Regarding Earthquake Countermeasures at Switching Stations, etc. for Ensuring Reliability of External Power at Hamaoka Nuclear Power Station(Report Concerning Follow-up Directive of METI's NISA)

On July 07, 2011, Chubu Electric Power submitted a report to the Ministry of Economy, Trade and Industry (METI)'s Nuclear and Industrial Safety Agency (NISA) after checking the design tolerance of switching station electric facilities and transformers at Hamaoka Nuclear Power Station. The check and report were in response to the NISA directive,(Note1) which was issued following damage to circuit breakers and other equipment at switching stations at Tokyo Electric Power Co., Inc.'s Fukushima Daiichi Nuclear Power Station when it was shaken by the Tohoku-Pacific Ocean Earthquake of March 11, 2011.

Recently, Tokyo Electric Power reported to NISA about its investigation into the causes of damage, etc. to electric facilities on and off the grounds of the Fukushima Daiichi Nuclear Power Station. NISA on January 19, 2012 issued a directive ordering an evaluation based on this report and also requiring countermeasures and an implementation plan.

In accordance with this directive, Chubu Electric Power determined to conduct a seismic resistance evaluation that uses a possible future earthquake at the Hamaoka Nuclear Power Station as the input seismic motion. This is to report that we submitted the implementation plan for this evaluation to NISA today.

1. Content of NISA follow-up directive

(1) In light of analysis results and causes of damage as revealed in Tokyo Electric Power's follow-up report ("Follow-up Report to ‘Regarding Response in Light of Report on Records Concerning Damage Status, etc., of Electric Facilities on and off the Grounds of the Fukushima Daiichi Nuclear Power Station' (Directive)") (January 19, 2012), NISA requires additional seismic evaluation that uses a possible future earthquake as the input seismic motion on switching station electric facilities and transformers at nuclear power station, etc. and also requires additional countermeasures.

(2) NISA requires that an implementation plan for the evaluation and countermeasures be submitted to NISA by February 17, 2012.

2. Implementation plan

(Note1)NISA directive: "Regarding Earthquake Countermeasures at Switching Stations, etc., for Ensuring Reliability of External Power Supply to Nuclear Power Stations, etc. (Directive)," issued by METI's NISA on June 07, 2011 (06.07.2011 NISA Number 1)

(Note2)If facility seismic evaluation results indicate that countermeasures are necessary, a follow-up report will be sent to the national government after countermeasures are complete.