system) reactor in which case the Pu will drop drastically.
(And before you scream that it needs special reactors - CANDU has been a commercial mainstay since the 60s and can do the Th-232 cycle and there are 42 CANDU and CANDU-derivate reactors running (for reference, there are 80 BWR running))
(Score: 4, Informative) by Aiwendil on Thursday January 11 2018, @05:50PM (3 children)
Critical explained:
Subcritial - number of neutrons available decreases (ie - it slows down)
Critical - number of neutrons available stays the same (ie - keeps at level)
Supercritical - number of neutrons available increases (ie - it speeds up)
Critical mass - smallest mass needed to be critical for a given geometry.
And regarding blowing up a nuclear reactor - just what yield are you worried about? Let's assume we somehow manage to strip away all the cladding and shape it into a nice round sphere (optimal for critical mass until you involve reflectors) that you somehow manged to get to explode - it would _top_out_ at about 6.5t (not megaton, not kiloton, but plain simple ton). And this would be inside a steel container inside couple of quite heavily reinforced concrete structures. Heck, you'd be better off airdropping the fuel (or even the empty fuel transport canister) on your target. (Heck, the fuel in a B52 is quite a bit more energy than that - so you'd be best of to kamikaze the target with the B52)
(Funnily enough, the easiest and fastest way to compress a nuclear reactor core to get to a fission explosion is to detonate a nuclear bomb above it (near as in inside the reactor building), but that would require a higher yield nuke than you'd get from the core)
But yeah, in theory it can blow up, just like in theory the hydrogen in your cup of coffee could spontaneously fusion and explode.
(Score: 0) by Anonymous Coward on Thursday January 11 2018, @09:03PM (1 child)
Actually, in my secret lab, I have developed exactly this, only without the "explode" part. Since "cold fusion" has gotten such a bad rap after some amateurs claimed to have achieved it, I dubbed my perfection of the technique "Hot Coffee Fusion". I have achieved sustained reaction that have keep a cup o' joe hot and tasty from more than a week without the need for any "warm me up" refills. I am working on a consumer appliance to implement my new discovery. I will call it "Mr. Fusion".
(Score: 0) by Anonymous Coward on Friday January 12 2018, @04:00AM
Well I, at least, fellow AC, see what you did there. Well played, AC. Bon hoffer.
(Score: 2) by turgid on Friday January 12 2018, @01:50PM
You forgot "prompt critical." That's when the proportion of neutrons produced by reactions involving prompt neutrons from the previous generation dominates over the delayed neutrons and the doubling time is measured in milliseconds rather than hours. That's when you have a problem.
I refuse to engage in a battle of wits with an unarmed opponent [wikipedia.org].