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Significance:
Sep 12, 2008
Identified By: NRC
Item Type: FIN Finding
Failure to Perform Bleeder Trip Valve Testing
The inspectors identified a finding of very low safety significance for Exelon’s failure to complete the testing described in the Updated Final Safety Analysis Report (UFSAR) for one of the third stage feedwater heater bleeder trip valves. Exelon entered this issue into the corrective action program under issue reports (IRs) 772753, 812344, 817399, and 817443, and on August 28, 2008, started testing bleeder trip valve XV-002-108B at the desired frequency stated in the UFSAR.
The inspectors determined that this finding is greater than minor because it is associated with the equipment performance attribute of the Mitigating Systems cornerstone and has the potential to adversely affect the cornerstone objective of ensuring the availability, reliability, and capability of systems that respond to initiating events to prevent undesirable consequences. Not testing the bleeder trip valves in accordance with the statements in the LGS UFSAR adversely impacted the assumptions in LGS’s turbine missile probability analysis thereby potentially increasing the probability for damage to safety-related plant equipment caused by the release of high-energy turbine components. The inspectors evaluated this finding using IMC 0609, Attachment 4, “Initial Screening and Characterization of Findings,” and determined the finding is of very low safety significance. The inspectors also determined that this issue has a problem identification and resolution cross-cutting aspect in the corrective action area because LGS did not thoroughly evaluate the potential impact of an identified problem on the operability of safety-related equipment. Specifically, Exelon did not evaluate the impact that deferred bleeder trip valve testing may have had on the probability that the operability of safety-related equipment could have been impacted by turbine missiles. (P.1(c))
Inspection Report# : 2008009 (pdf)
Significance: Jun 30, 2008
Identified By: NRC
Item Type: NCV NonCited Violation
Failure to Correct Adverse Condition Associated with Motor Operated Valves
The inspectors identified an NCV of Title 10 of the Code of Federal Regulation, Part 20 (10CFR50), Appendix B, Criterion XVI, Corrective Action, for not correcting a condition adverse to quality associated with safety-related motor operated valve motor control center auxiliary contact switches in a timely manner following the failure of the Unit 1 Core Spray Loop A test bypass primary containment isolation valve (HV-052-1F015A) to close on August 3, 2006. As a result, the Unit 2 RCIC turbine exhaust line vacuum breaker outboard primary containment isolation valve (HV-049-2F080) experienced a similar failure to close on June 4, 2008.
The finding was more than minor because it was associated with the structures, systems, and components and barrier containment performance attribute of the Barrier Integrity cornerstone and affected the objective to provide reasonable assurance that physical design barriers protect the public from radionuclide releases caused by accidents and events. The inspector assessed the finding using Phase 1 of IMC 0609, Appendix A, “Significance Determination Process for Reactor Inspection Findings for At-Power Situations” and determined the finding to be of very low safety significance (Green) because the finding did not represent an actual open pathway in the physical integrity of reactor containment. This finding has a cross-cutting aspect of Problem Identification and Resolution because Exelon did not take appropriate corrective actions to address safety issues and adverse trends in a timely manner, commensurate with the safety significance and complexity (P.1(d)). (Section 4OA2)
Inspection Report# : 2008003 (pdf)
Although the NRC is actively overseeing the Security cornerstone, the Commission has decided that certain findings pertaining to security cornerstone will not be publicly available to ensure that potentially useful information is not provided to a possible adversary. Therefore, the cover letters to security inspection reports may be viewed.
Significance: N/A Sep 12, 2008
Identified By: NRC
Item Type: FIN Finding
Identification and Resolution of Problems
The inspectors concluded that Exelon was generally effective in identifying, evaluating, and resolving problems. Specifically, Exelon personnel identified problems, entered them into the corrective action program at a low threshold, and prioritized issues commensurate with the safety significance. For most cases, Exelon appropriately screened issues for operability and reportability and performed causal analyses that appropriately considered extent of condition, generic issues, and previous occurrences. However, for one issue reviewed by the inspectors, an inadequate evaluation resulted in an NRC-identified finding. Corrective actions taken to address the problems identified in Exelon’s corrective action process were typically implemented in a timely manner.
The inspectors also concluded that, in general, Exelon adequately identified, reviewed, and applied relevant industry operating experience to Limerick Generating Station (LGS) operations. In addition, based on those items selected for review by the inspectors, Exelon’s audits and self-assessments were thorough and probing.
Based on the interviews the inspectors conducted over the course of the inspection, observations of plant activities, and reviews of individual corrective action program and employees concerns program issues, the inspectors did not identify any concerns that site personnel were not willing to raise safety issues nor did they identify conditions that could have had a negative impact on the site’s safety conscious work environment.
Inspection Report# : 2008009 (pdf)
Significance: Aug 19, 2008
Identified By: NRC
Item Type: NCV NonCited Violation
Failure to translate preventative maintenance practices described in design calculations used to upgrade the LGS 125 ton Reactor Building Bridge Crane into the approved crane inspection procedures.
A Green non-cited violation (NCV) of 10CFR Part 50, Appendix B, Criterion III, “Design Control” was identified. The NCV was related to the licensee’s failure to translate preventative maintenance practices described in design calculations used to upgrade the LGS 125 ton Reactor Building Bridge Crane into the approved crane inspection procedures.
The finding is more than minor because left uncorrected it could become a more significant safety concern if the crane components were allowed to degrade in an undetected manner. Specifically, the failure to develop the preventative maintenance practices would lead to operation of the crane in a degraded condition.
The inspectors used Inspection Manual Chapter 0609 Appendix M, "Significance Determination Process Using Qualitative Criteria," because other significance determination process guidance was not suited to provide reasonable estimates of the significance of this inspection finding. With the assistance of Region I management, the inspectors determined that the finding was of very low safety significance (Green) because there was no actual crane operation problems during any spent fuel handling activities.
Inspection Report# : 2008006 (pdf)
Last modified : May 01, 2009