On February 8, three Japanese utilities submitted reports to the Natural Resources and Energy Agency in which they concluded that there were no technical problems that would prevent nuclear plants from operating safely for 60 years.
The utilities are those with the oldest plants namely, Japan Atomic Power Co (Tsuruga 1, a BWR which went into commercial operation in 1970), Kansai Electric (Mihama 1, PWR – 1970) and Tokyo Electric (Fukushima Daiichi 1, BWR – 1971).
In April 1996 it was decided to draw up a national policy for extending the life of Japanese nuclear plants and these three utilities did their own in-house studies to evaluate long term operation of their oldest plants. Their conclusion was that, with suitable maintenance and inspections, the plants could operate for 60 years without safety problems.
At Fukushima maintenance and inspection procedures were reviewed for the main plant equipment and structures, paying particular attention to six pieces of equipment and one structural part which are very difficult to repair or replace (including the reactor pressure vessel and primary shielding concrete). In some cases, additional inspections would be advisable for certain machines, the main turbine and heat exchangers but, on the whole, present procedures would be sufficient. As Fukushima 1 will soon be 30 years old, Tokyo Electric intends to implement additional inspections into the current maintenance plan.
