Dramatic escalation in Japan 15 March 2011

World Nuclear News

Dramatic escalation in Japan 15 March 2011

http://www.world-nuclear-news.org/RS_Possible_damage_at_Fukushima_Daiichi_2_1503111.html

FIRST PUBLISHED 1.22am GMT UPDATE 1: 1.58am GMT Information from TV appearance, change of headline from 'Possible damage to Fukushima Daiichi 2'

CORRECTION: 1.58am GMT Removal of potential inaccuracy on torus' status in containment

UPDATE 2: 2.19am GMT Information from government, change of headline from 'Damage to Fukushima Daiichi 2'

UPDATE 3: 3.20am GMT Details on fire from PM's spokesman

UPDATE 4: 3.44am GMT Fire reported put out

Loud noises were heard at Fukushima Daiichi 2 at 6.10am this morning. A major component beneath the reactor is confirmed to be damaged. Evacuation to 20 kilometres is being completed, while a fire on site has now been put out.

Confirmation of loud sounds at unit 2 this morning came from the Nuclear and Industrial Safety Agency (NISA). It noted that "the suppression chamber may be damaged." It is not clear that the sounds were explosions in the usual sense.

Also known as the torus, this large doughnut-shaped structure sits in the centre of the reactor building at a lower level than the reactor. It contains a very large body of water to which steam can be directed in emergency situations. The steam then condenses and reduces pressure in the reactor system.

 The pressure in the pool was seen to decrease from three atmospheres to one atmosphere after the noise, suggesting possible damage. Radiation levels on the edge of the plant compound briefly spiked at 8217 microsieverts per hour but later fell to about a third that.

 A close watch is being kept on the radiation levels to ascertain the status of containment. As a precaution Tokyo Electric Power Company has evacuated all non-essential personnel from the unit. The company's engineers continue to pump seawater into the reactor pressure vessel in an effort to cool it.

 Fire put out at unit 4

 Prime minister Naoto Kan confirmed a fire burning at unit 4, which, according to all official sources, had never been a safety concern since the earthquake. This reactor was closed for periodic inspections when the earthquake and tsunami hit, therefore did not undergo a rapid and sudden shutdown. It was of course violently shaken and subject to the tsunami.

 Kan's spokesman Noriyuki Shikata said that there had been "a sign of leakage" while firefighters were at work, "but we have found out the fuel is not causing the fire." The fire is now reported extinguished.

 Evacuation ordered

 Kan has requested that evacuation from a 20 kilometer radius is completed and those between 20-30 kilometers should stay indoors. He said his advice related to the overall picture of safety developments at Fukushima Daiichi, rather than those at any individual reactor unit.

 Shikata added that radiation levels near the reactors had reached levels that would affect human health. It is thought that the fire had been the major source of radiation.

 Nuclear Energy Institute

 http://www.nei.org/newsandevents/information-on-the-japanese-earthquake-and-reactors-in-that-region/

 UPDATE AS OF 10:25 P.M. EDT, MONDAY, MARCH 14:

 Yukio Edano, Japan’s Chief Cabinet Secretary, during a live press conference at 10 p.m. EDT, said there is a fire at Fukushima Daiichi 4 that is accompanied by high levels of radiation between Units 3 and 4 at the site.

 The fire began burning at Unit 4 at around 6 a.m. Japan time on March 14 and is still burning. Fire fighters are responding to the fire. The reactor does not have fuel in the reactor, but there is spent fuel in the reactor (pool) and Edano said that he assumes radioactive substances are being released.

 “The substances are coming out from the No. 4 reactor and we are making the utmost effort to put out the first and also cool down the No. 4 reactor (pool).”

 Edano said that a blast was heard this morning at Unit 2 at about 6:30 a.m. A hole was observed in the number 2 reactor and he said there is very little possibility that an explosion will occur at Unit 2.

 “The part of the suppression chamber seems to have caused the blast,” Edano said. A small amount of radioactive substance seems to have been released to the outside.

 TEPCO workers continue to pump sea water at 1, 2 and 3 reactors. “The biggest problem is how to maintain the cooling and how to contain the fire at No. 4.” At 10:22 a.m. Japan time, the radiation level between units 2 and 3 were as high as 40 rem per hour. “We are talking about levels that can impact human health.” Edano said.

 Of the 800 staff that remained at the power plant, all but 50 who are directly involved in pumping water into the reactor have been evacuated.