Report on Initiatives to Enhance Seismic Safety at Hamaoka Nuclear Power Station Reactor No. 2
October 29, 2012
Chubu Electric Power Co.,Inc.
This is to announce that Chubu Electric Power, following a directive* of the then-Nuclear and Industrial Safety Agency (NISA) of the Ministry of Economy, Trade and Industry (METI), has compiled the results of its study of enhancing seismic safety at Hamaoka Nuclear Power Station Reactor No. 2 and today submitted its report to the Nuclear Regulatory Authority.
1. Initiatives policy
The reactor building, ground under the reactor building and fuel racks at Hamaoka Nuclear Power Station Reactor No. 2 are essential for assuring the spent fuel cooling function, sub-criticality function and containment function (including shielding), and these functions are in turn essential for ensuring the safety of spent fuel stored in the fuel pool at the reactor. We will confirm the seismic durability margin of the reactor at the target ground motion that was established to increase the seismic durability margins of Reactors No. 3-5 (approx. 1,000 Gal in horizontal direction).
We will also consider margins for ensuring fuel pool water and fuel sub-criticality, and upon doing so will report on measures necessary to increase these margins for safety.
2. Results of check based on initiatives policy
(1) Results of check of seismic durability based on target ground motion
We have confirmed that the reactor building, ground under the reactor building and fuel racks have sufficient seismic durability for the target ground motion.
(2) Consideration of margins for ensuring the safety of spent fuel
We have considered margins for ensuring fuel pool water and spent fuel sub-criticality and have confirmed that the margins are sufficient for ensuring the spent fuel cooling function, sub-criticality function and containment function.
3. Study of measures in light of findings
As noted in the previous paragraph, we have concluded that Hamaoka No. 2 has a sufficient margin of seismic durability, and that no measures are necessary to increase that margin.
* Then-NISA directive: "Regarding Implementation of Initiatives to Increase Seismic Safety at Hamaoka Nuclear Power Station Reactor No. 2," issued by METI's NISA on August 03, 2012 (20120801 NISA No. 3)