Japan earthquake forces thousands to evacuate in nuclear plant emergency | World news | The Guardian, 15 March “……….Failure of the cooling system – and the diesel back-up generator – at the Fukushima 1 plant in Onahama raises questions about what has gone wrong so far and what could happen in future. Another British nuclear engineer who asked not to be named said: “It is difficult to know exactly what has happened here but any shutdown is expensive and any systems failures of wider concern. The water cooling systems around the reactors are driven primarily by the nuclear power but if that is not working then via diesel generator.”Large said any complete power outage would quickly lead to the reactor overheating and the potential meltdown of the fuel under temperatures that could reach 1,200C. Different mechanical and chemical reactions could potentially lead to a hydrogen explosion, he added.All of this could be “astronomically” expensive given the heavily populated and insured population of Japan, said Large who has also visited Fukushima. The engineer said he was concerned that the nuclear industry and local political system had a reputation for considerable secrecy that would not make it easy to discern what had gone wrong.Earthquakes often close Japanese nuclear plants, some of which are built close to known faultlines. In 1999, 2004, 2005, 2007 and 2009 reactors shut down because of seismic activity.
Confidence in Japan’s nuclear safety was dented by a series of scandals in the late 1990s when the Tokyo Electric Power Company, owner of the Kashiwazaki-Kariwa plant, admitted falsifying safety data and concealing cracks in the core structures of its reactors. The same plant was seriously damaged by a major earthquake in 2007, but the owners tried to conceal a radiation leak. Much of the plant had to be closed for 21 months at a cost of more than $3bn.