Japan doubles plant radiation leak estimate

Jun 07, 2011
Handout photo issued by TEPCO shows workers spraying a dust inhibitor into buildings at the firm's crippled Fukushima nuclear power plant. Japan has more than doubled its initial estimate of radiation released from the nuclear plant in the week after the March 11 tsunami, ahead of the launch of an official probe Tuesday.

Japan has more than doubled its initial estimate of radiation released from the crippled Fukushima nuclear plant in the week after the March 11 tsunami, ahead of the launch of an official probe Tuesday.

The nation's watchdog, the Nuclear and Industrial Safety Agency (NISA), now says it believes 770,000 terabecquerels escaped into the atmosphere in the first week -- compared to its earlier estimate of 370,000 terabecquerels.

The findings were released on the eve of the first meeting Tuesday of an independent 10-member academic and that will look into the causes of the world's worst since Chernobyl a quarter-century ago.

The group's leader, a Tokyo University researcher on human error, Yotaro Hatamura, said at the meeting that "nuclear power has higher and is dangerous. It was a mistake to consider it safe".

NISA's new figure is closer to that of Japan's independent Commission which had initially estimated a release at 630,000 terabecquerels in the first month.

The revision, almost three months after the quake, is likely to fuel criticism of the initially slow and vague flow of information from the government, and plant operator Tokyo Electric Power Company (TEPCO).

An official scans a boy evacuated from the tsunami zone in Japan with a geiger counter to check radiation levels. Months of hosing operations at the stricken Fukuishima plant have left over 100,000 tons of highly radioactive water in buildings, basements and tunnels at the plant, and TEPCO is struggling to remove the runoff so it can resume crucial repair work.

Japanese experts have stressed that most of the released in the first days after the quake, amid a series of hydrogen explosions at the plant, was blown across the Pacific Ocean, not over inhabited areas.

Prime Minister Naoto Kan's special advisor on the , Goshi Hosono, said Monday that the latest findings were unlikely to affect the TEPCO roadmap to bring all reactors to stable "cold shutdown" by October-January.

NISA also said in its review that it believes much of the inside the three reactors melted down faster than previously believed after the tectonic disaster knocked out the plant's cooling systems.

The agency said melted fuel in unit one dropped to the bottom of the pressure vessel and damaged it some five hours after the quake hit the plant at 2:46 pm on March 11, followed by a 14-metre (46 foot) tsunami.

TEPCO-issued photo shows the control room of the second reactor at Fukushima nuclear power plant in northeast Japan. The nation's watchdog, the Nuclear and Industrial Safety Agency, now says it believes 770,000 terabecquerels of radioactive contamination escaped into the atmosphere in the first week -- compared to its earlier estimate of 370,000 terabecquerels.

The agency said the same happened in unit two at about 10:50 p.m. on March 14, and that number three suffered damage at 10:10 p.m. on March 14.

TEPCO has said it believes the molten fuel is now being cooled by water at the bottom of the number one, two and three reactor pressure vessels, citing the relatively low outside temperatures of the containers.

Months of hosing operations have left over 100,000 tons of highly radioactive water in buildings, basements and tunnels at the plant, and TEPCO is struggling to remove the runoff so it can resume crucial repair work.

Contaminated water has spilled or been released several times into the Pacific Ocean, and environmental group Greenpeace has warned that it has found unsafe radiation levels in marine species as far as 50 kilometres offshore.

TEPCO has been testing water decontamination equipment, some provided by US and French companies, to remove radioactive substances, oil and seasalt from the runoff water so it can be reused as a reactor coolant from about mid-June.

With the advent of the summer rainy season in the region, they have also started to ship to the plant 370 truck-sized water tanks with a total capacity of more than 40,000 tons to store excess contaminated .

Explore further: Tens of thousands expected at New York climate march

add to favorites email to friend print save as pdf

Related Stories

Areva to set up treatment system at Japan plant

Apr 19, 2011

French nuclear group Areva said Tuesday it will set up a system to treat radioactive water from a quake-hit Japanese power plant to allow power supplies and cooling systems to be repaired.

Robots to gauge radiation in Japan's quake-hit plant

Apr 18, 2011

The operator of Japan's stricken nuclear plant said Sunday it will send two remote-controlled robots into a reactor building damaged by a hydrogen explosion to gauge radiation and temperature levels.

Japan nuclear plant firm opens Twitter account

Mar 17, 2011

Tokyo Electric Power Co. (TEPCO), which operates the quake-hit Japanese nuclear reactors, opened an official Twitter account late Thursday, immediately drawing more than 117,000 followers.

Japan economy, Toyota feel effects of disaster

Apr 13, 2011

The impact of Japan's earthquake and nuclear crisis rippled through the economy Wednesday as the government downgraded its outlook and Toyota announced more temporary plant shutdowns overseas.

Japan disaster not similar to Chernobyl: officials

May 17, 2011

The potential health consequences of the nuclear crisis at Japan's Fukushima Daiichi plant are not equal to those caused by the disaster at Chernobyl, Japanese health officials said Tuesday

Recommended for you

Rio's Olympic golf course in legal bunker

Sep 18, 2014

The return of golf to the Olympics after what will be 112 years by the time Rio hosts South America's first Games in 2016 comes amid accusations environmental laws were got round to build the facility in ...

User comments : 1

Adjust slider to filter visible comments by rank

Display comments: newest first

hush1
not rated yet Jun 07, 2011
Where is ModernMystic? And the promise that the last PRV containment to the environment was 'unbreechable'.

Only your statement stands corrected.
The person, ModernMystic, stands forever.

Incorrigible.