Letter Sequence Response to RAI |
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MONTHYEARRS-21-037, Response to Request for Additional Information Regarding License Amendment Request to Adopt TSTF-505, Revision 22021-03-23023 March 2021 Response to Request for Additional Information Regarding License Amendment Request to Adopt TSTF-505, Revision 2 Project stage: Response to RAI ML21132A2882021-06-28028 June 2021 Issuance of Amendment No. 238, Adoption of Technical Specifications Task Force Traveler TSTF-505, Revision 2, Provide Risk Informed Extended Completion Times - RITSTF Initiative 4B Project stage: Approval ML21193A1302021-07-14014 July 2021 Correction to Amendment No. 238 Issued June 28, 2021, Technical Specifications Task Force Traveler TSTF-505, Revision 2, Provide Risk Informed Extended Completion Times - RITSTF Initiative 4B Project stage: Other 2021-06-28
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Category:Letter type:RS
MONTHYEARRS-23-097, Constellation Energy Generation, LLC, Advisement of Leadership Changes and Submittal of Updated Standard Practice Procedures Plans2023-10-12012 October 2023 Constellation Energy Generation, LLC, Advisement of Leadership Changes and Submittal of Updated Standard Practice Procedures Plans RS-23-090, Annual Report of Emergency Core Cooling System Evaluation Model Changes and Errors for Clinton Power Station2023-09-0707 September 2023 Annual Report of Emergency Core Cooling System Evaluation Model Changes and Errors for Clinton Power Station RS-23-080, Constellation Energy Generation, LLC, Application to Revise Technical Specifications to Adopt TSTF-264-A, Revision 0, 3.3.9 and 3.3.10 - Delete Flux Monitors Specific Overlap Requirement SRs2023-08-30030 August 2023 Constellation Energy Generation, LLC, Application to Revise Technical Specifications to Adopt TSTF-264-A, Revision 0, 3.3.9 and 3.3.10 - Delete Flux Monitors Specific Overlap Requirement SRs RS-23-081, Request for License Amendment to Revise Technical Specifications Related to Reactor Water Cleanup Isolation Instrumentation2023-08-21021 August 2023 Request for License Amendment to Revise Technical Specifications Related to Reactor Water Cleanup Isolation Instrumentation RS-23-085, Supplemental Information Related to Request for Partial Site Release2023-08-0303 August 2023 Supplemental Information Related to Request for Partial Site Release RS-23-077, Response to NRC Regulatory Issue Summary 2023-01, Preparation and Scheduling of Operator Licensing Examinations2023-06-16016 June 2023 Response to NRC Regulatory Issue Summary 2023-01, Preparation and Scheduling of Operator Licensing Examinations RS-23-073, Request for Partial Site Release2023-06-0707 June 2023 Request for Partial Site Release RS-23-042, Application to Revise Technical Specifications to Adopt TSTF-580, Provide Exception from Entering Mode 4 with No Operable RHR Shutdown Cooling2023-05-25025 May 2023 Application to Revise Technical Specifications to Adopt TSTF-580, Provide Exception from Entering Mode 4 with No Operable RHR Shutdown Cooling RS-23-049, Constellation Energy Generation, LLC, Report on Status of Decommissioning Funding for Reactors and Independent Spent Fuel Storage Installations2023-03-23023 March 2023 Constellation Energy Generation, LLC, Report on Status of Decommissioning Funding for Reactors and Independent Spent Fuel Storage Installations RS-23-039, Request for License Amendment to Revise Technical Specifications Section 3.8.3, Diesel Fuel Oil, Lube Oil, and Starting Air2023-03-0101 March 2023 Request for License Amendment to Revise Technical Specifications Section 3.8.3, Diesel Fuel Oil, Lube Oil, and Starting Air RS-23-045, Constellation Energy Generation, LLC Submittal of Fitness for Duty Performance Data Reports for 2022 Per 10 CFR 26.717(c) & 10 CFR 26.2032023-02-28028 February 2023 Constellation Energy Generation, LLC Submittal of Fitness for Duty Performance Data Reports for 2022 Per 10 CFR 26.717(c) & 10 CFR 26.203 RS-23-003, Constellation Energy Generation, LLC, Summary of Changes to Quality Assurance Topical Report, NO-AA-10, and Decommissioning Quality Assurance Program, NO-DC-102023-01-31031 January 2023 Constellation Energy Generation, LLC, Summary of Changes to Quality Assurance Topical Report, NO-AA-10, and Decommissioning Quality Assurance Program, NO-DC-10 RS-23-002, Application to Adopt TSTF-332, ECCS Response Time Testing2023-01-13013 January 2023 Application to Adopt TSTF-332, ECCS Response Time Testing RS-22-126, Constellation Energy Generation, LLC - Request to Use Provisions of a Later Edition of the ASME Boiler and Pressure Vessel Code, Section XI2022-11-30030 November 2022 Constellation Energy Generation, LLC - Request to Use Provisions of a Later Edition of the ASME Boiler and Pressure Vessel Code, Section XI RS-22-121, Notice of Intent to Pursue Subsequent License Renewal Applications2022-11-0909 November 2022 Notice of Intent to Pursue Subsequent License Renewal Applications RS-22-092, Nine and Quad Cities - Application to Revise Primary Containment Isolation Instrumentation Technical Specifications in Accordance with TSTF-306, Revision 2, Add Action to LCO 3.3.6.1 to Give Option to Isolate the Penetration2022-10-0303 October 2022 Nine and Quad Cities - Application to Revise Primary Containment Isolation Instrumentation Technical Specifications in Accordance with TSTF-306, Revision 2, Add Action to LCO 3.3.6.1 to Give Option to Isolate the Penetration RS-22-107, Annual Report of Emergency Core Cooling System Evaluation Model Changes and Errors for Clinton Power Station2022-09-29029 September 2022 Annual Report of Emergency Core Cooling System Evaluation Model Changes and Errors for Clinton Power Station RS-22-093, Advisement of Leadership Changes for Constellation Energy Generation, LLC and Submittal of Updated Standard Practice Procedures Plans2022-08-18018 August 2022 Advisement of Leadership Changes for Constellation Energy Generation, LLC and Submittal of Updated Standard Practice Procedures Plans RS-22-089, Additional Information Supporting Request for License Amendment to Revise the Secondary Containment Design Basis to Credit the Fuel Building Railroad Airlock2022-07-25025 July 2022 Additional Information Supporting Request for License Amendment to Revise the Secondary Containment Design Basis to Credit the Fuel Building Railroad Airlock RS-22-061, Request for License Amendment to Adopt TSTF-269, Revision 2, Allow Administrative Means of Position Verification for Locked or Sealed Valves2022-05-24024 May 2022 Request for License Amendment to Adopt TSTF-269, Revision 2, Allow Administrative Means of Position Verification for Locked or Sealed Valves RS-22-060, Request for License Amendment to Adopt TSTF-230, Revision 1, Add New Condition B to LCO 3.6.2.3, RHR Suppression Pool Cooling2022-05-24024 May 2022 Request for License Amendment to Adopt TSTF-230, Revision 1, Add New Condition B to LCO 3.6.2.3, RHR Suppression Pool Cooling RS-22-068, Constellation Radiological Emergency Plan Addendum Revision2022-05-19019 May 2022 Constellation Radiological Emergency Plan Addendum Revision RS-22-055, Submittal of Preliminary Decommissioning Cost Estimate and Spent Fuel Management Plan2022-04-18018 April 2022 Submittal of Preliminary Decommissioning Cost Estimate and Spent Fuel Management Plan RS-22-051, Constellation Energy Generation, LLC - Update to Correspondence Addressees and Service Lists2022-04-12012 April 2022 Constellation Energy Generation, LLC - Update to Correspondence Addressees and Service Lists RS-22-020, Request for License Amendment to Revise the Secondary Containment Design Basis to Credit the Fuel Building Railroad Airlock2022-04-0707 April 2022 Request for License Amendment to Revise the Secondary Containment Design Basis to Credit the Fuel Building Railroad Airlock RS-22-049, Constellation Energy Generation, LLC, Supplemental Information to Correct Typographical Errors in Constellation'S Application to Revise Technical Specifications to Adopt TSTF-541 Revision 2, Add Exceptions to Surveillance Requirements for2022-04-0404 April 2022 Constellation Energy Generation, LLC, Supplemental Information to Correct Typographical Errors in Constellation'S Application to Revise Technical Specifications to Adopt TSTF-541 Revision 2, Add Exceptions to Surveillance Requirements for V RS-22-045, Constellation Energy Generation, LLC, Response to NRC Regulatory Issue Summary 2022-01, Preparation and Scheduling of Operator Licensing Examinations2022-03-25025 March 2022 Constellation Energy Generation, LLC, Response to NRC Regulatory Issue Summary 2022-01, Preparation and Scheduling of Operator Licensing Examinations RS-22-027, Constellation, Response to Request for Additional Information Regarding Application to Revise Technical Specifications to Adopt TSTF-541 Revision 2, Add Exceptions to Surveillance Requirements for Valves and Dampers Locked in the Actuated2022-02-23023 February 2022 Constellation, Response to Request for Additional Information Regarding Application to Revise Technical Specifications to Adopt TSTF-541 Revision 2, Add Exceptions to Surveillance Requirements for Valves and Dampers Locked in the Actuated P RS-22-023, Constellation Energy Generation, LLC, Executed Trust Fund Agreement Amendment and Subordinate Trust Agreement2022-02-23023 February 2022 Constellation Energy Generation, LLC, Executed Trust Fund Agreement Amendment and Subordinate Trust Agreement RS-22-019, Constellation Energy Generation, LLC - Update to Correspondence Addressees and Service Lists2022-02-16016 February 2022 Constellation Energy Generation, LLC - Update to Correspondence Addressees and Service Lists RS-22-015, Notification of Completion of License Transfer and Request to Continue Processing Pending NRC Actions Previously Requested by Exelon Generation Company, LLC2022-02-0101 February 2022 Notification of Completion of License Transfer and Request to Continue Processing Pending NRC Actions Previously Requested by Exelon Generation Company, LLC RS-22-004, Supplement to Application to Adopt TSTF-554, Revision 1, Revise Reactor Coolant Leakage Requirements2022-01-0404 January 2022 Supplement to Application to Adopt TSTF-554, Revision 1, Revise Reactor Coolant Leakage Requirements RS-21-121, Proposed Changes to Decommissioning Trust Agreements and Master Terms2021-12-15015 December 2021 Proposed Changes to Decommissioning Trust Agreements and Master Terms RS-21-102, Annual Report of Emergency Core Cooling System Evaluation Model Changes and Errors2021-09-29029 September 2021 Annual Report of Emergency Core Cooling System Evaluation Model Changes and Errors RS-21-091, Implementation of Insider Threat Program Requirements Associated with the Voluntary Security Clearance Program and Advisement of Leadership Changes2021-09-13013 September 2021 Implementation of Insider Threat Program Requirements Associated with the Voluntary Security Clearance Program and Advisement of Leadership Changes RS-21-087, Additional Information Supporting Request for License Amendment to Revise Degraded Voltage Relay Allowable Values2021-08-31031 August 2021 Additional Information Supporting Request for License Amendment to Revise Degraded Voltage Relay Allowable Values RS-21-078, Response to Request for Additional Information for Application to Revise Technical Specification to Adopt TSTF-582, Reactor Pressure Vessel Water Inventory Control (RPV WIC) Enhancements, and TSTF-583-T, TSTF-582 Diesel2021-08-19019 August 2021 Response to Request for Additional Information for Application to Revise Technical Specification to Adopt TSTF-582, Reactor Pressure Vessel Water Inventory Control (RPV WIC) Enhancements, and TSTF-583-T, TSTF-582 Diesel RS-21-076, Application to Adopt TSTF-273, Safety Function Determination Program Clarifications2021-07-30030 July 2021 Application to Adopt TSTF-273, Safety Function Determination Program Clarifications RS-21-070, Proposed Alternative to Utilize Code Case N-8932021-06-30030 June 2021 Proposed Alternative to Utilize Code Case N-893 RS-21-063, Application to Adopt TSTF-554, Revision 1, Revise Reactor Coolant Leakage Requirements2021-06-30030 June 2021 Application to Adopt TSTF-554, Revision 1, Revise Reactor Coolant Leakage Requirements RS-21-069, Third Inservice Inspection Interval Relief Request I3R-182021-06-28028 June 2021 Third Inservice Inspection Interval Relief Request I3R-18 RS-21-054, Response to NRC Regulatory Issue Summary 2021-01, Preparation and Scheduling of Operator Licensing Examinations2021-04-29029 April 2021 Response to NRC Regulatory Issue Summary 2021-01, Preparation and Scheduling of Operator Licensing Examinations RS-21-039, Supplemental Information Regarding Application for Order Approving Transfers and Proposed Conforming License Amendments2021-03-25025 March 2021 Supplemental Information Regarding Application for Order Approving Transfers and Proposed Conforming License Amendments RS-21-037, Response to Request for Additional Information Regarding License Amendment Request to Adopt TSTF-505, Revision 22021-03-23023 March 2021 Response to Request for Additional Information Regarding License Amendment Request to Adopt TSTF-505, Revision 2 RS-21-028, Fitness for Duty Performance Data Reports - Annual 20202021-02-26026 February 2021 Fitness for Duty Performance Data Reports - Annual 2020 RS-21-032, Amended Decommissioning Trust Agreements2021-02-25025 February 2021 Amended Decommissioning Trust Agreements RS-21-014, License Amendment Request for One-Time Extension of the Containment Type a Integrated Leakage Rate Test Frequency2021-02-24024 February 2021 License Amendment Request for One-Time Extension of the Containment Type a Integrated Leakage Rate Test Frequency RS-21-030, Report on Status of Decommissioning Funding for Reactors and Independent Spent Fuel Storage Installations2021-02-24024 February 2021 Report on Status of Decommissioning Funding for Reactors and Independent Spent Fuel Storage Installations RS-21-005, Request for License Amendment to Revise Degraded Voltage Relay Allowable Values2021-01-20020 January 2021 Request for License Amendment to Revise Degraded Voltage Relay Allowable Values RS-21-001, Revised Proposed Alternative to Utilize Code Cases N-878 and N-880 for Carbon Steel Piping2021-01-0404 January 2021 Revised Proposed Alternative to Utilize Code Cases N-878 and N-880 for Carbon Steel Piping 2023-09-07
[Table view] Category:Response to Request for Additional Information (RAI)
MONTHYEARRS-22-089, Additional Information Supporting Request for License Amendment to Revise the Secondary Containment Design Basis to Credit the Fuel Building Railroad Airlock2022-07-25025 July 2022 Additional Information Supporting Request for License Amendment to Revise the Secondary Containment Design Basis to Credit the Fuel Building Railroad Airlock CNL-22-064, Response to Request for Additional Information Regarding Tennessee Valley Authority License Amendment Request to Revise Emergency Plan Implementing Procedure Regarding Seismic Event Emergency Action Level Change2022-06-0909 June 2022 Response to Request for Additional Information Regarding Tennessee Valley Authority License Amendment Request to Revise Emergency Plan Implementing Procedure Regarding Seismic Event Emergency Action Level Change RS-22-027, Constellation, Response to Request for Additional Information Regarding Application to Revise Technical Specifications to Adopt TSTF-541 Revision 2, Add Exceptions to Surveillance Requirements for Valves and Dampers Locked in the Actuated2022-02-23023 February 2022 Constellation, Response to Request for Additional Information Regarding Application to Revise Technical Specifications to Adopt TSTF-541 Revision 2, Add Exceptions to Surveillance Requirements for Valves and Dampers Locked in the Actuated P NMP1L3447, Constellation Energy Generation, LLC - Response to Request for Additional Information - Proposed Relief Request Associated with Reactor Pressure Vessel Water Level Instrumentation Partial Penetration Nozzle Repairs2022-02-0202 February 2022 Constellation Energy Generation, LLC - Response to Request for Additional Information - Proposed Relief Request Associated with Reactor Pressure Vessel Water Level Instrumentation Partial Penetration Nozzle Repairs JAFP-21-0087, Response to Request for Additional Information Regarding Request for Approval of Transfer of Licenses and Conforming Amendments2021-09-16016 September 2021 Response to Request for Additional Information Regarding Request for Approval of Transfer of Licenses and Conforming Amendments RS-21-087, Additional Information Supporting Request for License Amendment to Revise Degraded Voltage Relay Allowable Values2021-08-31031 August 2021 Additional Information Supporting Request for License Amendment to Revise Degraded Voltage Relay Allowable Values RS-21-078, Response to Request for Additional Information for Application to Revise Technical Specification to Adopt TSTF-582, Reactor Pressure Vessel Water Inventory Control (RPV WIC) Enhancements, and TSTF-583-T, TSTF-582 Diesel2021-08-19019 August 2021 Response to Request for Additional Information for Application to Revise Technical Specification to Adopt TSTF-582, Reactor Pressure Vessel Water Inventory Control (RPV WIC) Enhancements, and TSTF-583-T, TSTF-582 Diesel NMP2L2773, Company - Response to Request for Additional Information2021-06-30030 June 2021 Company - Response to Request for Additional Information JAFP-21-0044, Response to Request for Additional Information Regarding Request for Approval of Transfer of Licenses and Conforming Amendments2021-06-11011 June 2021 Response to Request for Additional Information Regarding Request for Approval of Transfer of Licenses and Conforming Amendments JAFP-21-0032, Response to Request for Additional Information - Proposed Alternative Concerning ASME Section XI Repair/Replacement Documentation for Replacement of Pressure Retaining Bolting2021-04-20020 April 2021 Response to Request for Additional Information - Proposed Alternative Concerning ASME Section XI Repair/Replacement Documentation for Replacement of Pressure Retaining Bolting ML21111A0042021-04-20020 April 2021 Response to Request to Request Clinton, Unit 1, COVID-19 Related Request for Exemption from Part 26 Work Hours Requirements RS-21-037, Response to Request for Additional Information Regarding License Amendment Request to Adopt TSTF-505, Revision 22021-03-23023 March 2021 Response to Request for Additional Information Regarding License Amendment Request to Adopt TSTF-505, Revision 2 RS-20-139, Response to Request for Additional Information Regarding License Amendment Requests to Adopt TSTF-505, Revision 2, and 10 CFR 50.692020-11-24024 November 2020 Response to Request for Additional Information Regarding License Amendment Requests to Adopt TSTF-505, Revision 2, and 10 CFR 50.69 RS-20-096, Response to Request for Additional Information Related to Relief Request I4R-07 for the Fourth Inservice Inspection Interval2020-08-13013 August 2020 Response to Request for Additional Information Related to Relief Request I4R-07 for the Fourth Inservice Inspection Interval RS-20-095, Response to Request for Additional Information Related to Relief Request I4R-06 for the Fourth Inservice Inspection Interval2020-08-13013 August 2020 Response to Request for Additional Information Related to Relief Request I4R-06 for the Fourth Inservice Inspection Interval ML20188A2642020-07-0606 July 2020 Clinton Power Station, R.E. Ginna Station, Limerick Station, Nine Mile Point Station & Peach Bottom Station - Proposed Alternative to Utilize Code Case OMN-26 - Response to Request for Additional Information RS-20-069, Additional Information Supporting Request for License Amendment Regarding Automatic Operation of Transformer Load Tap Changer2020-06-29029 June 2020 Additional Information Supporting Request for License Amendment Regarding Automatic Operation of Transformer Load Tap Changer RS-20-067, Response to Request for Additional Information Related to Relief Request I4R-01 for the Fourth Inservice Inspection Interval2020-05-13013 May 2020 Response to Request for Additional Information Related to Relief Request I4R-01 for the Fourth Inservice Inspection Interval RS-20-045, Response to Request for Additional Information Related to Relief Request 14R.05 for the Fourth Inservice Inspection Interval2020-04-0101 April 2020 Response to Request for Additional Information Related to Relief Request 14R.05 for the Fourth Inservice Inspection Interval RS-19-112, Response to Request for Additional Information Regarding License Amendment Request to Revise Technical Specifications Following Adoption of TSTF-542, Reactor Pressure Vessel Water Inventory Control2019-12-0505 December 2019 Response to Request for Additional Information Regarding License Amendment Request to Revise Technical Specifications Following Adoption of TSTF-542, Reactor Pressure Vessel Water Inventory Control NMP2L2711, Byron Station; Calvert Cliffs; Clinton Power Station; LaSalle County Station; Limerick Generating Station; and Nine Mile Point Nuclear Station - Proposed Alternative to Utilize Code Case N-8792019-10-16016 October 2019 Byron Station; Calvert Cliffs; Clinton Power Station; LaSalle County Station; Limerick Generating Station; and Nine Mile Point Nuclear Station - Proposed Alternative to Utilize Code Case N-879 JAFP-19-0057, Response to Request for Additional Information - Proposed Alternative to Utilize Code Cases N-878 and N-8802019-06-0404 June 2019 Response to Request for Additional Information - Proposed Alternative to Utilize Code Cases N-878 and N-880 NMP1L3279, Response to Request for Additional Information - Proposed Alternatives to Utilize Code Cases N-878 and N-880 for Plants2019-05-0101 May 2019 Response to Request for Additional Information - Proposed Alternatives to Utilize Code Cases N-878 and N-880 for Plants JAFP-19-0006, Response to Request for Additional Information - Proposed Alternative to Utilize Code Cases N-878 and N-8802019-01-0808 January 2019 Response to Request for Additional Information - Proposed Alternative to Utilize Code Cases N-878 and N-880 RS-18-150, Transmittal of Supplemental Information for Exelon Evaluation of Preliminary White Finding2018-12-20020 December 2018 Transmittal of Supplemental Information for Exelon Evaluation of Preliminary White Finding RS-18-143, Supplemental Information Supporting License Amendment Requests for Approval of Changes to Emergency Plan Staffing Requirements2018-11-29029 November 2018 Supplemental Information Supporting License Amendment Requests for Approval of Changes to Emergency Plan Staffing Requirements RS-18-103, Response to Request for Additional Information Concerning License Amendment Request to Revise Alternate Source Term Dose Calculation2018-08-29029 August 2018 Response to Request for Additional Information Concerning License Amendment Request to Revise Alternate Source Term Dose Calculation RS-18-097, Response to Request for Additional Information and Supplemental Information-License Amendment.2018-07-27027 July 2018 Response to Request for Additional Information and Supplemental Information-License Amendment. RS-18-067, Response to Request for Additional Information Regarding Generic Letter 2016-012018-05-29029 May 2018 Response to Request for Additional Information Regarding Generic Letter 2016-01 RS-18-061, Response to Request for Additional Information Regarding Decommissioning Funding Plans for Independent Spent Fuel Storage Installations (Isfsis)2018-05-0202 May 2018 Response to Request for Additional Information Regarding Decommissioning Funding Plans for Independent Spent Fuel Storage Installations (Isfsis) ML18025A7992018-01-25025 January 2018 Response to Request for Additional Information Regarding Generic Letter 2016-01 RS-17-145, Supplement to Application to Revise Technical Specifications to Adopt TSTF-542, Reactor Pressure Vessel Water Inventory Control2017-11-15015 November 2017 Supplement to Application to Revise Technical Specifications to Adopt TSTF-542, Reactor Pressure Vessel Water Inventory Control RS-17-079, Response to Request for Additional Information Regarding the Permanent Extension of Leak Rate Testing2017-06-0101 June 2017 Response to Request for Additional Information Regarding the Permanent Extension of Leak Rate Testing RS-17-044, Response to Request for Additional Information Regarding Proposed Alternative for the Use of Encoded Phased Array Ultrasonic Examination Techniques in Lieu of Radiography2017-03-13013 March 2017 Response to Request for Additional Information Regarding Proposed Alternative for the Use of Encoded Phased Array Ultrasonic Examination Techniques in Lieu of Radiography RS-17-020, Response to RAI Concerning License Amendment Request to Revise Technical Specification Section 5.5.13, Primary Containment Leakage Rate Testing Program, for Permanent Extension of Type a and Type C Leak Rate Test Frequencies2017-03-0202 March 2017 Response to RAI Concerning License Amendment Request to Revise Technical Specification Section 5.5.13, Primary Containment Leakage Rate Testing Program, for Permanent Extension of Type a and Type C Leak Rate Test Frequencies RS-16-121, Response to Request for Additional Information Concerning License Amendment Request to Incorporate Revised Alternative Source Term Dose Calculation in USAR2016-06-0202 June 2016 Response to Request for Additional Information Concerning License Amendment Request to Incorporate Revised Alternative Source Term Dose Calculation in USAR RA-16-049, Response to Request for Additional Information Regarding Requests to Withhold Emergency Preparedness Documents from Public Disclosure2016-05-26026 May 2016 Response to Request for Additional Information Regarding Requests to Withhold Emergency Preparedness Documents from Public Disclosure RS-16-077, Response to Request for Additional Information Regarding Request for License Amendment to Reduce the Reactor Steam Dome Pressure Specified in the Technical Specification 2.1.1, Reactor Core Sls.2016-04-14014 April 2016 Response to Request for Additional Information Regarding Request for License Amendment to Reduce the Reactor Steam Dome Pressure Specified in the Technical Specification 2.1.1, Reactor Core Sls. RS-15-278, Supplement to Request for Additional Information Regarding License Amendment Request for a One-Time Extension of the Shutdown Service Water Division 2 Subsystem Completion Time2015-10-20020 October 2015 Supplement to Request for Additional Information Regarding License Amendment Request for a One-Time Extension of the Shutdown Service Water Division 2 Subsystem Completion Time RS-15-260, Response to Request for Additional Information Regarding License Amendment Request for a One-Time Extension of the Shutdown Service Water Division 2 Subsystem Completion Time2015-09-30030 September 2015 Response to Request for Additional Information Regarding License Amendment Request for a One-Time Extension of the Shutdown Service Water Division 2 Subsystem Completion Time RS-15-141, Response to Request for Additional Information Regarding License Amendment Request to Revise Technical Specification 5.5.2, Primary Coolant Sources Outside Containment.2015-06-24024 June 2015 Response to Request for Additional Information Regarding License Amendment Request to Revise Technical Specification 5.5.2, Primary Coolant Sources Outside Containment. 2022-07-25
[Table view] |
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4300 Winfield Road Warrenville, IL 60555 630 657 2000 Office RS-21-037 March 23, 2021 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Clinton Power Station, Unit 1 Facility Operating License No. NPF-62 NRC Docket No. 50-461
Subject:
Response to Request for Additional Information Regarding License Amendment Request to Adopt TSTF-505, Revision 2
References:
- 1. Letter from P. R. Simpson (Exelon Generation Company, LLC) to U.S. NRC, "Application to Revise Technical Specifications to Adopt Risk Informed Completion Times TSTF-505, Revision 2, 'Provide Risk-Informed Extended Completion Times - RITSTF Initiative 4b,'" dated April 30, 2020
- 2. Email from J. Wiebe (U.S. NRC) to K. M. Nicely (Exelon Generation Company, LLC), "Clarification of Second Round RAI - Clinton TSTF-505 License Amendment Request," dated February 26, 2021 In Reference 1, Exelon Generation Company, LLC (EGC) requested an amendment to Facility Operating License No. NPF-62 for Clinton Power Station (CPS), Unit 1. The proposed change modifies Technical Specifications requirements to permit the use of Risk Informed Completion Times in accordance with TSTF-505, Revision 2, "Provide Risk-Informed Extended Completion Times - RITSTF Initiative 4b," (ADAMS Accession No. ML18183A493).
The NRC requested additional information that is needed to complete review of the proposed change in Reference 2. In response to this request, EGC is providing the attached information.
EGC has reviewed the information supporting findings of no significant hazards consideration, and the environmental consideration, that were previously provided to the NRC in Attachment 1 of Reference 1. The additional information provided in this submittal does not affect the bases for concluding that the proposed license amendment does not involve a significant hazards consideration. In addition, the additional information provided in this submittal does not affect the bases for concluding that neither an environmental impact statement nor an environmental assessment needs to be prepared in connection with the proposed amendment.
March 23, 2021 U.S. Nuclear Regulatory Commission Page 2 There are no regulatory commitments contained in this letter. Should you have any questions concerning this letter, please contact Mr. Kenneth M. Nicely at (630) 657-2803.
I declare under penalty of perjury that the foregoing is true and correct. Executed on the 23rd day of March 2021.
Respectfully, Patrick R. Simpson Sr. Manager Licensing
Attachment:
Response to Request for Additional Information cc: NRC Regional Administrator, Region III NRC Senior Resident Inspector - Clinton Power Station Illinois Emergency Management Agency - Division of Nuclear Safety
ATTACHMENT Response to Request for Additional Information DRA/APLB RAI 02.01 - Treatment of Sensitive Electronics in the Fire PRA In order to make a finding on the impact of assumptions made in the fire PRA (FPRA) on the proposed RICT program, the NRC staff, in DRA/APLB RAI 02 - Treatment of Sensitive Electronics, requested that the licensee describe the treatment of sensitive electronics for the FPRA, its consistency with the guidance in FAQ 13-0004, and the impact of any deviations on the proposed RICT program. The NRC staff's review of the licensee's response identified multiple assumptions in the modeling of sensitive electronics in the FPRA supporting this application.
The licensee's response explains that the caveats cited in FAQ 13-0004 about configurations, such as surface-mounted electronics, that invalidate the FAQ 13-0004 approach (i.e.,
configurations for which damage to the sensitive electronics could happen at a lower thermal threshold than identified in FAQ 13-0004) were not explicitly addressed in its FPRA. The response assumes that consideration of such configurations would have negligible impact on fire risk in fire scenarios where only the ignition source and sensitive electronics are damaged from the fire because of the functions associated with sensitive electronics (e.g., a single logic channel).
The licensee identified a gap in its analysis where the exposed sensitive electronics are at a distance away from the ignition source such that damage to sensitive electronics would occur beyond the zone of influence (ZOI) of the ignition source determined by thermoset failure criteria in FAQ 13-0004 (i.e., the ZOI of the ignition source using the sensitive electronics damage criteria extends beyond the ZOI using the thermoset criteria in FAQ 13-0004). To address this gap, the response indicated that a "beyond ZOI" scenario was developed and a full physical analysis unit (PAU) burnout was assumed if a fire from an ignition source has the potential to grow beyond the ZOI of the ignition source. It appears to the NRC staff that the "beyond ZOI" scenario is an assumption made as a modeling simplification. It is unclear to the NRC staff whether this assumption captures the full impact of the gap cited by the licensee. As a result, the NRC staff is unable to evaluate the impact of this assumption on the proposed RICTs.
In its response, the licensee included a limited sampling of sensitive electronics to conclude that the sensitive electronics either 1) have no impact on a PRA credited function, or 2) aren't damaged in the fire or their failure is modeled in the FPRA scenarios. The limited sampling is insufficient to determine the impact of the modeling of sensitive electronics in the FPRA on the RICTs.
Based on the observations above, the licensee's fire PRA includes assumptions related to modeling of sensitive electronics that are simplifications made for modeling convenience.
Based on the available information, the NRC staff is unable to determine the potential impact of these assumptions on the proposed RICTs and therefore, whether these assumptions constitute key assumptions for this application. Therefore, address the following:
Provide justification for the negligible impact on the RICT calculations from the assumptions for modeling sensitive electronics in the licensee's FPRA. The justification can include:
Page 1
ATTACHMENT Response to Request for Additional Information A) A sensitivity study showing that guaranteed failure of sensitive electronics has a minimal impact on the RICTs calculated for LCOs that are most likely to be affected by sensitive electronics. As a part of the response, identify those functions that sensitive electronics perform in the plant.
OR B) A detailed explanation of the technical basis for the negligible impact. The explanation should:
- 1) Discuss the functions that sensitive electronics perform in the plant, which of these functions are modelled in the FPRA, and why none of the modeled sensitive electronics can have more than negligible impact on the RICT calculations. Include confirmation that the "sampling results" provided in Table APLB-02-1 of the response are based on a walkdown of sensitive electronics in the plant and that the dispositions provided can be considered to be representative of those sensitive electronics.
- 2) Summarize your fire PRA modeling approach for evaluating sensitive electronics.
In this summary, discuss whether a range of targets sets is assumed in the fire modeling approach for ignition sources, i.e., whether the target sets range from non-propagating fires constrained to the ignition source to scenarios of full PAU burnout. Also, indicate in general how the scenario frequency is established for a target set. Discuss whether the fire PRA modeling analysis is complete with respect to the state of practice or whether gaps exist in this analysis.
- 3) If sensitive electronics are incompletely analyzed in your PRA, then provide an assessment (e.g., a sensitivity study) on the impact of modelling these sensitive electronics at a lower heat flux damage threshold of 3 kW/m2 and 65°C for solid state controls components as recommended in Sections 8.5.1.2 and H.2 of NUREG/CR-6850(ADAMS Accession No. ML052580118).
Response
A. N/A - See response to part B below.
B. Technical Basis for Negligible Impact
- 1) Functions of Sensitive Electronics at Clinton Power Station In response to the previous revision of this RAI, a plant walkdown was conducted by the Site Risk Management Engineer (SRME) and a Senior Reactor Operator (SRO) on September 11, 2020, to identify the presence of sensitive electronics in the risk-significant areas of Clinton Power Station (CPS). These areas included the Switchgear Rooms, Auxiliary Electric Equipment Room (AEER), and the Main Control Room (MCR) which account for approximately 62% of the Fire CDF and 48% of the Fire LERF.
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ATTACHMENT Response to Request for Additional Information Details regarding the types of sensitive electronics observed in these areas are provided below:
- Switchgear Rooms Temperature transmitters for starting switchgear room cooling were the only observed sensitive electronics in the switchgear rooms. Since switchgear room cooling is not modeled in the PRA, and fires originating in the switchgear rooms already fail the various equipment located in the rooms, failure of these transmitters will have no impact on the RICT calculations.
- AEER The offsite power Open Phase Detection system and various overcurrent relays were observed in the AEER. Given that offsite power is failed in all propagating fire scenarios postulated in this area (due to the targets selected within the zone of influence of the ignition source), failure of these sensitive electronics will have no impact on the RICT calculations (since failure of these sensitive electronics are already captured by other fire-induced failures of offsite power).
In addition, ground indicators were observed on the DC MCCs located in the AEER; however, these indicators are not modeled in the Fire PRA. Therefore, failure of these sensitive electronics would have no impact on the RICT calculations.
- MCR In the MCR, various temperature / level indicators were observed on a variety of main control boards (MCBs) and back panels located within the MCR complex (e.g., main steam line temperature, various room temperatures, diesel oil tank level, etc.).
For MCB fires, NUREG/CR-6850 Appendix L approach is utilized for developing and defining MCB fire scenarios. For each subpanel, the appropriate failures are postulated based upon the controls / indications provided on the panel (e.g., if RHR A controls are located on the panel, RHR A is failed for all fire scenarios that postulate damage to that subpanel). Therefore, failure of the sensitive electronics is captured by the system / function surrogate mapping approach utilized for scenario development.
For the back panel fires, a similar approach is used. System / function surrogate mappings are identified by evaluating the controls / indications on each panel and mapping those representative failures in the PRA. In addition, cable to/from endpoint data was reviewed to identify any additional systems / functions that should be failed. Therefore, failure of the sensitive electronics is captured by the system / function surrogate mapping approach utilized for scenario development.
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ATTACHMENT Response to Request for Additional Information For MCR Abandonment fire scenarios, the time to abandonment for the various heat release rates and ignition sources are driven by the smoke layer height and optical density rather than the smoke layer temperature. Since operators would abandon the MCR prior to fire-induced failure of the sensitive electronics, FAQ 13-0004 is not applicable for MCR abandonment fire scenarios.
In summary, the sensitive electronics identified during the walkdown were not associated with Fire PRA credited equipment or their failures were already accounted for by other targets in the target set (e.g., fire-induced failure of a different component that supports the same function). These insights are representative of sensitive electronics found in other areas not explicitly evaluated as part of the walkdown. Therefore, the current approach is appropriate and suitable for risk-informed applications.
- 2) Treatment of Sensitive Electronics The Clinton Fire PRA treats sensitive electronics as contained within the electrical cabinets such that the cabinet walls, top, front, and back doors shield the components from radiant energy of an exposure fire and the thermoset failure criteria is retained for these components, which is consistent with FAQ 13-0004. The caveats (e.g., surface-mounted electronics) specified in FAQ 13-0004 are the only aspects of the FAQ that are not explicitly evaluated; however, the insights from part B(1) of this response clearly demonstrate that the caveats presented in FAQ 13-0004 do not pose a challenge to the general treatment of sensitive electronics.
Fire Scenario Development Approach Figure 3-1 of the Fire Scenario Development Notebook (CL-PRA-021.07.01) [1]
summarizes the Fire Propagation Event Tree (FPET) which summarizes the fire scenario development approach.
For each ignition source, a determination is made as to whether or not detailed scenario development is required. If a detailed scenario is not required (e.g., ignition source is located in a non-risk-significant area), then an undeveloped full room burnout is postulated. Otherwise, detailed fire modeling is developed for the ignition source. The detailed fire modeling considers fire growth, secondary combustibles, fire propagation, and detection / suppression as a function of time and heat release rate. Based on the results of the detailed fire modeling, the following types of scenarios are developed, the appropriate targets are selected, and the ignition source's fire ignition frequency is apportioned to the respective scenarios based upon the overall likelihood of target damage for the specified end state.
- "Green": Non-Propagating (i.e., ignition source only)
- "Yellow": Propagating - Finite (i.e., failure of all targets within a user-defined zone of influence identified via walkdowns and/or drawing reviews; more than one Yellow scenario may be assigned to the same single ignition source)
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ATTACHMENT Response to Request for Additional Information
- "Orange": Propagating - Growing (i.e., if the fire is capable of growing beyond the user-defined zone of influence(s), then this portion of the fire is conservatively treated as a full room burnout)
- "Magenta": Multi-Compartment Analysis In summary, the fire scenario development approach used for the Clinton Fire PRA is consistent with the state of practice used in the industry and fully meets the ASME/ANS PRA Standard.
- 3) N/A - See responses to part B(1) and B(2) for details.
REFERENCES
[1] Clinton Power Station Fire PRA, Fire Scenario Development Notebook, CL-PRA-021.07.01, Rev. 2, February 2020 Page 5