United States Nuclear Regulatory Commission - Protecting People and the Environment

Frequently Asked Questions About Increased Oversight at Pilgrim Nuclear Power Plant

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Why was Pilgrim in Column 4 of the Action Matrix?

In addition to the "White" finding under the Mitigating Systems Cornerstone, which was identified in the first quarter of 2015, Pilgrim was already in the Degraded Cornerstone Column of the Reactor Oversight Process (ROP) Action Matrix for more than five consecutive quarters as of Jan. 1, 2015, due to two open "White" inputs under the Initiating Events Cornerstone. These "White" inputs involved the failure to address, in a timely manner, the causes of the multiple unplanned shutdowns that occurred in 2013. The coincidence of the longstanding Degraded Initiating Events Cornerstone negative inputs and the new "White" finding under the Mitigating Systems Cornerstone constitute a Multiple/Repetitive Degraded Cornerstone as defined in Inspection Manual Chapter 0305. As a result, the NRC determined that the performance at Pilgrim nuclear power plant was in the Multiple/Repetitive Degraded Cornerstone Column of the ROP Action Matrix as of the beginning of the first quarter of 2015. Therefore, in addition to ROP baseline inspections, the NRC conducted a supplemental inspection in accordance with Inspection Procedure 95003, "Supplemental Inspection for Repetitive Degraded Cornerstones, Multiple Degraded Cornerstones, Multiple Yellow Inputs or One Red Input."

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Did entry into Column 4 mean Pilgrim was unsafe?

No, the specific issues that drove Pilgrim to Column 4 were of low to moderate safety significance. However, Pilgrim did not resolve the issues associated with the Initiating Events Cornerstone in a timely manner. Prior to the resolution of these issues, a "White" finding associated with the Mitigating Systems cornerstone was identified. It indicated the need for additional NRC oversight in order to arrest any further decline in performance. The enhanced NRC oversight, inspection and assessment described in Column 4 allowed the NRC to closely monitor for indications of unacceptable performance. If at any time NRC determined that performance had declined to an unacceptable level, the NRC would have taken additional regulatory action, up to and including the issuance of a shutdown order.

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What was the underlying cause of the performance problems at Pilgrim?

Pilgrim exhibited weaknesses in the Corrective Action Program in terms of identifying, evaluating and completing corrective actions in a timely manner. As a result, Pilgrim experienced equipment problems that led to unplanned scrams/shutdowns and challenges to safety-related equipment. Some of the issues were repetitive in nature, such as loss of off-site power events and Safety Relief Valve failures. The NRC conducted a three-phase diagnostic Supplemental Inspection in accordance with Inspection Procedure 95003. That inspection effort went beyond what the routine baseline inspection program and allowed the NRC to assess Pilgrim's Corrective Action Program (CAP) and obtain an understanding of the depth and breadth of the safety, organizational, and performance issues at the site. For Pilgrim the inspection was conducted in three Phases, 'A' through 'C'. Phases 'A' and 'B' were completed in January and April of 2016, respectively. The onsite portion of Phase 'C' was completed on Jan. 13, 2017. The inspection report was issued on May 10, 2017, and documented the results of the inspection, including a discussion of what the inspection team determined to be the most significant contributors to Pilgrim's poor performance.

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What did the NRC do to ensure that Pilgrim remained safe to operate while these problems were addressed?

The NRC completed the IP 95003 inspection in three phases 'A', 'B' and 'C'. The focus of the first two phases ('A' and 'B') was to ensure that performance at Pilgrim was not continuing to degrade by taking a close examination at recent Pilgrim CAP performance. The results of these inspections determined that Pilgrim remained safe. Phase 'C' of the inspection, the most comprehensive effort, completed the full diagnostic inspection of the causes for the degraded performance. Prior to the completion of Phase 'C', the baseline inspection program and IMC 0305 provide a number of regulatory tools to ensure increased oversight in monitoring for any additional performance decline and to verify that the plant continues to operate safely. For instance, the NRC increased baseline (routine) inspection sampling over and above our normal sampling in some areas, i.e. problem identification and resolution. In addition, the NRC completed quarterly performance reviews regarding Pilgrim that focused on monitoring for potential additional performance decline. If any of these activities identified the need for additional regulatory actions, actions would have been taken and this would have been communicated by letter publicly. The NRC also engaged Entergy with more frequent site visits, and Entergy was required to discuss progress of its performance improvement plan with the Commission at public meetings in June 2016, 2017 and 2018. During this time if there were indications of degrading performance, the NRC would have taken additional regulatory actions, as warranted, including additional supplemental inspections, a demand for information, or issuance of an order, up to and including a plant shutdown.

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Considering Pilgrim's recent poor safety performance, why has the NRC not ordered the plant shutdown?

On Sept. 1, 2015, the NRC issued a "White" finding and Notice of Violation to Pilgrim because Entergy had not adequately addressed a significant equipment problem that caused a failure of one of the plant's Safety Relief Valves in February 2013 and then resulted in a similar failure in January 2015. This issue combined with a failure to adequately address the causes of multiple reactor shutdowns at Pilgrim in 2013 were indications of degrading performance that moved the plant into Column 4 (the "Repetitive Degraded Cornerstone" Column) of the NRC Action Matrix.

During this period, based on the NRC's rigorous oversight and assessment program, the NRC determined that Pilgrim continued to operate safely. The issues that moved Pilgrim into Column 4 were of low to moderate safety significance; and the increased oversight, inspection, and assessment directed by the assessment process for a plant in Column 4 allowed us to closely monitor for indications of unacceptable performance that would require the plant to be moved to Column 5. If at any time it was determined that performance at Pilgrim had declined to an unacceptable level with respect to public safety, the NRC would not have hesitated to take additional regulatory action up to and including the issuance of a shutdown order.

During the period in which Pilgrim was in Column 4, in accordance with Inspection Manual Chapter 0305, Section 10.02e, the following items established the NRC's basis for not moving Pilgrim to Column 5 and issuing a shutdown order:

  1. While in Column 4, there were no additional escalated enforcement violations, and the IP 95003 inspection team identified only one potential greater than Green finding.
  2. While in Column 4, there were not multiple safety significant examples where the licensee was determined to be outside of its design basis. The inspection record did not identify multiple significant performance issues in design and configuration control and the NRC, therefore, concluded was adequate performance in design and configuration control at Pilgrim.
  3. There was not a pattern of failure of licensee management controls to effectively address previous safety significant findings to prevent recurrence.

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How many other plants have been under this level of increased oversight?

Nine since the inception of the Reactor Oversight Process:

  1. Indian Point 2000-2002
  2. Oconee 2002
  3. Cooper 2002-2004
  4. Point Beach 2003-2006
  5. Perry 2004-2007
  6. Palo Verde 2006-2009
  7. Fort Calhoun 2011
  8. Browns Ferry 2011-2014
  9. Arkansas Nuclear One 2014-2018

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What corrective actions did Entergy take to address the loss of offsite power events that have occurred at Pilgrim during winter storms in recent years?

To mitigate the potential for a repeat of previous winter storm events at Pilgrim, the plant has revised procedures to direct operators to place the plant in a safe condition based on impending or in progress weather conditions. The procedure revisions direct operators to take action based on criteria that considers information provided by National Weather Service forecasts and available through the plant's meteorological towers when the weather event is in progress. The information used includes:  winter storm and blizzard watches and warnings, forecasted and actual sustained wind speed and direction, and forecasted and actual snowfall rates.

The actions directed by the procedure based on these criteria, in the most severe cases include plant shutdown and cooldown. Other actions include plant walk downs, pre-emptive power reductions, topping off diesel fuel tanks, manually starting and loading emergency diesel generators and staging additional personnel and emergency response equipment. For the most severe cases, like Winter Storm Juno, the intent of the directed action is to reduce the risk of core damage due to a loss of offsite power by reducing the plant's heat load before the loss of offsite power occurs. Therefore, when weather conditions indicate that the probability of loss of offsite power is high based on the procedure's specified criteria, the procedure changes now direct shutting the plant down and immediately placing the shutdown cooling system in service to cool down to <200°Ϝ. Cooling the plant down to <200°Ϝ significantly reduces the cooling demand on the plants safety equipment and significantly increases the amount of time that the plant can remain safe without off-site power.

Since Winter Storm Juno, the plant has also implemented a temporary modification to increase the reliability of switchyard components during severe winter weather. The modification was intended to minimize the potential for flashover events like the one that occurred during Winter Storm Juno. The modification provides two portable generators and power packs that supply power to nine heat lamps positioned around key breakers and transformers in the switchyard.  These heat lamps are used to warm the bushings associated with this equipment, which prevents snow packing and ice accumulation on the bushings that led to flashover during Winter Storm Juno. Although there is no prior history of use for this type of equipment at other nuclear power plants in this country, there is operating history from at least one fossil plant in western Pennsylvania that indicates some success with this method. In addition the performance of the lamps during this past winter's (2016) storms indicates that they are capable of reducing the likelihood of snow packing and ice accumulation on the bushings.

None of the specific actions completed by Entergy to address these concerns, including the new shutdown criteria, were directed by NRC requirements; however, in accordance with NRC regulations, Entergy was required to take corrective actions to address the problems that occurred during Winter Storm Juno in 2015. The NRC reviewed and inspected Entergy's switchyard modifications and operating procedure changes and determined that they adequately addressed the concerns identified during Winter Storm Juno. The actions taken reduce the probability of a loss of offsite power and significantly reduce the risk of core damage if a loss of offsite power occurs. This, combined with the fact that the plant is designed to cope with the duration of a typical station blackout event for the associated geographic area, ensure that the plant remains safe for these types of events.

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In recent years, Pilgrim has experienced several weather-related unplanned shutdowns, continued issues associated with the switchyard, and a scram in January 2018. How can the NRC continue to conclude that Pilgrim is operating safely?

On-site NRC inspectors have performed reviews of Pilgrim operational performance during recent weather-related events, and through our assessment to date, we have concluded that the site took appropriate actions in response to predicted and actual weather conditions during these events. These actions were performed in accordance with plant procedures, which (as discussed above) were revised following the 2015 events related to Winter Storm Juno.

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The inspection reports keep stating that Entergy is entering these issues into their corrective action program for resolution. How can the NRC have confidence in Entergy's corrective action program to resolve these issues given the results of the last Problem Identification and Resolution inspection?

One of the basic tenets of the Reactor Oversight Process is that licensees identify and correct problems. The Action Matrix describes a graded approach for addressing performance issues and was developed with the philosophy that within a certain level of safety performance, licensees would address their performance issues without additional NRC engagement beyond the baseline inspection program. Pilgrim was not placed in the "Unacceptable Performance Column", (Column 5). Further, the NRC's 2017 biennial Problem Identification and Resolution inspection report noted the following, regarding Entergy's corrective action program (CAP):

"Entergy was generally effective in identifying, evaluating, and resolving problems. Entergy personnel were typically effective at identifying problems and entering them into the CAP at a low threshold. In general, Entergy prioritized and evaluated issues commensurate with the safety significance of the problems. Corrective actions were generally implemented in a timely manner."

The inspection team did note, in several cases, "that the level of detail associated with the documentation of issues being entered into the CAP was less than adequate and as a result challenged Pilgrim's ability to effectively classify and evaluate issues." However, this observation does mean that the NRC has concluded that Entergy's Cap is ineffective.

A licensee's corrective action program would be considered ineffective if the NRC lost confidence in the ability of this program to maintain an appropriate level of safety by correcting adverse conditions. This could be evidenced by significant fundamental weaknesses in most areas of the program (identification, evaluation, resolution), across multiple cornerstones of safety. A corrective action program with significant fundamental weaknesses could manifest itself as a significant event at a station affecting the health and safety of the public, or multiple highly risk significant findings.

At this point, the NRC does not consider Pilgrim's corrective action program to be ineffective.  Previous baseline inspections associated with the corrective action program and the 95003 inspection have determined the program remains generally effective. Additionally, the Confirmatory Action Letter included actions intended to address corrective action program performance issues, and those actions have been confirmed to be complete and adequate through NRC CAL follow-up inspections.

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Will the NRC reduce inspection as the station approaches permanent shutdown, and will Residents remain on-site following permanent shutdown?

NRC Oversight will continue through completion of decommissioning. The NRC will continue to perform inspections and normal oversight of Pilgrim in accordance with IMC 0305, "Operating Reactor Assessment Program," and IMC 2515, "Light Water Reactor Inspection Program – Operations Phase".

  • The resident office will remain staffed through permanent shutdown, and until all fuel is removed from the reactor vessel. Resident inspectors will remain vigilant and continue to conduct ROP baseline inspection activity consistent with other Column 1 plants.
  • The NRC staff will conduct quarterly assessment reviews with senior management to closely monitor and review Pilgrim activities during the approach to permanent shutdown to assure Entergy maintains its focus on the safe operation of the plant. The ROP inspection process allows inspectors to conduct additional focused inspection in areas of concern during this period.

Following permanent shutdown and removal of fuel from the reactor, one Resident Inspector will remain on-site during the transition to decommissioning. This is consistent with recent NRC oversight, as performed at Oyster Creek in late 2018, and Vermont Yankee in early 2015.

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What process was used to evaluate Pilgrim's readiness to exit Column 4?

The process discussed below, including the Supplemental 95003 inspection, the CAL inspection, and the assessment of sustained performance improvement, were conducted in accordance with ROP oversight for a Column 4 plant, as discussed in NRC Inspection Manual Chapter (IMC) 0305, "Operating Reactor Assessment Program"

After Pilgrim was placed in Column 4, in early 2015, Entergy evaluated the performance issues that led to Pilgrim's performance decline and devised a Recovery Plan. In late 2016, the NRC then reviewed the adequacy of Entergy's recovery plan using NRC Supplemental Inspection Procedure (IP) 95003 that included a thorough review of several key performance areas, as well as an independent assessment of the site's safety culture.

In 2018, the NRC conducted follow-up inspections that reviewed Entergy's implementation of its Recovery Plan to ensure the commitments from the Confirmatory Action Letter were met and that the original findings that resulted in the transition to Column 4 were addressed. Then, the results of these inspections were combined with Pilgrim's NRC performance indicator results and the results of other ROP baseline inspections to determine whether there was sufficient evidence to indicate there was sustained performance improvement at Pilgrim.

After all CAL commitments were confirmed complete, and the NRC determined that Entergy has demonstrated sustained performance improvement throughout 2018, and the NRC issued the assessment letter to document Pilgrim's transition from Column 4 back to Column 1 as of March 4, 2019.

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While in Column 4 how much additional inspection effort was committed to Pilgrim as compared to other plants?

Normal baseline inspection activities at the average single unit Column 1 plant in Region I required just under 5,700 hours to complete in 2018. At Pilgrim, in 2018 around 11,300 hours of inspection-related activities were completed. This included approximately 3,800 hours of confirmatory action letter commitment inspections and just over 1,800 hours of additional communication and assessment activities. Considering these numbers in 2018 alone, the activities called for by the heightened oversight for Pilgrim required just over 5,600 hours of additional oversight activities when compared to similar single unit sites operating in Action Matrix Column 1.

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Why is Pilgrim going from Column 4 of the NRC Action Matrix directly to Column 1 of the NRC action matrix?

The NRC Action Matrix describes a graded approach for addressing plant performance issues based on inputs from inspection findings and performance indicators. The Action Matrix can be found in Inspection Manual Chapter (IMC) 0305, as Figure 1. A plant receives additional oversight as it transitions from left (Column 1) to right (Column 5) in the Action Matrix.

Once a plant adequately performs the actions as written in IMC 0305 for the corresponding Action Matrix column, then that plant returns to the Action Matrix column that is represented by its applicable Action Matrix inputs.

In the case of a Column 4 plant such as Pilgrim, the two major milestones to transition from Column 4 to Column 1 are the closure of the Confirmatory Action Letter and the demonstration of sustained improvement. Once a plant transitions to Column 4, the NRC performs a 95003 inspection to determine the causes of degraded performance. Following the inspection, the licensee commits to specific actions to address all of the causes of degraded performance and the commitments are documented in the confirmatory action letter. The NRC inspects the completion of these commitments through Confirmatory Action Letter inspections. During this process, the plant remains in Column 4 unless performance further degrades. If that were to occur, the NRC can transition the plant to Column 5 in the Action Matrix. Throughout this process, the NRC continues to inspect and assess plant performance with baseline inspections. The results of baseline inspections while the plant is in Column 4 are considered in the transition process through demonstration of sustained improvement.

Once the NRC verified Pilgrim successfully completed all 156 items listed in the Confirmatory Action Letter and demonstrated sustained improvement, the NRC determined Pilgrim met the criteria to transition out of Column 4. Once this decision was made, the NRC reviewed the current Action Matrix inputs open at Pilgrim and placed them in the corresponding Action Matrix column. In this case, Pilgrim had all green (very low safety significance) inspection findings and performance indicators therefore, the plant was moved to Column 1, Licensee Response Column, in accordance with IMC 0305 and the Action Matrix.

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Page Last Reviewed/Updated Tuesday, March 19, 2019