05000338/FIN-2010006-01
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Finding | |
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| Title | Failure to Remove Particulate Insulation to Meet Strainer Performance Requirements |
| Description | In August 2006, Atomic Energy Canada Limited (AECL) performed testing of potential containment debris loading. Cal-Sil and Microtherm insulation produced debris-induced head losses above the allowable values for the planned design for the RS and LHSI containment sump strainers. VEPCO implemented DC 07-004 in the spring, 2007 to remove Cal-Sil and Microtherm insulation from Unit 2 and also implemented DC 05-014 to install the modified containment sump strainers. VEPCO implemented DC 07-129 in fall 2007 to remove undesired insulation from Unit 1, and DC 05-013 to install modified containment sump strainers. On February 29, 2008, VEPCO submitted a supplemental response for North Anna Units 1 and 2 for NRC GL 2004-02. The submittal included a list of corrective actions including the removal of all Microtherm insulation from Unit 2. Unit 1 was identified as having no Microtherm insulation inside containment. In November 2008 VEPCO implemented and completed field changes to DC 05-013 (Unit 1) and DC 05-014 (Unit 2) to update the North Anna licensing basis to meet the requirements of with GL 2004-02 (except for in-vessel effects). The NRC reviewed and accepted VEPCOs response to GL 2004-02 with the exception of in-vessel effects in a letter dated May 28, 2009. The team did not identify an immediate safety concern for this issue of concern because both units were shutdown at the time of this inspection activity. The team monitored licensee activities during the inspection weeks and noted these activities were focused on the removal of all the Microtherm insulation identified in both units. The team determined that the licensee has performed a reasonable search to identify Cal-Sil and Microtherm insulation inside containment and has either removed the insulation or properly analyzed leaving it in containment. The team determined additional inspection was required to determine if a performance deficiency existed. In order to properly disposition this issue of concern, additional inspection would be required to better understand: 1) the licensees formal cause determinations for how both Cal-Sil and Microtherm insulation in both units was originally missed; 2) planned licensee corrective actions to address any potential programmatic issues identified in the formal cause determinations; 3) NRC reliance on correspondence between NRC and VEPCO related to GL-2004-02; and 4) NRC understanding of the licensees design as documented in the current Safety Evaluation Report for North Anna Units 1 and 2. This issue of concern was identified as URI 05000338/339/2010006-01, Failure to Remove Particulate Insulation to Meet Strainer Performance Requirements. |
| Site: | North Anna  |
|---|---|
| Report | IR 05000338/2010006 Section 4OA5 |
| Date counted | Dec 31, 2010 (2010Q4) |
| Type: | URI: |
| cornerstone | No Cornerstone |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 93812 |
| Inspectors (proximate) | E Crowe G Mccoy J Earglew Pursleya Alen A Nielsen A Sengupta C Fletcher D Mas G Kolcum G Macdonald G Mccoy J Reece M Cain M Speck M Yoo R Carrion R Clagg R Hamilton R Kellner S Sandal |
| INPO aspect | |
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Finding - North Anna - IR 05000338/2010006 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Finding List (North Anna) @ 2010Q4
Self-Identified List (North Anna)
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