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Category:Letter type:RA
MONTHYEARRA-19-091, Commitment Change Summary Report - 20192019-12-27027 December 2019 Commitment Change Summary Report - 2019 RA-19-080, Response to Request for Additional Information (RAI) Related to Oyster Creek Nuclear Generating Station - Post-Shutdown Decommissioning Activities Report2019-10-18018 October 2019 Response to Request for Additional Information (RAI) Related to Oyster Creek Nuclear Generating Station - Post-Shutdown Decommissioning Activities Report RA-19-076, Request for Continuation of NRC Actions and Approvals Following Transfer of the Licenses from Exelon Generation to Holtec Decommissioning International, LLC2019-09-12012 September 2019 Request for Continuation of NRC Actions and Approvals Following Transfer of the Licenses from Exelon Generation to Holtec Decommissioning International, LLC RA-19-065, Signature Verification and Acceptance of Amendment 19 to Indemnity Agreement No B-37 to Renewed Facility License No. DPR-162019-08-28028 August 2019 Signature Verification and Acceptance of Amendment 19 to Indemnity Agreement No B-37 to Renewed Facility License No. DPR-16 RA-19-052, Security Plan, Training Qualification Plan, Safeguards Contingency Plan, (Revision 18)2019-06-11011 June 2019 Security Plan, Training Qualification Plan, Safeguards Contingency Plan, (Revision 18) RA-19-023, Annual Radioactive Effluent Release Report for 20182019-04-30030 April 2019 Annual Radioactive Effluent Release Report for 2018 RA-19-019, Submittal of Changes to Technical Specifications Bases2019-04-12012 April 2019 Submittal of Changes to Technical Specifications Bases RA-19-012, Supplement for License Amendment Request - License Condition Revision for Removal of Cyber Security Plan Requirements2019-03-0707 March 2019 Supplement for License Amendment Request - License Condition Revision for Removal of Cyber Security Plan Requirements RA-19-007, Response to RAI and Supplemental Information Re Request for Changing Emergency Preparedness License Amendment 294 Effective Date (Change to Adiabatic Heat-Up Calculation)2019-02-13013 February 2019 Response to RAI and Supplemental Information Re Request for Changing Emergency Preparedness License Amendment 294 Effective Date (Change to Adiabatic Heat-Up Calculation) RA-19-003, Amendment No. 17 to Indemnity Agreement No. 8-372019-01-0808 January 2019 Amendment No. 17 to Indemnity Agreement No. 8-37 RA-18-103, Annual Sea Turtle Incidental Take Report - 20182018-12-13013 December 2018 Annual Sea Turtle Incidental Take Report - 2018 RA-18-080, License Amendment Request: License Condition Revision for Removal of Cyber Security Plan Requirements2018-11-12012 November 2018 License Amendment Request: License Condition Revision for Removal of Cyber Security Plan Requirements RA-18-098, License Amendment Request Supplement - Proposed Change of Effective and Implementation Dates of License Amendment No. 294, Oyster Creek Emergency Plan for Permanently Defueled Emergency Plan and Emergency Action Level Scheme2018-11-0606 November 2018 License Amendment Request Supplement - Proposed Change of Effective and Implementation Dates of License Amendment No. 294, Oyster Creek Emergency Plan for Permanently Defueled Emergency Plan and Emergency Action Level Scheme RA-18-097, Exelon Nuclear Radiological Emergency Plan and Addendum Revisions2018-10-24024 October 2018 Exelon Nuclear Radiological Emergency Plan and Addendum Revisions RA-18-092, License Amendment Request - Proposed Change of Effective and Implementation Dates of License Amendment No. 294, Oyster Creek Emergency Plan for Permanently Defueled Emergency Plan and Emergency Action Level Scheme2018-10-22022 October 2018 License Amendment Request - Proposed Change of Effective and Implementation Dates of License Amendment No. 294, Oyster Creek Emergency Plan for Permanently Defueled Emergency Plan and Emergency Action Level Scheme RA-18-093, Request to Reinitiate Consultation Regarding the OCNGS Sea Turtle Incidental Take Statement2018-10-16016 October 2018 Request to Reinitiate Consultation Regarding the OCNGS Sea Turtle Incidental Take Statement RA-18-091, Request to Reclassify Oyster Creek Nuclear Generating Station Under 10 CFR 171.15, Annual Fees: Reactor Licenses and Independent Spent Fuel Storage Licenses2018-10-0101 October 2018 Request to Reclassify Oyster Creek Nuclear Generating Station Under 10 CFR 171.15, Annual Fees: Reactor Licenses and Independent Spent Fuel Storage Licenses RA-18-090, Notice Regarding Proposed Amendment No. 1 to Master Terms for Decommissioning Trust Agreements2018-10-0101 October 2018 Notice Regarding Proposed Amendment No. 1 to Master Terms for Decommissioning Trust Agreements RA-18-083, Certification of Permanent Removal of Fuel from the Reactor Vessel for Oyster Creek Nuclear Generating Station2018-09-25025 September 2018 Certification of Permanent Removal of Fuel from the Reactor Vessel for Oyster Creek Nuclear Generating Station RA-18-088, Radiological Emergency Plan Addendum Revision. Includes EP-AA-1010, Addendum 3, Revision 4, Emergency Action Levels for Oyster Creek.2018-09-25025 September 2018 Radiological Emergency Plan Addendum Revision. Includes EP-AA-1010, Addendum 3, Revision 4, Emergency Action Levels for Oyster Creek. RA-18-087, Response to Request for Additional Information (RAI) Related to Post-Shutdown Decommissioning Activities Report2018-09-24024 September 2018 Response to Request for Additional Information (RAI) Related to Post-Shutdown Decommissioning Activities Report RA-18-084, Secondary Containment Capability Test2018-09-14014 September 2018 Secondary Containment Capability Test RA-18-078, Submittal of Sea Turtle Incidental Take Report 2018-0042018-08-15015 August 2018 Submittal of Sea Turtle Incidental Take Report 2018-004 RA-18-077, Sea Turtle Incidental Take Report 2018-0032018-08-14014 August 2018 Sea Turtle Incidental Take Report 2018-003 RA-18-072, Pressure and Temperature Limit Report Revision 12018-06-29029 June 2018 Pressure and Temperature Limit Report Revision 1 RA-18-066, Response to Questions Pertaining to Licensed Operator2018-06-18018 June 2018 Response to Questions Pertaining to Licensed Operator RA-18-070, Submittal of Sea Turtle Incidental Take Report 2018-001 on June 04, 20182018-06-0808 June 2018 Submittal of Sea Turtle Incidental Take Report 2018-001 on June 04, 2018 RA-18-068, Response to Request for Additional Information (RAI) Regarding Request for Approval of Decommissioning Quality Assurance Program, Revision 0 for Oyster Creek Nuclear Generating Station2018-06-0606 June 2018 Response to Request for Additional Information (RAI) Regarding Request for Approval of Decommissioning Quality Assurance Program, Revision 0 for Oyster Creek Nuclear Generating Station RA-18-065, Registration of Use of Cask to Store Spent Fuel2018-05-31031 May 2018 Registration of Use of Cask to Store Spent Fuel RA-18-059, Request for Relief and Rescission of Commission Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events2018-05-30030 May 2018 Request for Relief and Rescission of Commission Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events RA-18-055, 10 CFR 50.46 Annual Report2018-05-23023 May 2018 10 CFR 50.46 Annual Report RA-18-053, Update to Spent Fuel Management Plan2018-05-21021 May 2018 Update to Spent Fuel Management Plan RA-18-052, Supplement to Request for Exemption from 10 CFR 50.54(w)(1), Concerning On-Site Property Damage Insurance and Supplement to Request for Exemption from 10 CFR 140.11(a)(4), Concerning Primary and Secondary ...2018-05-0808 May 2018 Supplement to Request for Exemption from 10 CFR 50.54(w)(1), Concerning On-Site Property Damage Insurance and Supplement to Request for Exemption from 10 CFR 140.11(a)(4), Concerning Primary and Secondary ... RA-18-049, Registration of Use of Cask to Store Spent Fuel2018-05-0707 May 2018 Registration of Use of Cask to Store Spent Fuel RA-18-046, Oyster Creek, Transmittal of Annual Radiological Environmental Operating Report for 20172018-04-30030 April 2018 Oyster Creek, Transmittal of Annual Radiological Environmental Operating Report for 2017 RA-18-047, Annual Radioactive Effluent Release Report for 20172018-04-30030 April 2018 Annual Radioactive Effluent Release Report for 2017 RA-18-018, Submittal of Changes to Technical Specifications Bases2018-04-13013 April 2018 Submittal of Changes to Technical Specifications Bases RA-18-021, Request for Exemption from Record Retention Requirements2018-04-12012 April 2018 Request for Exemption from Record Retention Requirements RA-18-028, Request for Rescission of Commission Order Modifying License with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions (Order Number EA-13-109)2018-04-12012 April 2018 Request for Rescission of Commission Order Modifying License with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions (Order Number EA-13-109) RA-18-027, Request for Rescission of Commission Order Modifying Licenses with Regard to Reliable Spent Fuel Pool Instrumentation (Order Number EA-12-051)2018-04-12012 April 2018 Request for Rescission of Commission Order Modifying Licenses with Regard to Reliable Spent Fuel Pool Instrumentation (Order Number EA-12-051) RA-18-036, Response to Request for Additional Information (RAI) and Supplement Regarding License Amendment Request - Proposed Defueled Technical Specifications and Revised License Conditions for Permanently Defueled ...2018-03-29029 March 2018 Response to Request for Additional Information (RAI) and Supplement Regarding License Amendment Request - Proposed Defueled Technical Specifications and Revised License Conditions for Permanently Defueled ... RA-18-019, Request for Exemption from 10 CFR 50.54(w)(1), Concerning On-Site Property Damage Insurance2018-03-29029 March 2018 Request for Exemption from 10 CFR 50.54(w)(1), Concerning On-Site Property Damage Insurance RA-18-020, Request for Exemption from 1 O CFR 140.11 (a)(4), Concerning Primary and Secondary Liability Insurance2018-03-29029 March 2018 Request for Exemption from 1 O CFR 140.11 (a)(4), Concerning Primary and Secondary Liability Insurance RA-18-032, Revision to Commitments Relating to Resolution of Anchor Darling Double Disc Gate Valve Part 21 Issues2018-03-27027 March 2018 Revision to Commitments Relating to Resolution of Anchor Darling Double Disc Gate Valve Part 21 Issues RA-18-034, Request for Exemption from 10 CFR 50.82(a)(8)(i)(A) and 10 CFR 50.75(h)(1)(iv)2018-03-22022 March 2018 Request for Exemption from 10 CFR 50.82(a)(8)(i)(A) and 10 CFR 50.75(h)(1)(iv) RA-18-015, Withdrawal of Application to Revise Technical Specifications to Implement BWRVIP-18, Revision 2-A and Relief Request for Extension of Torus Examinations2018-02-15015 February 2018 Withdrawal of Application to Revise Technical Specifications to Implement BWRVIP-18, Revision 2-A and Relief Request for Extension of Torus Examinations RA-18-014, Response to Request for Additional Information (RAI) and Supplemental Regarding License Amendment Request - Proposed Changes to the Oyster Creek Emergency Plan for Permanently Defueled Emergency Plan and Emergency Action Level Scheme2018-02-13013 February 2018 Response to Request for Additional Information (RAI) and Supplemental Regarding License Amendment Request - Proposed Changes to the Oyster Creek Emergency Plan for Permanently Defueled Emergency Plan and Emergency Action Level Scheme RA-18-008, Summary of Changes to Quality Assurance Topical Report, NO-AA-102018-02-0808 February 2018 Summary of Changes to Quality Assurance Topical Report, NO-AA-10 RA-18-010, Supplement to Relief Request for Extension of Torus Examinations2018-01-24024 January 2018 Supplement to Relief Request for Extension of Torus Examinations RA-17-086, Commitment Change Summary Report - 20172017-12-21021 December 2017 Commitment Change Summary Report - 2017 2019-09-12
[Table view] Category:Licensee Response to Notice of Violation
[Table view] |
Text
N Exelon Generation RA-15-021 10CFR 2.201 March 13, 2015 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001
Subject:
Response to Apparent Violation EA-14-178 Oyster Creek Nuclear Generating Station Renewed Facility Operating License No. DPR-16 NRC Docket No. 50-219
Reference:
NRC Letter to Exelon, Oyster Creek Nuclear Generating Station - NRC PreliminaryYellow Finding/OldDesign Issue, dated February 11, 2015.
The referenced letter identified an apparent violation that is being considered for escalated enforcement action related to an NRC inspection performed at the Oyster Creek Nuclear Generating Station regarding the failure of two electromagnetic relief valves (EMRVs). The letter allows for a response to the apparent violation in writing prior to the NRC making its enforcement decision. Exelon Generation Company, LLC accepts the apparent violation and agrees that the failure of the EMRVs is an old design issue and is not indicative of current station performance. During the analysis phase of the EMRV failure response, the following issues were identified associated with the common cause contribution to the significance and are described below.
In the referenced letter, it is not apparent that realistic assumptions for CCF methodology and qualitative information regarding the Exelon investigative information were applied with respect to the NRC CCF evaluation. As identified in the NRC Inspection Report 2014009 (Section 7 of Attachment 3), "Common Cause Failure- As discussedpreviously and in the following licensee risk insightsparagraph,the conditionalEMRV common cause failure probabilitysignificantly influences the final risk estimate, resulting in a potential order of magnitude difference." It is therefore recognized that the treatment of CCF assumptions is the dominant contributor to determining the significance for the performance deficiency.
Realistic treatment of the EMRV failures is prescribed in the Significance and Enforcement Review Panel (SERP) Process. The guidance document, IMC 0609.01, SIGNIFICANCE AND ENFORCEMENT REVIEW PANEL PROCESS, states in part that "The staff should make realistic assumptions in the bases for its significance determinations." Furthermore, IMC 0609.01 states that "Qualitative, as well as quantitative, information should be
considered in deriving a color recommendation." The issues identified below indicate that realistic assumptions and qualitative information may not have been fully considered when determining a significance for the deficiency:
" The RASP methodology requires that an observed equipment failure or degradation to be classified as having either the potential for CCF or not as applied to the associated CCF group. If it is qualitatively determined that the potential for CCF exists, the SPAR model quantitative methodology assumes with 100% certainty that CCF exists for the observed issue. This methodology therefore represents a binary input (i.e., assume either no CCF or complete CCF due to the observed issue), with no clear process for evaluating CCF in a potential "middle ground" based on available information related to the cause and extent of condition of the failure.
- The full conditional CCF probability is applied to all components in the group with the failed component, regardless of the details or cause associated with the failure. This approach for determining the conditional CCF probabilities (i.e., alpha factors) used in Probabilistic Risk Assessment (PRA) and Standardized Plant Analysis Risk (SPAR) models includes all inter-component dependencies not captured explicitly in the models. Applying the full conditional CCF probability calculated in the SPAR model in this manner is likely to overestimate the risk impact of a failure in an SDP evaluation.
- Using the Alpha methodology (as was applied in this case) for determining the conditional CCF probabilities is not in the spirit of achieving realistic results. Key investigative facts provided by Exelon are not addressed in the inspection report and do not appear to have been incorporated in the SPAR CCF calculation including 1) no history for similar failures in more than 40 years of plant operation; 2) no evidence of abnormally high vibration in the operating cycle leading up to the failure of the two EMRVs; 3) the time-dependent nature of the failure mechanism and 4) the fact that the remaining three EMRVs exhibited significantly less degradation, passed their operability test, and were known to not be in a failed state.
" Lastly, following plant shutdown on July 7, 2014 to support extent of condition inspection, all five EMRV actuators stroked satisfactorily during as-found testing.
Consideration of these qualitative facts in determining the CCF contribution would, in Exelon's view, lead to a more realistic estimate of the significance of the deficiency in question.
Should you have any questions concerning this letter, please contact Michael McKenna, Regulatory Assurance Manager, at (609) 971-4389.
Garey Stathes Site Vice President Oyster Creek Nuclear Generating Station cc: US NRC, Administrator, Region I US NRC, Senior Resident Inspector
bcc: Sr. Vice President, Mid-Atlantic Operations Site Vice President-OCNGS Plant Manager-OCNGS Director Operations-OCNGS Sr. Mgr. - Operations Spt & Svcs Shift Ops Superintendent - OCNGS Operations Support Manager - OCNGS Director, Site Training-OCNGS Manager, OCNGS Operations Training Manager, Regulatory Assurance-OCNGS Sr. Regulatory Assurance Engineer-OCNGS Manager, Licensing Manager, OCNGS Nuclear Oversight Commitment Coordinator Director, Mid-Atlantic Licensing Sr. Manager, PRA - Corporate Greenlee, Scot Krueger, Greg Records Management - OC