Guidelines for Response in Relation to Ensuring Reliability of External Power Sources for Hamaoka Nuclear Power Station Units No. 1 and 2 (Report in Response to Directive from Nuclear and Industrial Safety Agency, Ministry of Economy, trade and Industry)

Following the Tohoku-Pacific Ocean Earthquake which occurred on March 11, 2011, the Nuclear and Industrial Safety Agency (NISA) issued a directive (*1) concerning measures to ensure the reliability of external power sources for nuclear power stations in operation and under construction. Chubu Electric Power submitted a report to NISA in response to this directive. (Reported May 16, 2011, July 07, 2011, February 17, 2012)  

NISA issued a further directive (*2) to Chubu Electric Power concerning measures to ensure the reliability of external power sources for Hamaoka Nuclear Power Station Units No. 1 and 2 on February 17, 2012.

Based on this directive, Chubu Electric Power today submitted a report to NISA concerning guidelines for response in relation to ensuring the reliability of external power sources for Hamaoka Nuclear Power Station Units No. 1 and 2.

1. Content of Nuclear and Industrial Safety Agency directive

Given that spent fuel from Hamaoka Nuclear Power Station Units No. 1 and 2, presently being decommissioned, is being stored in spent fuel storage facilities, it is considered essential to inspect measures for ensuring the reliability of external power sources based on the status of equipment in the facility.

Report to NISA by March 19, 2012 concerning guidelines for responses in the cases of Units No. 1 and 2 in relation to items indicated in the directive regarding ensuring the reliability of external power sources.

2. Guidelines for response

(1)Hamaoka Unit No. 1

Given that only one spent fuel rod is stored in the spent fuel storage facilities for Unit No. 1, evaluate the effect of radiation exposure on the public in the event of release of the radioactive substances in the spent fuel rod to the exterior, thus verifying that the safety of the facility will be unaffected irrespective of the reliability of external power sources.

(2)Hamaoka Unit No. 2

Given that 1,312 spent and new fuel rods are stored in the spent fuel storage facility for Unit No. 2, evaluate the ability of equipment put in place as part of emergency safety measures to maintain the level of water in the spent fuel pools in these facilities even in the event of a failure of power for water injection and cooling functions, thus verifying that the safety of the facility will be unaffected irrespective of the reliability of external power sources.

Chubu Electric Power will submit a report to NISA when the results of evaluations based on these guidelines have been compiled.

(*1) "Ensuring Reliability of External Power at Nuclear Power Stations and Reprocessing Facilities (Directive)" (4.15.2011 NISA No. 3), issued by the Nuclear and Industrial Safety Agency, Ministry of Economy, Trade and Industry on April 15, 2011; "Regarding Earthquake Countermeasures at Switching Stations, etc., for Ensuring Reliability of External Power Supply to Nuclear Power Stations, etc. (Directive)," (06.07.2011 NISA No. 1), issued by the Nuclear and Industrial Safety Agency, Ministry of Economy, Trade and Industry on June 07, 2011; "Regarding Earthquake Countermeasures at Switching Stations, etc., for Ensuring Reliability of External Power Supply to Nuclear Power Stations, etc. (Additional Directive)" (1.17.2012 NISA No. 1), issued by the Nuclear and Industrial Safety Agency, Ministry of Economy, Trade and Industry on January 19, 2012  

(*2) "Ensuring Reliability of  External Power Sources for Hamaoka Nuclear Power Station Units No. 1 and 2 (Directive)" (02.17.2012 NISA No. 1), issued by the Nuclear and Industrial Safety Agency, Ministry of Economy, Trade and Industry on February 17, 2012