Application submitted for US molten salt research reactor

Post by acidburnNSA » Mon, Aug 22, 2022, 7:54 PM UTC

PaulHoule wrote: post #24

dangerlibrary wrote: post #12

So, in a conventional reactor, you use nuclear fission to heat/pressurize water and then use your hot, slightly radioactive steam turn a turbine. This mostly works because moving even very hot, very high pressure water around is kind of a solved problem in industry. In a molten salt reactor, you use nuclear fission to melt various corrosive salts into a fluid, and this is good because molten salts store a lot more en…

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…

Post by thoughtpeddler » Mon, Aug 22, 2022, 8:11 PM UTC

Post by mikewarot » Mon, Aug 22, 2022, 8:21 PM UTC

YakBizzarro wrote: post #63

mikewarot wrote: post #61

I'm surprised the reactor needs a moderator, I would assume that a liquid fuel reactor could be controlled far better by controlling flow into and out of the critical mass. It's all at normal pressures, just hot (temperature and radiation wise), so just bog standard plumbing practices for handling fluid levels should work. Being able to scramble the reactor by just dumping the contents through a set of diverters into…

A moderator is not used to control the reaction, but to make it possible. The neutrons produced by fission, have high kinetic energy, and fuel has a small cross section for neutrons at such high energy. A neutron moderator slows down the neutrons, making them more likely to interact with the uranium and split them. typically water is a good moderator, but here they use graphite for obvious reason (high temperature sa…

  1 - https://www.youtube.com/watch?v=LmlAYnFF_s8

Post by HPsquared » Mon, Aug 22, 2022, 8:26 PM UTC

ortusdux wrote: post #53

dangerlibrary wrote: post #12

So, in a conventional reactor, you use nuclear fission to heat/pressurize water and then use your hot, slightly radioactive steam turn a turbine. This mostly works because moving even very hot, very high pressure water around is kind of a solved problem in industry. In a molten salt reactor, you use nuclear fission to melt various corrosive salts into a fluid, and this is good because molten salts store a lot more en…

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…

Post by ars » Mon, Aug 22, 2022, 8:32 PM UTC

YakBizzarro wrote: post #47

ars wrote: post #41

Earlier quoted context omitted.

> slightly radioactive steam For anyone worried about this, the longest lived unstable isotope of oxygen (that is heavier than stable oxygen) has a half life of 26 seconds. Hydrogen can become deuterium which is stable, and finally tritium which is not. Tritium has a long half life of 12 years, but is low energy and very easily shielded (just don't eat it). There is very very little tritium - first you'd have to make…

Not compltly accurate. It's true that the half-life of tritium is short compared to long lived actinides. However, like hydrogen, it diffuses very easily and it's not easy to contain. In fact, it's one of the few things emitted in the environment during normal reactor operations. As beta emitter, you are right that it's dangerous only when ingested, but it's very easy to breath of to get it from other ambient sources