The Higashidori nuclear power plant in Japan is unlike than any other nuclear power station in the country in that two of the four reactors at the station are operated by the Tohoku Electric Power Company and the other two reactors are operated by the Tokyo Electric Power Company.
Tohoku Electric, who operates the Unit 1 and Unit 2 reactors, submitted a request for safety screening by the Nuclear Regulation Authority on Tuesday.
According to the utility, it was able to raise the estimated strength of an earthquake that could be sustained by the plant from 450 gals to 600 gals.
Some experts however have advised the NRA that geological faults under the station are at high risk of movement in the future. Some of the fault lines are only 200 meters from one of the reactor buildings.
Inspectors from the NRA have conducted four on-site investigations at the Higashidori nuclear power plant, but have not yet made a final determination as to whether the fault lines should prevent future operations at the nuclear power plant.
In 2013, a panel of experts assembled by the NRA found two faults which run under the nuclear power station are highly likely active. Tohoku Electric disputed the findings presented by the panel of experts and argued that the distortion in the strata was likely caused by the soil absorbing water – an argument which was not considered valid by NRA Commissioner Kunihiko Shimazaki.
Yasuo Awata, chief scientist for the National Institute of Advanced Industrial Science and Technology also did not consider the utilities explanation for the displacement to be credible, saying that the “description of the Tohoku Electric Power does not make sense.”
Officials from the NRA have hinted that they would not begin screening of the facility until experts reached a conclusion about the risks from the faults.
The utility does not believe the faults are active and is pushing the NRA to conduct screening activities while it also continues its analysis of the faults.
Tohoku Electric is also planning to construct an off-site emergency command center, which is estimated to be completed by March 2016.