NISA indicated that regarding maintenance system for main facilities (7 facilities)^*1 which were needed to maintain the stable cold shutdown of water injection system for reactor pressure vessels and primary containment vessels, some parts of required maintenance plan such as frequency and contents of maintenance has not been formulated. On March 19, 2012, we received an instruction document^*2 from the Nuclear and Industrial Safety Agency (NISA) of the Ministry of Economy, Trade and Industry. On the inspection in FY2011, NISA pointed out the violation of Chapter 132 (Maintenance) in Safely Regulation on this event.

With this event, NISA indicated as below.

On Chapter 132 of the safety regulation, it is ruled that a maintenance method by equipment /facility and a maintenance plan which provides the maintenance method (if necessary, includes preparation of consumables) should be formulated based on the manual. On the inspection, regarding main facilities (7 facilities) which are necessary for maintaining the stable cold shutdown of water injection system for reactor pressure vessels and primary containment vessels, it was found that some parts of the required maintenance plan had not been formulated and the management system for consumables and spare parts had some deficiencies. As a result, NISA judged that some of the important processes had not been conducted in the maintenance for the 7 facilities and considered this as a violation of safety regulation.

(Press release issued on March 19, 2012)

On April 19, 2012, we submitted a report regarding the cause of the safety regulation violation and necessary prevention countermeasures to NISA.

(Press release issued on April 19, 2012)

Today, we received an instruction document^*3 from NISA titled "Safety Regulation Violation Found during the First FY2011 Safety Inspection at TEPCO Fukushima Daiichi Nuclear Power Station (Additional Instructions)". Based on this document, we will make our every effort in implementing necessary measures to follow the instructions.

End

*1 Main facilities (7 facilities)
(1) Water injection system for reactor pressure vessels and primary containment vessels
(2) Function of PCV to prevent a hydrogen explosion
(3) Spent fuel pool
(4) Injection system of boric acid solution for RPV and PCV
(5) Highly concentrated contaminated water decontamination facility, accumulation system (tank), spent sludge storage facility, cesium absorption tower and affiliated facility (transfer pipes transfer pumps)
(6) Buildings in which highly concentrated contaminated water is stored or accumulated
(7) Electrical systems

*2 Instruction document
"Safety Regulation Violation at TEPCO Fukushima Daiichi Nuclear Power Station (Instructions)" (March 15, 2012, NISA, No.4)

*3 Instruction document
"Safety Regulation Violation Found during the First FY2011 Safety Inspection at TEPCO Fukushima Daiichi Nuclear Power Station (Additional Instructions)" (June 19, 2012, NISA, No.2)

The instruction documents are only available in Japanese. We apologize for any inconvenience this may cause.