Japan said Friday it would tighten its rules on the reporting of nuclear incidents after the recent revelation of a series of past near misses. Industry minister Akira Amari said power firms would be required to report all cases of dislodged nuclear control rods, not just those that cause uncontrollable chain reactions known as "criticality accidents".
"These cases may develop into a problem that threatens safety," he said at a news conference. Tokyo Electric Power Co admitted Thursday that five nuclear control rods came off a reactor in central Fukushima prefecture almost 30 years ago, apparently causing chain reactions reportedly lasting more than seven hours. The control rods are designed to regulate the distribution of power in the reactor and can stop a nuclear reaction if needed.
A series of past incidents have come to light since Hokuriku Electric Power Co admitted last week that it failed to report a June 1999 incident that caused a 15-minute uncontrollable chain reaction. Nobody was hurt but news of the cover-up provoked an outcry as the incident took place just three months before one of Japan's worst nuclear accidents which killed two workers and exposed 600 people to radiation.
The government is encouraging power companies to reveal all past incidents in a bid to restore public confidence and improve safety. Chief Cabinet Secretary Yasuhisa Shiozaki said Tokyo Electric Power's criticality accident was "something that must not occur."
The power companies "must recover the trust from people and work to secure their lives," said Shiozaki, the government's top spokesman. Resource-poor Japan relies on nuclear power for 30 percent of its needs, but the construction of reactors is frequently met with public resistance due to safety concerns. Japan, the only nation ever attacked with atomic bombs, is also sensitive about possible radiation leakage from nuclear reactor plants.