05000338/FIN-2007009-02
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Finding | |
|---|---|
| Title | Lack of an Effective Program to Detect and Correct Degredations in Unit 2 Ssps Cards |
| Description | Based on review of past testing records, the team concluded that the licensees program was unable to detect card or component degradation. The licensee did not have a preventative maintenance program or procedure, rather, relied upon the surveillance testing (to verify operability) and system redundancy to ensure availability and reliability. The licensee had a KIMKA automated printed circuit board tester for approximately one year. This tester can detect failed or degraded components on the circuit cards. After the event, the licensee used the tester to identify the failed Zener diode, as well as two other degraded components on the card. The team observed that the licensee initiated an engineering review in 2005 to identify logic cards susceptible to failure which could cause inadvertent transients and/or spurious safety actuations. The review identified 144 SSPS cards from both units (including the universal card A-313 which caused the June 29 spurious SI), that should be evaluated further through a formalized preventative program in order to improve system reliability. The team did not find any evidence that any action was taken to address the susceptibility after this engineering review. Based upon card failures in other systems during 2006 and 2007, the licensees corrective action program identified short term corrective actions that were initiated to review and implement a replacement and refurbishment program for the SSPS cards. The licensees review was completed by March 2007, prior to a Unit 2 refueling outage. The implementation of the program was to be completed within 90 days (June 2007). However, there was no evidence that this program was implemented by the scheduled 15 due date. The inspectors also noted the surveillance procedures for the SSPS cards were not changed. In addition, the team noted that there was no formal maintenance program to identify, trend, or predict failure of degraded components in the SSPS system. The team identified a URI for the lack of an effective program to detect and correct degradations in the Unit 2 SSPS logic cards. This item will remain unresolved pending review and evaluation of the licensees final root cause report, engineering testing data, and diode failure analysis. This URI is identified as 05000339/2007009-02: Lack of an Effective Program to Detect and Correct Degradations in Unit 2 SSPS Cards. |
| Site: | North Anna  |
|---|---|
| Report | IR 05000338/2007009 Section 4OA3 |
| Date counted | Sep 30, 2007 (2007Q3) |
| Type: | URI: |
| cornerstone | Mitigating Systems |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 71153 |
| Inspectors (proximate) | J Rivera-Ortiz G Laska A Vargas-Mendez J Reece J Dodson E Lea R Clagg M Courseyf Ehrhardts Walker J Reece B Mckay |
| INPO aspect | |
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Finding - North Anna - IR 05000338/2007009 | |||||||||||||||||||||||
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Finding List (North Anna) @ 2007Q3
Self-Identified List (North Anna)
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