<China's nuke plans> Excellent article. I hadn't realized China was building new designs. As with solar and coal, new global capacity is dominated by China and other emerging markets.
re AP1000 Westinghouse design:
Simplicity is good: fewer pumps, fewer valves, etc. Passive is better than active, to improve the safety of any design. In past nuclear accidents, active safety systems have failed. So, a 3-day supply of cooling water, gravity-fed into the reactor, is a good idea. But if such a system had been in place at Fukushima or Chernobyl, it would not have prevented or lessened the damage. In both cases, it took a lot longer than 3 days to get the cooling water flowing again. A diversion channel from a nearby river or reservoir might provide water for enough time.
But what will they do with that 8 million pounds of water they will run through the reactor every 3 days? As best as I can tell from their website, it gets released as steam into the atmosphere. Not good.
The control room can be isolated from outside contamination, with its own 3-day air supply. That should motivate them: "fix it in 3 days, or start breathing the radioactive air." Nice.
ap1000.westinghousenuclear.com
<China is also building a pebble-bed reactor, a dream of nuclear scientists since German engineers tried to build one in the 1960s. This kind of reactor should run at extremely high temperatures—900C (1,650F) or more; other reactors operate at around 400C—and use helium as a coolant and graphite instead of water as a moderator, which slows down neutrons in a reactor’s core to increase the chances of inducing nuclear fission. If successful, it would be the first full-size prototype of this technology. If unsuccessful, it would be a costly, dangerous mess to clean up.... Germany’s pebble-bed prototype, which was never operational, cost €5.5 billion ($7.3 billion) to decontaminate.>
If it works, great. Higher temperatures means more efficient, which might make this design economic. Higher temps also mean, when things go wrong, they go wrong faster. I hope they have a large supply of extra graphite and helium available, just in case. The Chinese probably have cheaper clean-up methods: if something goes wrong, they probably plan to put the mess on a barge, tow it out to sea, and sink it. That's what the Russians did with some of their used reactors. |
