United States Nuclear Regulatory Commission - Protecting People and the Environment

Additional NRC Oversight at Pilgrim Nuclear Power Plant


Photograph of Pilgrim Nuclear Power PlantPilgrim Nuclear Power Station, in Plymouth, Mass., was under enhanced oversight by the NRC from 2015 to 2019. Specifically, in September 2015, the agency announced the finalization of a "White" (low to moderate safety significance) inspection finding that stemmed from issues involving the plant's safety relief valves (ML15230A217). Based on that enforcement action, in combination with two earlier "White" findings received by the plant, the NRC moved Pilgrim to Column 4 of the agency's Action Matrix, which dictates the agency's level of oversight at plants (ML15243A259).

The NRC embarked on a review process that entailed three phases and numerous hours of inspection to review the causes for Pilgrim's performance decline and the actions included in Entergy's recovery plan (ML16060A018, ML16144A027, ML17129A217). Following the completion of the NRC's phased review process, the NRC issued a Confirmatory Action Letter outlining the actions that Pilgrim was expected to complete before the NRC would consider moving the plant out of Column 4 (ML17214A088).

The NRC inspection of the adequacy and effectiveness of Entergy's completion of the actions included in the Confirmatory Action Letter was completed during five quarterly team inspections conducted between December 2017 and January 2019 (ML18032A463, ML18164A224, ML18282A039, ML18305A834, ML19023A057). The last of the five inspections, completed in January 2019, determined that all actions committed to in the Confirmatory Action Letter were complete and effective.

In February 2019, the NRC completed its end-of-cycle assessment of Pilgrim's performance in 2018. The NRC determined that Entergy had adequately addressed the Action Matrix inputs that led to Pilgrim's placement in Column 4; satisfactorily completed all Recovery Plan items identified in Enclosure 2 of the Pilgrim Confirmatory Action Letter; and that Pilgrim had demonstrated sustained performance improvement throughout 2018. The 2018 Annual Assessment Letter was issued on March 4, 2019, and communicated the assessment results (ML19063A126). As of the date of the letter, the Pilgrim Confirmatory Action Letter was closed, and the NRC transitioned Pilgrim out of Column 4 into the Licensee Response Column (Column 1) of the ROP Action Matrix.

For more information based on official correspondence, see the Communications tab.


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The NRC determined that the performance at Pilgrim was in the Multiple/Repetitive Degraded Cornerstone Column (Column 4) of the Reactor Oversight Process (ROP) Action Matrix at the beginning of the first quarter of 2015 after a White finding under the Mitigating Systems Cornerstone was issued on September 1, 2015, that was associated with a safety relief valve failure that occurred in January 2015 (ML15230A217). Pilgrim had already been in the Degraded Cornerstone Column (Column 3) of the ROP Action Matrix for more than five consecutive quarters as of Jan. 1, 2015. This was due to two open White inputs under the Initiating Events Cornerstone that were caused by "greater-than-green" performance indicators that resulted from a high number of unplanned scrams in 2013. In Supplemental Inspection Report 05000293/2014008 (ML15026A069), dated Jan. 26, 2015, the NRC noted that Pilgrim did not adequately evaluate the causes or take timely corrective actions to address the issues associated with the high number of unplanned scrams in 2013. As a result, the two White inputs under the Initiating Events Cornerstone remained open for greater than five consecutive quarters and were in effect when the new White finding under the Mitigating Systems Cornerstone was identified in March 2015, per Special Inspection Report 05000293/2015007 (ML15147A412), dated May 27, 2015. The duration of the original inputs combined with the repetitive nature of the new White finding highlighted persistent weaknesses in the Pilgrim Corrective Action Program that had contributed to repeated unplanned scrams and equipment failures that were consistent with "Repetitive Degraded Cornerstone" as defined in NRC Inspection Manual Chapter (IMC) 0305, "Operating Reactor Assessment Program."

For more information based on official correspondence, see the Communications tab.

Inspection Approach

In accordance with the NRC's Reactor Oversight Process, subsequent to Pilgrim's entry into Column 4 of the Action Matrix, the NRC conducted a three-phased supplemental inspection using Inspection Procedure (IP) 95003, "Supplemental Inspection for Repetitive Degraded Cornerstones, Multiple Degraded Cornerstones, Multiple Yellow Inputs or One Red Input." Phase 'A' was conducted during the week of Jan. 16, 2016 (ML16060A018), and Phase 'B' was completed during the week of April 4, 2016 (ML16144A027). Phase 'C' entailed three weeks of onsite inspection, which were completed between November 2016 and January 2017 (ML17129A217). A public exit meeting with the licensee was conducted on March 21, 2017, at the Plymouth Memorial Hall to discuss the preliminary results of the inspection (ML17103A413).

Based on the plant's persistent corrective action program weaknesses, the 95003 supplemental inspection focused on the Pilgrim corrective action program and safety culture assessment (reference sections 02.02 and 02.07 through 02.09 of IP 95003). Under the affected Strategic Performance Area of Reactor Safety of the Reactor Oversight Program, NRC supplemental inspections at Pilgrim focused on the key attributes of human performance, procedure quality and equipment performance. The NRC used baseline inspections to sample and assess the other key attributes within the Reactor Safety area -- design, configuration control and emergency response -- and confirmed that performance within these attributes remained acceptable.

The NRC's Region I office conducted quarterly performance assessments of Pilgrim while the plant was in Column 4. The NRC also increased the number of baseline inspection activities performed at Pilgrim and conducted targeted Problem Identification and Resolution samples focused in the areas of previous performance issues.

The Phase 'A' and 'B' inspections were conducted in accordance with IP 95003, Section 02.02, and served as partial completion of this portion of the IP. Phase 'A' reviewed various aspects of the plant's CAP to determine whether continued operation of Pilgrim was acceptable and whether additional regulatory actions were necessary to arrest declining plant performance. Phase 'B' looked at overall corrective action program performance since the last problem identification and resolution inspection completed in August 2015. It focused on progress in improving the plant's performance in the area of corrective actions.

The results of the 'A' and 'B' phases, along with insights from recent baseline and team inspections, informed the final scope for the Phase 'C' inspection, which completed the remaining requirements of the IP 95003 inspection procedure. The inspection provided an in-depth review of Entergy's root cause evaluation and Recovery Plan and also completed an independent review of what led to the decline in plant performance. Based on the results of the IP 95003 inspection and the actions Pilgrim completed to address NRC concerns identified during the IP 95003 inspection, the NRC identified the key corrective actions from the Pilgrim Recovery Plan and issued a Confirmatory Action Letter to document these commitments. The commitments listed in the Confirmatory Action Letter were required to be completed before the NRC would consider transitioning Pilgrim out of Column 4.

For more information based on official correspondence, see the Communications tab.

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Assessment:

In February 2019, the NRC completed its 2018 End-of-Cycle performance assessment for Pilgrim. For this assessment the NRC staff considered the results of NRC inspections, including the five team inspections performed to follow up on the Confirmatory Action Letter commitments, plant performance indicators, safety equipment reliability, Entergy's decision-making and response to plant events, and enforcement actions since Pilgrim was placed in Column 4, as described in the Sept. 1, 2015, follow-up assessment letter (ML15243A259).

In accordance with the criteria established in Inspection Manual Chapter (IMC) 0305, "Operating Reactor Assessment Program," and the Pilgrim Confirmatory Action Letter (ML17214A088) for transitioning from the Multiple/Repetitive Degraded Cornerstone Column (Column 4) of the Reactor Oversight Process Action Matrix, the NRC determined that Entergy addressed all of the Action Matrix inputs that led to Pilgrim's placement in Column 4; satisfactorily completed all Recovery Plan items identified in Enclosure 2 of the Pilgrim Confirmatory Action Letter; and that Pilgrim had demonstrated sustained performance improvement throughout 2018 (ML19063A126). Therefore, as of the date of the 2018 Annual Assessment Letter, the Pilgrim Confirmatory Action Letter was closed, and the NRC transitioned Pilgrim out of Column 4 into the Licensee Response Column (Column 1) of the Action Matrix. Because all inspection findings had very low safety significance (i.e., Green), and all performance indicators in 2018 remained within the expected range (i.e., Green), the NRC plans to conduct ROP baseline inspections at Pilgrim in 2019.

Completed Activities:

The NRC completed an Inspection Procedure (IP) 95003 inspection, as required for all Column 4 plants. The inspection was conducted in three phases ('A' through 'C') (ML15352A128). The Phase 'A' and 'B' inspections were completed in January and April of 2016, respectively (ML16060A018 and ML16144A027). These inspections reviewed aspects of the Pilgrim corrective action program and determined that Pilgrim continued to operate safely, that continued operation was acceptable, and that additional regulatory action was not required. The Phase 'C' inspection team completed three weeks of on-site inspection on Jan. 13, 2017, a public exit meeting was held on March 21, 2017, and the inspection report issued on May 10, 2017 (ML17129A217).

On Aug. 2, 2017, the NRC issued a Confirmatory Action Letter (CAL) (ML17214A088) addressing the corrective actions that needed to be completed before the NRC considered transitioning Pilgrim out of Column 4 of the ROP Action Matrix. The five quarterly CAL follow-up team inspections assessed Entergy’s progress in completing these corrective actions. The inspections were completed between December 2017 and January 2019. The final CAL follow-up inspection report was issued on Jan. 23, 2019 (ML19023A057). The result of these inspections concluded that all actions were satisfactorily completed by Pilgrim and were effective in accordance with the measures established by the Pilgrim Recovery Plan (ML17212A571).

The Pilgrim 2018 Annual Assessment Letter (ML19063A126) was issued on March 4, 2019. The letter returned Pilgrim to Column 1 as of the date of the letter, based on the results of the NRC inspection and assessment activities.

Planned Activities:

Although Pilgrim has returned to Column 1 of the Action Matrix the NRC will continue to conduct quarterly reviews of the performance with senior regional management and more frequent management site visits to monitor Pilgrim's transition from an operating plant to a decommissioning plant.

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Page Last Reviewed/Updated Tuesday, March 19, 2019