(348.3482) WISE Amsterdam - The fact that a regular inspection of the Mihama plant last summer failed to spot the possible danger has led critics to further question the adequacy of current inspection technology.
The second accident occurred on 21 February at reactor unit 2 of the Kariwa plant in Kashiwazaki, Niigata Prefecture. A steam turbine stopped due to abnormal pressure. Officials from Tokyo Electric Power, which owns and operates the plant, said the turbine was stopped after the output of a lubrication pump dropped suddenly. An investigation is underway, but as of 22 February, they claimed that no radioactivity was released.
The third accident, which clearly involved a leak of radioactivity, occurred the following day, 22 February, at a boiling water reactor (524 MW) at Tokyo Electric's Onagawa plant. The plant is approximately 25 miles northeast of Tokyo. Japanese nuclear safety officials are calling the incident a "minor one", but we have no figures on how much radioactivity was actually released. They also say that the leaked radiation was contained within the plant. The leak was apparently due to problems with a bolt connecting steam pipes. Opera-tion of the reactor was continued while workmen replaced the defective bolt.
The troubled reactor at the Kariwa nuclear complex is one of three now in operation. Two more are under construction, with another two under consideration. If all seven reactors were to be built, the complex would produce a total of 8.212 million kilowatts of electricity.
The Onawaga reactor is the only reactor presently in operation at that complex. A second reactor (825 MW BWR) is under construction there.
Since the first accident, the government has announced new guidelines on shutting down nuclear plants that experience sudden increases in radioactivity. Reactors will now have to be shut down if there is an increase of 20% or more. Up to now, reactor operators have had no percentage guidelines.
Japan now has 41 nuclear reactors in operation, according to year-end figures released by the Inter-national Atomic Energy Association. These supply approximately 9% of the country's energy needs. According to a long-term energy supply outlook report released last October, the government wants to rely on nuclear power for 16.9% of Japan's energy needs by the year 2010. This would require the construction of 40 additional nuclear reactors.
Japan's anti-nuclear groups intend to demand an immediate halt to all operations of the country's PWRs. Baku Nishio, a spokesperson for the Citizen's Nuclear Information Center in Tokyo, says that the more than 30 groups under the Center's umbrella will be lodging complaints with Japan's Ministry of International Trade and Industry (MITI) and the Kansai Electric Power Co., owner of the Mihama PWRs.
Sources:
- Environment News Service (via GreenNet, kin.nonukejapa, topic 62, 25 Feb. 1991 and topic 63, 25 Feb. 1991).
- Nuclear Power Reactors in the World (Austria), April 1990 Edition.
Contact: Citizens' Nuclear Information Center, 4F Yoshinobu Bldg., 2-10-11, Motoasakusa, Taito-ku, Tokyo 111, Japan; tel: +81-33-843-0596; fax: +81-33-843-0597]
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