On April 27th, 2011, we received an instruction of "Investigation of cause 
and development of preventive measures regarding exposure exceeding dose 
limit to radiation dose engaged person at Fukushima Daiichi Nuclear Power 
Station*1" from Nuclear and Industrial Safety Agency (NISA), 
Ministry of Economy, Trade and Industry. 
 
Since then, we have implemented the investigation of cause and development 
of preventive measures, based on the NISA's instruction and reported the 
result of the investigation and the preventive measures to NISA. Based on 
this report, female employees have been prohibited to work in Fukushima 
Daiichi Nuclear Power Plant. 
                    (Previously announced on April 27th and May 2nd, 2011) 
 
After that, as we accomplished the target of Step 2, we confirmed 
significantly decrease of effective dose as the result of the effort for 
working environment and radiation attenuation on this plant. 
 
According to the above, regarding the female radiation workers at this 
plant, we summarized the investigation result of operational change to 
enable to engage female radiation workers to the working at the particular 
indoors*2 where has relatively-low radiation dose under the statutory dose 
limit*3 (5 mSv / 3 months) and reported the summary to NISA today. 
 
Since we have reported about this operational change to NISA and it 
confirmed the adequacy of the contents, we will start the operation as 
soon as the completion our preparation after improvement of infrastructure 
etc. 
 
We will continue our effort to keep the stability of the plants and to 
improve the work environment. 
 
 (Attachment) 
Operational Change of female radiation workers at Fukushima Daiichi 
Nuclear Power Plant 
*The aforementioned attachments are only available in Japanese. We 
apologize for any inconvenience this may cause. 
 
*1 Instruction notice 
 Investigation of cause and development of preventive measures regarding 
 exposure exceeding dose limit to radiation dose engaged person at 
 Fukushima Daiichi Nuclear Power Station 
 (Instruction) 
                                                      No.4 April 27th 2011 
                                                           April 27th 2011 
On April 27th, NISA is received from you the report stating that /mean 
dose exposure from January 1st to March 31st (4th quarter) to the person 
(woman) who had been engaged in the work after Tohoku - Pacific Ocean 
Earthquake is exceeding the dose limit (5mSv/3month) set in the Article 
6-1-3 of Regulation of Provision Concerning the Installment, Operation, 
etc. of Practical Generation Reactors based on Article 9-1-1 of Regulation 
Concerning the installment, Operation etc. of Practical Generation 
Reactors (The Ministry of International Trade and Industry Order No.77 of 
1978). 
 
For this reason, we strictly worn you and instruct to investigate cause 
and develop preventive measures and verify dose management system at 
Fukushima Daiichi Power Station and develop countermeasure based on this 
verification, and report it to us no later than May 2nd 2011. 
 
*2 Particular indoors 
Main Anti-Earthquake Building, Service Building of Unit 5 and 6, Rector 
building, Turbine building, Radiation wastes treatment facility building, 
and Rest station. 
 
*3  Statutory dose limits 
Section 9-1-1 of Regulation on the installation and operation of nuclear 
power generators: 
Stipulates that exposure dose of workers may not exceed the limits set 
force by the Minister of Economy, Trade and Industry 
 
Section 4-2 of Regulation on the prevention of ionizing radiation injury 
Section 6-3 of Notice on the exposure dose limits based on section 4-2 of 
Regulation on the prevention of ionizing radiation injury: 
Stipulates that the effective radiation dose of a female worker may not 
exceed 5 mSv in 3 months