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Category:E-Mail
MONTHYEARML24012A0492024-01-11011 January 2024 Request for Additional Information Regarding Final Response to Generic Letter 2004-02 ML23311A1682023-11-0707 November 2023 NRR E-mail Capture - Constellation - Fleet Request - Acceptance of Proposed Alternative for Examinations of Examination Category C-B Steam Generator Nozzle-to-Shell Welds and Nozzle Inside Radius Sections (L-2023-LLR-0053 and L-2023-LLR-005 ML23311A1692023-11-0707 November 2023 NRR E-mail Capture - Constellation - Fleet Request - Acceptance of Proposed Alternative for Examinations of Exam Categories B-B, B-D, and C-A SG Pressure Retaining Welds and Full Penetration Welded Nozzles (L-2023-LLR-0055 and L-2023-LLR-00 ML23304A0152023-10-30030 October 2023 NRR E-mail Capture - Final RCI - Constellation Energy Generation, LLC - Calvert Cliffs 1 & 2 - Exemption from Security Rule (L-2023-LLE-0033) ML23181A0732023-06-30030 June 2023 NRR E-mail Capture - Acceptance Review for Calvert Cliffs TSTF-59A ML23160A0222023-06-0606 June 2023 NRR E-mail Capture - Calvert Cliffs - Long Term Coupon Surveillance Program RAI ML23156A0102023-06-0404 June 2023 NRR E-mail Capture - Calvert Cliffs - RAI License Amendment Request for Emergency Desiel Generator ML23080A1002023-03-21021 March 2023 NRR E-mail Capture - Acceptance Review for Calvert Cliffs Repair Replacement of Saltwater System Buried Piping ML23080A0672023-03-21021 March 2023 NRR E-mail Capture - Acceptance Review for Calvert Cliffs Unit 1 - LAR to Modify the Long-Term Coupon Surveillance Program ML23026A1332023-01-26026 January 2023 NRR E-mail Capture - Acceptance Review for Calvert Cliffs Deletion of License Condition for Decommissioning Trust LAR ML22354A2622022-12-20020 December 2022 NRR E-mail Capture - Constellation Energy Generation, LLC - Fleet Request - Acceptance of Request to Use Certain Provisions of the 2019 Edition of the ASME BPV Code, Section XI ML22342B1462022-11-21021 November 2022 NRR E-mail Capture - Acceptance Review for TSTF 295A ML22325A0052022-11-18018 November 2022 NRR E-mail Capture - Constellation Energy Generation, LLC - Fleet Request - Acceptance of License Amendment Request to Adopt TSTF-273-A, Revision 2 ML22255A0132022-09-0909 September 2022 NRR E-mail Capture - NRC Acceptance Review of Braidwood, Byron, Calvert Cliffs, Ginna - License Amendment Request to Adopt TSTF-577 ML22200A0782022-07-19019 July 2022 NRR E-mail Capture - Constellation Energy Generation, LLC - Fleet Request to Use Honeywell Mururoa V4F1 R Supplied Air Suits ML22271A0772022-05-0606 May 2022 NRR E-mail Capture - Final RAIs 9.1.2021 Constellation Relief Request ML22129A0132022-05-0606 May 2022 NRR E-mail Capture - Draft RAIs for Requests for Alternatives I4R-17, I4R-23, ISI-05-018, I6R-10 ML22091A2392022-04-0101 April 2022 NRR E-mail Capture - Calvert Cliffs - Formal RAI for Proposed Alternative for Examinations of Certain Pressurizer Welds ML22091A0852022-04-0101 April 2022 NRR E-mail Capture - Braidwood and Byron - Final RAI Regarding Proposed Alternative for Various Pressurizer Welds (EPID L-2021-LLR-0035 and 0036) ML22091A2402022-03-23023 March 2022 NRR E-mail Capture - (External_Sender) Salem Generating STATION-INCIDENTAL Take of Atlantic Sturgeon Collected on 03/22/2022 ML22075A1912022-03-16016 March 2022 NRR E-mail Capture - Acceptance for Review of Proposed Alternative Repair Method for Buried Class 3 Saltwater System Piping ML22088A1562022-03-0202 March 2022 NRR E-mail Capture - Byron, Braidwood, Calvert Cliffs, and Ginna - Non-acceptance of Application to Revise Technical Specifications 5.6.5.b, the Core Operating Limits Report (COLR) ML22059B0602022-02-28028 February 2022 Change to Review Schedule Regarding Proposed Alternative for Various Pressurizer Welds ML22060A0172022-02-23023 February 2022 NRR E-mail Capture - Calvert Cliffs Nuclear Power Plant, Units 1 and 2 - Withdraw of Draft RAI Regarding Proposed Alternative for Various Pressurizer Welds ML22041B5362022-02-10010 February 2022 NRR E-mail Capture - Constellation Energy Generation, LLC - Request for Additional Information Regarding Fleet License Amendment Request to Adopt TSTF-541 ML21281A1402022-01-14014 January 2022 Acceptance for Review of Proposed Alternative ISI-05-018 for Examinations of Steam Generator Pressure Retaining Welds and Full Penetration Welded Nozzles ML21301A0672021-10-28028 October 2021 NRR E-mail Capture - Exelon Generation Company, LLC - Acceptance of License Amendment Request to Adopt TSTF-541 ML21295A5712021-10-22022 October 2021 NRR E-mail Capture - Acceptance for Review of Proposed Alternative ISI-05-019 for Pressure Testing of Certain Portions of ASME Section XI Class 2 Auxiliary Feedwater Piping ML21287A0322021-10-13013 October 2021 Request for Additional Information Re Proposed Alternative for Pressurizer Circumferential and Longitudinal Shell-to-Head Welds and Nozzle-to-Vessel Welds ML21286A5902021-10-0505 October 2021 Acceptance for Review of Proposed Alternative ISI-05-017 for Examinations of Examination Category C-B Steam Generator ML21287A0932021-10-0505 October 2021 Request for Additional Information: Calvert Cliffs 1 & 2 LAR to Revise Spent Fuel Pool Cooling - Shutdown Cooling Systems Licensing Basis (EPID L-2021-LLA-0112) (Email) ML21256A1902021-09-10010 September 2021 NRR E-mail Capture - Exelon Generation Company, LLC - Request for Additional Information Regarding License Transfer Application ML21214A0202021-08-0909 August 2021 License Amendment Request to Change Spent Fuel Pool Cooling Design Basis ML21215A3502021-08-0303 August 2021 NRR E-mail Capture - Exelon Generation Company, LLC - Acceptance of License Amendment Request to Adopt TSTF-554 ML21201A0482021-07-19019 July 2021 Acceptance of Requested Licensing Action to Change Spent Fuel Pool Cooling Design Basis ML21180A1562021-06-28028 June 2021 Request for Additional Information Regarding License Amendment Request Concerning Containment Sump ML21152A1232021-06-0101 June 2021 Acceptance for Review of Proposed Alternative ISI-05-016 Involving Examination of Pressurizer Circumferential and Longitudinal Shell-to-Head Welds and Nozzle-to-Vessel Welds (EPID L-2021-LLR-0037) (Email) ML21154A0132021-05-28028 May 2021 NRR E-mail Capture - Extension of Comment Period for the Exelon Generation Company, LLC License Transfer Application ML21154A0112021-05-28028 May 2021 NRR E-mail Capture - Extension of Comment Period for the Exelon Generation Company, LLC License Transfer Application ML21154A0142021-05-28028 May 2021 NRR E-mail Capture - Extension of Comment Period for the Exelon Generation Company, LLC License Transfer Application ML21144A2132021-05-24024 May 2021 NRR E-mail Capture - Exelon Generation Company, LLC - Request for Additional Information Regarding License Transfer Application ML21117A0442021-04-26026 April 2021 NRR E-mail Capture - Exelon Generation Company, LLC - Proposed Fleet Alternative to Documentation Requirements for Pressure Retaining Bolting ML21084A2532021-03-24024 March 2021 NRR E-mail Capture - Exelon Generation Company, LLC - Acceptance of License Transfer Application ML21062A0652021-03-0101 March 2021 NRR E-mail Capture - Exelon Generation Company, LLC - Request for Additional Information Regarding Proposed Fleet Alternative to Documentation Requirements for Pressure Retaining Bolting ML21049A2572021-02-18018 February 2021 Request for Additional Information Byron/Dresden Proposed Changes to Site Emergency Plans to Support Post-Shutdown and Permanently Defueled Conditions (EPID-2020-LLA-0240 & EPID-2020-LLA-0237) ML21033A8552021-02-0202 February 2021 NRR E-mail Capture - Exelon Generation Company, LLC - Fleet Alternative Request to Expand the Use ASME Codes Cases N-878 and N-880 ML21029A3302021-01-29029 January 2021 NRR E-mail Capture - Exelon Generation Company, LLC - Request for Additional Information Regarding Fleet Alternative Request to Use ASME Code Case N-885 ML21022A0092021-01-21021 January 2021 Request-Calvert Cliffs-Exelon Generation Co., LLC ML20352A3802020-12-17017 December 2020 Acceptance of Requested Licensing Action to Add Containment Sump Technical Specifications ML20350B5582020-12-14014 December 2020 NRR E-mail Capture - Exelon Generation Company, LLC -Alternative Request for Documentation of Replacement of Pressure Retaining Bolting 2024-01-11
[Table view] Category:Request for Additional Information (RAI)
MONTHYEARML24012A0492024-01-11011 January 2024 Request for Additional Information Regarding Final Response to Generic Letter 2004-02 ML23219A1662023-08-16016 August 2023 Request for Additional Information Regarding Proposed Alternative to the Requirements for Repair/Replacement of Saltwater (SW) System Buried Piping (EPID: L-2023-LLR-0006) - Non-proprietary ML23160A0222023-06-0606 June 2023 NRR E-mail Capture - Calvert Cliffs - Long Term Coupon Surveillance Program RAI ML23156A0102023-06-0404 June 2023 NRR E-mail Capture - Calvert Cliffs - RAI License Amendment Request for Emergency Desiel Generator ML22179A2112022-06-28028 June 2022 Notification of Conduct of a Fire Protection Team Inspection ML22129A0132022-05-0606 May 2022 NRR E-mail Capture - Draft RAIs for Requests for Alternatives I4R-17, I4R-23, ISI-05-018, I6R-10 ML22271A0772022-05-0606 May 2022 NRR E-mail Capture - Final RAIs 9.1.2021 Constellation Relief Request ML22091A0852022-04-0101 April 2022 NRR E-mail Capture - Braidwood and Byron - Final RAI Regarding Proposed Alternative for Various Pressurizer Welds (EPID L-2021-LLR-0035 and 0036) ML22091A2392022-04-0101 April 2022 NRR E-mail Capture - Calvert Cliffs - Formal RAI for Proposed Alternative for Examinations of Certain Pressurizer Welds ML22041B5362022-02-10010 February 2022 NRR E-mail Capture - Constellation Energy Generation, LLC - Request for Additional Information Regarding Fleet License Amendment Request to Adopt TSTF-541 ML21287A0322021-10-13013 October 2021 Request for Additional Information Re Proposed Alternative for Pressurizer Circumferential and Longitudinal Shell-to-Head Welds and Nozzle-to-Vessel Welds ML21287A0932021-10-0505 October 2021 Request for Additional Information: Calvert Cliffs 1 & 2 LAR to Revise Spent Fuel Pool Cooling - Shutdown Cooling Systems Licensing Basis (EPID L-2021-LLA-0112) (Email) ML21256A1902021-09-10010 September 2021 NRR E-mail Capture - Exelon Generation Company, LLC - Request for Additional Information Regarding License Transfer Application ML21187A2232021-07-29029 July 2021 Temporary Instruction 2515/194 Inspection Documentation Request ML21180A1562021-06-28028 June 2021 Request for Additional Information Regarding License Amendment Request Concerning Containment Sump ML21144A2132021-05-24024 May 2021 NRR E-mail Capture - Exelon Generation Company, LLC - Request for Additional Information Regarding License Transfer Application ML21130A0382021-05-21021 May 2021 Memo to File - Draft Request for Additional Information Relief Request CISI-03-01 Concerning Containment Unbonded Post-Tensioning System Inservice Inspection Requirements ML21117A0342021-05-0505 May 2021 Request for Additional Information Regarding Proposed Alternative to Use ASME Code Case N-893 ML21062A0652021-03-0101 March 2021 NRR E-mail Capture - Exelon Generation Company, LLC - Request for Additional Information Regarding Proposed Fleet Alternative to Documentation Requirements for Pressure Retaining Bolting ML21053A3142021-02-22022 February 2021 Information Request for a Triennial Baseline Design Bases Assurance Inspection (Team); Inspection Report 05000317/2021010 and 05000318/2021010 ML21049A2572021-02-18018 February 2021 Request for Additional Information Byron/Dresden Proposed Changes to Site Emergency Plans to Support Post-Shutdown and Permanently Defueled Conditions (EPID-2020-LLA-0240 & EPID-2020-LLA-0237) ML21029A3302021-01-29029 January 2021 NRR E-mail Capture - Exelon Generation Company, LLC - Request for Additional Information Regarding Fleet Alternative Request to Use ASME Code Case N-885 ML20275A0032020-09-30030 September 2020 Request for Additional Information Regarding Alternative Request Re Inservice Inspection Impracticality (L-2020-LLR-0089) ML20167A2532020-06-15015 June 2020 Second Request for Additional Information Regarding License Amendment Request Concerning Emergency Diesel Generator Surveillance Requirements for Frequency and Voltage Tolerances ML20157A0782020-06-0505 June 2020 Request for Additional Information Regarding License Amendment Request Concerning Emergency Diesel Generator Surveillance Requirements for Frequency and Voltage Tolerances ML20153A7042020-06-0101 June 2020 NRR E-mail Capture - Preliminary RAI for Fleet Request to Use Alternative OMN-26 ML20135H0132020-05-14014 May 2020 IP 71111.17T (50.59) List of Documents Request ML20083F5892020-03-21021 March 2020 Request for Additional Information Regarding License Amendment Request Concerning Reactor Coolant Pump Flywheel Inspection Program ML19275H1362019-10-0202 October 2019 NRR E-mail Capture - Exelon Generation Company, LLC - Request for Additional Information Regarding Request to Use ASME Code Case N-879 ML19261B2202019-09-18018 September 2019 Request for Additional Information Regarding Final Response to Generic Letter 2004-02 ML19179A0612019-07-19019 July 2019 Three Mile Point 1 - Supplemental Information Needed to Proposed Alternative to Use ASME Code Case N-879 ML19155A1612019-06-11011 June 2019 Changes to Draft Request for Additional Information Request to Adopt 10 CFR 50.69, Risk-Informed Categorization and Treatment of Systems, Structures and Components ML19155A1272019-06-0404 June 2019 Request for Additional Information Regarding Request to Adopt 10 CFR 50.69 Risk Informed Categorization and Treatment of Systems, Structures, and Components ML19070A0192019-03-11011 March 2019 Request for Additional Information Regarding Exemption Request from 10CFR50.46(A)(1) to Support Resolution of GSI-191 ML19025A1202019-01-24024 January 2019 NRR E-mail Capture - Calvert Cliffs, Fitzpatrick, and Nine Mile Point - Request for Additional Information Regarding License Amendment Request to Revise Emergency Response Organization Staffing ML18347A3972018-12-13013 December 2018 Request for Additional Information Regarding Relocation of Emergency Operation Facility ML18138A1372018-05-22022 May 2018 Plants, Units 1 and 2 - Request for Additional Information Regarding Risk Informed Technical Specification Completion Times (CAC Nos. MF7415 and MF7416; EPID L-2016-LLA-0001) ML18128A3842018-05-0808 May 2018 Plants, Units 1 and 2 - Draft Request for Additional Information Regarding Risk-Informed Technical Specification Completion Times (CAC Nos. MF7415 and MF7416; EPID L-2016-LLA-0001) ML18102A2372018-04-12012 April 2018 NRR E-mail Capture - Calvert Cliffs, Ginna, and Nine Mile Point - Request for Additional Information Regarding License Amendment Request to Revise Emergency Action Level Schemes (EPID-L-2017-LLA-0237) ML18067A1482018-03-0808 March 2018 Enclosurequest for Additional Information (Letter to P. R. Simpson Request for Additional Information Regarding Exelon Generating Company, Llc'S Decommissioning Funding Plan Update for Independent Spent Fuel Storage Installation) ML17345A0912018-01-19019 January 2018 Plants, Units 1 and 2 - Request for Additional Information Regarding Alternative Request SI-RR-01, Rev. 0 (CAC Nos. MG0068 and MG0069; EPID L-2017-LLR-0078) ML17346A9092017-12-21021 December 2017 Request for Additional Information Regarding Risk-Informed Technical Specification Completion Times (CAC Nos. MF7415 and MF7416; EPID L-2016-LLA-0001) ML17331B1342017-12-12012 December 2017 2, and R.E. Ginna Nuclear Power Plant - Request for Additional Information - Regarding ML17304A9412017-11-13013 November 2017 Request for Additional Information Regarding Risk-Informed Technical Specification Completion Times (CAC Nos. MF7415 and MF7416; EPID L-2016-LLA-0001) ML17285B1962017-10-27027 October 2017 Request for Additional Information Regarding Generic Letter 2016-01, Monitoring of Neutron-Absorbing Materials in Spent Fuel Pools. ML17075A0152017-03-16016 March 2017 E-mail from R. Guzman to E. Villar - Calvert Cliffs Unit Nos. 1 and 2 - Request for Additional Information License Amendment Request - Control Room Emergency Ventilation System ML17062A4912017-03-0303 March 2017 NRR E-mail Capture - Exelon Generation Company, LLC - Request for Additional Information Regarding Fleet Alternative to RPV Threads in Flange Examination (CAC Nos. MF8712-MF8729) ML16222A1252016-08-0909 August 2016 Request for Additional Information - Relief Request No. RR-ISI-04-11, 2016/08/08 E-mail from R.Guzman to T.Loomis ML15299A2792015-11-0303 November 2015 Request for Additional Information Regarding Relief Request for Dissimilar Metal Butt Welds ML15230A0322015-08-13013 August 2015 Request for Additional Information Regarding the National Association Standard 805 License Amendment Request Fire Protection 2024-01-11
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Text
From: Mayer, Annie To: Loomis, Thomas R:(Exelon Nuclear)
Cc: Mayer, Annie
Subject:
Calvert Cliffs Nuclear Power Plant, Units 1 and 2 - Request for Additional Information re: Proposed Alternative for Pressurizer Circumferential and Longitudinal Shell-to-Head Welds and Nozzle-to-Vessel Welds (EPID L-2021-LLR-0037)
Date: Wednesday, October 13, 2021 2:40:39 PM Hello Tom, By letter dated May 12, 2021 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML21133A297), Exelon Generation Company, LLC (Exelon, the licensee) requested U.S. Nuclear Regulatory Commission (NRC) approval of an alternative, RS 21-056, pursuant to Title 10 of the Code of Federal Regulations (10 CFR) 50.55 a(z)(1)
(i) to the requirements of American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME Code) at Calvert Cliffs Nuclear Plant Units 1 and 2 (Calvert Cliffs 1 and 2). The proposed alternatives for Braidwood Station Units 1 and 2 and Bryon Station Units 1 and 2 included in the letter are being reviewed separately. The proposed alternative would allow the licensee to forego ASME Code, Section XI-required examinations of various pressurizer welds through the end of the extended licenses.
The NRC staff has determined that additional information is needed to complete its review of the request. The draft request for additional information (RAI) was sent to you on October 1, 2021, and a clarification call was held with your staff on October 13, 2021. It was agreed that Exelon would provide a response no later than November 19, 2021.
REQUEST FOR ADDITIONAL INFORMATION Pursuant to 10 CFR 50, Paragraph 50.55a(z)(1), the licensee proposed to increase the inservice inspection (ISI) interval for the subject components to the end of the current approved period of extended operation, from the current ASME Code Section,Section XI requirement of 10 years. Paragraph 50.55a(z)(1) of 10 CFR requires the licensee to demonstrate that the proposed alternative provides an acceptable level of quality and safety. The licensee referred to the analyses in nonproprietary Electric Power Research Institute (EPRI) Report No. 3002015905, "Technical Bases for Inspection Requirements for PWR Pressurizer Head, Shell-to-Head, and Nozzle-to-Vessel Welds", December 2019 (ADAMS Accession No. ML21021A271) to support the proposed alternative in the submittal. The licensee also included an applicability evaluation of EPRI Report 3002015905 to Calvert Cliffs 1 and 2 in the submittal.
RAI 1
In Appendix D of the licensees submittal, the licensee stated that Calvert Cliffs 1 and 2 does not track thermal transients. The licensee instead provided fatigue usage factors and environmental-assisted fatigue usage factors. The licensee stated that Calvert Cliffs 1 and 2 meet the design limits for fatigue usage factor up to 60 years of operation. The staff notes that compliance with design requirements does not imply that the probabilistic fracture mechanics (PFM) evaluation in EPRI Report 3002015905 is an appropriate basis for inspection relief for the Calvert Cliffs 1 and 2 pressurizer welds. While the application provides some insight relative to the EPRI report modeling, the staff is unable to compare these results with the population of cycles modeled in the EPRI report. This is particularly
important in that several of the subject components also received low inspection coverage values, creating combined uncertainties relative to the applicability of the EPRI model. An appropriate technical basis should include a discussion for why the analyzed fatigue histories are a reasonable representation of the actual fatigue histories.
Provide a technical basis related to fatigue history, irrespective of compliance with design requirements, for why the generic PFM in EPRI Report 3002015905 is an appropriate basis for inspection relief at Calvert Cliffs 1 and 2.
RAI 2
The requested alternative relies on the applicability of the conclusions of EPRI Report 3002015905 to the subject components to justify the requested alternative. The staff notes that the report demonstrates that successful preservice inspection (PSI) and ISI impact calculated outcomes for the subject components, particularly significant for the limiting component in the analysis (i.e. approaching the risk criterion used in the report).
The staff noted that for both Calvert Cliffs units the results of the PSI were not reported, and for a significant number of the components, low inspection volumes were achieved. In addition, the staff understands that the PROMISE model is unable to model situations where a specific volume of a component cannot be inspected in successive inspections (i.e.
the program generates a new miss chance for each inspection round, modeling a random chance that any modeled flaw may be identified by a modeled inspection round). The lack of verifiable PSI results coupled with low inspectability of a large volume of material is not well addressed by the sensitivity studies reported in the EPRI report.
Provide a technical basis related to how the subject pressurizer welds at the Calvert Cliffs units, in particular the pressurizer welds with less than 50 percent coverage, can be considered adequately represented by the modeling in the EPRI Report; or otherwise justified.
RAI 3
In Table 4 of Attachment 1 to the licensees submittal, the licensee provided the inspection history of the pressurizer welds in scope of the alternative request for Calvert Cliffs 1 and 2. Table 4 shows that upper and lower shell welds 2-401B and 2-401C for both units have no documented examination history. In footnote 4 of Table 4, the licensee states that, for Successive Inspection Intervals, ASME Section XI requires only 1 foot of weld to be volumetrically examined. The staff notes that compliance with ASME Section XI requirements does not imply that the generic PFM evaluation in EPRI Report 3002015905 is an appropriate basis for inspection relief for the subject welds.
The NRC staff has previously addressed conclusions in EPRI Report 3002015905 that are based upon PFM evaluations of the PSI-only case, since PSI-only examination does not account for performance monitoring (see Section 10 of Salem Generating Station Unit Nos. 1 and 2 - Authorization and Safety Evaluation for Alternative Request No. SCI4R-200 (EPID L-2020-LLR-0103), ADAMS Accession No. ML21145A189). An appropriate technical basis should include a discussion for why the analyzed examination histories in the EPRI report are a reasonable representation of the actual examination histories. Also, the staff notes that footnote 4 of Table 4 does not provide a complete explanation of the
ASME Section XI requirements that led to no documented examination history for the subject welds.
- a. Provide a technical basis related to examination history, irrespective of compliance with Section XI requirements, for why the generic PFM in EPRI Report 3002015905 is an appropriate basis for inspection relief for upper and lower shell welds 2-401B and 2-401C at Calvert Cliffs 1 and 2.
- b. Provide an expanded explanation of the ASME Section XI requirements related to upper and lower shell welds 2-401B and 2-401C, including specific reference to relevant ASME Section XI paragraphs.
Docket Nos. 50-317, 50-318 Thank you, Andrea (Annie) Mayer Technical Assistant NRR/DORL 301-415-1081 andrea.mayer@nrc.gov