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A finding of very low safety significance … A finding of very low safety significance (Green) and associated non-cited violation (NCV) of 10 CFR 50, Appendix B, Criterion V, Instructions, Procedures and Drawings, was self-revealed through repetitive low pressure alarms on a recently overhauled control rod drive (CRD) hydraulic control unit (HCU) accumulator. Specifically, the work instructions for overhaul of the HCU for CRD 2-0305-34-59 were not appropriate to the circumstances in that the wrong part number for the bottom O-ring was listed and as a result, the wrong sized O-ring was installed in the safety related application. The wrong O-ring allowed nitrogen pressure to leak out of the HCU accumulator after the HCU was returned to service. After the part discrepancy was identified, the licensee stopped all work on the HCU until the parts list was corrected and the procedure was updated to add the catalogue identification number for each part to the applicable steps. The HCU overhaul was completed and retested satisfactorily. An extent of condition review was performed to identify and evaluate other potential instances where the parts list may have been used. The inspectors determined that the development and implementation of an informal parts list was a significant contributor to the performance deficiency and identified that this issue had a cross-cutting aspect in the area of Human Performance Work Control in that the licensee did not plan the activity with sufficient rigor to support long-term equipment reliability without reliance on manual actions (H.3(b)). This performance deficiency was determined to be more than minor because it adversely affected the Mitigating Systems Cornerstone objective to ensure availability, reliability, and capability of mitigating systems for the Equipment Performance attribute because frequent manual operator actions were required to be taken to maintain reliability of the affected accumulator. The inspectors determined the finding could be evaluated using the Significance Determination Process in accordance with IMC 0609, Appendix A, The Significance Determination Process (SDP) For Findings At-Power. The inspectors answered No to all questions of Exhibit 2, Mitigating Systems Screening Questions, Section C Reactivity Control Systems, and therefore, the finding screened as Green or very low safety significance. as Green or very low safety significance.

Discovered date

23:59:59, 30 September 2013 +

Docket

05000254 + and 05000265 +

Event date

23:59:59, 30 September 2013 +

Finding integer

1 +

Finding type

Non-cited violation +

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Identified by

Self-revealing +

Inspection Manual Chapter

NRC Inspection Manual 0609/Appendix A, The Significance Determination Process (SDP) for Findings At-Power +

Inspection procedure

IP 71152, Problem Identification and Resolution (PI&R) +

Inspection report

IR 05000254/2013004 +

Inspector

Christine Lipa +, David Jones +, C Mathews +, B Cushman +, Jason Draper +, John Bozga +, Robert Murray +, Valerie Myers +, Luke Haeg +, Matthew Mitchell + and Stephen Bell +

Modification date"Modification date" is a predefined property that corresponds to the date of the last modification of a subject and is provided by <a rel="nofollow" class="external text" href="https://www.semantic-mediawiki.org/wiki/Help:Special_properties">Semantic MediaWiki</a>.

03:47:55, 28 September 2017 +

Person