ID :
185196
Mon, 05/30/2011 - 05:11
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Shortlink :
https://oananews.org//node/185196
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Cooling System Briefly Stops at Fukushima No. 5 Reactor
Fukushima, May 29 (Jiji Press)--The cooling system at the No. 5 reactor of the crippled Fukushima No. 1 nuclear power plant stopped working briefly, operator Tokyo Electric Power Co. <9501> said Sunday.
The company said it completed work to switch to a backup seawater pump shortly past 12:30 p.m. Sunday (3:30 a.m. GMT) and restored the cooling system at around 12:50 p.m. The work started shortly past 8:10 a.m.
The company said it was aware of the malfunction of the pump at around 9:15 p.m. Saturday. The pump is used to send seawater to a heat exchanger that cools the reactor core and spent fuel pool.
The reactor water's temperature rose to as high as 94.8 degrees Celsius by 12:49 p.m. Sunday from 44.0 degrees Celsius at 9 a.m. Saturday. The temperature fell to 64.9 degrees Celsius by 4 p.m. Sunday.
The cooling system stopped working for at least over 15 hours, a situation that could have sent the temperature above 100 degrees Celsius.
The No. 5 reactor was brought to a cold shutdown, a situation in which the temperature is below 100 degrees Celsius, on March 20, nine days after the massive earthquake and tsunami hit northeastern Japan.
The pump's malfunction was apparently caused by insulation failure at a motor, company officials said.
Tokyo Electric had already reported the pump problem to the Nuclear and Industrial Safety Agency and local municipalities, Junichi Matsumoto, a senior official for the company's nuclear operation, said.
But he added that the problem should have been made public Saturday night. The company plans to have two seawater pumps operate anytime, beginning early next month.
The safety agency received a report from the company about the pump failure at around 9:30 p.m. Saturday.
Hidehiko Nishiyama, a spokesman for the Nuclear and Industrial Safety Agency, said the agency found no need to immediately disclose the information as an emergency.
END
The company said it completed work to switch to a backup seawater pump shortly past 12:30 p.m. Sunday (3:30 a.m. GMT) and restored the cooling system at around 12:50 p.m. The work started shortly past 8:10 a.m.
The company said it was aware of the malfunction of the pump at around 9:15 p.m. Saturday. The pump is used to send seawater to a heat exchanger that cools the reactor core and spent fuel pool.
The reactor water's temperature rose to as high as 94.8 degrees Celsius by 12:49 p.m. Sunday from 44.0 degrees Celsius at 9 a.m. Saturday. The temperature fell to 64.9 degrees Celsius by 4 p.m. Sunday.
The cooling system stopped working for at least over 15 hours, a situation that could have sent the temperature above 100 degrees Celsius.
The No. 5 reactor was brought to a cold shutdown, a situation in which the temperature is below 100 degrees Celsius, on March 20, nine days after the massive earthquake and tsunami hit northeastern Japan.
The pump's malfunction was apparently caused by insulation failure at a motor, company officials said.
Tokyo Electric had already reported the pump problem to the Nuclear and Industrial Safety Agency and local municipalities, Junichi Matsumoto, a senior official for the company's nuclear operation, said.
But he added that the problem should have been made public Saturday night. The company plans to have two seawater pumps operate anytime, beginning early next month.
The safety agency received a report from the company about the pump failure at around 9:30 p.m. Saturday.
Hidehiko Nishiyama, a spokesman for the Nuclear and Industrial Safety Agency, said the agency found no need to immediately disclose the information as an emergency.
END
