Back to 2007 listReport Submitted on Hamaoka Nuclear Power Station Reactor No. 4 Seismic Safety Assessment Results as Based on New Seismic Durability Guidelines
January 25, 2007
Chubu Electric Power Co., Inc.
On September 20, 2006, the Nuclear and Industrial Safety Agency sent a letter to Chubu Electric ordering a seismic safety assessment as based on new seismic durability guidelines following the Nuclear Safety Commission's revision of the "Seismic Design Evaluation Guideline for Nuclear Power Reactor Facilities." Chubu Electric subsequently wrote an assessment report and submitted it to the agency on October 18.
(This was previously announced on October 18, 2006.)
Presently Chubu Electric is performing seismic safety assessments under the new seismic durability guidelines at all reactors of the Hamaoka Nuclear Power Station, but today submitted a report to the Nuclear and Industrial Safety Agency with results from the completed evaluation of Reactor No. 4.
The Hamaoka Nuclear Power Station provides adequate seismic safety against standard ground motion S2 with maximum acceleration of 600 gal at bedrock. The results are being checked in a national government safety review which will include many experts and specialists. In addition, the Central Disaster Prevention Council will confirm that there is sufficient seismic safety assurance in the event of the anticipated Tokai earthquake.
Further, a new standard ground motion Ss, consisting of four types, has been decided on in accordance with the new seismic durability guidelines. Of these, although the standard ground motion Ss that causes the greatest maximum acceleration is about the same as standard ground motion S2 in the band where the unique cycles of facilities were concentrated, this standard ground motion exceeds S2 at the shortest cycle end and at the long cycle end, and maximum acceleration reached 800 gal at bedrock.
Presently, we have used the newly created standard ground motion Ss to perform an assessment of Reactor No. 4's facilities critical to seismic resistance, confirming the seismic safety, and we have just reported to the national government.
We are further evaluating the seismic safety of other reactors under the new seismic durability guidelines. The results for Reactor No. 3, which were to have been reported at the same time as those from No. 4, will require more time to compile. We now expect to submit that report in February.
Reference:
Overview of Seismic Safety Assessment Plan for Hamaoka Nuclear Power Station
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