A Nuclear Regulation Authority panel said Wednesday it remains convinced that geological faults running under Tohoku Electric Power Co.'s atomic power plant in Aomori Prefecture are active, indicating the facility's sole reactor cannot be restarted.
The panel reached the same conclusion in an earlier meeting. On Wednesday, however, Tohoku Electric officials were given the opportunity to argue their claim that clay swollen with water was responsible for deformations in geological layers.
"There were no facts that made us correct the recognition we reached earlier," Kunihiko Shimazaki, the head of the panel and an NRA commissioner, told reporters after the meeting.
He also said he expects the utility to evaluate the impact of the faults on the assumption they are active.
Although the faults don't run directly beneath the sole reactor at the Higashidori complex, a reassessment of the plant's quake resistance, as demanded by the panel, will keep the reactor offline for the foreseeable future.
The faults deemed active, including two dubbed F-3 and F-9, run parallel and lengthwise through the plant's premises.
Observed at the southern end of the plant, they are known to stretch to the north, close to the reactor 1 building and to adjacent land that Tokyo Electric Power Co. intended to build its own Higashidori plant on.
The panel members have pointed to irregular elevated areas and other findings that indicate the faults are active.