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Category:Memoranda
MONTHYEARML22130A1702022-05-20020 May 2022 Summary of April 21, 2022, Public Meeting to Discuss Potential Emergency Preparedness License Amendment Request ML22028A3502022-01-21021 January 2022 Green Mountain Power, 2021 Annual Summary of Special Nuclear Committee ML21027A0232021-01-28028 January 2021 Summary of January 26, 2021 Closed Meeting with Dominion Energy Regarding Performance of Force on Force Exercises in a Pandemic Environment ML19165A1192019-06-14014 June 2019 Memoranda to File Environmental Assessment and Finding of No Significant Impact for the Virginia Electric and Power Company, Dominion Energy Kewaunee, Inc., and Dominion Nuclear Connecticut, Inc.'S Decommissioning Funding Plans Submitted ML17271A0532017-09-29029 September 2017 2017 Summary of Annual Decommissioning Funding Status Reports for Reactors in Decommissioning ML16088A2042016-03-28028 March 2016 Memo T Bowers from s Ruffin, Technical Assistance Requests - Review 2015 Tri-Annual Decommissioning Funding Plans for Multiple Independent Spent Fuel Storage Installations W/ Encl 2 (Template) ML16088A2052016-03-28028 March 2016 Enclosure 1 - (72.30 DFP Reviews to Be Completed 2015) - Memo T Bowers from s Ruffin, Technial Assistance Requests - Review 2015 Tri-Annual Decommissioning Funding Plans for Multiple Independent Spent Fuel Storage Installations ML15075A1922015-03-26026 March 2015 Reactor Coolant System Alloy 600 Inspection Program for License Renewal Commitment No. 14. (Tac No. MF3433) ML13031A1832013-02-0505 February 2013 Closed Meeting Announcement Millstone Drop-In ML13032A0572013-01-30030 January 2013 2012 Annual Summary of the Green Mountain Power Special Nuclear Committee ML12178A6132012-06-27027 June 2012 Notice of Forthcoming Pre-Application Meeting with Dominion Nuclear Connecticut, Inc. to Discuss a Proposed Millstone Power Station, Unit 2, License Amendment Request Concerning Spent Fuel Pool Criticality Re-Analysis ML13196A2202012-06-0606 June 2012 Memo from B. Balsam, NRR and D. Logan, NRR to J. Susco, NRR on Summary of Section 7 Consultation Activities Related to the National Marine Fisheries Service'S Final Rule to List the Atlantic Sturgeon ML11271A1782011-10-0303 October 2011 Review of Topical Report, Revision 11 for Kewaunee Power Station and ISFSI, Millstone Power Station, Units 1, 2, & 3 and ISFSI, North Anna Power Station, Units 1 & 2 and ISFSI, Surry Power Station, Units 1 & 2 and ISFSI (Tac ME6649, ME6650, ML11250A1712011-09-14014 September 2011 Notice of Forthcoming Meeting with Petitioner Requesting Action Under 10 CFR 2.206 Regarding Immediate Suspension of the Operating Licenses of General Electric (GE) Mark 1 Boiling Water Reactors (Bwrs) ML1116804602011-06-30030 June 2011 Review of Commitment Change Report for 2009 ML1103106822011-02-0101 February 2011 Revised Notice of Forthcoming Public Meeting with Dominion Nuclear Connecticut, Inc., to Discuss Millstone Power Station Licensing Activities ML1100701752011-01-11011 January 2011 Request for Technical Assistance on Request for Exemption Form Certain Requirements of 10 CFR 73.55 for Millstone Power Station, Unit 1 ML1035103202010-12-20020 December 2010 30-Day Report of Emergency Core Cooling System Model Change ML1033305502010-12-15015 December 2010 Potential Notice of Enforcement Discretion for the Turbine Driven Auxiliary Feedwater Pump ML1031202422010-11-0808 November 2010 Notice of Teleconference with Dominion Nuclear Connecticut, Inc. to Discuss Millstone Power Station, Unit No. 3 Generic Letter 2004-02 Supplemental Response ML1030100732010-10-28028 October 2010 Meeting Notice Milestone Power Station Revised 10 CFR 73.55 ML1019502842010-07-14014 July 2010 Notice of Forthcoming Public Teleconference with Dominion Nuclear Connecticut, Inc. to Discuss Millstone Power Station, Unit No. 3 Generic Letter 2004-02 Supplemental Response ML1008204222010-03-26026 March 2010 Notice of Conference Call with Dominion Nuclear Connecticut, Inc. to Discuss Millstone Power Station, Unit Nos 2 and 3 Generic Letter 2004-02 Supplemental Responses ML1003314992010-03-0101 March 2010 Notice of Conference Call with Dominion Nuclear Connecticut, Inc., to Discuss Millstone Power Station, Unit Nos. 2 and 3 Generic Letter 2004-02 Supplemental Responses ML0931406252009-11-17017 November 2009 Summary of Teleconference Verbal Authorization for Relief Request RR-89-67 ML0913401332009-05-15015 May 2009 Notice of Forthcoming Meeting with Dominion Nuclear Connecticut, Inc. to Discuss the Submittal of a License Amendment Request Regarding the Removal of Charging Pumps from the Technical Specifications for Millstone Power Station, Unit No. 2 ML0906205722009-03-0303 March 2009 Meeting Minutes of the Power Uprates Subcommittee, July 8, 2008 ML0811500912008-04-23023 April 2008 Proposed Stretch Power Uprate to Millstone Power Station, Unit 3 ML0807400842008-03-14014 March 2008 Draft Regulatory Guide for Comment ML0734708412007-12-11011 December 2007 Drop-In Visit from Dominion (Millstone) ML0730304052007-10-31031 October 2007 E. Marinos Memo Technical Assistance Request-Dominion Resources, Inc.'S December 6, 2006, Request for Exemption from 10 CFR 74.13(a) Requirements Regarding Material Status Report Submittal Time Frame ML0715100542007-05-31031 May 2007 Closeout of TAC Numbers for Licensing Activities That Do Not Require Staff Review ML0710201942007-04-24024 April 2007 Draft Open Items from Staff Audit of Corrective Actions to Address Generic Letter 2004-02 ML0707902492007-03-20020 March 2007 Facsimile Transmission, Draft Request for Additional Information Regarding Steam Generator Tube Integrity ML0634902692007-01-11011 January 2007 Memo: K. Mcconnell to M. Lesar - Notice of Environmental Assessment and Finding of No Significant Impact Related to Partial Exemption from 10 CFR Part 50, Recordkeeping Requirements - Millstone Power Station, Unit 1 ML0633901162006-12-19019 December 2006 Fax - Draft Request for Additional Information Regarding Post-Maintenance/Modification Surveillance Requirements ML0630701472006-12-12012 December 2006 Facsimile Transmission, Draft Request for Additional Information ML0631101502006-11-13013 November 2006 Request for Additional Information Regarding Human Factors - Millstone, Unit 2, Alternate Source Term License Amendment Request ML0626800242006-10-0202 October 2006 Transfer of Project Management Responsibilities ML0625100662006-09-29029 September 2006 Facsimile Transmission, Draft Request for Additional Information Regarding Extension of Integrated Leakage Rate Test Interval ML0619500042006-07-14014 July 2006 Facsimile Transmission, Draft Request for Additional Information Regarding Post Maintenance/Modification Surveillance Requirements ML0619500092006-07-14014 July 2006 Facsimile Transmission, Draft Request for Additional Information Regarding Relaxation Request IR-2-46, Reactor Pressure Vessel Head Inspections ML0617805592006-07-10010 July 2006 Revised Closeout Letter for Bulletin 2003-01, Potential Impact of Debris Blockage on Emergency Sump Recirculation at Pressurized-Water Reactors. ML0617701952006-06-26026 June 2006 Closeout of Tac Number for Licensing Activities Incorrectly Identified for Staff Review ML0606702532006-03-24024 March 2006 Facsimile Transmission, Draft Request for Additional Information to Be Discussed in an Upcoming Conference Call ML0608601632006-03-21021 March 2006 Handouts to Applicants (Folder 3) ML0604005082006-03-0202 March 2006 Facsimile Transmission, Draft Request for Additional Information to Be Discussed in an Upcoming Conference Call ML0602700882006-01-31031 January 2006 Facsimile Transmission Draft Request for Additional Information to Be Discussed in an Upcoming Conference Call (Tac No. MC8327) ML0602502612006-01-26026 January 2006 Facsimile Transmission, Draft Request for Additional Information to Be Discussed in an Upcoming Conference Call ML0528500672005-10-25025 October 2005 Facsimile Transmission RAI to Be Discussed in an Upcoming Conference Call 2022-05-20
[Table view] Category:Report
MONTHYEARML24170B0532024-06-10010 June 2024 DOM-NAF-2-P/NP-A, Revision 0.5, Reactor Core Thermal-Hydraulics Using the VIPRE-D Computer Code ML24093A1022024-04-0101 April 2024 Alternative Request IR-4-13, Proposed Alternative Request to Support Steam Genera Tor Channel Head Drain Modification ML24086A4802024-03-22022 March 2024 Alternative Request IR-4-14, Proposed Alternative Request to Defer ASME Code Section XI Inservice Inspection Examination for Pressurizer and Steam Generator Pressure-Retaining Welds and Full Penetration Welded Nozzles ML23324A4222023-11-20020 November 2023 Reactor Vessel Internals Inspections Aging Management Program Submittal Related to License Renewal Commitment 13 ML23324A4302023-11-20020 November 2023 Alloy 600 Aging Management Program Submittal Related to License Renewal Commitment 15 ML23188A0202023-07-26026 July 2023 Closeout of Generic Letter 2004-02, Potential Impact of Debris Blockage on Emergency Recirculation During Design Basis Accidents at Pressurized-Water Reactors ML23151A0742023-06-12012 June 2023 Review of the Spring 2022 Steam Generator Tube Inspection Report ML23103A2282023-04-12012 April 2023 Stations Units 1 and 2; Millstone Power Station Units 2 and 3, DOM-NAF-2-P/NP-A, Revision 0.4, Reactor Core Thermal-Hydraulics Using the VIPRE-D Computer Code ML22353A6202022-12-19019 December 2022 Request for Approval of Appendix F Fleet Report DOM-NAF-2-P, Qualification of the Framatome ORFEO-GAIA and ORFEO-NMGRID CHF Correlations in the Dominion Energy VIPRE-D Computer Code ML22193A1432022-06-23023 June 2022 5 to Updated Final Safety Analysis Report, Technical Requirements Manual Current Through Change No. 207 ML21175A2472021-06-24024 June 2021 2020 Annual Report of Emergency Core Cooling System (ECCS) Model Changes Pursuant to the....- ML21113A1352021-04-27027 April 2021 Review of the Spring 2017 Steam Generator Tube Inspection Report ML21042B3212021-02-11011 February 2021 Stations, Units 1 & 2; Millstone Power Station, Units 2 & 3 - Request for Approval of Fleet Report DOM-NAF-2 Qualification of the Framatome BWU-I CHF Correlation in the Dominion Energy VIPRE-D Computer Code ML20352A3342020-12-17017 December 2020 Proposed Alternative Requests RR-05-04 and IR-4-02, Use of Alternative Pressure/Flow Testing Requirements for Service Water System Supply Piping ML20345A3682020-12-16016 December 2020 Review of the Fall 2017 and Spring 2019 Steam Generator Tube Inspection Reports ML20247J6162020-09-0303 September 2020 Request to Use a Provision of a Later Edition of the American Society of Mechanical Engineers Boiler and Pressure Vessel Code, Section XI ML20171A5342020-08-13013 August 2020 Staff Assessment of Flood Hazard Focused Evaluation and Integrated Assessment ML20203M1602020-07-20020 July 2020 VA Elec. & Power Co., Dominion Energy Nuclear Co. Inc., Dominion Energy Sc Inc., Millstone Power Station 2, N. Anna & Surry Power Stations 1 & 2, Virgil C. Summer Station 1, Updated Anchor Darling Double Disc Gate Valve Information & Status ML20105A0782020-04-14014 April 2020 Supplement to License Amendment Request to Revise TS 3.8.1.1, A.C. Sources - Operating, to Support Maintenance and Replacement of the 'A' Reserve Station Service Transformer and 345 Kv South Bus Switchyard Components ML19352B8982019-12-17017 December 2019 Proposed Alternative Request RR-05-05, Containment Unbonded Post-Tensioning System Inservice Inspection Requirements ML19246A1162019-10-0707 October 2019 Supplement to Staff Assessment of Response to 10 CFR 50.54(F) Information Request - Flood Causing Mechanism Reevaluation(Epid Nos. 000495\05000336\L- 2015-JLD-0011 and 000495\05000423\L-2015-JLD-0012 - (2019Aug21) ML19249B7682019-08-29029 August 2019 Enclosure 3 - Millstone Power Station EAL Technical Bases Documents Final (Updated) ML19249B7742019-08-29029 August 2019 Enclosure 5 - Surry Power Station EAL Technical Bases Document Final (Updated) ML19249B7782019-08-29029 August 2019 Enclosure 6 - Millstone Power Station, Unit 2, Comparison Matrix RCS Pot. Loss A.1 ML19249B7722019-08-29029 August 2019 Enclosure 4 - North Anna Power Station, EAL Technical Bases Document Final (Updated) ML19211B1682019-07-24024 July 2019 Day Special Report for One Train of Reactor Vessel Level Monitor Inoperable ML19070A2172019-04-0303 April 2019 Supplement to Interim Staff Response to Reevaluated Flood Hazards Submitted in Response to 10 CFR 50.54(f) Information Request - Flood - Causing Mechanism Reevaluation ML19064A5902019-02-28028 February 2019 Proposed Alternative Request IR-3-39, Alternative to ASME Code, Section XI, IWA-4221(C), to Permit Two Fillet Welds Not in Compliance with the Construction Code to Remain in Service ML19011A1722019-01-0404 January 2019 Enclosure 3, Attachments 2C-3C - MPS3 EAL Technical Bases Document (Marked-Up) ML19011A1732019-01-0404 January 2019 Enclosure 4 - North Anna Power Station Units 1 & 2, EAL Scheme Revisions-Supporting Documents ML19011A1742019-01-0404 January 2019 Enclosure 5 - Surry Power Station, EAL Scheme Revisions-Supporting Documents ML18256A2002018-10-0303 October 2018 Staff Assessment of Response to 10 CFR 50.54(f) Information Request - Flood-Causing Mechanism Reevaluation (EPID L00495\05000336 L-2015-JLD-0011 and 00495\05000423\L-2015-JLD-0012) ML18247A2752018-06-18018 June 2018 Technical Requirements Manual ML17187A1692017-06-28028 June 2017 Mitigating Strategies Assessment (MSA) Report) ML17108A3272017-04-0606 April 2017 Reactor Vessel Standby Surveillance Capsule Z Dosimetry Analysis and Storage Confirmation ML17051A0012017-02-27027 February 2017 Summary of the NRC Staff'S Review of the Spring 2015 Steam Generator Tube Inservice Inspections ML16193A6702016-06-30030 June 2016 ISFSI - 10 CFR 50.59, 10 CFR 72.48 Change Report for 2014 and 2015, and Commitment Change Report for 2015 ML15328A2682015-12-15015 December 2015 Staff Assessment of Information Provided Pursuant to Title 10 of the Code of Federal Regulations Part 50, Section 50.54(f) Seismic Hazard Reevaluations for Recommendation 2.1 of the Near-Term Task Force Review ML15275A2882015-10-19019 October 2015 Summary of the NRC Staff'S Review of the Fall 2014 Steam Generator Tube Inservice Inspections ML15253A2062015-09-0101 September 2015 ANP-3315NP, Revision 0, Millstone Unit 2 M5 Upgrade, Small Break LOCA Analysis Licensing Report. ML15194A0572015-06-30030 June 2015 ISFSI - NRC Commitment Change Report for 2014 ML15078A2062015-03-12012 March 2015 to Engineering Evaluation 14-E16, Dominion Flooding Hazard Reevaluation Report for Millstone, Units 2 and 3, in Response to 50.54(F) Information Request Regarding Near-Term Task Force Recommendation 2.1: Flooding, Pp. 2-58 Through 2-125 ML15078A2082015-03-12012 March 2015 to Engineering Evaluation 14-E16, Dominion Flooding Hazard Reevaluation Report for Millstone, Units 2 and 3, in Response to 50.54(F) Information Request Regarding Near-Term Task Force Recommendation 2.1: Flooding, Pp. 2-172 Through the End ML15078A2072015-03-12012 March 2015 to Engineering Evaluation 14-E16, Dominion Flooding Hazard Reevaluation Report for Millstone, Units 2 and 3, in Response to 50.54(F) Information Request Regarding Near-Term Task Force Recommendation 2.1: Flooding, Pp. 2-126 Through 2-171 ML15078A2052015-03-12012 March 2015 to Engineering Evaluation 14-E16, Dominion Flooding Hazard Reevaluation Report for Millstone, Units 2 and 3, in Response to 50.54(F) Information Request Regarding Near-Term Task Force Recommendation 2.1: Flooding, Pp. 1 Through 2-57 ML14220A0172014-07-30030 July 2014 Startup Test Report for Cycle 23 ML13338A4332014-01-31031 January 2014 Interim Staff Evaluation Relating to Overall Integrated Plan in Response to Order EA-12-049 (Mitigation Strategies) ML14013A2712014-01-30030 January 2014 Staff Assessment of the Seismic Walkdown Report Supporting Implementation of Near-Term Task Force Recommendation 2.3 Related to the Fukushima Dai-Ichi Nuclear Power Plant Accident ML13357A3982014-01-24024 January 2014 Mega-Tech Services, LLC Technical Evaluation Report Regarding the Overall Integrated Plan for Milestone Power Station, Unit 2, TAC No.: MF0858 ML14006A1592014-01-0808 January 2014 Mega-Tech Services, LLC Technical Evaluation Report Regarding the Overall Integrated Plan for Millstone Power Station, Unit 3, TAC No.: MF0859 2024-06-10
[Table view] Category:Miscellaneous
MONTHYEARML23324A4302023-11-20020 November 2023 Alloy 600 Aging Management Program Submittal Related to License Renewal Commitment 15 ML23188A0202023-07-26026 July 2023 Closeout of Generic Letter 2004-02, Potential Impact of Debris Blockage on Emergency Recirculation During Design Basis Accidents at Pressurized-Water Reactors ML23151A0742023-06-12012 June 2023 Review of the Spring 2022 Steam Generator Tube Inspection Report ML22353A6202022-12-19019 December 2022 Request for Approval of Appendix F Fleet Report DOM-NAF-2-P, Qualification of the Framatome ORFEO-GAIA and ORFEO-NMGRID CHF Correlations in the Dominion Energy VIPRE-D Computer Code ML21113A1352021-04-27027 April 2021 Review of the Spring 2017 Steam Generator Tube Inspection Report ML20345A3682020-12-16016 December 2020 Review of the Fall 2017 and Spring 2019 Steam Generator Tube Inspection Reports ML20247J6162020-09-0303 September 2020 Request to Use a Provision of a Later Edition of the American Society of Mechanical Engineers Boiler and Pressure Vessel Code, Section XI ML20171A5342020-08-13013 August 2020 Staff Assessment of Flood Hazard Focused Evaluation and Integrated Assessment ML20105A0782020-04-14014 April 2020 Supplement to License Amendment Request to Revise TS 3.8.1.1, A.C. Sources - Operating, to Support Maintenance and Replacement of the 'A' Reserve Station Service Transformer and 345 Kv South Bus Switchyard Components ML19211B1682019-07-24024 July 2019 Day Special Report for One Train of Reactor Vessel Level Monitor Inoperable ML17187A1692017-06-28028 June 2017 Mitigating Strategies Assessment (MSA) Report) ML17108A3272017-04-0606 April 2017 Reactor Vessel Standby Surveillance Capsule Z Dosimetry Analysis and Storage Confirmation ML17051A0012017-02-27027 February 2017 Summary of the NRC Staff'S Review of the Spring 2015 Steam Generator Tube Inservice Inspections ML16193A6702016-06-30030 June 2016 ISFSI - 10 CFR 50.59, 10 CFR 72.48 Change Report for 2014 and 2015, and Commitment Change Report for 2015 ML15328A2682015-12-15015 December 2015 Staff Assessment of Information Provided Pursuant to Title 10 of the Code of Federal Regulations Part 50, Section 50.54(f) Seismic Hazard Reevaluations for Recommendation 2.1 of the Near-Term Task Force Review ML15275A2882015-10-19019 October 2015 Summary of the NRC Staff'S Review of the Fall 2014 Steam Generator Tube Inservice Inspections ML15194A0572015-06-30030 June 2015 ISFSI - NRC Commitment Change Report for 2014 ML14220A0172014-07-30030 July 2014 Startup Test Report for Cycle 23 ML14013A2712014-01-30030 January 2014 Staff Assessment of the Seismic Walkdown Report Supporting Implementation of Near-Term Task Force Recommendation 2.3 Related to the Fukushima Dai-Ichi Nuclear Power Plant Accident ML13303B9072013-10-17017 October 2013 10 CFR 71.95 Report - 8-120B Cask Certificate of Compliance Noncompliance Due to an Inadequate Vendor Leak Test Procedure ML13192A1022013-07-18018 July 2013 Closure Evaluation for 30-Day Report for Emergency Core Cooling System Model Changes Pursuant to the Requirements of 10 CFR 50.46 ML12362A3922012-11-30030 November 2012 Spent Fuel Pool Criticality Analysis with No Credit for Boraflex. ML12353A2422012-11-27027 November 2012 Report in Response to March 12, 2012 Information Request Regarding Seismic Aspects of Recommendation 2.3 ML12187A1752012-06-25025 June 2012 ISFSI - 10 CFR 50.59, 10 CFR 72.48 Change Report for 2010 and 2011, and Commitment Change Report for 2010 and 2011 ML12151A3592012-06-0707 June 2012 End of Cycle 20 Steam Generator Tube Inservice Inspection Report Review ML12046A8362012-01-31031 January 2012 Inservice Inspection Program - Owner'S Activity Report ML12031A1472012-01-25025 January 2012 Day Report for Emergency Core Cooling System Model Changes of 10 CFR 50.46 ML1116002202011-06-13013 June 2011 Exhibit D (Part 3): Millstone 2001 Safstor Cost Analysis (Normal Dollars) ML1028504382010-09-30030 September 2010 Attachments 2, 3, 5, 7, 8 & 9, to 10-579A, Westinghouse Electric Co. LLC, WCAP-17071-NP, H*: Alternate Repair Criteria for the Tubesheet Expansion Region in Steam Generators with Hydraulically Expanded Tubes (Model F), Revision 2, Dated Sep ML1019403352010-06-30030 June 2010 Units, 1, 2, 3, & ISFSI, 10 CFR 50.59, 10 CFR 72.48 Change Report for 2008 and 2009, and the Commitment Change Report for 2009 ML1012704392010-05-0505 May 2010 Y020100187 - List of Historical Leaks and Spills at U.S. Commercial Nuclear Power Plants ML1009702062010-03-29029 March 2010 Chemistry Procedure, Liquid Waste Sample Sink, Rev. 003-00 ML0931701762009-11-12012 November 2009 Part 3 of 4--Weld Overlay Examination Report 2R19 ML0931701732009-11-12012 November 2009 Part 2 of 4--Weld Overlay Examination Report 2R19 ML0931701662009-11-12012 November 2009 Part 1 of 4--Weld Overlay Examination Report 2R19 ML0931701852009-09-23023 September 2009 Part 4 of 4--Weld Overlay Examination Report 2R19 ML0921908942009-08-0404 August 2009 Units 1 & 2, Millstone, Units 2 and 3 and Kewaunee - Approved Topical Report DOM-NAF-2, Revision 0.1-A ML0913204602009-04-28028 April 2009 2008 Occupational Radiation Exposure Information ML0901303822008-12-26026 December 2008 Revision 002 to CP 3804L Procedure Action Request, Pass Containment Air Sample, Dated 12/26/2008 ML0830903962008-10-24024 October 2008 End of Cycle 18 Steam Generator Tube Inspection Report ML0827701132008-09-30030 September 2008 Response to Request for Additional Information Regarding Spent Fuel Pool Storage License Amendment Request ML0819800752008-07-0707 July 2008 Revision to Control Room and OSC Assembly Area Building 475 1st Floor, and SAP Locker ML0818406072008-07-0101 July 2008 Final Evaluation of Weld Overlay Examinations in Refueling Outage 18 ML0727504022007-09-27027 September 2007 Alternative Request RR-89-64 for Use of a Limited One-Sided Ultrasonic Examination Technique LBDCR 07-MP2-034 ML0720003902007-07-13013 July 2007 Attachment 1, Millstone Power Station Unit 3, License Amendment Request, Stretch Power Uprate, Descriptions, Technical Analysis and Regulatory Analysis for the Proposed Operating License and Technical Specifications Changes ML0715203992007-05-30030 May 2007 Fy 2007 Final Fee Rule Workpapers ML0713501882007-05-17017 May 2007 Review of Steam Generator Tube Inservice Inspection Report for the 2005 Refueling Outage at Millstone Power Station, Unit No. 2 ML0713502492007-05-0808 May 2007 Steam Generator Tube Plugging Report ML0708805652007-03-28028 March 2007 Response to Request for Additional Information Regarding an Alternative for the Weld Overlay of Pressurizer Nozzle Welds ML0705903272007-02-27027 February 2007 Fitness-For-Duty Program Semi-Annual Performance Data Report 2023-07-26
[Table view] |
Text
August 28, 2002 NOTE TO: Cynthia Carpenter, Chief Inspection Program Branch Division of Inspection Program Management Office of Nuclear Reactor Regulation Patrick D. OReilly Operating Experience Risk Applications Branch Division of Risk Analysis and Applications Office of Nuclear Regulatory Research FROM: Mark F. Reinhart, Chief/RA/
Licensing Section Probabilistic Safety Assessment Branch Division of Systems Safety and Analysis Office of Nuclear Reactor Regulation
SUBJECT:
RESULTS OF THE MILLSTONE PLANT UNIT 2 SDP PHASE 2 NOTEBOOK BENCHMARKING VISIT During May, 2002, NRC staff and a contractor visited the Millstone site to compare the Millstone Plant Unit 2 (MP2) Significance Determination Process (SDP) Phase 2 notebook and licensees risk model results to ensure that the SDP notebook was generally conservative.
MP2's PSA did not include external initiating events so no sensitivity studies were performed to assess the impact of these initiators on SDP color determinations. In addition, the results from analyses using the NRCs draft Revision 3i Standard Plant Analysis Risk (SPAR) model for MP2 were also compared with the licensees risk model. The results of the SPAR model benchmarking effort will be documented in a separate trip report to be prepared by the Office of Research.
In the review of the MP2 SDP notebook, it was found that some changes to the SDP worksheets were needed to reflect how the plant is currently designed and operated. Twenty nine hypothetical inspection findings were processed through the SDP notebook. Results from this effort indicated that the total risk impacts modeled in the SDP notebook were underestimated by 14 percent, overestimated by 34 percent, and adequately estimated by 52 percent. The reviewers found that if fourteen fixes were made to the SDP notebook, the results would be 3 percent underestimation and 27 percent overestimation of risk impacts.
Attachment A describes the process and results of the comparison of the MP2 SDP Phase 2 Notebook and the licensees PSA.
Attachments: As stated CONTACT: P. Wilson, SPSB/DSSA/NRR 301-415-1114
August 28, 2002 NOTE TO: Cynthia Carpenter, Chief Inspection Program Branch Division of Inspection Program Management Office of Nuclear Reactor Regulation Patrick D. OReilly Operating Experience Risk Applications Branch Division of Risk Analysis and Applications Office of Nuclear Regulatory Research FROM: Mark F. Reinhart, Chief/RA/
Licensing Section Probabilistic Safety Assessment Branch Division of Systems Safety and Analysis Office of Nuclear Reactor Regulation
SUBJECT:
RESULTS OF THE MILLSTONE PLANT UNIT 2 SDP PHASE 2 NOTEBOOK BENCHMARKING VISIT During May, 2002, NRC staff and a contractor visited the Millstone site to compare the Millstone Plant Unit 2 (MP2) Significance Determination Process (SDP) Phase 2 notebook and licensees risk model results to ensure that the SDP notebook was generally conservative.
MP2's PSA did not include external initiating events so no sensitivity studies were performed to assess the impact of these initiators on SDP color determinations. In addition, the results from analyses using the NRCs draft Revision 3i Standard Plant Analysis Risk (SPAR) model for MP2 were also compared with the licensees risk model. The results of the SPAR model benchmarking effort will be documented in a separate trip report to be prepared by the Office of Research.
In the review of the MP2 SDP notebook, it was found that some changes to the SDP worksheets were needed to reflect how the plant is currently designed and operated. Twenty nine hypothetical inspection findings were processed through the SDP notebook. Results from this effort indicated that the total risk impacts modeled in the SDP notebook were underestimated by 14 percent, overestimated by 34 percent, and adequately estimated by 52 percent. The reviewers found that if fourteen fixes were made to the SDP notebook, the results would be 3 percent underestimation and 27 percent overestimation of risk impacts.
Attachment A describes the process and results of the comparison of the MP2 SDP Phase 2 Notebook and the licensees PSA.
Attachments: As stated CONTACT: P. Wilson, SPSB/DSSA/NRR 301-415-1114 Accession#ML022400783 NRR-096 G://spsb/wilson/Millstone2bench.wpd OFFICE SPSB *RI SC:SPSB NAME PWilson:nyc JTrapp MReinhart DATE 08/28/02 07/30/02 08/28/02 OFFICIAL RECORD COPY
SUMMARY
REPORT ON BENCHMARKING TRIP to the Milestone Plant Unit 2 (MP2)
(May 15 and 16, 2002)
M. A. AZARM (BNL)
Energy Sciences and Technology Department Brookhaven National Laboratory Upton, NY 11973-5000 June 2002
Table of Contents Page
- 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
- 2. Summary Results from Benchmarking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
- 3. Proposed Revisions to Rev 0 SDP Notebook . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 3.1 Specific Changes to the Rev 0 SDP Notebook for Milestone Plant Unit 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 3.2 Generic Changes in IMC 0609 for Guidance to NRC Inspectors . . . . . . . . . . . . . 9 3.3 Generic Change to the SDP Notebook . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
- 4. Discussion on External Events . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 List of Tables Page Table 1 Comparison of Sensitivity Calculations between SDP Phase 2 Worksheets and MP2 RAWs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Table 2 Comparative Summary of the Benchmarking Results . . . . . . . . . . . . . . . . . . . . . . 7
-iv-
- 1. Introduction A benchmarking of the Milestone plant Unit 2 (MP2) SDP risk-informed inspection notebook was conducted during a plant site visit on May 15-16, 2002. NRC staff (J. Trapp and P. Wilson) supported by BNL staff (M. A. Azarm) participated in this benchmarking exercise.
In preparation of the plant site visit, BNL staff reviewed the MP2 SDP notebook and evaluated a set of hypothetical inspection findings using the Rev 0 SDP worksheets, plant system diagrams and information in the licensees updated PSA. A copy of the site visit agenda was sent to the licensee by NRC staff (P. Wilson) prior to the meeting.
The major activities performed during this plant site visit were:
- 1. Discussed licensees comments on the Rev 0 SDP notebook.
- 2. Obtained listings of the Risk Achievement Worth (RAW) values for basic events of the internal event PRA for average maintenance model.
- 3. Identified a target set of basic events for the benchmarking exercise.
- 4. Performed benchmarking of the Rev 0 SDP worksheets with considerations of the licensees proposed modifications to the SDP notebook.
- 5. Identified areas of discrepancies and reviewed the licensees PSA model to determine the underlying reasons. Proposed additional changes to the SDP notebook when appropriate.
- 6. Performed a benchmarking exercise using the Revision 3i SPAR model for the MP2 (by Mr.
J. Schroeder from INEEL)
The benchmarking exercise provided insights for significant improvement to the SDP notebook.
The revised SDP notebook should provide either similar or slightly more conservative significance characterization (i.e., maximum by one color) than the licensees PRA model in about 100% (i.e.,
no underestimation) of the cases analyzed.
The importance of this benchmarking trip was well demonstrated by significant reduction in both the number of over and under estimations. The number of overestimations were reduced from 10 to 7 and the number of underestimations were reduced from 4 to 0. These reductions in number of overestimations and underestimations were primarily attributed to more realistic modeling of the success criteria for feed and bleed and improved modeling of two initiators; Loss of one DC bus and Loss of IA.
- 2. Summary Results from Benchmarking This Section provides the results of the benchmarking exercise. The results of benchmarking analyses are summarized in Table 1. Table 1 consists of six column headings. In the first column, the out-of-service components (human and recovery actions) are identified for the case analyses.
The second column shows the associated colors based on the Rev 0 SDP notebook. The third column shows the RAW values based on the licensees latest PSA model. The site color estimated based on the RAW values are shown in the fourth column. The colors assigned for significance characterization from using the modified Rev 0 SDP worksheets after incorporation of the licensees comments are shown in the fifth column. The comparative results from the colors assigned by the licensees latest PSA and the modified notebooks are shown in the sixth column.
These comparative results are categorized as Over, Match, and Under standing for cases that were overestimated, matched, and underestimated. Finally, some clarifying notes and the reasons for any differences in second and the fifth column which resulted from incorporating the licensees comments into Rev 0 SDP notebook are noted in the sixth column. The summary statistics of the benchmarking results is provided in Table-2. This table shows the summary results obtained through benchmarking for both the Rev 0 SDP and the revised notebooks. Examination of both Tables 1 and 2 show that the revised SDP notebook should provide either similar or slightly more conservative significance characterization (i.e.,maximum by one color) than the licensee's PRA model in about 97% (i.e., one case of underestimation) of the cases analyzed. There was a total of eight cases out of 29 cases analyzed that the revised SDP resulted in more conservative colors.
No specific reasons were found for seven cases of overestimations by one color. These differences were expected to be caused by slightly different reliability and human error probabilities used in the licensees PSA model compare to the generic values in the SDP notebook, and the extensive use of counting rules used in SDP evaluation.
Failure of a LPSI train was characterized by W in the licensees PSA, corresponding to a RAW value of 1.03 (border line of white and green). The SDP notebook estimated a green color for this event (two greens next to white). No specific reason was found for this slight underestimation.
The importance of this benchmarking trip was well demonstrated by the significant reduction in both the number of over and under estimations. The number of overestimations was reduced from 10 to 8 and the number of underestimations were reduced from 4 to 1. These reductions in number of overestimations and underestimations were primarily attributed to more realistic modeling of the success criteria for feed and bleed and improved modeling of two initiators; Loss of one DC bus and Loss of IA.
Table 1: Summary of Benchmarking Results for Milestone Unit 2 Internal Events CDF is 5.83E-5, therefore, the RAW thresholds are: W = 1.02, Y = 1.2, and R = 2.72 Component SDP Internal Site SDP Comments Out of Service Worksheet RAW1 Color Worksheet Results Results (before) (after)
TDAFW Pump R 1.5 Y R OVER P4 due to SDP counting rule MDAFW Pump R 6.02 R R MATCH P9A/P9B HPSI Pump Y 14.1 R R MATCH P41A, or C due to improved Feed and Bleed success criteria HPSI Pump Y 1.134 W Y OVER Swing due to SDP Counting rule P41B LPSI Train Y 1.03 W G Under P42A or B Slight Underestimatio, Removed the credit for rapid depressurization EDG 15G-12U R 1.4 Y Y MATCH EDG 15G-13U R 1.4 Y Y MATCH 1/2 MSIVs FTC W 1.5 Y Y MATCH use of Rev-1 generic credit for MSIVs Both MSIVs FTC R 4.08 R R MATCH PZR PORV FTO Y 1.7 Y Y MATCH FB Function 2-RC-402/404 PORV FTC Y 3.2 R R MATCH Block Valve FTC W 1.102 W Y OVER 2-RC-403,405 Safety Valve W 1.0 G W OVER FTO One train of CAR Y 1.0 G W OVER (2 fans) Change in credit for CONT from 6 to 3 1 ADV Y 1.307 Y Y MATCH MS-190A, 190B 1SGFP G 1.001 G G MATCH (mitigation)
Loss of 125VDC R 116 R R MATCH bus 201-A/B Loss of 1 Battery R 1.042 W W MATCH Charger Train (A redundancy in battery or B) chargers Loss of 1 480 R 31 R R MATCH VAC Bus 22E or F
Loss of one R 51 R R MATCH Battery (A or B)
Loss of one Y 1.3 Y Y MATCH RBCCW pump (P-11 A, B, or C)
One SW Pump R 1.369 Y R OVER (P5A,B, or C)
One Train of ESF R 2.8 R R MATCH Room Cooling (F15A or B) 1 Train of CS G 1.01 G W OVER (P43A or B) change of credit for CONT from 6 to 3 1 SIT G 1.0 G G MATCH (T39A-D)
One train of IA Y 1.08 W W MATCH Compressor modifying the LIA model Loss of IA R R R MATCH Loss of one PDP W 3.2 R R MATCH charging modifying the event tree P18A,B, or C for loss of one DC bus Prevent Boron R 2.166 Y R OVER Precipitation Table 2: Comparative Summary of the Benchmarking Results Total Number SDP Notebook SDP Notebook of Cases Before (Rev 0)
After (Rev 1)
Compared Number of Percentage Number of Percentage Cases Cases (29) (29)
SDP: Less 4 14% 1 3%
Conservative SDP: More 10 34% 8 27%
Conservative SDP: Matched 15 52% 20 70%
- 3. Proposed Revisions to Rev 0 SDP Notebook Based on insights gained from the plant site visit, a set of revisions is proposed for the Rev 0 SDP notebook. The proposed revisions are based on licensee comments on the Rev 0 SDP notebook, better understanding of the current plant design features, consideration of additional recovery actions, use of revised Human Error Probabilities (HEPs) and initiator frequencies, and the results of benchmarking.
3.1 Specific Changes to the Rev 0 SDP Notebook for MP2 The licensee provided several comments for minor revisions to the SDP Notebook. The suggested changes mainly dealt with the dependency matrix, updated footnotes associated with the worksheets, and revised HEP values. All of these changes will be incorporated in the SDP worksheets. In addition, several major revisions that directly impacted the color assignments by the SDP evaluation were discussed with the licensee and their resolutions were identified in the meeting. The proposed revisions are discussed below:
- 1. Modify the success criteria for Feed and Bleed per Engineering Record NGP 5.31, Rev 005 provided by the licensee. As an example for Transient, SGTR, and TPCS , use 2/2 HPSI pumps and 1/3 charging pumps.
- 2) Remove LIA from the initiating event column in Table-2 for main Steam.
- 3) Remove SGTR from the initiating event column in Table-2 for SDC.
- 4) Add except LSW to the initiating event column in Table-2 for RBCCW.
- 5) Remove note 5 in Table 2.
- 6) Globally change the credit for HPR from multi-train system to an operator action = 3. Add a footnote that says, an operator action is required to close the mini-flow valve (OALPMINI) with a HEP value of 1.0E-3.
- 7) Globally change the total credit for Containment heat removal (CONT) from 2 multi-train system to one multi-train system accounting for common support systems for fan coolers and CS.
- 8) Add a footnote under LLOCA that RBCCW and ESF room cooling is not needed for LPSI pump cooling.
- 9) Simplify the SGTR event tree to require both EIHP and AFW if not isolated.
- 10) Modify the event tree and the sequences for loss of a DC bus to account for possibility of SORV and RCP seal LOCA. As a result of loss of a DC bus, the associated AC bus should be assumed failed. Therefore, the would be no power to close the block valve associated with the open PORV. Also loss of DC causes loss of one train of RBCCW. Thereby seal cooling would be lost to the associated RCPs. The PSA currently assumes that seal LOCA would be inevitable and operation of either the remaining charging pump or HPSI pump is required to prevent core damage.
- 11) Remove the worksheet and the event tree for LVAC1030.
- 12) In loss of IA, credit feed and bleed. For HPI use the criteria of 2/2 HPSI and 1/3 charging pump.
- 13) Each diesel oil supply tank has a T.S. volume of 12,000 gallons (T-48A and T-48B). This would be sufficient to provide diesel fuel oil for both EDGs for a period of 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, and then one EDG to continue for approximately 3.5 days. Two trains of fuel transfer would supply fuel to diesel oil supply tank from an under ground tank. The fuel oil transfer pumps are fed from vital power sources. However, there are not seismically qualified and the underground tank is considered as a non-safety component.
- 14) The battery chargers are of sufficient capacity to provide the SI loads if the associated battery is not available.
3.2 Generic Change in IMC 0609 for Guidance to NRC Inspectors No specific recommendation for changes to IMC 0609 was identified as a result of this benchmarking exercise.
3.3 Generic Change to the SDP Notebook No generic change was identified.
- 4. Discussion on External Events The PSA for MP2 currently does not integrate the external events; therefore no activity was performed on this item during the benchmarking site visit.