Kyushu Electric Power Co. on Tuesday restarted the No. 4 reactor at its Genkai nuclear power plant in Saga Prefecture, which had been shut down since it developed trouble Oct. 4. Due to the nature of the trouble, it was not legally required to get prior approval for the restart from the town of Genkai and the Saga prefectural government in accordance with agreements on plant safety. The reactor was not subject to a stress test either, since it had not been going through a regular inspection.
But the restart of the reactor will deepen people’s distrust of Kyushu because its problem behavior has been exposed and its decision to restart the reactor gives the impression that it gives priority to securing profits rather than safety.
The firm is known to have manipulated a public discussion meeting in 2005 on the introduction of MOX plutonium-uranium fuel to the Genkai plant. And in October it snubbed a third-party committee’s report on the discussion manipulation.
Kyushu decided to restart the reactor although it and the company’s five other reactors will stop operations in December due to regular inspections. A high-ranking Kyushu official said that there was no need to continue the stoppage of a reactor that can be operated. By restarting the Genkai No. 4 reactor, the firm can save ¥300 million to ¥400 million a day by cutting the costs of buying fuel for thermal power stations, for a total of more than ¥10 billion over 1½ months.
The 1.18 million kilowatt reactor automatically shut down Oct. 4 because a signal pointed to a failure to maintain vacuum inside the condenser, which turns steam into water. This trouble occurred about 10 minutes after workers started repair work on a valve following procedural instructions. The instructions contained errors — a failure to distinguish between work while a reactor is in operation and work after it has shut down.
On Oct. 31, the Nuclear and Industrial Safety Agency accepted as appropriate the firm’s report on the trouble and ways to rectify the instructions. But it must be asked whether a power company that makes errors in procedural instructions for a reactor is really aware of its severe responsibility. NISA should not only fully explain why it accepted the firm’s report but also fully examine its old and new instructions and make public the findings.