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The inspectors identified a finding of ver … The inspectors identified a finding of very low safety significance and associated NCV of 10 CFR Part 50, Appendix B, Criterion V, Instructions, Procedures, and Drawings, for the licensees failure to provide adequate procedures for flow balancing of the ESW System. Specifically, the ESW flow balance procedure did not include acceptance criteria to limit or evaluate minimum throttle valve seat to disc clearance, and subsequent potential for clogging if the clearance was set less than the screen mesh size (1/16 inch) of the upstream ESW strainer. At least one throttle valve in the system (V13-48 for High Pressure Coolant Injection room cooler Train B) was determined to had been set below this screen mesh size. The licensee performed a prompt operability determination for this room cooler and concluded with reasonable assurance that the throttle valve currently had a clearance dimension of at least 1/16 inch. The licensee entered the issue into their Corrective Action Program to correct the flow balance procedure as necessary. Additionally, during the next scheduled flow balancing of the ESW system in September 2014 the licensee will confirm that this valve is open at least 1.2 turns (minimum required for a seat clearance of 1/16 inch). The inspectors determined the performance deficiency was more than minor because, if left uncorrected, it would have the potential to lead to a more significant safety concern. Specifically, material small enough to pass the strainers could choke flow downstream of V13-48 or other throttle valves, thus preventing one or more ESW cooled components from performing their safety-related function. The inspectors assessed this finding for significance in accordance with NRC Manual Chapter 0609, Appendix A, Attachment 1, Significance Determination Process (SDP) for Reactor Inspection Findings for At-Power Situations, and determined that it was of very low safety significance (Green), in that no actual loss of safety system function was identified due to existing system conditions. The inspectors did not identify a cross-cutting aspect associated with this finding because the finding was not representative of the licensee's current performance.ive of the licensee's current performance.

Discovered date

23:59:59, 30 September 2014 +

Docket

05000331 +

Event date

23:59:59, 30 September 2014 +

Finding integer

5 +

Finding type

Non-cited violation +

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Identified by

NRC identified +

Inspection Manual Chapter

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

Inspection procedure

IP 71111.21 +

Inspection report

IR 05000331/2014008 +

Inspector

Ann Marie Stone +, C Edwards +, N Valos +, J Chiloyan +, Benny Jose +, Alan Dahbur + and Jonathan Braisted +

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>.

12:59:16, 25 September 2017 +

Person