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The inspectors identified a self-revealing … The inspectors identified a self-revealing finding after Palo Verde Nuclear Generating Station failed to adequately perform maintenance activities associated with main condenser tube sheet coatings in Unit 3. As a result, a degraded tube was not replugged following coating and failed on January 15, 2011, resulting in high sodium levels in the condensate system. Operators entered the abnormal operating procedures for condenser tube rupture and reduced power to 40 percent power to facilitate troubleshooting and repairs. The licensee concluded that Work Order 3384533 and Procedure 31MT-9ZZ19, Tube Plugging of Secondary Heat Transfer Components, did not provide adequate instructions for the removal, accountability, and reinstallation of permanent plugs during maintenance. The licensee also concluded that engineering verification inspection practices were inadequate and no procedural guidance existed for the verification. The licensee completed repairs to the main condenser and returned Unit 3 to full power. The licensee entered the performance deficiency into the corrective action program as Palo Verde Action Request 3580739 and implemented immediate corrective actions to revise the pre-job brief checklist and maintenance work instructions for condenser tube plugging. The licensee has not completed all corrective actions for this issue. The inspectors determined that the performance deficiency is more than minor because it affected the equipment reliability attribute of the Initiating Events Cornerstone and affected the cornerstone 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 NRC Manual Chapter 0609, Attachment 4, Phase 1 - Initial Screening and Characterization of Findings, the inspectors concluded that the finding is of very low safety significance (Green) because it did not contribute to both the likelihood of a reactor trip and the likelihood that mitigation equipment or functions would not be available. This finding had a crosscutting aspect in the area of human performance associated with the resources component because the licensee failed to provide complete, accurate and up-to-date procedures and work packages for tube sheet coating, replugging and verification (H.2(c)).ing, replugging and verification (H.2(c)).

Discovered date

23:59:59, 31 March 2011 +

Docket

05000528 +, 05000529 + and 05000530 +

Equipment trip

Reactor Trip +

Event date

23:59:59, 31 March 2011 +

Finding integer

5 +

Finding type

Finding +

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INPO aspect

WP.3 +

Identified by

Self-revealing +

Inspection Manual Chapter

NRC Inspection Manual 0609 +

Inspection procedure

IP 71153, Event Followup +

Inspection report

IR 05000528/2011002 +

Inspector

Ryan Lantz +, M Baquera +, B Rice +, D Graves +, J Bashore +, Louis Carson +, Ron Kopriva +, Natasha Greene +, Matt Young + and Michael Brown +

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>.

19:05:52, 30 September 2017 +

Person