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Post by David B. Benson on May 23, 2019 21:54:10 GMT 9.5
Nuclear Technology Abandoned Decades Ago Might Give Us Safer, Smaller Reactors M. Mitchell Waldrop 2019 Feb 26 Discover Magazine
competently reviews the history and recent progress of fast neutron reactors. Unusually clear exposition.
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Post by engineerpoet on May 24, 2019 1:22:02 GMT 9.5
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Post by cyrilr on May 24, 2019 22:58:13 GMT 9.5
Thanks, a good article with some fun anecdotes in it.
One thing I took issue with is the idea of a water cooled reactor being like a paper house with fire sprinklers.
A paper house with fire sprinklers is a lot safer than living in a tent flooded with smoke from coal and dung fires inside the tent. In fact, the WHO estimates that 3+ million a year die from indoor smoke. 7 million a year die from burning stuff. We really need to stop burning stuff.
A water cooled reactor is very safe, millions of times safer than a coal fired powerplant. I work in the field of molten salt reactor development and it is easy to get stuck in this "every other reactor type is bad" reasoning. No need to lose perspective on nuclear power, just because next-gen reactors are better. Anything's better than coal!
Besides some of the new LWRs have pretty good "fire sprinklers" - passive cooling and injection systems. ESBWR and Kerena reactors for example have passive decay heat removal and passive containment cooling. The Emergency Condenser of the Kerena reactor appears to be particularly passive, initiated passively on nothing but a coolant level drop. That's a pretty good fire sprinkler.
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Post by Roger Clifton on May 26, 2019 17:27:05 GMT 9.5
The author argues that breeder reactors are bad whereas MSRs are good. To me this feels treacherous, it's a bit like throwing your brother out to the cannibals.
In particular, he avoids pointing out that routinely-burnt fuel produces isotopically impure plutonium, useless to bomb makers. Instead he indulges the myth that reactor grade plutonium is "pure plutonium" and a proliferation risk. In support of that nonsense he says that India used "spent fuel" to make bombs, although they almost certainly used a very lightly irradiated fuel, far from spent. Similarly he says that the backlog of routinely used fuel presents a storage problem. He does not point out that it is a backlog waiting for reprocessing, which is a political problem, not a storage problem.
I would much rather agree with him that a fleet of MSRs should consume the backlog of PWR used fuel. However practicality indicates that operators of an MSR fleet would behave like the operators of PWRs. They would almost certainly prefer MSR fuel to be topped up with easy-to-handle clean uranium, enriched to 20% U235, and its used fuel sent to indefinite storage via some ponds out the back of the reactor.
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Post by David B. Benson on May 26, 2019 20:08:54 GMT 9.5
Molten Salt Reactors Updated Dec 2018 World Nuclear Association
offers a technical tour of the various designs. A recommended survey.
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Post by engineerpoet on May 26, 2019 20:09:25 GMT 9.5
In particular, he avoids pointing out that routinely-burnt fuel produces isotopically impure plutonium, useless to bomb makers. Instead he indulges the myth that reactor grade plutonium is "pure plutonium" and a proliferation risk. The plutonium produced by the BN-800 is sufficiently well-irradiated that it contains about 17% Pu-240. It is utterly useless for weapons: www.world-nuclear.org/information-library/nuclear-fuel-cycle/fuel-recycling/plutonium.aspxOn top of this, the pyroprocessing system invented for the Integral Fast Reactor retains some minor actinides and fission products in the plutonium fraction. This makes it not merely useless for weapons, but actively unsafe to handle outside a hot cell (perfectly good as fuel though). Last and perhaps most important, an IFR-style fuel cycle eliminates uranium enrichment and the proliferation risk of uranium weapons along with it. It might be desirable to re-enrich the uranium from used LWR fuel to make initial FBR cores, but you'd only do this until the LWR fuel was gone. It would be possible to take IFR-derived plutonium and run it through the PUREX process to remove the FPs and minor actinides, but you'd still have something like 17% Pu-240 in the product. The spontaneous fission rate of Pu-240 is sky-high and makes any device made with so much almost certain to "fizzle" rather than explode as designed. The claim that a breeder-based energy economy leads to nuclear holocaust is not merely erroneous, it is the precise opposite of the truth.
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Post by cyrilr on May 26, 2019 21:31:35 GMT 9.5
"Last and perhaps most important, an IFR-style fuel cycle eliminates uranium enrichment and the proliferation risk of uranium weapons along with it."
This is skating on thin ice, E-P.
It implies that uranium enrichment is a big proliferation risk and therefore, an argument that any reactor that isn't a fast reactor has a big proliferation risk.
The problem is the whole proliferation argument is like all the other arguments brought up against nuclear: fabrications. Lies. Half-truths. Fake news.
They were invented as ammo in a shooting barrage against nuclear power.
The people who use these arguments don't want you to solve any problems; they simply use fabricate arguments against nuclear power. They are not genuinely concerned about proliferation, or waste storage, and so on, only inasmuch as it allows them to block nuclear anything. Environmentalists are not happy when a nuclear plant installs a diffuser system for its thermal reject into the sea, or installs strainers in the intake. These features protect the environment, but it makes the environmentalists unhappy because they have one less argument against nuclear anything.
So, when you propose a solution, these people are only angered, because admitting to any solution would deplete their ammo stocks to use against nuclear anything.
And if your solution is such that a new reactor type has it but all others don't, then you've only opened yourself to a major vulnerability in your defence: your opponents will now claim that there is a problem, since you proposed a solution, therefore let us close down every reactor that isn't the IFR, which is every reactor currently operating.
This is poor strategy.
Much better to call a spade a spade: proliferation is not an argument against nuclear power. It was fabricated by opponents to block nuclear development since that suited their ulterior agendas.
Personally I think we need to talk about the proliferation of weapons from solar power. Since solar power needs fossil backup, and fossil is the primary material with which real weapons such as explosives are made, real weapons like guns and grenades that kill real people every year unlike imagined nuclear attacks, it stands to reason that blocking solar power will assist in reducing real weapons proliferation.
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Post by David B. Benson on May 26, 2019 21:57:04 GMT 9.5
cyrilr, that was amusing but wrong. Solar requires backup but that need not be burning carbon. Here in the Pacific Northwest we have ample hydropower for that purpose. The pumped hydro schemes in the USA are desirous of more work.
More generally, note that many of the advanced nuclear power plants being proposed are capable of load following.
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Post by engineerpoet on May 26, 2019 23:50:02 GMT 9.5
This is skating on thin ice, E-P. It implies that uranium enrichment is a big proliferation risk and therefore, an argument that any reactor that isn't a fast reactor has a big proliferation risk. Not the reactor. The industry that makes LWR fuel. I don't think you can argue that this isn't already well-known and universally acknowledged. The big deal with Iran and N. Korea is that they had/have enrichment systems that aren't under non-proliferation monitoring. That's most of the raison d'etre of the IAEA. How much easier would the IAEA's job be if the whole world embraced a switch to fast-spectrum reactors and pyroprocessing, so that there was no longer any need for an enrichment industry? Given the huge inventories of DU lying around, we wouldn't need a uranium mining industry for a long time either. No need for UF6, save perhaps in thermal-spectrum MSRs. So many dual-use technologies would go by the wayside. There's no need to monitor what is simply forbidden, is there?
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Post by engineerpoet on May 27, 2019 0:18:29 GMT 9.5
Solar requires backup but that need not be burning carbon. Here in the Pacific Northwest we have ample hydropower for that purpose. That's nice if you've got it, but even if you cover the electric grid you still have fossil fuels entrenched in other parts of the economy. I know for a fact that even the PNW doesn't have enough water storage to replace heating fuel and vehicle fuel. Yeah, right. If you could lift the entire volume of Lake Erie up by 100 feet, it wouldn't store enough energy to run the US grid for more than a couple of weeks. Dealing with seasonal ebbs in "renewables" requires MONTHS of storage. I'm still working out some of the details, but my first cut on a USA-scale total nuclear energy system would allow for something around 1.4 TW of electric generation, still over 1 TW if used in co-generating mode. That's continuous, not based on storage, and doesn't reflect some efficiencies not yet added into the model. I am going to have to dig into things like the rate of heating fuel consumption during northern cold snaps, but I strongly suspect that load-following would become a non-issue. The reactor could just run at 100% all the time and use e.g. electrofuel production as a major dump load.
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Post by cyrilr on May 27, 2019 4:02:48 GMT 9.5
cyrilr, that was amusing but wrong. Solar requires backup but that need not be burning carbon. Here in the Pacific Northwest we have ample hydropower for that purpose. The pumped hydro schemes in the USA are desirous of more work. More generally, note that many of the advanced nuclear power plants being proposed are capable of load following. No, amusing and not wrong in most cases. Just because some areas have hydro doesn’t refute the argument. Here in Holland, we got no hydro, but lots of gas
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Post by engineerpoet on May 27, 2019 5:30:27 GMT 9.5
Here in Holland, we got no hydro, but lots of gas And at least one field you can't use any more because subsidence is creating too many earthquakes. I'm expecting a trial of Allam-cycle plants in Holland just as soon as NetPower goes looking for demonstrations elsewhere. CO2 takes more volume than methane and a zero-emission gas plant would be a huge coup for Amsterdam. Eliminating subsidence would be the icing on the cake.
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Post by David B. Benson on May 27, 2019 13:44:04 GMT 9.5
cyrilr, in The Netherlands you could obtain backup from the nuclear power plants in France.
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Post by cyrilr on May 27, 2019 23:38:53 GMT 9.5
This is skating on thin ice, E-P. It implies that uranium enrichment is a big proliferation risk and therefore, an argument that any reactor that isn't a fast reactor has a big proliferation risk. Not the reactor. The industry that makes LWR fuel. I don't think you can argue that this isn't already well-known and universally acknowledged. The big deal with Iran and N. Korea is that they had/have enrichment systems that aren't under non-proliferation monitoring. That's most of the raison d'etre of the IAEA. How much easier would the IAEA's job be if the whole world embraced a switch to fast-spectrum reactors and pyroprocessing, so that there was no longer any need for an enrichment industry? Given the huge inventories of DU lying around, we wouldn't need a uranium mining industry for a long time either. No need for UF6, save perhaps in thermal-spectrum MSRs. So many dual-use technologies would go by the wayside. There's no need to monitor what is simply forbidden, is there? Of all the people, I wouldn't have had you down for being sensitive to group-think. Sure, it is universally acknowledged in the USA that Iran and N. Korea have/had enrichment systems. This has nothing to do with commercial LWR tech or its fuel supply chain, anymore than the nearest steel mill has anything to do with N. Korea's missile defence and canon systems - which by the way, are made of steel. It is universally acknowledged that nuclear power is the most dangerous way to boil water, that Chernobyl killed millions, and that Chernobyl is an argument against nuclear power. It is universally acknowledged that spent fuel is an unsolved problem of apocalyptic proportions, and that nuclear power is inherently risky. Just because something is commonly acknowledged doesn't mean it's correct. One of my biggest shocks as I studied nuclear was that every single argument against it was either fabricated whole or a rather simple technical item. IAEA job being easy w/o enrichment? In some ways, yes. In others, no, if you use lots of IFRs. It is about fissile material accounting, and co-locating pyro processing (which by the way isn't proven at scale yet) at every powerplant doesn't help with the accounting. Moreover, making the IAEAs job easy isn't high on my priority list. High on my list is to prevent dangerous pollution and climate change. "any old iron" is appropriate from my viewpoint. Even a modified RBMK (with reduced void coefficient and improved control rod blades) would be preferable to continued use of coal. We all have our favorite reactor design. I'm professionally involved in molten salt reactor development. I see no need to provide slander against other reactor types, nor to cater to the minds of the anti-nukes. The last thing that we should be proliferating is fabricated arguments.
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Post by cyrilr on May 27, 2019 23:45:10 GMT 9.5
cyrilr, in The Netherlands you could obtain backup from the nuclear power plants in France. True enough and is being done right now. Longer term we really need to generate our own power. France is fine but it is 2 countries away, there are non trivial infrastructure challenges to fully depending on France for power, plus the politics of dependence making this a difficult option. We've got two great sites, one in Borssele and one in the Eemshaven, a few big nukes or several SMRs co located there could close down all our coal power stations. I have a plan where just 3 sites would generate 100% of today's power, plus almost all light duty vehicles (as PHEVs/EVs) plus most space heating (via heat pumps) with a modest number of reactors. It would be a good start.
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Post by engineerpoet on May 28, 2019 2:53:56 GMT 9.5
it is universally acknowledged in the USA that Iran and N. Korea have/had enrichment systems. This has nothing to do with commercial LWR tech or its fuel supply chain On the contrary, it has EVERYTHING to do with LWR tech and its fuel supply chain. The gaseous diffusion plant at Oak Ridge was instrumental in producing the weapons-grade uranium which went into the Little Boy bomb—a bomb, you ought to know, that was so stone-axe reliable that no need was seen to test one before dropping them on the enemy. When South Africa got the bomb, it did it by enriching uranium. When North Korea sought the bomb, it first tried to make weapons-grade Pu... and failed, judging from the fizzle-level yield of its first tests. Pyongyang then went with tried-and-true uranium enrichment. For some reason you, I, Environmental Progress, Californians for Green Nuclear Power, and the Breakthrough Institute, among others, are outside this universe you posit. You can't posit that uranium enrichment has nothing to do with fission bombs. History says otherwise. Doesn't mean it's false either, and it does make it something to take seriously unless you have contrary evidence. I wouldn't have had you down for being so historically ignorant. Edit: Y12 was the calutron plant at Oak Ridge. K25 was the gaseous diffusion plant which fed it to speed up production.
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Post by cyrilr on May 28, 2019 16:19:39 GMT 9.5
You missed the point completely, EP.
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Post by Roger Clifton on Jun 2, 2019 11:55:37 GMT 9.5
As CyrilR pointed out the "Integrated" in "Integrated Fast Reactor" is not complete in that the on-site electroprocessing is not yet fully proven. However what has been established over several years was the melt-refining, that is, melting the used fuel in a ZrO2 pot so that the more chemically active fission products and some of the actinides react with the oxide and are left in a "skull", a skin on the wall of the pot. ("Plentiful Energy", Ch8) Topped up, the cleaned fuel alloy is cast or extruded into pellets to be returned to the reactor. The process is simple enough to be done with a small number of remote tools on used fuel that has been aged for only a couple of weeks. The skulls could later be transported to a central facility more tooled up to perhaps do the electroprocessing – or at least aqueous processing – to separate the actinides from the fission products for return to the top-up. For that scenario, the R&D has already been done.
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Post by David B. Benson on Jun 2, 2019 15:43:09 GMT 9.5
The original meaning of "integrated", as in the Integrated Fast Reactor, is that the primary heat exchanger is internal to the reactor. In this way the reactor fluid never leaves the reactor.
In this sense, the Nuscale SMR is an integrated reactor design, for example.
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Post by engineerpoet on Jun 2, 2019 22:31:13 GMT 9.5
It's not "integrated" fast reactor. It's Integral Fast Reactor; the entire fuel cycle is integral to the plant.
I think that feature is clever but it's hardly essential, as it only defers the issue of transporting fuel and it impedes scaling by preventing excess fissiles from being used to start new units until the existing unit closes.
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Post by David B. Benson on May 11, 2020 11:13:58 GMT 9.5
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Post by David B. Benson on May 13, 2020 13:02:23 GMT 9.5
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Post by David B. Benson on Jul 11, 2020 9:11:32 GMT 9.5
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Post by David B. Benson on Sept 22, 2020 9:56:10 GMT 9.5
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