Compilation of Data concerning Faults and Other Geological Features around the Hamaoka Nuclear Power Station (Report concerning Additional Directive of the METI's NISA)
August 30, 2011
Chubu Electric Power Co.,Inc.
As Chubu Electric Power proceeds with the seismic safety evaluation of the Hamaoka Nuclear Power Station as guided by the new seismic durability guidelines that the Nuclear and Industrial Safety Agency (NISA) is currently implementing, we are compiling information about changes in the earth's crust, seismic activity, etc. as based on a directive* issued by NISA to be used for reevaluating the possibility of faults and other activity. This is to announce that today Chubu Electric Power submitted its report to NISA.
1. Content of Nuclear and Industrial Safety Agency directive
Members of the nuclear power industry were directed to study the amount of change in the earth's crust and circumstances of earthquakes since the earthquake of March 11, 2011 within the necessary distance, based on, for example, faults that were judged to have not been considered in terms of seismic design. They were also directed to perform geological reconnaissance and report the results in cases where it could not be ruled out that the fault should have been considered.
2. Report content
At the Hamaoka Nuclear Power Station, Chubu Electric Power studied the amount of change in the earth's crust resulting from earthquakes since March 11, 2011, as well as the circumstances of those earthquakes along faults that had not been considered in terms of seismic design, and investigated the possibility that any of these faults should have been considered.
The investigation was based mainly on public data such as GPS observations of the Geospatial Information Authority of Japan (GSI), hypocenter distribution from the Japan Meteorological Agency and evaluations done by the Headquarters for Earthquake Research Promotion Earthquake Research Committee.
The results indicated that in the vicinity of the Hamaoka Nuclear Power Station, since no remarkable change was found in strain caused by changes in the earth's crust or in the circumstances of earthquakes since March 11, 2011, there are no new faults that need to be considered. We judged that the results would not affect our judgment of faults, etc. that had not been considered in terms of seismic design as reported to NISA on May 31, 2011.
Chubu Electric Power will continue to gather information on these earthquakes, and any new knowledge will be properly reflected in future evaluations.
* Nuclear and Industrial Safety Agency (Ministry of Economy, Trade and Industry) Directive: "Regarding the response to the addition of opinions upon considered by NISA in relation to the report of the evaluation results on seismic safety of existing nuclear power reactor facilities etc. in light of the new Seismic Regulatory Guide for based on the 2011 Tohoku District -Off the Pacific Ocean Earthquake (Additional Directive)" (June 03, 2011, NISA No.1).