In order to prevent the situation that exposure dose of each worker
exceeds the statutory exposure dose limits*1 during the emergency work at
Fukushima Daiichi Nuclear Power Station, we have implemented the
determination of exposure dose*2 by measuring internal exposure of workers
with high external exposure dose.
We hereby disclose the result of measurement as the determination of
exposure dose for the workers with more than 100 mSv of external exposure
dose at the end of March completed.
1.Number of workers subject to the measurement
21 (workers with more than 100 mSv of external exposure dose during the
emergency work at the end of March)
2.Result of measurement (total exposure dose from external and internal
exposure and number of workers)
200-250 mSv: 2
150-200 mSv: 8
100-150 mSv: 11
3.Maximum exposure dose
External exposure dose: 201.80 mSv
Internal exposure dose: 39 mSv
Effective exposure dose: 240.80 mSv(total dose from external and
*1: exposure dose limit
The exposure dose limit for the emergency situation in the emergency
response measures implementation area from the day of declaration of
a nuclear emergency situation until the day of cancellation of such
declaration is stipulated to be 250 mSv.
*2: determination of exposure dose
Determining the exposure dose by adding exposure dose during the stay in
Main Anti-Earthquake Building to the exposure dose during the work and
evaluating the committed effective dose of internal exposure.