For the record
Another quick post on nuclear power, probably the last for a while. Most of my discussion about nuclear power has been on the question of whether expansion of nuclear power is, or is likely to be, a cost-effective way of reducing CO2 emissions. The answer, as revealed by the failure of the heavily subsidised “nuclear renaissance” in the US, is “no”. But, for the existing (mostly Generation II, see over fold) plants, there’s a separate question – does it make sense to close them down early, or, alternatively to seek to extend their lives.
Since this issue comes up a lot, I thought I would state my position clearly. Nuclear power is an almost exact substitute for coal, has no CO2 emissions and (except where particular vulnerabilities have been demonstrated) comparable or lower health and safety risks (these numbers can be played with in various ways). The marginal cost of generating power from existing plants is low. Problems like waste disposal will have to be addressed anyway, and a few more reactor-years worth won’t make much difference.
So, except where there are particular vulnerabilities that are too costly to repair, I favor keeping existing plants open as long as they can be kept in good repair.
A quick typology of nuclear plants (cribbed from Wikipedia, where you can get more detail if you want)
Generation I refers to the first experimental plants, now all retired
Generation II refers to designs from the mid-60s to about 1990. Nearly all operational nuclear plants, including some now being completed after long delays, are in this class
Generation III refers to designs with improved safety features and other advances, developed from 1990 to the early 2000s. Virtually none of these were built
Generation III+ refers to the current state of the art for plants now being built. In practice, the Westinghouse AP-1000 is the only serious contender (some prospect of 20+ being built)
Generation IV refers to hoped-for future evolutions on this path
Finally, there are various vaporware proposals, such as thorium reactors, the Integral Fast Reactor, small modular reactors and so on. None of these has got past the prototype stage, and most not even that far.