TOKYO (AP) – The operator of the destroyed Fukushima nuclear power plant said on Monday that two seismometers at one of the three melted reactors were taken out of service last year and did not collect data when a strong earthquake hit the area earlier this month .
The recognition raised new questions about whether the company’s risk management has improved since a massive earthquake and tsunami in 2011 destroyed much of the plant.
The malfunctioning seismometers appeared during a meeting of the Nuclear Regulatory Authority on Monday to discuss the new damage caused by a magnitude 7.3 earthquake that struck the region on 13 February. damage to their primary isolation chambers.
The operator, Tokyo Electric Power Co., has been repeatedly criticized for coverage and delayed disclosure of problems at the plant.
Regulators asked TEPCO at the hearing why it has no seismological data from the Unit 3 reactor for Saturday’s quake, and utility officials acknowledged that both seismometers failed – one in July and one in October – and were not never repaired.
TEPCO also said that the seismometers, except for two, in the reactor buildings that survived the 2011 disaster were submerged by tsunami water and were never replaced.
During Monday’s hearing, regulators expressed concern about the drop in water levels and pressure in the primary isolation chambers of Units 1 and 3 due to the possibility that the earthquake may have extended existing damage or opened new leaks. and urged the usefulness of checking for increased levels of radiation in the groundwater around the reactor buildings.
TEPCO said so far no anomalies have been detected in the water samples.
The new damage could further complicate the already difficult process of decommissioning the plant and could add to the large amounts of contaminated water stored in the plant.
Since the 2011 disaster, cooling water has steadily escaped from damaged primary insulation vessels in the basements of reactor and turbine buildings, where the volume increases as groundwater drains. The water is pumped and treated, then part of it is reused as cooling water, while the rest is stored in about 1,000 tanks.
TEPCO initially reported that there were no factory anomalies since Saturday’s quake. On Monday, however, it is said that about 20 of the tanks slipped slightly due to the earthquake, a storage container carrying radioactive waste was tilted, and the asphalt pavement of the plant was cracked.