China is heading for a nuclear accident if it continues with current construction plans, says former state nuclear physicist and prominent critic He Zuoxiu
Some members of the nuclear power industry rely too much on theoretical calculations, when only experience can provide real accuracy.
The lifetime of nuclear reactors is calculated in “reactor-years”. One reactor year means one reactor operating for one year. The world’s 443 nuclear power plants have been running for a total of 14,767 reactor-years, during which time there have been 23 accidents involving a reactor core melting. That’s one major accident every 624 reactor years.
But according to the design requirements, an accident of that scale should only happen once every 20,000 reactor years. The actual incidence is 32 times higher than the theory allows.
Some argue this criticism is unfair. After all, 17 of those 23 accidents were caused by human error – something hard to account for in calculations. But human error is impossible to eliminate, and cannot be ignored when making major policy decisions.
Even if we set aside the accidents attributed to human error, technical failings have caused core melting once every 2,461 reactor-years. That’s still more than eight times the theoretical calculation.
Lessons from the US, Russia and Japan
The US and former Soviet Union had been operating nuclear power for 267 and 162 reactor-years respectively before a major accident occurred. Japan managed to get to 1,442 reactor-years before Fukushima struck.
How long can China’s nuclear industry stay “safe”?
China already has 15 nuclear power stations, and looks set to have 41 by 2015. These have been built using various different models, with technology imported from France, Russia, the US and Canada. There’s also the Taishan plant, which uses an adapted Chinese-developed nuclear submarine reactor. Mostly, China’s existing nuclear power stations use second-generation technology.
China is projected to have 71 nuclear power stations by 2020. If we use the figure of 4,922 reactor-years as explained above, then China will “most probably” suffer a major nuclear accident within the next 69 years.
Chinese nuclear technology can be regarded as approaching global levels, with similar design, safety and operational standards. But to reduce costs, Chinese designs often cut back on safety. In the past, earthquake-resilience was lower than in Japan, for example. China also has much less experience of this sector than Japan.
Qian Shaojun, a member of the Chinese Academy of Engineering, has repeatedly said that nuclear safety relies on experience – you cannot claim something is safe until it has been operating for a certain number of reactor years. Japan has at least 10 times as many reactor-years of experience as China.
Read more at Chinese nuclear disaster “highly probable” by 2030