Wednesday, March 28, 2012

Fukushima No. 2 reactor radiation has reach an extremely high level up to 73 sieverts per hour

TOKYO (Kyodo) -- The operator of the Fukushima Daiichi nuclear power plant said Tuesday that the radiation dose inside the crippled No. 2 reactor stood at an extremely high level between 31.1 and 72.9 sieverts per hour, underscoring the existence of radioactive substances from the melted fuel inside the structure.

Tokyo Electric Power Co. measured the radiation level by inserting a long dosimeter into the round-bottomed, flask-shaped primary containment vessel, where fuel is thought to be accumulating at the bottom following the nuclear accident last year.

Human beings could die within one month once exposed to 7 sieverts and within several days once exposed to 20 sieverts or more. Usually, when an ordinary reactor is not operating, the radiation level is low enough for workers to enter inside, according to the utility known as TEPCO.

The highest radiation dose was measured at about 4 meters from the bottom and about 1 meter away from the vessel's interior wall. The utility said it could not check a deeper area because the dosimeter had no camera attached.

The utility's spokesman Junichi Matsumoto said he cannot immediately tell whether the latest outcome will affect the current road map toward scrapping the Nos. 1 to 4 units, but added that the data can be used to study what kind of devices should be developed for the decommissioning work. Read More