Regarding the inadequate equipment maintenance (some equipments being not inspected at the specified timing of inspection)* found at Kashiwazaki-Kariwa Nuclear Power Station, we submitted a report including the results of investigation on the inspection plans at our nuclear power stations, cause of this issue and recurrence prevention measures to the Nuclear and Industrial Safety Agency (NISA) of the Ministry of Economy, Trade and Industry on February 28, 2011.
On March 2, 2011, NISA judged this matter (inadequate equipment maintenance) to be a noncompliance to the technical specification for the nuclear reactor facility of our nuclear power stations, and instructed us to investigate the root cause and discuss recurrence prevention measures for this issue and report the results.
In our root cause analysis, 20 cases (representative cases attributable to the same cause per each operation process) were selected. We submitted an interim report including our plan to conduct organizational factor extraction and discuss recurrence prevention measures to NISA on August 13, 2012. (Previously announced on August 13, 2012)
After reviewing the cases selected when the interim report was created, 22 representative cases were selected for direct factor/organizational factor extraction and recurrence prevention measures were discussed.
A report addressing the root cause of the issue and recurrence prevention measures has been submitted to the Nuclear Regulatory Authority today. We will make efforts in implementing the recurrence prevention measures developed in order to improve operation quality.
Attachment
"Direct Cause, Root Cause Attributed to the Organizational System and Recurrence Prevention Measures of the Technical Specification Noncompliance Due to Inadequate Equipment Maintenance at Kashiwazaki-Kariwa Nuclear Power Station, Fukushima Daiichi Nuclear Power Station and Fukushima Daini Nuclear Power Station (Outline)" (PDF 112KB)
* Inadequate equipment maintenance (some equipments being not inspected at the specified timing of inspection)
At the third technical specification inspection in 2010 conducted by NISA (which started on November 30, 2010), some equipments were found to have been not inspected at the specified timing of inspection. In response to this, we received a direction from NISA to investigate for similar cases at our nuclear power stations on December 21, 2010. We reported our investigation results, identified cause and recurrence prevention measures on February 28, 2011.
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