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Category:Letter type:NRC
[Table view] Category:Response to Request for Additional Information (RAI)
MONTHYEARRA-23-0136, Duke Energy Response to Request for Additional Information Regarding Proposed Alternative for Steam Generator Welds in Accordance with 10 CFR 50.55a(z)(1)2023-07-20020 July 2023 Duke Energy Response to Request for Additional Information Regarding Proposed Alternative for Steam Generator Welds in Accordance with 10 CFR 50.55a(z)(1) RA-23-0154, Duke Energy - Response to Request for Additional Information Regarding Proposed Alternative for Pressurizer Welds in Accordance with 10 CFR 50.55a(z)(1)2023-07-20020 July 2023 Duke Energy - Response to Request for Additional Information Regarding Proposed Alternative for Pressurizer Welds in Accordance with 10 CFR 50.55a(z)(1) RA-23-0142, Mcguire, Units 1 and 2, Oconee, Units 1, 2, and 3, H. B. Robinson, Unit 2, Response to Request for Additional Information Regarding the License Amendment Request to Revise Restrictive Technical Specification Surveillance Require2023-07-0707 July 2023 Mcguire, Units 1 and 2, Oconee, Units 1, 2, and 3, H. B. Robinson, Unit 2, Response to Request for Additional Information Regarding the License Amendment Request to Revise Restrictive Technical Specification Surveillance Require RA-22-0195, Response to Request for Additional Information (RAI) for the Proposed Method to Manage Aging Due to Environmentally Assisted Fatigue for the Safety Injection Nozzle2022-06-29029 June 2022 Response to Request for Additional Information (RAI) for the Proposed Method to Manage Aging Due to Environmentally Assisted Fatigue for the Safety Injection Nozzle RA-22-0147, Duke Energy Carolinas, LLC, and Duke Energy Progress, LLC, Response to Request for Additional Information (RAI) Regarding License Amendment Request for Relocating the Duke Energy Emergency Operations Facility2022-05-13013 May 2022 Duke Energy Carolinas, LLC, and Duke Energy Progress, LLC, Response to Request for Additional Information (RAI) Regarding License Amendment Request for Relocating the Duke Energy Emergency Operations Facility RA-22-0102, Response to Request for Additional Information (RAI) Regarding Revision 1 of DPC-NE-1007-P, Conditional Exemption of the EOC Mtc Measurement Methodology2022-04-0707 April 2022 Response to Request for Additional Information (RAI) Regarding Revision 1 of DPC-NE-1007-P, Conditional Exemption of the EOC Mtc Measurement Methodology RA-22-0003, Response to Requests for Additional Information for Reactor Vessel Closure Stud Exam Extension Alternative2022-01-31031 January 2022 Response to Requests for Additional Information for Reactor Vessel Closure Stud Exam Extension Alternative RA-21-0321, Response to Request for Additional Information (RAI) Regarding Refuel 24 (C2R24) Inservice Inspection (ISI) and Steam Generator Inspection (SG-ISI) Report2021-12-14014 December 2021 Response to Request for Additional Information (RAI) Regarding Refuel 24 (C2R24) Inservice Inspection (ISI) and Steam Generator Inspection (SG-ISI) Report RA-21-0063, 1, 2; Catawba Nuclear Station 1, 2; H. B. Robinson Steam Electric Plant 2; Mcgguire Nuclear Station 1, 2; Oconee Nuclear Station 1, 2, 3; Shearon Harris Nuclear Power Plant 1 - Response to RAI Re Amend for Emergency Plan2021-03-11011 March 2021 1, 2; Catawba Nuclear Station 1, 2; H. B. Robinson Steam Electric Plant 2; Mcgguire Nuclear Station 1, 2; Oconee Nuclear Station 1, 2, 3; Shearon Harris Nuclear Power Plant 1 - Response to RAI Re Amend for Emergency Plan RA-21-0032, Duke Energy - Response to Requests for Additional Info for Request to Use a Provision of Later Edition & Addenda of the ASME Boiler & Pressure Vessel Code, Section XI for Repair/Replacement Activities in Accordance with 10 CFR 50.55a(g)(42021-02-11011 February 2021 Duke Energy - Response to Requests for Additional Info for Request to Use a Provision of Later Edition & Addenda of the ASME Boiler & Pressure Vessel Code, Section XI for Repair/Replacement Activities in Accordance with 10 CFR 50.55a(g)(4)( RA-21-0017, Response to Request for Additional Information Re License Amendment Request to Revise Tech Spec 3.8.1 to Reduce Emergency Diesel Generator Maximum Steady State Voltage2021-01-29029 January 2021 Response to Request for Additional Information Re License Amendment Request to Revise Tech Spec 3.8.1 to Reduce Emergency Diesel Generator Maximum Steady State Voltage RA-20-0104, Response to NRC Request for Additional Information - Catawba Nuclear Station-SG Report (RA-19-0391)-C2R232020-04-0606 April 2020 Response to NRC Request for Additional Information - Catawba Nuclear Station-SG Report (RA-19-0391)-C2R23 RA-20-0002, Response to Request for Additional Information (RAI) Regarding License Amendment Request to Revise Technical Specification 3.4.3, RCS Pressure and Temperature (P/T) Limits2020-02-13013 February 2020 Response to Request for Additional Information (RAI) Regarding License Amendment Request to Revise Technical Specification 3.4.3, RCS Pressure and Temperature (P/T) Limits RA-19-0280, Response to NRC RAI Clarifications Regarding License Amendment Request Proposing Changes to the Technical Specifications 3.8.12019-07-10010 July 2019 Response to NRC RAI Clarifications Regarding License Amendment Request Proposing Changes to the Technical Specifications 3.8.1 RA-19-0189, Supplement to Response for Request for Additional Information Regarding License Amendment Request Proposing Changes to the Technical Specifications 3.8.12019-04-0808 April 2019 Supplement to Response for Request for Additional Information Regarding License Amendment Request Proposing Changes to the Technical Specifications 3.8.1 RA-19-0004, Response to NRC for Additional Information (RAI) Regarding License Amendment Request Proposing Changes to the Technical Specifications 3.8.1 for Catawba Nuclear Station, Units 1 and 22019-03-0707 March 2019 Response to NRC for Additional Information (RAI) Regarding License Amendment Request Proposing Changes to the Technical Specifications 3.8.1 for Catawba Nuclear Station, Units 1 and 2 RA-19-0026, Response to Request for Additional Information (RAI) Regarding Proposed Alternative to the Depth Sizing Qualification Requirement of Appendix Viii, Supplements 2 and 10 (18-GO-001)2019-02-11011 February 2019 Response to Request for Additional Information (RAI) Regarding Proposed Alternative to the Depth Sizing Qualification Requirement of Appendix Viii, Supplements 2 and 10 (18-GO-001) RA-18-0162, Response to March 12, 2012, Request for Information Enclosure 2, Recommendation 2.1, Flooding, Required Response 3, Flooding Focused Evaluation Summary Submittal2018-12-0606 December 2018 Response to March 12, 2012, Request for Information Enclosure 2, Recommendation 2.1, Flooding, Required Response 3, Flooding Focused Evaluation Summary Submittal RA-18-0097, (Cns), Units 1 and 2 - Response to NRC Requests for Additional Information (Rais) License Amendment Request to Revise Technical Specification Section 3.7.8, Nuclear Service Water System2018-08-17017 August 2018 (Cns), Units 1 and 2 - Response to NRC Requests for Additional Information (Rais) License Amendment Request to Revise Technical Specification Section 3.7.8, Nuclear Service Water System CNS-18-023, (Cns), Units 1 and 2 - Response to NRC Requests for Additional Information (Rais) License Amendment Request to Revise Technical Specification Section 3.7.8, Nuclear Service Water System2018-05-0808 May 2018 (Cns), Units 1 and 2 - Response to NRC Requests for Additional Information (Rais) License Amendment Request to Revise Technical Specification Section 3.7.8, Nuclear Service Water System NRC-18-0016, Response to Request for Additional Information (Set 2) Regarding License Amendment Request to Revise Technical Specifications to Eliminate Main Steam Line Radiation Monitor Reactor Trip and Primary Containment Isolation System Group 1..2018-02-21021 February 2018 Response to Request for Additional Information (Set 2) Regarding License Amendment Request to Revise Technical Specifications to Eliminate Main Steam Line Radiation Monitor Reactor Trip and Primary Containment Isolation System Group 1.. CNS-17-058, Supplement to the High Frequency Supplement to Seismic Hazard Screening Report, Response to NRC Request for Information Pursuant to 10 CFR 50.54(f) Regarding Recommendation 2.1 of the Near-Term Task Force Review of Insights from the Fukus2017-12-28028 December 2017 Supplement to the High Frequency Supplement to Seismic Hazard Screening Report, Response to NRC Request for Information Pursuant to 10 CFR 50.54(f) Regarding Recommendation 2.1 of the Near-Term Task Force Review of Insights from the Fukushi CNS-17-061, Third Ten-Year Inservice Inspection Plan, Limited Volumetric Examinations Response to NRC Requests for Additional Information2017-12-21021 December 2017 Third Ten-Year Inservice Inspection Plan, Limited Volumetric Examinations Response to NRC Requests for Additional Information CNS-17-047, Response to NRC Inspection Report 05000414/2017012 and Preliminary White Finding2017-08-29029 August 2017 Response to NRC Inspection Report 05000414/2017012 and Preliminary White Finding RA-17-0039, Response to Request for Additional Information (RAI) Regarding 10 CFR 50.55a(z)(1)Proposed Alternative to ASME Section XI Threads in Flange Examination (17-GO-001)2017-08-0909 August 2017 Response to Request for Additional Information (RAI) Regarding 10 CFR 50.55a(z)(1)Proposed Alternative to ASME Section XI Threads in Flange Examination (17-GO-001) RA-17-0035, Supplement to License Amendment Request Proposing Changes to Technical Specification 3.5.1, AC Sources - Operating.2017-07-20020 July 2017 Supplement to License Amendment Request Proposing Changes to Technical Specification 3.5.1, AC Sources - Operating. RA-17-0036, Supplement to the Response to Request for Additional Information Regarding Application to Revise Technical Specifications to Adopt Multiple Technical Specification Task Force Travelers2017-07-17017 July 2017 Supplement to the Response to Request for Additional Information Regarding Application to Revise Technical Specifications to Adopt Multiple Technical Specification Task Force Travelers RA-17-0029, Response to Request for Additional Information Regarding Application to Revise Technical Specifications to Adopt Multiple Technical Specification Task Force Travelers2017-06-0808 June 2017 Response to Request for Additional Information Regarding Application to Revise Technical Specifications to Adopt Multiple Technical Specification Task Force Travelers CNS-17-031, Response to NRC Requests for Additional Information End of Cycle 21 Refueling Outage Inservice Inspection Report and Steam Generator Inservice Inspection Summary Report2017-05-24024 May 2017 Response to NRC Requests for Additional Information End of Cycle 21 Refueling Outage Inservice Inspection Report and Steam Generator Inservice Inspection Summary Report CNS-17-004, Response to NRC Request for Additional Information on License Amendment Request to Adopt National Fire Protection Association (NFPA) 805 Performance-Based Standard for Fire Protection for Light-Water Reactor Generating Plants.2017-01-26026 January 2017 Response to NRC Request for Additional Information on License Amendment Request to Adopt National Fire Protection Association (NFPA) 805 Performance-Based Standard for Fire Protection for Light-Water Reactor Generating Plants. CNS-16-077, Expedited Seismic Evaluation Process Closeout, Response to NRC Request for Information Pursuant to 10 CFR 50.54(f) Regarding Recommendations 2.1 of the Near-Term Task Force Review of Insights from the Fukushima Dai-ichi Accident2016-12-0808 December 2016 Expedited Seismic Evaluation Process Closeout, Response to NRC Request for Information Pursuant to 10 CFR 50.54(f) Regarding Recommendations 2.1 of the Near-Term Task Force Review of Insights from the Fukushima Dai-ichi Accident CNS-16-066, Stations - Supplemental Information Regarding Reevaluated Seismic Hazard Screening and Prioritization Results - Response to NRC Request for Information, Per 10CFR50.54(f) Regarding Recommendation 2.1 of the Near-Term Task..2016-10-20020 October 2016 Stations - Supplemental Information Regarding Reevaluated Seismic Hazard Screening and Prioritization Results - Response to NRC Request for Information, Per 10CFR50.54(f) Regarding Recommendation 2.1 of the Near-Term Task.. RA-16-0035, Response to Request for Additional Information (RAI) Regarding Application for Emergency Operations Facility (EOF) Consolidation2016-10-0303 October 2016 Response to Request for Additional Information (RAI) Regarding Application for Emergency Operations Facility (EOF) Consolidation CNS-16-064, License Amendment Request to Adopt National Fire Protection and Revised Response to Probabilistic Risk Assessment Request for Additional Information 242016-09-0707 September 2016 License Amendment Request to Adopt National Fire Protection and Revised Response to Probabilistic Risk Assessment Request for Additional Information 24 CNS-16-051, License Amendment Request (LAR) to Adopt National Fire Protection Association (NFPA) 805 Performance-Based Standard for Fire Protection for Light-Water Reactor Generating Plants, Response to NRC Request for Additional Information (RAI) an2016-08-0202 August 2016 License Amendment Request (LAR) to Adopt National Fire Protection Association (NFPA) 805 Performance-Based Standard for Fire Protection for Light-Water Reactor Generating Plants, Response to NRC Request for Additional Information (RAI) and ML16204A0602016-07-20020 July 2016 Spent Fuel Pool Evaluation Supplemental Report, Response to NRC Request for Information Pursuant, Regarding Recommendation 2.1 of the Near-Term Task Force Review of Insights from the Fukushima Dai-ichi Accident RA-16-0027, Response to NRC Regulatory Issue Summary 2016-09 Preparation and Scheduling of Operator Licensing Examinations2016-07-14014 July 2016 Response to NRC Regulatory Issue Summary 2016-09 Preparation and Scheduling of Operator Licensing Examinations CNS-16-043, Additional Information Regarding Flood Hazard Reevaluation Report, Response to Request for Information Pursuant to Title 10 of the Code of Federal Regulations 50.54(f) Regarding Recommendations 2.1, 2.3, and 9.3 of the Near-Term Task Forc2016-06-23023 June 2016 Additional Information Regarding Flood Hazard Reevaluation Report, Response to Request for Information Pursuant to Title 10 of the Code of Federal Regulations 50.54(f) Regarding Recommendations 2.1, 2.3, and 9.3 of the Near-Term Task Force CNS-16-035, License Amendment Request to Revise Technical Specifications Permanent Extension of Type a and Type C Leak Rate Test Frequencies, Responses to NRC Requests for Additional Information CAC Nos. MF7265 and MF72662016-06-20020 June 2016 License Amendment Request to Revise Technical Specifications Permanent Extension of Type a and Type C Leak Rate Test Frequencies, Responses to NRC Requests for Additional Information CAC Nos. MF7265 and MF7266 CNS-16-022, Supplemental Information to the Final Notification of Full Compliance with Order EA-12-049,Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond Design Basis External Events and with Order EA-12-051, Et2016-03-31031 March 2016 Supplemental Information to the Final Notification of Full Compliance with Order EA-12-049,Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond Design Basis External Events and with Order EA-12-051, Et A MNS-16-023, Response to Request for Supplemental Information Needed for Acceptance of Requested Licensing Action Regarding License Amendment Request for Control Room Chilled Water System Technical Specifications2016-03-16016 March 2016 Response to Request for Supplemental Information Needed for Acceptance of Requested Licensing Action Regarding License Amendment Request for Control Room Chilled Water System Technical Specifications ML16102A1562016-03-11011 March 2016 Proposed Technical Specifications Amendments, TS 3.4.1, Reactor Coolant System Pressure, Temperature and Flow Departure from Nucleate Boiling Limits, Response to NRC Request for Additional Information ML16055A2272016-02-19019 February 2016 Response to Request for Additional Information and Emergency Action Level Technical Bases Document, Revision 1, Redline Version. Part 1 of 4 ML16055A2282016-02-19019 February 2016 Response to Request for Additional Information and Emergency Action Level Technical Bases Document, Revision 1, Redline Version. Part 2 of 4 CNS-16-010, Response to Request for Additional Information and Emergency Action Level Technical Bases Document, Revision 1, Clean Version. Part 4 of 42016-02-19019 February 2016 Response to Request for Additional Information and Emergency Action Level Technical Bases Document, Revision 1, Clean Version. Part 4 of 4 ML16055A2302016-02-19019 February 2016 Response to Request for Additional Information and Emergency Action Level Technical Bases Document, Revision 1, Redline Version. Part 3 of 4 RA-16-0006, Response to NRC Request for Additional Information (RAI) Regarding Application to Use Alternate Fission Gas Gap Release Fractions2016-02-0101 February 2016 Response to NRC Request for Additional Information (RAI) Regarding Application to Use Alternate Fission Gas Gap Release Fractions ML15324A0832015-11-16016 November 2015 License Amendment Request (LAR) for Measurement Uncertainty Recapture (Mur) Power Uprate, Response to NRC Requests for Additional Information (Rais) CNS-15-086, License Amendment Request (LAR) for Changes to Technical Specification (TS) 3.3.2, Engineered Safety Feature Actuation System (ESFAS) Instrumentation and TS 3.3.5, Loss of Power (LOP) Diesel Generator (DG) Start..2015-10-23023 October 2015 License Amendment Request (LAR) for Changes to Technical Specification (TS) 3.3.2, Engineered Safety Feature Actuation System (ESFAS) Instrumentation and TS 3.3.5, Loss of Power (LOP) Diesel Generator (DG) Start.. CNS-15-075, License Amendment Request (LAR) for Changes to Technical Specification (TS) 3.3.2, Engineered Safety Feature Actuation System (ESFAS) Instrumentation and TS 3.3.5, Loss of Power (LOP) Diesel Generator (DG) Start..2015-08-17017 August 2015 License Amendment Request (LAR) for Changes to Technical Specification (TS) 3.3.2, Engineered Safety Feature Actuation System (ESFAS) Instrumentation and TS 3.3.5, Loss of Power (LOP) Diesel Generator (DG) Start.. 2023-07-07
[Table view] |
Text
Keith J. Polson Senior Vice President and CNO DTE Energy Company 6400 N. Dixie Highway, Newport, MI 48166 Tel: 734.586.6515 Fax: 734.586.4172 Email: keith.polson@dteenergy.com February 21, 2018 NRC-18-0016 U.S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, DC 20555-0001 Fermi 2 Power Plant NRC Docket No. 50-341 NRC License No. NPF-43
Subject:
Response to Request for Additional Information (Set 2) Regarding License Amendment Request to Revise Technical Specifications to Eliminate Main Steam Line Radiation Monitor Reactor Trip and Primary Containment Isolation System Group 1 Isolation Functions
References:
- 1) DTE Electric Letter to NRC, License Amendment Request to Revise Technical Specifications to Eliminate Main Steam Line Radiation Monitor Reactor Trip and Primary Containment Isolation System Group 1 Isolation Functions, NRC-17-0012, dated August 24, 2017 (ML17237A176)
- 2) NRC Letter to DTE, Fermi 2 - Supplemental Information Needed for Acceptance of Requested Licensing Action RE:
License Amendment Request to Revise Technical Specifications to Eliminate Main Steam Line Radiation Monitor Reactor Trip and Primary Containment Isolation System Group 1 Isolation Functions (CAC No. MG0228; EPID L-2017-LLA-0274),
dated October 10, 2017 (ML17271A220)
- 3) DTE Electric Letter to NRC, Supplemental Information Regarding License Amendment Request to Eliminate Main Steam Line Radiation Monitor Reactor Trip and Primary Containment Isolation System Group 1 Isolation Functions, NRC-17-0066, dated October 18, 2017 (ML17298A185)
In Reference 1, DTE Electric Company (DTE) submitted a license amendment request (LAR) to revise the Fermi 2 Technical Specifications (TS) to eliminate the main steam line radiation monitor (MSLRM) reactor trip and primary containment isolation system (PCIS) Group 1 isolation functions. Supplemental information was
USNRC NRC-18-0016 Page 2 requested by the NRC in Reference 2 and DTE subsequently submitted a supplement to the LAR in Reference 3. In an email from Ms. Sujata Goetz to Mr. Jason Haas dated January 29, 2018, the NRC sent DTE a request for additional information (RAI) regarding this LAR. The response to the RAI is enclosed.
No new commitments are being made in this submittal.
Should you have any questions or require additional information, please contact Mr. Scott A. Maglio, Manager -Nuclear Licensing, at (734) 586-5076.
I declare under penalty of perjury that the foregoing is true and correct.
Executed on February 21, 2018 Keith J. Polson Senior Vice President and CNO
Enclosure:
Response to Request for Additional Information cc: NRC Project Manager NRC Resident Office Reactor Projects Chief, Branch 5, Region III Regional Administrator, Region III Michigan Public Service Commission Regulated Energy Division (kindschl@michigan.gov)
Enclosure to NRC-18-0016 Fermi 2 NRC Docket No. 50-341 Operating License No. NPF-43 Response to Request for Additional Information
Enclosure to NRC-18-0016 Page 1 Response to Request for Additional Information By application dated August 24, 2017, (Agencywide Documents Access and Management System (ADAMS) Accession No. ML17237A176), DTE Energy Company (DTE or licensee) requested to revise Fermi 2 technical specifications (TS) to eliminate the main steam line radiation monitor (MSLRM) reactor trip and Primary Containment Isolation System (PCIS) Group 1 Isolation Functions. The NRC staff has reviewed the information provided by the licensee in support of the proposed license amendment and the staff requests additional information.
SRXB RAI-1 The August 24, 2017, application requests elimination of MSLRM functions for initiating: 1) a reactor protection system (RPS) automatic reactor trip and 2) the associated (Group 1) primary containment isolation system (PCIS) automatic closure of the main steam isolation valves (MSIVs) and main steam line (MSL) drain valves. The licensees justifications for eliminating the MSLRM trip and isolation functions are based on the approach documented in the Boiling Water Reactor Owners Group (BWROG) General Electric (GE) Licensing Topical Report NEDO-31400A.
- a. In addition to the control rod drop accident (CRDA) analysis, are there other MSLRM trip function credited for other accident or transient analyses at Fermi 2? If so, discuss the events, including any plan to eliminate the trip function and resulting impacts on the outcome for those events.
- b. The proposed TS changes requirements for the MSLRM trip function from the Fermi TS Table 3.3.1.1-1, Reactor Protection System Instrumentation. The proposed changes also remove requirements for PCIS Group 1 isolation from TS Table 3.3.6.1-1, Primary Containment Isolation Instrumentation. However, the MSLRM isolation function in TS Table 3.3.6.1-1 is relocated and retained for the current existing PCIS Group 2 isolation of the reactor water sample line. NRC staff concludes that this change will defeat portions of MSLRM high radiation trip function logic circuitry in the reactor protection RPS and PCIS. Will there be any impact on the operation of the RPS or PCIS with respect to other intended safety functions? If so, discuss.
RESPONSE
1.a. The MSLRM functions for initiating a RPS automatic reactor trip and Group 1 PCIS automatic closure of the MSIVs and MSL drain valves are not credited in the proposed CRDA analysis revision described in the Fermi 2 license amendment request (LAR). The MSLRM function for initiating automatic Group 2 PCIS isolation of the reactor water sample line is credited in the proposed CRDA analysis revision in the LAR. However, none of these MSLRM functions are credited for any other accident or transient analyses at Fermi 2.
Enclosure to NRC-18-0016 Page 2 1.b After implementation of the proposed TS changes, the MSLRM functions for initiating a RPS automatic reactor trip and Group 1 PCIS automatic closure of the MSIVs and MSL drain valves will be removed. However, the MSLRMs will continue to monitor the MSLs for radiation and there will be no impact on the operation of RPS or PCIS with regard to other safety functions. The MSLRM function for initiating automatic Group 2 PCIS isolation of the reactor water sample line will be retained. In addition, new MSLRM functions to automatically trip the mechanical vacuum pumps (MVPs) and gland seal exhausters (GSEs) will be added. All other RPS and PCIS function trip logic will remain unaffected by the proposed TS changes and all other intended safety functions will continue to be met as designed.
Enclosure to NRC-18-0016 Page 3 SRXB RAI-2 Operating data presented in GE topical report NED0-31400A indicates that the MSLRMs have initiated eight reactor shutdowns from 1980 through October 1992, but none of the shutdowns were the result of fuel degradation. The shutdowns were the result of instrument failures, chemistry excursions, radiation monitor maintenance errors, and other causes.
For Fermi 2 specifically, state how many plant shutdowns have been caused by the MSLRM trip function. For each shutdown discuss the cause for those MSLRM trip function initiations, including whether any of the shutdowns were the result of actual fuel degradation, and whether the shutdown was unnecessary.
RESPONSE
Fermi 2 has not experienced any plant shutdowns caused by the MSLRM functions. Although Fermi 2 has not directly experienced any plant shutdowns, the removal of the MSLRM functions identified in the LAR is being pursued to eliminate the vulnerability to an inadvertent plant shutdown with loss of normal heat sink, such as those experienced by other plants as described in NEDO-31400A.
Enclosure to NRC-18-0016 Page 4 SRXB RAI-3 The August 24, 2017, application on page 7 of Enclosure 1 states that Above 10% rated thermal power, control rod reactivity worth is reduced such that the effects of postulated rod drop are not sufficient to cause significant fuel damage. In order for the NRC staff to evaluate the impact of the proposed license amendment on the CRDA analytical results, provide the following information, as it relates to the current CRDA analysis of record, and how the proposed changes would impact the degree of fuel damage:
- c. Other than to eliminate the MSLRM trip and the related isolation functions proposed for the CRDA in the licensee's application, will there be any other changes of parameters and assumptions that are made for a CRDA analysis at Fermi 2? If so, discuss the changes and its impact on the CRDA analysis results.
- d. In the Fermi 2 CRDA analysis which trip function of the RPS is credited to scram the reactor, and does this change as a result of eliminating the MSLRM high radiation trip function? If so, discuss the impact of the change.
- e. Other than radiological consequences, discuss whether there is any impact from eliminating the MSLRM high radiation trip function on the degree of fuel damage during a CRDA or any other adverse impact on the core or the plant.
- f. Has the number of fuel rods predicted to fail and melt changed for a CRDA as a result of eliminating the MSLRM high radiation trip function? If so, discuss.
RESPONSE
3.c. The LAR explicitly requested approval to extend the Alternate Source Term (AST) methodology to the CRDA analysis. As a result, the LAR provided a detailed description of parameters and assumptions associated with the new AST-based CRDA analysis. Other than those changes described in the LAR, no other changes to parameters and assumptions are being made for the Fermi 2 CRDA analysis.
3.d The MSLRM high radiation reactor trip function was not previously credited to initiate reactor trip in the CRDA analysis. Elimination of this reactor trip has no impact on the CRDA analysis. In the event of a CRDA, the neutron monitoring system will shut down the reactor in the response to the high flux condition. Specifically, TS Table 3.3.1.1-1 Function 2.c (Average Power Range Monitors Neutron Flux - Upscale) is credited to trip the reactor during a CRDA. Therefore, the credited reactor trip is not changed.
3.e The degree of damaged fuel as a result of the CRDA is determined by a bounding analysis by the fuel vendor for the particular fuel design. The bounding analysis does not credit the MSLRM high radiation trip function. Therefore, the degree of damaged fuel is not
Enclosure to NRC-18-0016 Page 5 impacted by the elimination of the trip function. There are no other adverse impacts on the core or plant.
3.f The number of failed fuel rods assumed is 1200 as described in the LAR. The value was selected for the AST-based CRDA analysis in the LAR based on the bounding analysis by the fuel vendor for the particular fuel design for Fermi 2. The value was not revised as a result of eliminating the MSLRM high radiation trip function.