The diminishing band of nuclear power fans had some rare good news recently. Two of the leading designs for new nuclear power plants -- the AP1000, designed by US company Westinghouse, and the EPR, developed by Areva in France -- achieved criticality (that is, the state where nuclear fuel sustains a fission chain reaction) in June. Both the plants are in China, at Sanmen and Taishan respectively.

But good news for nuclear power is never unmixed, and that’s certainly the case here. The construction process was as overtime and over-budget as usual, though not as badly as in the West, where construction of similar plants is running as much as a decade behind schedule. In the course of this protracted process, both Westinghouse and Areva have gone bankrupt. 

These plants will require a fair bit of operating experience before it can be said whether they actually function as designed. Since the design took place in the 1980s and 1990s, the latest nuclear power plants have the unfortunate distinction of being simultaneously untried and obsolescent.