Japan doubles estimate of initial radiation release from Fukushima nuclear plant
By MITSURU OBE
6 June 2011 TOKYO — The Japanese government, providing fresh evidence on the severity of a nuclear disaster at the Fukushima Daiichi nuclear complex, more than doubled Monday its estimate for the amount of radiation released from the plant in the first week of the crisis in March. The Nuclear and Industrial Safety Agency, a government nuclear watchdog, also said it believes that reactor cores at some of the units at the complex melted much more quickly than the plant operator previously suggested, citing recent evidence suggesting initial efforts to inject seawater water into the reactors failed to achieve positive results. NISA said it now estimates the total amount of radiation released into the atmosphere in the first week of the crisis at 770,000 terabecquerels. This compares with NISA’s previous estimate, released on April 12, of 370,000 terabecquerels for the first month of the crisis. NISA has pointed out that most of the radiation was released in the first week. A terabecquerel is equivalent to one trillion becquerels. The latest figure is still only about 10% of the radiation released from the 1986 Chernobyl disaster, which is estimated at 5.2 million terabecquerels, NISA said. But the sharp upward revision shows that the failure to contain the crisis swiftly resulted in greater radioactive contamination of surrounding regions than previously thought. [But consider the recent estimate of an additional 720,000 terabecquerels in the 100 million liters of contaminated water, and we have around 1.49 million terabecquerels, which puts us at about 29% of Chernobyl, and rising. – Des] The new estimate brings NISA’s estimate more in line with that of another government watchdog, the Nuclear Safety Commission, which has projected the total radiation release at 630,000 terabecquerels.
