JAPAN | Two reactors ran at full capacity for months without final clearance

Posted on July 6, 2011


Two reactors shut down for regular inspections have now been running at full capacity for months despite not receiving the final clearance from the Nuclear and Industrial Safety Agency (NISA).

The No. 3 reactor at the Tomari nuclear power plant in Hokkaido and the No. 1 reactor at the Oi nuclear power plant in Fukui Prefecture are still technically in “control operation,” the final procedure for regular safety maintenance.

Normally, a control operation, in which the reactor gradually reaches full capacity for a load performance test, takes one month to complete.

The two reactors have now been in full operation for four months in this “test” mode.

NISA said the plant operators, Hokkaido Electric Power Co. and Kansai Electric Power Co., have not violated any laws.

But the continued running of these reactors for final testing could cause a backlash among a public that has lost confidence in the safety of nuclear facilities amid the ongoing crisis at the Fukushima No. 1 nuclear power plant.

Governors of prefectures that host nuclear power plants have been under pressure not to approve the restart of commercial operations of reactors that were shut down for regular inspections.

But they, as well as the economy ministry, are concerned about electricity shortages in the summer if the reactors remain idle.

The capacity of the No. 3 reactor at the Tomari plant is 0.912 gigawatts, representing 14 percent of Hokkaido Electric’s power supply.

The No. 1 reactor at the Oi plant, with a capacity of 1.175 gigawatts, supplies 4 percent of the electricity in areas served by Kansai Electric.

If reactors continue to run at full capacity in the control operation stage, local governments can still say they have not officially approved their restart for commercial use, although the two operations are essentially the same thing.

The Hokkaido and Fukui governors have so far shown no intention of taking action against the utilities.

Hideo Kobayashi, professor of safety engineering at Yokohama National University, said letting the control operation continue for months is the result of a “political” decision.

“A proper approach is that an electric power company should request a final check,” Kobayashi said. “Based on the request, the central government should present a direction for safety and try to win the consent of the public.”

The Oi No. 1 reactor went off-line in December and the Tomari No. 3 reactor in January for regular inspections conducted every 13 months.

After clearing about 50 safety inspection requirements, the Tomari reactor entered control operation on March 7 and the Oi reactor on March 10.

The two reactors were scheduled to resume commercial operations in early April. But the plant operators were forced to change the schedule after the March 11 Great East Japan Earthquake and tsunami triggered the Fukushima nuclear crisis.

Since then, residents living near the nation’s 54 nuclear reactors have grown skeptical on whether the plants can withstand such large-scale natural disasters.

In March and June, NISA instructed utilities to secure emergency power sources at nuclear plants to ensure the cooling systems will operate properly if an earthquake or tsunami cuts the main power supply.

On June 18, Banri Kaieda, minister of economy, trade and industry, said utilities could restart their reactors because additional safeguard steps taken were “appropriate.”

Hokkaido Electric and Kansai Electric continued full operations of the two reactors under control operation when these safety requests were made. They have yet to ask NISA to do final checks to confirm the reactors are working properly.

Under the Electric Utilities Industry Law, a plant operator faces a maximum fine of 300,000 yen ($3,700) for avoiding regular safety checks.

But NISA said the two utilities were not in violation of the law because all safety procedures have been completed, except for the request for the final check.

“We conduct a final check based on the request of an electric power company,” a NISA official said. “We have no plans to ask companies to undergo it.”

The two utilities said they have not announced that the two reactors were actually running at full capacity because of a “lack of understanding” from local governments.

The local governments themselves have shown a willingness to let the reactors continue to run under control operation.

Hokkaido Governor Harumi Takahashi indicated that she would not demand a halt to the control operation of the No. 3 reactor at the Tomari plant nor oppose its restart for commercial operations.

“The No. 1 reactor (shut down for maintenance) is also under inspection, just like the No. 3 reactor,” Takahashi told a news conference on June 22.

The Fukui prefectural government also appears willing to leave the decision on operations of the No. 1 reactor at the Oi plant in the hands of the central government and Kansai Electric.

Twenty-two other reactors in Japan were shut down for regular inspections. They have not reached the control operation stage.

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