Blackout March 19 - Asahi

UPDATE: Cooling units for spent fuel pools remain suspended at Fukushima plant

http://ajw.asahi.com/article/0311disaster/fukushima/AJ201303190020

THE ASAHI SHIMBUN

Cooling systems remained suspended as of 1 p.m. on March 19 for spent fuel pools and other facilities of the crippled Fukushima No. 1 nuclear power plant, Tokyo Electric Power Co. said.

The shutdown occurred after a power outage around 7 p.m. on March 18 in the main quake-resistant building at the Fukushima plant.

Power was restored, but the cooling systems were still not operating for spent fuel pools in the No. 1, No. 3 and No. 4 reactor buildings, TEPCO said. The cooling system for a common fuel pool, a radioactive water decontamination system and several other facilities have also been suspended.

TEPCO said March 19 that the outage was likely caused by a defect in a temporary switchboard for the No. 3 and No. 4 reactors.

The company planned to confirm the cause and restart cooling operations on March 19. It is considering supplying electricity to cooling systems from a different source.

Industry minister Toshimitsu Motegi on March 19 told TEPCO to restore the operations as soon as possible.

The utility said the cooling facilities for nuclear reactors are 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 water in the No. 4 reactor’s pool was the highest at 31.6 degrees as of 1 p.m., and it will reach TEPCO’s safety standard of 65 degrees in about four days if its cooling system remains suspended.

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.”

During his news conference, Motegi said the announcement should have been made earlier.

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.

Crippled Japanese nuclear plant suffers blackout

http://ajw.asahi.com/article/0311disaster/fukushima/AJ201303190013

THE ASSOCIATED PRESS

A power failure at Japan's tsunami-damaged nuclear plant on March 18 night has left three fuel storage pools without fresh cooling water for hours, the plant's operator said.

Tokyo Electric Power Co. said the power failure at the Fukushima No. 1 nuclear power plant was brief at its command center but continued for hours at three of the seven fuel storage pools and at several other facilities, including one that treats water contaminated with radioactivity.

TEPCO said the reactors were unaffected and no other abnormalities were found. TEPCO spokesman Takeo Iwamoto said the utility plans to restore power to the pool cooling systems as soon as it can determine the cause of the failure.

The utility said the nuclear fuel stored in the pools will remain safe for at least four days without fresh cooling water.

The March 11, 2011, earthquake and tsunami destroyed the plant's power and cooling systems, causing three reactor cores to melt and fuel storage pools to overheat. The plant is now using makeshift systems.