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On January 31, 2012, Wolf Creek identified … On January 31, 2012, Wolf Creek identified that in-service inspection for the second 10-year period were missed for two valves. Valves BB8379A and BB8379B are chemical and volume control system alternate charging check valves to reactor coolant system loop four. Both are ASME Code Class 1 valves. In 1987, valve BB8379B had a leak at the body-to-bonnet joint and its studs were re-torqued. The valve continued to leak a small amount. Subsequently, valves BB8379A and BB8379B each had a seal cap, or leakage control device, installed on December 9, and 28, 1987, respectively.0 Title 10 CFR 50.55a(g)(4) requires licensees to follow the pressure test requirements of the ASME Code Section XI. ASME Code, Section XI, IWA-5240, requires visual examinations as part of system pressure tests. ASME Code Section XI, IWA-5242, 1998 Edition through 2000 addenda, requires pressure retaining bolted connections for VT-2 visual examinations in borated water systems. Contrary to the above, from September 3, 1995, to the present, Wolf Creek did not perform a visual inspection of the valve body-to-bonnet studs. This finding was more than minor because it impacted the Initiating Events Cornerstone and its attribute of equipment performance. Specifically, it affected the objective to limit the likelihood of those events that upset plant stability and challenge critical safety functions during shutdown as well as power operations. Using Inspection Manual Chapter 0609, Appendix A, The Significance Determination Process (SDP) for Findings At-Power, this finding was determined to be of very low safety significance because an evaluation was able to demonstrate structural integrity. Specifically, stud stress was not sufficiently close to the yield stress to cause a loss of integrity. Therefore, the finding does not contribute to both the likelihood of a reactor trip and the likelihood that mitigation equipment will not be available. The licensee has entered this issue into their corrective action program as condition reports 48493 and 48494. Wolf Creek planned to remove the seal caps and perform the inspection in the next refueling outage.e inspection in the next refueling outage.

Discovered date

23:59:59, 30 June 2012 +

Docket

05000482 +

Equipment trip

Reactor Trip +

Event date

23:59:59, 30 June 2012 +

Finding integer

3 +

Finding type

Non-cited violation +

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Identified by

Licensee-identified +

Inspection Manual Chapter

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

Inspection report

IR 05000482/2012003 +

Inspector

Nestor Makris +, N O'Keefe +, L Ricketson +, A O'Donnell +, C Long +, Louis Carson +, Natasha Greene +, Charley Peabody + and Casey Alldredge +

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>.

15:45:08, 30 May 2018 +

Person