Neutron emission from the nuclear reactor causes the fragility of the wall of the reactor. It is thought to depend on the total amount of emission as well as the emitting speed of the neutron. It means aging of the reactor deteriorates its stuructural integrity. It could cause a serious accident in certain time after its construction. It is inevitable.
Our administrative agency, NISA, which has handled the safety issue of the nuclear power plants since the beginning of nuclear power administration, is reported to investigate the aging problem of the nuclear power plants in Japan. 19 of them are 30 years old or older, even though the nuclear power plants were originally designed to be used for only 16 years. I seriously suspect that they won't be capable of this investigation. For the past years, together with the power companies, they have built up the myth that nuclear power plants are so safe that no accidents could occur. They won't break that safety myth by themselves. This investigation should be executed by researchers which include some on the side having criticized the nuclear power policy.
If serious accidents should occur with this aging process, it would result in much worse damage and nuclear pollution in larger area than that in Fukushima. The risk management capability of the government and the national administration is questioned now.