TOKYO, Nov. 27 (Kyodo) — Nuclear Regulation Authority Chairman Shunichi Tanaka said Wednesday that it could be difficult for reactors at the Kashiwazaki-Kariwa nuclear plant to pass the safety screening process if Tokyo Electric Power Co. says it will only use a planned key safety system after securing local approval.
"In that situation, we will probably not give a green light," Tanaka told a press conference, referring to the process of checking whether the plant's Nos. 6 and 7 units are qualified to resume operations in light of new regulations introduced following the 2011 Fukushima Daiichi nuclear power plant disaster.
The safety equipment in question is a filtered venting system, which can reduce radioactive substances when gas and steam need to be released to prevent damage to reactor containment vessels.
Installation of such systems has become mandatory for commercial reactors in Japan, but there is concern over the radiation exposure risk the systems pose to residents living around nuclear power plants.
TEPCO, facing strong distrust from Niigata Gov. Hirohiko Izumida, said the equipment will not be used without securing local approval when it filed for NRA safety assessments of the Kashiwazaki-Kariwa reactors in late September.
While noting that the NRA will "not interfere in the relations between local governments and utilities," Tanaka also expressed concern that regulators may have to reassess the reactors' safety in the event that TEPCO fails to secure local approval.
"We cannot allow the operation of various facilities that should ensure safety to be changed without permission," he said.
The NRA plans to hold its second safety screening session for the Kashiwazaki-Kariwa reactors on Thursday, during which regulators are expected to present what they see will be the main points of discussion.
TEPCO is eager to bring the idled Kashiwazaki-Kariwa plant back online as it is facing a tough business situation due to the massive costs stemming from the Fukushima crisis that began in March 2011. Restarting some of its reactors will help the utility cut huge costs for importing fuel for thermal power generation.
The Nos. 6 and 7 reactors are advanced boiling water reactors and the newest among the seven units at the Kashiwazaki-Kariwa plant, the world's largest nuclear power plant with a combined output capacity of 8.2 million kilowatts.
All 50 commercial reactors in Japan are currently offline and safety checks on some of them started after new regulations were introduced in July.