Tepco submits final report on Fukushima I-1

1 January 2003

Tepco has submitted its final report to the Ministry of Economy, Trade and Industry (METI) following suspension of operations at Fukushima I-1 due to alleged data falsification.

The report confirms results of inspections conducted at the unit in October, which showed that air had apparently been injected into the primary containment vessel during leak tests in 1991 and 1992 in order to decrease leakage rate measurement results. Tepco said that the report confirms that "dishonest acts had taken place". However, it added: "No dishonest practice was found in any other leak tests conducted in the past at any nuclear power plant." Tepco has dismissed one employee and punished eight others over the data falsification. Hitachi, which undertook some of the inspections that led to data falsification, said that it would reduce the salary of its president and three others, as well as one at an affiliated firm.

The nine Tepco employees were held responsible for being involved in manipulating checks on the leak-tightness at Fukushima I-1 in 1991 and 1992. Such an act violates the Nuclear Reactor Regulation Law. However, Tepco will not be punishing any directors, because its president and chairman resigned in September to take responsibility for the scandal.

According to the Tepco report, five Tepco employees, including the dismissed one, decided during a 1991 check to inject compressed air into the container after failing to maintain an air-pressure reading. The report said that they ordered Hitachi workers to inject the air to give acceptable pressure readings inside the unit. During a 1992 check, engineers found a valve from which air was leaking, and six Tepco employees ordered Hitachi workers to seal off a pipe around the valve. The air pressure did not stabilise, prompting those involved to inject air into the container to give acceptable pressure readings inside the unit.

In addition to regular maintenance shutdowns, the company needs to conduct unscheduled inspections at some facilities following revelations of falsified reports on reactor defects. Tepco had hoped to keep Fukushima I-2 and I-6 running, but the company has now told the Fukushima prefectural government that it plans to shut them down sometime between late March and early April in response to the prefecture's call for thorough inspections.

Meanwhile, Chubu Electric Power Company has postponed the closure of two units at its Nishinagoya oil-burning plant as a result of the current outage of all four units at its Hamaoka nuclear power plant.

Referring to the Hamaoka outage, Chubu said: "Taking these circumstances into account, we have decided to postpone the closure of the fifth and sixth units at Nishinagoya, which was planned for the end of October, in order to secure a steady electricity supply in the future. We will decide whether to close the fifth unit after assessing the progress of recovery work at Hamaoka, while we will resume the procedure for closing the sixth unit." Chubu has also started commercial operation at the new, fifth unit of its Hekinan coal-burning plant. However, the company said it would continue working to "maintain an optimum balance of thermal, hydro and nuclear power sources".

A total of 13 Japanese nuclear units are currently reported to be off line.

As a result of the inspection incidents, the Diet has revised the country's Electric Utility Law and the Nuclear Reactor Regulation Law. The revisions provide for tougher penalties in the event that utilities withhold information or violate other rules related to nuclear power safety. In addition, the Nuclear and Industrial Safety Commission will receive increased powers to inspect reactors suspected of possible violations. The laws have adopted standards that will allow an operator to continue running a reactor even if damage is found at its facilities or in its equipment, but only after an estimation of how much the damage is likely to increase. The laws will also enable the government's Nuclear Safety Commission to investigate possible misdemeanours, in addition to the nuclear safety agency under METI.



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