Monday, September 02, 2024

Back to pebble bed

Sabine Hossenfelder has posted another video about something I used to post about in the early days of this blog:  pebble bed nuclear reactors.

I used to follow a now defunct website by an enthusiast who wrote about progress in the development of this type of reactor, particularly with a group that wanted to build one in South Africa. (The link is still in the sidebar.)   The idea of the reactor sounded very encouraging - the design of the fuel meant it really couldn't melt down - a passive safety system that should work regardless of power outages or other problems.

However, the South African project never got going, and although China went ahead and developed one (which is what Sabine's video is about), I did read back in the day about a German research reactor of this type that had a lot of problems - particularly with the fuel pellets breaking up and causing a real radioactive mess inside the core that was difficult to deal with.   (I'm pretty sure I also read someone claiming if the pellets at high temperature were exposed to air, they could burn, which is not ideal!  But I could be wrong about that.)

Anyway, Sabine's video is about the Chinese doing an actual "will it meltdown" test of their reactor, and it passed.

However, she doesn't mention the German reactor experience at all - but many people in comments have.   

Some claim that the fuel pellet design has changed and improved since the German attempt - but given the huge number of pellets needed in these reactors, I wonder how hard it is to guarantee that you won't have some break apart (and how hard they will be to remove) during the life of the reactor.   (I think - but could be wrong! - that the pellets, which are re-circulated through the reactor - move down through it via gravity - and hence having some pellets split could well represent a major problem if the pieces somehow jam the flow of the pellets.)  This really seems the major problem, as far as I can tell.

Anyhow, here's her video:


1 comment:

  1. Anonymous8:04 am

    We just have to go about these things slowly, with a low Daily Cash allowance, until we get it right. To get in the way of nuclear is unacceptable sabotage. The coal we burn has got 14 times the energy in fissionable materials. So when we export coal we are giving away a potential of future energy abundance beyond our wildest imaginations.

    Obviously given this reality, the leftist take on all things is objectively insane and ridiculous. We have a huge problem with insane people getting in the way. I blame the fact oc so many well to do people living a life as expensive welfare queens in the public sector. This has to be the source of the mental dysfunction.

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