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points by pjc50 3 days ago | 0 comments

A was Magnox and B was AGR. A collectible set of British dead end nuclear technologies.

C is not a great idea but like HS2 failing to finish it would also be a disaster.

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

Long discussion: https://www.worksinprogress.news/p/why-british-nuclear-flopp...

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.

[–] 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...