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*" from Nuclear and Industrial Safety Agency(NISA),
Ministry of Economy, Trade and Industry.
(previously announced on April 27th, 2011)

Since then, we have implemented the investigation of cause and development
of preventive measures, based on the NISA's instruction. Today, we
reported the result of the investigation and the preventive measures to
NISA as attached.

(Attachment)
Report on 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 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. 

Attachment1-4: Report on investigation of cause and development of 
               preventive measures regarding exposure exceeding dose limit 
               to radiation dose engaged person at Fukushima Daiichi 
               Nuclear Power Station (PDF 77.1KB) 
Attachment5: Trend of Radioactive Volume in the Main Anti-Earthquake 
             Building (Before and After Installation of the Covers) 
                                                        (PDF 18.8KB) 
Attachment6: Overview and Effects of Countermeasures for Environment 
             Improvement In the Main Anti-Earthquake Building of Fukushima 
             Daiichi NPS (PDF 203KB) 
Attachment7: Replacement of Floor Mat in the Main Anti-Earthquake Building 
             (Plane) (PDF 273KB)