We have been measuring and evaluating the external and internal exposure
doses of the site workers engaged in emergency work at Fukushima Daiichi
Nuclear Power Station.
On June 13 we submitted reports to the Ministry of Health, Labor and
Welfare regarding the evaluation results of the external exposure doses of
the site workers engaged in emergency work before the end of March 2011
and the primary evaluation results *1 of the internal exposure doses of
workers who were measured with whole-body counters (WBC) before the end of
May out of the said workers.
Subsequently, we have compiled and submitted reports to the Ministry of
Health, Labor and Welfare, regarding the primary evaluation results of
the internal exposure doses of the site workers who were measured by WBC
by June 18 per the annex.
As for the workers whose primary evaluation results are showing
significant values*2, we will carry out a reevaluation based on the exact
dates when they took in radioactive materials, which will be determined
through a hearing investigation. Moreover, workers whose results indicate
relatively high values will be subjected to a more detailed WBC
administered by the Japan Atomic Energy Agency.
*1: Primary evaluation of internal exposure doses
Prior to the official evaluation based on the exact period when workers
took in radioactive materials, a tentative evaluation may be conducted in
the event that each worker took in all amounts of radioactive materials
only on the date when the worker started work at the site (March 12, if
engaged initially) when the exposure dose amounts were at their peak.
*2: Significant values
It is regarded as 2mSv which is equivalent to the recorded level.
<Annex>
Site Workers' Exposure Doses during Emergency Work at Fukushima Daiichi
Nuclear Power Station(PDF 11.6KB)
<Attachment>
Distribution of external exposure doses and internal exposure doses
(Primary evaluation) (PDF 68.1KB)