points by SillyUsername 3 days ago | 0 comments
Thanks for the correction, what specifically makes them dead end that we can't re-use the designs - e.g. use modern parts?
[–] pjc50 3 days ago
[–] rwmj 2 days ago
Molten sodium as a cooling liquid always struck me as a "courageous decision" (to quote Yes Minister). Is there really nothing else that can do the job?
[–] pjc50 2 days ago
It's an annoying tradeoff: if you want something that's liquid at 600C, it pretty much either has to be a metal, or heavily pressurized (i.e. the PWR, the pressurized water reactor everyone has converged on).
Or you go for a gas. But then you're not able to use water as a moderator, so it either has to be a "fast neutron" design (which the few liquid sodium reactors are) or use a graphite moderator (flammable, lifespan issues with neutron cracking).
The unexplored corner is https://en.wikipedia.org/wiki/Gas-cooled_fast_reactor : plumbing is "safe" apart from being incredibly hot, but you still have to deal with fast neutrons smashing up the reactor from the inside on an atomic level.
[–] metal_am 2 days ago
Radiation damage is no joke!
[–] speed_spread 2 days ago
> PWR
CANDU works fine too.
[–] justincormack 3 days ago
Something about AGR in this great Stross piece https://www.antipope.org/charlie/blog-static/rants/nothing-l...
Magnox: un-enriched fuel, designed for weapons, low operating temperature.
AGR: too complicated, can't be refuelled without complete shutdown.
PWR has emerged as the only viable design, and even that is too complicated compared to solar+batteries.
Basically, plumbing is the enemy. Every joint is a potential failure. If what's in the pipe is radioactive or corrosive or explosive (in the case of molten sodium, all three), that's extra bad. So there's tremendous cost of inspections.