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  4. 2016.06.28

Reactors at Takahama Nuclear Power Plant






The nuclear reactors No.1 and No.2 at the Takahama Plant of the Kansai Electric Power Co. worked over 40 years. The Nuclear Regulation Authority gave June 20 permission to extend a period of operation up to 60 years, prior to the date July 6 when prolongation procedures will be closed. Responding to the government’s decision, a lawsuit is filed to repeal the approval of extension.


GOVERNMENT CONTEMPLATES EXTENSION BY ANOTHER 20 YEARS


The No.1 Reactor began commercial operation in 1974, and No.2, in 1975. They are of the pressurized water reactors (PWR) with the output of 826 thousand kilo-watt. After the disaster at the Fukushima plants, the Act on the Regulation of Nuclear Source Material, Nuclear Fuel Material and Reactors was revised and implemented in 2013. It provides 40 years of service as a rule and allows extension of service up to 60 years in maximum if such an operation is endorsed. The recent decision on the No.1 and No.2 reactors at the Takahama station is of the first case.


Last-minute Push


The two reactors cleared the regular safety tests held last April. But a seismic resistance test on the reactors and buildings were omitted on the ground it will be done after the remodeling works finish. As for the corresponding measures to be taken by the plant to meet the new criteria, only the policies and plans were approved. The current authorization of operation will terminate on July 7. The April test is regarded to be a hasty examination to be in time for restarting.


Tests to check deterioration are required when applying for extension of operation. A plan of seismic retrofit must be approved by the government. Old power stations have difficulties in verification: reactors and buildings are more fragile. Pressure vessels are exhausted by neutrons emanating at the time of fission (neutron embrittlement). They are more delicate and vulnerable to pressure when reactors are cold.


Litigation Filed


In total 76 people from 14 prefectures, including Fukui, Aichi, Gifu, Mie, Kyoto and Tokyo, filed a suit on April 14 to the Nagoya District Court. They demand the Regulation Authority to revoke the permission of extension exceeding 40 years. This is the first court
case to contend safety of old nuclear facilities in the country.


The plaintiffs criticize that the Authority has not conducted stringent examination on problems stemming from long service and on risks of accidents, including a hydrogen explosion. They emphasize that the law stipulates a period o f 40 years of service as a rule and that extension is to be allowed exceptionally when safety is well secured, and demand to apply the 40-year rule on the two units.


The group points out, citing that the new criteria request to replace flammable cables with fire-resistant ones as a safety measure. But the replacement job has been done only for 60% of the total length of 1300 kilo-meter-long cables and the rest part is to be covered with fire-proof sheet. The plaintiffs condemn that the Authority deviates of its jurisdiction in terms that it has approved the alterative modus operandi without conducting a demonstration test.


The Authority sets as 700 gal the standard earthquake vibration, which is similar to those applied to the comparatively new No.3 and No.4 reactors at Takahama. Judging from the level of 1580 gal recorded in the recent earthquake in Kumamoto, Kyushu, the norm is very low and far from reliable in ensuring safety.


Nuclear Power Can be Abolished


It is five years since the disaster at Fukushima plant. The Abe government, rejecting people’s voices, maintains a policy to restart nuclear power generation and extend a service period of reactors. It has been proven that people can live on without electricity generated at the nuclear plants. The government must create a society that does not depend on nuclear power and engage in decommissioning reactors. A decision to extend service up to 60 years ? it is beyond sincere discussions.



June 28, 2016







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