Anyone know of any software work being done around Nuclear? I don't care what it is, just looking to play a bit more with the space, Open Source, data sourcing. I really mean I don't care what it is, just wanna learn a bit more about it and be a bit more involved.
Application submitted for US molten salt research reactor
101–110 of 217 posts
Re: Application submitted for US molten salt research reactor
#102A 1MW research reactor. Anyway, why is it always a fluoride salt? Is it because of the melting point or because of some nuclear property? I imagine there is some very relevant reason, because a less reactive anion (even chlorine) would be much easier to work with.
Fluoride salts are good for fissile uranium + fertile thorium. If you want to work with a plutonium/uranium 238 cycle then chloride salts are a better choice. Plutonium doesn't dissolve very well in fluorides. Molten chloride reactors can have performance characteristics right out of science fiction, it seems possible for such a reactor to not only breed more fuel but to destroy the long-lived (500 year) fission prod…
From your perspective, given that Thorium salt reactors are part of India's 3rd stage Nuclear plan, where is this technology in general? I assume that they're leading the pack, but I don't really know.
Re: Application submitted for US molten salt research reactor
#103Anyone know of any software work being done around Nuclear? I don't care what it is, just looking to play a bit more with the space, Open Source, data sourcing. I really mean I don't care what it is, just wanna learn a bit more about it and be a bit more involved.
Same question here!
Re: Application submitted for US molten salt research reactor
#104Earlier quoted context omitted.
Does it even need to be a metal? (Since the pressure is so low strength requirements are lower)... How about ceramic or glass (or quartz), or something else non-metal?
non-metals have their own problems and glass tends to have some really weird properties. I would think a major one would be their failure mode. Metals flex and expand before they eventually fail. Glass/ceramic is fine until suddenly it isn't and has a total failure. Think of a window being hit. If it were metal it would probably deform but if it is glass it shatters. Next would be joining them on-site. If needed, met…
Glass is already basically welded, or maybe it's more like brazing. But an oxyacetylene torch can be used to work with glass just as well as to cut or weld metal.
Metals also have weird properties. Like tempering and hardening based on temperature. In an industrial setting you need expert welders with deep knowledge of the materials or a weld is going to fail and ruin your day.
So it doesn't seem like a huge leap to me actually, assuming ceramics or glass actually have desirable properties.
Re: Application submitted for US molten salt research reactor
#105Earlier quoted context omitted.
People thought this stuff https://haynesintl.com/docs/default-source/pdfs/new-alloy-br... (which is practically stainless steel without the steel) was good for this use but when it was tried in this system it did not hold up very well https://en.wikipedia.org/wiki/Molten-Salt_Reactor_Experiment... but it was believed that some small change in the formula such as adding Niobium could clear the problem up. What's neede…
If it's designed with replacement in mind, a graphite moderator isn't all that bad. It can even be a safety advantage, in that if you drain the fuel out of the vessel it's taken away from its moderator.
I must not be parsing this correctly. Taking fuel away from the moderator sounds like a safety disadvantage. Maybe I don't know what a moderator does.
Re: Application submitted for US molten salt research reactor
#106Earlier quoted context omitted.
> But I was under the impression that the main stumbling block for molten salt reactors was that high-energy corrosion resistant materials for containing / moving molten salt simply don't exist (yet). Is this also an issue for molten salt / liquid metal batteries[1][2] that have been proposed as a grid scale energy storage solution for renewables? The way I understand it, molten salt is used as the membrane separatin…
Molten salt / liquid metal batteries normally use alkaline salts, so steel holds it pretty well.
I see. So there is a pretty simple explanation. Thanks.
Re: Application submitted for US molten salt research reactor
#107Earlier quoted context omitted.
You are correct about the corrosion issue. I've done some work developing molten salt resistant claddings. The main culprit is chromium leaching, which de-alloys most of the metals approved for reactor design. The leeching happens at the grain boundaries, so you will hear 'intergranular attack' as a research focus. A close second problem is the radiation itself. Elements in both the containment vessel and salt transm…
Does it even need to be a metal? (Since the pressure is so low strength requirements are lower)... How about ceramic or glass (or quartz), or something else non-metal?
It doesn't, but any material used needs to withstand 4 extremes - high temperatures (650-850 C), corrosion (dissolves uranium), very high neutron flux, and US govt. regulation.
Graphite is the current favorite non-metal option. It is already widely used in traditional reactors, so it is approved, and its interaction with radiation is well understood. On the other hand, its interaction with radiation and molten salt is not as well understood, but hopefully this test reactor and others like it will solve that.
One of my favorite solutions seals the reactor in with a crane and 8 graphite containment vessels. The best estimate of the lifespan of structural graphite in this environment is ~7 years, so the plan would be to monitor the system and move the reactor to a new vessel as needed. The goal is 50 year life-span for these reactors.
Anyway, there is research into alternate materials, but to really test them you need to expose them to both molten salts and radiation. And if they pass, you need to get government approval. The last material to get govt approval was Hastelloy N, and I heard the process was a slog.
Re: Application submitted for US molten salt research reactor
#108Earlier quoted context omitted.
non-metals have their own problems and glass tends to have some really weird properties. I would think a major one would be their failure mode. Metals flex and expand before they eventually fail. Glass/ceramic is fine until suddenly it isn't and has a total failure. Think of a window being hit. If it were metal it would probably deform but if it is glass it shatters. Next would be joining them on-site. If needed, met…
Composites? Such as the stuff used in Aviation?
Most of those contain plastics which are usually not good for high temperatures but also have long chain molecules which get broken by neutrons and other particles and cannot heal defects the way metals can.
Re: Application submitted for US molten salt research reactor
#109Earlier quoted context omitted.
One of those safety improvements -- a freeze plug -- passively halts the reaction in the event of a power cut. The reactor sits on top of a vault that has a larger volume separated by a narrow tube containing molten salt that has been frozen into a plug by cryocoolers powered by the turbines themselves. If the pumps stop for any reason, then the plug quickly melts and the molten fluid from the reactor drains into the…
Freeze plugs sound super cool, but this part breaks my brain: > containing molten salt that has been frozen into a plug Presumably salt can't be both molten and frozen at once, or is there something about this domain that I don't understand?
I wrote it that way to aid the reader in understanding what the plug material was composed of. I didn't want the reader to think that the material was water ice.
Yes, the material is the frozen state of the once liquid reactor fluid.
I hope that clears it up, and would welcome a better way of explaining it!
Re: Application submitted for US molten salt research reactor
#110Earlier quoted context omitted.
Your view really depends on the design. CANDU (Canadian reactor design) is moderated via deuterium in which case there is a LOT of it circulating in the reactor core. The heavy water is syphoned off to a tritium separation unit for recovery. With a market value of $30,000 a gram, there is a clear incentive to recover it ;)
Some buddies who work on CANDU tell me they have tritium contamination everywhere as a result of this. From what they tell me it's not really a big safety issue, mostly more annoying than anything.
It is annoying because it is detectable!