[HN Gopher] BYU profs create new nuclear reactor to produce nucl...
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BYU profs create new nuclear reactor to produce nuclear energy more
safely
Author : sergiotapia
Score : 40 points
Date : 2022-10-06 21:24 UTC (1 hours ago)
(HTM) web link (news.byu.edu)
(TXT) w3m dump (news.byu.edu)
| idiotsecant wrote:
| The basic problem for molten salt reactors is that the various
| reactor components are exposed to hot salts that are chemically
| corrosive, while being bombarded by radioactive particles. This
| is of course quite problematic when your goal is a machine that
| makes electricity consistently for decades. Equipment failures
| are an inevitability because we don't know of a material that has
| the properties needed to survive this kind of application.
| Curious how (or whether) the authors of this design approached
| this problem.
| 9wzYQbTYsAIc wrote:
| The newly oublished patent is for something described as a
| "salt wall" if that helps your imagination.
| [deleted]
| jakedata wrote:
| Typical university press release doesn't provide any actually
| useful information. They have not created anything yet. They have
| a theoretical design. Good for them I guess.
| SeanLuke wrote:
| Well they still might build it I imagine. Back in the 1960s BYU
| had a working nuclear reactor right on campus which produced a
| few watts of energy. The underground facility was standing at
| least as recently as the early 1990s.
| themodelplumber wrote:
| I remember hearing about that, and related rumors from
| coworkers at BYU. They'd point out the guesstimated location
| as we drove around campus in our work vehicle.
|
| This always dovetailed really nicely, in our opinion, with
| the plain-as fact that Zion and her people would eventually
| become the envy of the world and could already easily out-
| engineer the best engineers that any first-world nation could
| muster.
|
| The same sentiments were shared in classrooms with the topic
| of internet backbones "coincidentally passing right through"
| Utah. Why was it so? Well because the Lord would insist upon
| only the finest internet for his finest priesthood-engineers
| in the latter days, of course. Do your home teaching!
|
| There were lots of lovely little cultural side-alley
| discussions like these.
| fatcat500 wrote:
| > If there is not enough of a flow of cooling water, the rods can
| overheat, and the entire facility is at risk for a nuclear
| meltdown.
|
| This is not true. Water is the moderator in a light-water
| reactor. Without water the reaction will stop. Water is both the
| coolant and the moderator, unlike the Chernobyl reactors, which
| used graphite as the moderator.
| gh02t wrote:
| What you say is technically true but you're forgetting decay
| heat. The fission chain reaction stops if you remove the
| moderator in any sane LWR design, but the fission products in
| the fuel will continue to generate a very large amount of heat
| for quite a while. This is exactly what happened at Fukushima
| and TMI.
|
| https://en.wikipedia.org/wiki/Decay_heat#Power_reactors_in_s...
|
| Some reactor designs can dissipate this decay heat with passive
| circulation, while most require active pumps to circulate for a
| while after shutdown. But a total loss of coolant is probably
| going to result in fuel melt to some extent.
| hairytrog wrote:
| Which is equally a problem for a molten salt cooled reactor.
| If molten salt leaks or pumping stops, you're gonna get a
| melt down in your molten salt reactor. That is unless it's
| running at super low power density - like these guys:
| https://www.usnc.com/mmr/, in which case no cooling fluid or
| pumps or even natural circulation apparently are needed to
| keep it from melting.
| gh02t wrote:
| MSRs have an advantage though, which is that a) fuel melt
| is obviously not a problem and b) if something goes out of
| control you can pull the drain plug and drain the entire
| core into multiple crit-safe storage pools. Dividing the
| core up makes it easier to handle the decay heat, though
| I'm not sure exactly what any of the current designs do in
| detail. Fission product gasses are also not soluble in most
| of the fuels for MSRs which makes it easy to filter them
| out, which reduces the decay heat to an extent and also
| mitigates the reactivity feedback effect from xenon that
| caused the Chernobyl disaster.
|
| Not that it's all sunshine and roses, hot salts are awfully
| corrosive and that's been the primary engineering challenge
| on every MSR design I'm aware of.
| hairytrog wrote:
| Molten-salt-fuel reactors, as described in this article, are so
| lame... "It's already melted, so you can't have a meltdown." lol.
| More seriously, molten-salt-cooled reactors have some promise.
| They use solid fuel, usually TRISO particles, and are cooled by
| molten salts, which we now have lots of experience with from
| solar salt power systems. If you are interested in molten-salt-
| cooled reactors outside of this lame press release - check out
| Kairos Power. Their website sucks butt. But they are the main
| player in molten salt-cooled reactors - funded by Henry Laufer of
| Renaissance Technologies. They actually have the engineering and
| financing to get one built, and are reportedly doing very well
| with NRC (unlike OKLO - lolz).
| sergiotapia wrote:
| >A typical nuclear power plant is built with a little over one
| square mile to operate to reduce radiation risk, with the core
| itself being 30 ft x 30 ft. Memmott's molten salt nuclear reactor
| is 4 ft x 7ft, and because there is no risk of a meltdown there
| is no need for a similar large zone surrounding it. This small
| reactor can produce enough energy to power 1000 American homes.
| The research team said everything needed to run this reactor is
| designed to fit onto a 40-foot truck bed; meaning this reactor
| can make power accessible to even very remote places.
|
| Sounds too good to be true! Wonderful news
| gh02t wrote:
| Worth noting that this is not really unique to this reactor,
| and the technology has been around for a while (including
| multiple basically fully functional demonstration reactors that
| were actually built, though they weren't without their
| technical issues). NuScale's design for example, which is a
| very different design and also much closer to commercial
| rollout, has a similar greatly reduced need for a large
| exclusion zone (https://www.nei.org/news/2018/nrc-staff-agrees-
| smrs-wont-nee...).
|
| This article is reporting on what amounts to a paper reactor
| design, which is really only like 0.1% of the effort required
| to actually _build_. There are plenty of good design concepts
| for new and fancy reactors, but the business, regulatory, and
| PR side is where the challenges really lie. But this general
| technology is a big deal in the nuclear industry right now and
| it seems increasingly likely that they might finally build some
| fully functional plants. Strictly speaking they _are_ actively
| building some MSR plants, but given the not great track record
| of actually completing new nuclear plants I will remain
| pessimistic until they are ready to go critical.
| hairytrog wrote:
| Not sure it's a justified reduction in exclusion zone. Yes
| they use natural circulation to get rid of decay heat if they
| lose power to run the pumps. BUT - they can't tolerate
| multiple reactors failing at once, they can't tolerate more
| than a few control rod withdrawals, and they can't tolerate
| clogging of the flow channels - Which to me, seem like
| reasonable accidents. The reduction in exclusion zone for
| NuScale is not really justified. If they get a reduction, you
| can expect the big ass reactors to also get a reduction...
| gh02t wrote:
| I don't really have an opinion on the matter and I think
| it's a fair question to consider, but I'll note that the
| NRC obviously disagrees. At least for now, they could
| always change their mind. I _seriously_ doubt that they
| would ever significantly reduce the exclusion zone
| requirement for any of the currently operating reactors,
| however.
| hairytrog wrote:
| I think that's fair. I bet new large power plants will
| get the NuScale treatment and reduced exclusion zone
| though.
| jbverschoor wrote:
| What's different in the actual design of the tractor compared to
| other MSRs/LFTR? No talk about any of this
| moffkalast wrote:
| MSRs can do everything except leave the impossibly heat and
| corrosion resistant lab.
|
| Maybe we should just build them in orbit without containment
| and let the surface tension hold it together or something.
| jbverschoor wrote:
| But the article is talking about MSR
| moffkalast wrote:
| Only mentions something about making them smaller, not sure
| how that would solve the core (pun intended) issues.
| 9wzYQbTYsAIc wrote:
| If you look for the actual design, you will come across a
| newly published patent in the name of the mentioned
| researcher.
| 9wzYQbTYsAIc wrote:
| If you read the article, you would see that the MSR design
| would allow for recycling of the salt and the extraction of
| the valuable byproducts.
|
| Also, this reactor is designed to fit onto a 40-foot truck
| for transport to remote areas and can power up to 1000 homes.
| moffkalast wrote:
| Not sure how that helps if it melts through the floor, the
| truck, and then the ground when you turn it on. Those are
| nice improvements, but adding a red paint job to a wingless
| plane won't make it fly.
|
| Suppose you could use some kind of ablative material, but
| that would mean short runtimes and constant expensive
| refits. Sort of like taking that wingless plane and
| launching it with a trebuchet. Technically makes it fly but
| not in any way that matters.
| 9wzYQbTYsAIc wrote:
| According to his patents, the molten salt is the coolant
| and it would flow multiple stages of salt through the
| system.
|
| https://patents.justia.com/inventor/matthew-memmott
| [deleted]
| eecc wrote:
| Molten salt reactors are nothing new. It would be truly wonderful
| if these folks solved the corrosion issues associated to
| circulating high-temperature molten salts, and the ever-recurring
| military-grade fuel proliferation risk associated with spent fuel
| reprocessing.
| spencercwood wrote:
| I found another article that talked about corrosion:
|
| > While the DoE is still investigating ways to get around these
| showstopping corrosion issues, Prof Memmott said that his team,
| along with Alpha Tech Research Corp (the commercializing
| partner for the BYU MSR, and of which Memmott is director and
| senior technical advisor), believe they have solved the problem
| by removing water and oxygen from the salt, massively reducing
| the corrosion issue.
|
| https://www.theregister.com/2022/10/05/micro_molten_salt_rea...
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