Based upon the directive document of NISA on June 6, 2011, entitled, "Regarding the Response to the Addition of NSC's Opinion, Taking into Account the 2011 Off the Pacific Coast of Tohoku Earthquake, on NISA's Examination of the Reported Evaluation on Seismic Safety of Existing Nuclear Power Reactor Facilities, etc. in Light of the Current Regulatory Guide for Reviewing Seismic Design (Additional Direction)" (June 3, 2011 NISA No.1), we reported to the Nuclear and Industrial Safety Agency (NISA) of the Ministry of Economy, Trade and Industry (NISA) on August 30 and December 27, 2011.
(Previously announced on August 30 and December 27, 2011)
Since it was confirmed that there were errors in the part of the report which was submitted to NISA thereafter, we have corrected them and submitted to NISA today.
END
Attachment:
Correction of the part of the report based upon "Regarding the Response to the Addition of NSC's Opinion, Taking into Account the 2011 Off the Pacific Coast of Tohoku Earthquake, on NISA's Examination of the Reported Evaluation on Seismic Safety of Existing Nuclear Power Reactor Facilities, etc. in Light of the Current Regulatory Guide for Reviewing Seismic Design (Additional Direction)" (PDF 153KB)
The aforementioned attachments are only available in Japanese.
We apologize for any inconvenience this may cause.
* Additional directive document
"Regarding the Response to the Addition of NSC's Opinion, Taking into Account the 2011 Off the Pacific Coast of Tohoku Earthquake, on NISA's Examination of the Reported Evaluation on Seismic Safety of Existing Nuclear Power Reactor Facilities, etc. in Light of the Current Regulatory Guide for Reviewing Seismic Design (Additional Direction)"
(June 3, 2011 NISA No.1)
The Nuclear and Industrial Safety Agency (NISA) directed the nuclear power operators in the direction, "Regarding the Response to the Addition of NSC's Opinion, Taking into Account the 2011 Off the Pacific Coast of Tohoku Earthquake, on NISA's Examination of the Reported Evaluations of Seismic Safety of Existing Nuclear Power Reactor Facilities, etc. in Light of the Current Regulatory Guide for Reviewing Seismic Design (Direction)" (April 28, 2011, 06.03.2011 N No. 4), to report necessary information out of existing information from previous geological surveys, in order to find out whether some faults possibly fall under the requirement for seismic design considerations on existing nuclear power reactor facilities, etc. (hereinafter, "faults that require consideration"). The nuclear power operators submitted the required report to NISA on May 31, 2011.
Among the faults, etc. that the nuclear power operators considered as not requiring seismic design considerations, there was one case where a fault actually appeared on the earth's surface due to earthquakes that occurred on or after March 11, 2011.
Based on the above, NISA believes that in order to obtain information that can be utilized in a re-evaluation of the possibility of fault activities, etc., further examinations must be done and additional information must be collected on faults that the nuclear power operators deem from past examinations as not requiring seismic consideration, in order to find out if they are actually faults that require consideration. Therefore, NISA directs the nuclear power operators to investigate the amount of crustal movement accompanying the earthquakes that occurred on or after March 11, 2011, and the occurrence of earthquakes, within a necessary distance from each fault that the operators deemed as not requiring seismic design consideration. If the possibility cannot be denied that a fault could be one that requires consideration, then an exploration of the earth's surface, etc. should be conducted and reported to NISA by August 31, 2011.
