ML11285A306

Response to NRC Special Inspection Report 05000293-11-012; Preliminary White Finding

ML11285A306
Person / Time
Site:	Pilgrim
Issue date:	10/03/2011
From:	Rich Smith Entergy Nuclear Operations
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
2.11.058, IR-11-012
Download: ML11285A306 (11)

Text

SEn Wgy Entergy Nuclear Operations, Inc.

Pilgrim Nuclear Power Station 600 Rocky Hill Road Plymouth, MA 02360 Robert G. Smith, P.E.

October 3, 2011 Site Vice President United States Nuclear Regulatory Commission Attn: Document Control Desk Washington, D.C. 20555

SUBJECT:

Entergy Nuclear Operations, Inc.

Pilgrim Nuclear Power Station Docket No. 50-293 License No. DPR-35 Pilgrim Nuclear Power Station (PNPS) Response to NRC Special Inspection Report 05000293/2011012; Preliminary White Finding

REFERENCE:

NRC Letter to Robert G. Smith, EA-2011-174, Pilgrim Nuclear Power Station - NRC Special Inspection Report 05000293/2011012; Preliminary White Finding, dated September 1, 2011.

LETTER NUMBER: 2.11.058

Dear Sir or Madam:

The letter provides Entergy's written response to the preliminary white finding identified in the NRC Special Inspection Report 05000293/2011012 (Reference 1). The preliminary white finding is related to the automatic reactor scram event which occurred on May 10, 2011.

Entergy has reviewed the NRC Special Inspection Report. A summary of our review is provided in Attachments 1 and 2.

Entergy has taken this reactor scram event very seriously both at the site and fleet level.

Entergy has internalized the sequence of events leading up to the reactor scram and takes full responsibility for implementing the appropriate corrective actions. Entergy has full confidence in our operating staff, management team and our ability to safely operate the plant.

There are no new commitments made in this letter.

Please contact Mr. Joseph R. Lynch at (508) 830-8403 if there are any questions regarding this response.

Sincerely, Robert G. Smith RGS/JLlfxm

Entergy Nuclear Operations,Inc. Letter Number 2.11.058 PilgrimNuclear Power Station Page 2 - Entergy Response to NRC Preliminary White Finding Related to the Automatic Reactor Scram on Hi-Hi-Flux on May 10, 2011. - Entergy Response to NRC Preliminary White Finding Related to the Automatic Reactor Scram on Hi-Hi-Flux on May 10, 2011, IMC 0609, Appendix M, Table 4.1 cc Mr. William Dean Mr. Richard V. Guzman, Project Manager Regional Administrator, Region I Plant Licensing Branch 1-1 U. S. Nuclear Regulatory Commission Division of Operating Reactor Licensing 475 Allendale Road Office of Nuclear Reactor Regulation King of Prussia, PA 19406-1415 U.S. Nuclear Regulatory Commission Resident Inspector's Office Mail Stop 0-8-C2A U.S. Nuclear Regulatory Commission Washington, DC 20555-0001 Resident Inspector's Office U.S. Nuclear Regulatory Commission

ATTACHMENT 1 to Letter Number 2.11.058 Entergy Response to NRC Preliminary White Finding Related to the Automatic Reactor Scram on Hi-Hi-Flux on May 10, 2011

Entergy Nuclear Operations,Inc. Letter Number 2.11.058 PilgrimNuclear Power Station Attachment 1 NRC Finding Summary Preliminary White: A self revealing finding was identified involving failure of Pilgrim personnel to implement conduct of operations and reactivity control standards and procedures during reactor start-up, which contributed to an unrecognized subcriticality followed by an unrecognized return to criticality and subsequent reactor scram.

The significance of the finding has preliminarily been determined to be White, or of low to moderate significance. The finding is also associated with one apparent violation of NRC requirements specified by Technical Specification 5.4, "Procedures." There was no significant impact on the plant following the transient because the event itself did not result in power exceeding license limits or fuel damage. Additionally, interim corrective actions were taken, which included removing the Pilgrim control room personnel involved in the event from operational duties pending remediation, providing additional training for operators not involved with the event, and providing increased management oversight presence in the Pilgrim control room while long-term corrective actions were developed.

The finding is more than minor because it was associated with the Human Performance attribute of the Initiating Events cornerstone and affected the cornerstone objective of limiting the likelihood of those events that upset plant stability and challenge critical safety functions during power operations. Specifically, the failure of Pilgrim personnel to effectively implement conduct of operations and reactivity control standards and procedures during a reactor startup caused an unrecognized subcriticality followed by an unrecognized return to criticality and subsequent reactor scram. Because the finding primarily involved multiple human performance errors, probabilistic risk assessment tools were not well suited for evaluating its significance. The inspection team determined that the criteria for using IMC 0609, Appendix M,"Significance Determination Process Using Qualitative Criteria," was met, and the finding was evaluated using this guidance.

NRC Baseline Significance Determination Process Review The inspection team evaluated the finding using guidance criteria provided in IMC 0609, Appendix M,"Significance Determination Process Using Qualitative Criteria" because probabilistic risk assessment tools were not well suited to evaluate the multiple human performance errors associated with this issue. Preliminarily, the NRC has determined this finding to be of low to moderate safety significance based on the qualitative assessment.

There was no significant impact on the plant following the transient because the event itself did not result in power exceeding license limits or fuel damage. Additionally, corrective actions were taken which included removing the Pilgrim control room personnel involved in the event from operational duties pending remediation, providing additional training for the operators not involved in the event, and providing increased management oversight presence in the Pilgrim control room while long-term corrective actions were developed.

Attachment 4 to NRC Inspection Report 0500293/2011012 identifies the NRC Significance Determination Process review that was performed.

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Entergy Nuclear Operations,Inc. Letter Number 2.11.058 PilgrimNuclear Power Station Attachment 1 Entergy Response Entergy has taken this reactor scram event very seriously both at the site and fleet level.

Entergy has internalized the sequence of events leading up to the reactor scram and takes full responsibility for implementing the appropriate corrective actions. The primary cause of the event and the cross cutting aspect, as documented in the NRC inspection report, is consistent with the findings of Pilgrim's Root Cause Evaluation (RCE) Report.

Corrective Actions As documented in the RCE, PNPS initiated immediate corrective actions to address the event and to preclude the possibility of similar events occurring in the future. These actions included:

• Retrained crew members on criticality and heating range operation.

• Disqualified involved individuals pending investigation, accountability assessment, and remediation.

• Established interim guidance requiring Operations Management, Reactor Engineering, and Crew review following any negative reactivity addition in STARTUP prior to adding positive reactivity (Standing Order 11-04) prior to 5/11/2011 startup.

• Revised & implemented startup Just-In-Time Training (JITT) to include lessons learned managing heat-up.

• Established immediate Operations Management oversight for 100% of the time in Startup Mode.

• Implemented station senior management oversight program for duration of RFO18 startup

• Implemented Fleet Significant Event Response Team (SERT)

• Coached Reactor Engineers on standards & expectations regarding advocacy &

intrusiveness during reactivity manipulations

• Corrected deficiency associated with control rod 30-11.

• Completed a case study of this event in Operations training to ensure all crews were provided with the event details and lessons learned.

Additional significant corrective actions planned as a result of the event include:

• Implement 200 hours0.00231 days <br />0.0556 hours <br />3.306878e-4 weeks <br />7.61e-5 months <br /> of plant operations department management (including cross crew) control room observations using Entergy Fleet Procedure EN-OP-1 17 and identify gaps to established standards.

" Perform assessments of operations performance and observations from coaching and other oversight input. Review results of observations and corrective actions taken monthly with Site Directors.

• Revise JITT to make heating range a required element of the module and require successful completion of evaluation.

A detailed search of the Entergy Fleet Paperless Condition Reporting System (PCRS) and the INPO Operating Experience (OE) database was conducted for operating experience concerning reactor scrams during startup activities to ascertain whether there has been any commonality to the IRM Hi-Hi Flux scram experienced at Pilgrim Station.

The search found numerous examples of industry operating experience which were applicable to this event. While the causes of this event indicate shortfalls in execution consistent with established standards instead of process weaknesses, site management considers it prudent to perform additional reviews of INPO SOER 10-2 and by extension Page 3 of 5

Entergy Nuclear Operations,Inc. Letter Number 2.11.058 PilgrimNuclear Power Station Attachment ]

INPO SOERs, 07-01 and 96-01. The review will identify any additional corrective actions that may be required. A corrective action has been assigned within the root cause analysis to conduct this review.

Review of the NRC Significance Determination Entergy has reviewed the NRC Special Inspection Report 050000293/2011012 and preliminary white finding determination based upon the qualitative significance determination process found in NRC Inspection Manual Chapter (IMC) 0609, Appendix M. This significance determination identifies that improper use and execution of certain procedures, coupled with weak work control practices, had the potential to increase human error probability for credited operator actions. As documented in our Root Cause Evaluation, we concur that Human Performance was a key contributor to the event of May 10, 2011.

In arriving at the decision to perform a Special Inspection, the NRC utilized the criteria in NRC IMC 0309, "Reactive Inspection Decision Basis for Reactors," because one of the deterministic criteria was met due to concerns pertaining to licensee operational performance. Specifically, certain human performance errors contributed to the unanticipated automatic reactor scram.

Entergy reviewed the risk assessment basis that was documented in the Special Inspection Team Report because it differed from the risk significance conservatively estimated by our Risk Assessment staff who worked closely with the NRC Region 1 SRA staff. Based upon the plant conditions just prior to the event which included a power level of approximately 1.7%, start-up conditions, low decay heat and all safety systems functioned as designed; the resultant conditional core damage probability (CCDP) was determined to be in the high E-7 range. This differed from the CCDP summarized in the Inspection Team Report, but may not have triggered a Special Inspection Team (SIT) in accordance with IMC 0309.

The Special Inspection Team Report goes on further to conclude that the SIT was based upon a combination of both the risk evaluation and the human performance errors that occurred during the event. This in itself does not change the overall risk or consequences of the event, which is important because the overall finding significance within the NRC Significance Determination Process is risk based.

Entergy also performed a review of the IMC 0609, Appendix M qualitative risk criterion, as well as the SIT report documented in Attachment 4 to Special Inspection Report 050000293/2011012. A qualitative assessment of significance for any event can vary based upon the precursors to the event, conservative decision-making during the event and immediate actions taken following the event, so the eight (8) qualitative decision-making attributes in IMC 0609, Appendix M were considered by Entergy and summarized in to this letter.

Entergy concurs with the NRC that the majority of the attributes described in Appendix M are applicable to this event insofar as determining the overall significance of the event. Where Entergy has a differing perspective on a specific attribute, it is documented in Attachment 2 to this letter. Entergy respectfully requests that the NRC Special Inspection Team (SIT) and management consider these differences as well as the overall quantitative risk of this event in determining the final significance determination.

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Entergy Nuclear Operations,Inc. Letter Number 2.11.058 PilgrimNuclear Power Station Attachment 1 Conclusion/Summary Entergy understands the importance of the qualitative decision attributes and their applicability to the overall significance determination for this event. As noted in Attachment 2 to this letter and as discussed above, Entergy offers a differing perspective on certain specific attributes evaluated by the NRC during the Special Inspection. Entergy respectively requests that the NRC Special Inspection Team (SIT) and management consider these differences as well as the overall quantitative risk of this event in determining the final significance determination.

Entergy has internalized the significance of this event and have committed to a comprehensive set of corrective actions to preclude recurrence and raise human performance standards to a new level of excellence. This will include conduct of operations, reactivity control standards, procedural adherence, and management oversight of performance in all plant departments.

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ATTACHMENT 2 to Letter Number 2.11.058 Entergy Response to NRC Preliminary White Finding Related to the Automatic Reactor Scram on Hi-Hi-Flux on May 10, 2011 IMC 0609, Appendix M, Table 4.1

Entergy Nuclear Operations,Inc. Letter Number 2.11.058 PilgrimNuclear Power Station Attachment 2 IMC 0609, APPENDIX M, TABLE 4.1 Qualitative Decision-Making Attributes for NRC Management Review

1. The SDP is the preferred path for determining the significance of Findings in the Reactor Oversight Process (ROP).

2. IMC 0609 Appendix M is used when the existing SDP guidance is not adequate to provide a reasonable estimate of the significance.

Decision Attribute Applicable to Basis for Input to Decision - Provide qualitative Decision? and/or quantitative information for management review and decision- making.

Finding can be bounded No Entergy concurs that this qualitative decision-using qualitative and/or making attribute is not applicable to the quantitative information? significance decision.

Defense-in-Depth affected? Yes Entergy concurs that this qualitative decision-making attribute is applicable to the significance decision.

Performance Deficiency Yes Entergy concurs that this qualitative decision-effect on the Safety Margin making attribute is applicable to the significance maintained? decision.

The extent the performance No The identified performance deficiency did not deficiency affects other degrade physical plant equipment nor equipment. challenged the three fission product barriers.

While the Root Cause Evaluation identified ineffective just-in-time (JIT) training and procedural adherence deficiencies associated with key elements of plant start-up, it is speculative to conclude that operator performance had the potential to adversely affect other plant equipment.

It should be further noted that no operator during this event went outside of his assigned roles and responsibilities, which obviated the potential to affect the operation of equipment, which requires operator manual action to function.

Entergy requests that this qualitative decision-making attribute be reconsidered as an input to the significance decision.

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Entergy Nuclear Operations,Inc. Letter Number 2.11.058 Pilgrim NuclearPower Station Attachment 2 Decision Attribute Applicable to Basis for Input to Decision - Provide qualitative Decision? and/or quantitative information for management review and decision- making.

Degree of degradation of N/A failed or unavailable component(s)

Period of time (exposure No The Entergy Root Cause Evaluation reviewed time) affect on the precursors to this event that had the potential to performance deficiency. explain performance issues contributing to this event. Industry Operating Experience (OE) such as INPO SOER 10-2, SOER 07-01 and self-assessments identified gaps to excellence that contributed to organizational and programmatic weaknesses. These important tools for learning from industry and fleet experience are ongoing, dynamic and are not easily tied back to a specific exposure time.

The SIT report properly characterizes this attribute as complicated by the fact that Pilgrim was not the subject of any significant licensed operator performance issues prior to the May 10, 2011 event. This consistent performance is further reinforced by current and past Human Performance cross-cutting area aspects which have not risen to a theme under the Reactor Oversight Process (ROP).

Entergy requests that this qualitative decision-making attribute be reconsidered as an input to the significance decision because it is not clearly supported by a slow degradation in performance or a decline in observed behaviors.

The likelihood that the Yes Entergy concurs with the NRC conclusions that licensee's recovery actions Entergy's recovery action plan will successfully would successfully mitigate mitigate the performance deficiency.

the performance deficiency.

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Entergy Nuclear Operations,Inc. Letter Number 2.11.058 Pilgrim Nuclear Power Station Attachment 2 Decision Attribute Applicable to Basis for Input to Decision - Provide qualitative Decision? and/or quantitative information for management review and decision- making.

Additional qualitative Yes Entergy has internalized the significance of this circumstances associated event and have committed to a comprehensive with the finding that regional set of corrective actions to preclude recurrence management should and raise human performance standards to a consider in the evaluation new level of excellence. This will include process. conduct of operations, reactivity control standards, procedural adherence, and management oversight of performance in all plant departments.

Entergy will look forward to demonstrating the effectiveness of our corrective actions through NRC baseline inspection activities and through consistent, safe and regulatory compliant operations.

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