Press Release
Report of the Results of Seismic Safety Assessment and Assessment of Ensuring Reliability of External Power Sources for Reactors No. 1 & 2, Hamaoka Nuclear Power Station
March 29, 2012
Chubu Electric Power Co.,Inc.
Chubu Electric Power today submitted to NISA (Nuclear and Industrial Safety Agency) a summary of the results of seismic safety assessment (Note 2) and assessment of ensuring reliability of external power sources for Hamaoka Nuclear Power Station Reactors No. 1 and 2, presently being decommissioned, in light of the New Seismic Durability Guidelines (Note 1).
1 Overview of Seismic Safety Assessment, etc. Report
(1) Reactor No. 1, Hamaoka Nuclear Power Station
Concerning Reactor No. 1, in considering that there is only one spent fuel rod being stored in the spent fuel storage facility of this reactor, in place of a seismic safety assessment of the facilities being conducted, an assessment was conducted on radiation-exposure levels in surrounding communities, based upon a premise of radiation, etc. escaping to the environment outside the facilities from those radioactive materials that are stored within the storage facilities. The levels were confirmed to be under 5 mSv, which is the judgment standard effective dose for an accident specified by the Nuclear Safety Commission (NSC).
(2) Reactor No. 2, Hamaoka Nuclear Power Station
Concerning Reactor No. 2, in considering that there are 1,312 spent and new fuel rods being stored in the spent fuel storage facility of this reactor, seismic safety assessment of the storage facility (Note 3), etc. was carried out, and all the "cooling functions," "sub-criticality functions," and "containment functions" necessary for ensuring safety were confirmed to be unimpaired.
2 Overview of Report in Relation to Ensuring Reliability of External Power Sources for Hamaoka Nuclear Power Station Reactors No. 1 and 2
In review of the above seismic safety assessment, based on the current satus of the facility, it was determined that there is no need for power sources for reactors no. 1 and 2, and that the safety of the facility was unaffected irrespective of the reliability of external power sources.
(Note 1) "Seismic Design Evaluation Guidelines for Power Generation Nuclear Power Reactor Facilities" revised by the Nuclear Safety Commission (NSC) on September 19, 2006.
(Note 2) Instructions issued by the Ministry of Economy, Trade and Industry Nuclear and Industrial Safety Agency (12.22.2009 NISA No. 3) requested seismic safety assessment of the respective facilities and report of the results in light of the New Seismic Durability Guidelines. However, this requirement shall not apply for each respective facility if it is technologically determined that there is no danger of excessive radiation-exposure levels in surrounding communities, even based upon a premise of radiation escaping to the environment outside the facilities from those radioactive materials that are stored within the facilities. Only in such cases, the respective assessment shall be reported instead.
(Note 3) In seismic safety assessments, the standard ground motion Ss (horizontal-motion peak acceleration of 800 cm/s2) found in the "Seismic Safety Assessment Results Report in Response to Revisions of the ‘Seismic Design Evaluation Guidelines for Nuclear Power Reactor Facilities' for Reactor No. 4, Hamaoka Nuclear Power Station" (submitted January 25, 2007) was used.