nuclear-news

Confusion in estimating Fukushima radiation

TEPCO estimate sees more radiation than NISA’s, The Yomiuri Shimbun, 24 May 12 Tokyo Electric Power Co. has estimated the total amount of radioactive substances discharged from its Fukushima No. 1 nuclear power plant measured 760,000 terabecquerels, 1.6 times the estimate released by the Economy, Trade and Industry Ministry’s Nuclear and Industrial Safety Agency in February.

One terabecquerel is equal to 1 trillion becquerels.

TEPCO will include the estimate in a final report to be compiled by an
in-house accident investigation committee in June. The firm has also
begun explaining how it arrived at the figure to local governments in
Fukushima Prefecture.

There are two ways to estimate the amount of discharged radioactive
substances. One way is to base calculations on the degree of damage to
the reactor core. The other is to reverse calculate based on the
density of radioactive substances found in the atmosphere and
seawater. As a result, there will be differences in estimates
depending on how the figures were obtained.

NISA released an estimate of 770,000 terabecquerels in June last year,
and another estimate of 480,000 terabecquerels in February. The
Cabinet Office’s Nuclear Safety Commission released an estimate of
570,000 terabecquerels in August last year.

TEPCO combined the two methods and repeated its calculations under
different conditions. It reached a final estimate of 400,000
terabecquerels of iodine-131 and 360,000 terabecquerels of
cesium-137….. http://www.yomiuri.co.jp/dy/national/T120523005514.htm

May 24, 2012 - Posted by Christina Macpherson | environment, Fukushima 2012, Reference