The cooling systems restarted for spent fuel pools in the No. 1 and No. 4 reactor buildings at the crippled Fukushima nuclear plant on March 19, although operations for other facilities remained suspended.
The cooling systems restarted for spent fuel pools in the No. 1 and No. 4 reactor buildings at the crippled Fukushima nuclear plant on March 19, although operations for other facilities remained suspended.
The shutdown of cooling systems occurred after a power outage around 7 p.m. on March 18 in the main quake-resistant building at the Fukushima No. 1 plant, Tokyo Electric Power Co., the plant’s operator, said.
Power has been restored, and cooling operations for the spent fuel pool for the No. 1 reactor resumed at 2:20 p.m., the Nuclear Regulation Authority said.
The cooling system for the spent fuel pool in the No. 4 reactor building resumed at 4:13 p.m., TEPCO said.
But by late afternoon on March 19, the cooling systems were still not operating for the spent fuel pool in the No. 3 reactor building and a common fuel pool. A radioactive water decontamination system and several other facilities were also not running.
TEPCO earlier said it planned to confirm the cause of the problem and have all cooling operations restarted on March 19. It is considering supplying electricity to cooling systems from a different source.
The company said the power outage was likely caused by a defect in a temporary switchboard for the No. 3 and No. 4 reactors.
The utility said the cooling facilities for the nuclear reactors were operating normally, and monitoring posts have shown no changes in radiation levels in the area.
The spent fuel pools in the No. 1, No. 3 and No. 4 reactor buildings together hold 2,491 fuel assemblies. The common pool stores 6,377 fuel assemblies.
The temperature of the water in the No. 4 reactor’s pool had climbed to 31.6 degrees at 1 p.m.
Industry minister Toshimitsu Motegi told TEPCO to restore the operations as soon as possible. He also scolded the company for the delay in disclosing the latest problem at the stricken nuclear plant.
TEPCO announced the power outage more than three hours after it occurred.
“We thought we had better make a report after confirming and summarizing the situation at the facilities,” a TEPCO official said. “We are extremely sorry because it took us so long.”
At the Fukushima No. 1 plant, cooling systems for spent fuel pools were suspended in the No. 3 reactor building in July 2011, in the No. 2 and No. 3 reactor buildings in January 2012 and in the No. 4 reactor building in June 2012 due to a blackout and other reasons.