Letter Sequence RAI |
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EPID:L-2017-LLR-0133, Relief Request RR-4-13, Use of a Risk-Informed Process as an Alternative for the Selection of Class 1 and Class 2 Piping Welds (Open) |
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MONTHYEARRC-17-0123, Relief Request RR-4-13, Use of a Risk-Informed Process as an Alternative for the Selection of Class 1 and Class 2 Piping Welds2017-10-30030 October 2017 Relief Request RR-4-13, Use of a Risk-Informed Process as an Alternative for the Selection of Class 1 and Class 2 Piping Welds Project stage: Request ML17331B1472017-11-21021 November 2017 NRR E-mail Capture - Virgil C. Summer, Unit 1 -Acceptance of Relief Request (RR-4-13), Use of Risk-Informed Process as an Alternative for the Selection of Class 1 and Class 2 Piping Welds Project stage: Acceptance Review ML18023B0692018-02-15015 February 2018 Request for Additional Information Relief Request (RR-4-13), Use of Risk-Informed Process as an Alternative for the Selection of Class 1 and Class 2 Piping Welds Project stage: RAI RC-18-0036, (Vcsns), Unit 1 - Relief Request RR-4-13, Use of a Risk-Informed Process as an Alternative for the Selection of Class 1 and Class 2 Piping Welds - Response to Request for Additional Information2018-04-0202 April 2018 (Vcsns), Unit 1 - Relief Request RR-4-13, Use of a Risk-Informed Process as an Alternative for the Selection of Class 1 and Class 2 Piping Welds - Response to Request for Additional Information Project stage: Response to RAI ML18186A5882018-07-19019 July 2018 Relief Request (RR-4-13) for Use of a Risk-Informed Process as an Alternative for the Selection of Class 1 and Class 2 Piping Welds. Project stage: Other 2018-02-15
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Category:Letter
MONTHYEARML24038A0322024-02-0707 February 2024 (Vcsns), Unit 1, 10 CFR 21 Report - Emergency Diesel Generator Flash Contactor Relay IR 05000395/20230042024-01-31031 January 2024 Integrated Inspection Report 05000395/2023004 ML24022A1582024-01-22022 January 2024 (Vcsns), Unit 1 - Reply to a Notice of Violation: EA-23-093 ML24022A1202024-01-22022 January 2024 Notification of Target Set Inspection and Request for Information (NRC Inspection Report 05000395/2024403) ML24018A0112024-01-18018 January 2024 CFR 21 Report Emergency Diesel Generator Fuel Oil Piping IR 05000395/20240112024-01-17017 January 2024 Notification of VC Summer Station Comprehensive Engineering Team Inspection - U.S. Nuclear Regulatory Commission Inspection Report 05000395/2024011 ML23361A1042023-12-21021 December 2023 Inservice Testing Program for Pumps and Valves Fifth Interval Update and Associated Relief and Alternative Requests IR 05000395/20230912023-12-21021 December 2023 Final Significance Determination of a White Finding and Notice of Violation and Assessment Followup Letternrc Inspection Report 05000395/2023091 ML23354A1802023-12-20020 December 2023 301 Examination Report with Cover Letter ML23347A0492023-12-12012 December 2023 Technical Specification Bases Changes Updated Through November 2023 ML23334A2462023-11-30030 November 2023 Request for Exemption from Enhanced Weapons, Firearms Background Checks, and Security Event Notifications Implementation ML23334A2372023-11-30030 November 2023 (Vvsns), Unit 1 - Annual Commitment Change Summary Report ML23332A1942023-11-28028 November 2023 (Vcsns), Unit 1, Correction of Typographical Error in License Amendment Request - Inverter Allowed Outage Time (AOT) Extension ML23317A2242023-11-0909 November 2023 (Vcsns), Unit 1 - License Amendment Request - Inverter Allowed Outage Time (AOT) Extension ML23289A1172023-11-0303 November 2023 Tribal Request for Scoping Comments Concerning the Environmental Review of the V.C. Summer SLRA ML23289A1152023-11-0303 November 2023 Ltr to R. Nelson - Request for Scoping Comments Concerning the Environmental Review of the V.C. Summer SLRA ML23289A1162023-11-0303 November 2023 Ltr to W. Emerson - Request for Scoping Comments Concerning the Environmental Review of the V.C. Summer SLRA IR 05000395/20234032023-11-0101 November 2023 Material Control and Accounting Program Inspection Report 05000395/2023403 Cover IR 05000395/20230032023-11-0101 November 2023 Integrated Inspection Report 05000395/2023003 ML23284A1792023-10-16016 October 2023 Subsequent License Renewal Application Online Reference Portal ML23275A0142023-10-11011 October 2023 SLRA - Acceptance and Opportunity for Hearing - Letter ML23284A1662023-10-10010 October 2023 (Vcsns), Unit 1 - Request for Regulatory Conference; (EA-23-093) IR 05000395/20230902023-10-0404 October 2023 NRC Inspection Report 05000395/2023090 and Preliminary Yellow Finding and Apparent Violation IR 05000395/20230112023-09-27027 September 2023 Focused Engineering Inspection Report 05000395/2023011 ML23250A3112023-09-20020 September 2023 Request to Revise Reactor Vessel Material Surveillance Capsule Withdrawal Schedules ML23244A2352023-09-18018 September 2023 Request to Use a Subsequent Edition of the ASME Code, Section XI ML23230A0012023-09-15015 September 2023 Request to Use a Provision of a Previous Edition of the ASME Boiler and Pressure Vessel Code, Section XI, for Non-Destructive Examinations ML23235A0432023-09-0505 September 2023 Receipt and Availability of the Subsequent License Renewal Application IR 05000395/20234012023-08-30030 August 2023 Security Baseline Inspection Report 05000395/2023401 ML23242A1192023-08-29029 August 2023 (Vcsns), Unit 1 - Inservice Inspection (ISI) Owner'S Activity Report (OAR) for Refueling Outage 27 ML23243B0362023-08-25025 August 2023 Request for FEMA Consultation on the Dominion Energy Proposal to Consolidate the Emergency Operations Facility for the Virgil C. Summer Nuclear Station Unit 1 IR 05000395/20230052023-08-23023 August 2023 Updated Inspection Plan for Virgil C. Summer Nuclear Station (Report 05000395 2023005) ML23233A1752023-08-17017 August 2023 Application for Subsequent Renewed Operating License IR 05000395/20230022023-08-14014 August 2023 Integrated Inspection Report - Integrated Inspection Report 05000395/2023002 and Apparent Violation IR 05000395/20230102023-08-12012 August 2023 Biennial Problem Identification and Resolution Inspection Report 05000395/2023010 ML23207A1102023-07-26026 July 2023 NRC Regulatory Issues Summary 2023-01 Preparation and Scheduling of Operator Licensing Examinations IR 05000395/20234412023-07-17017 July 2023 95001 Supplemental Inspection Report 05000395/2023441 and Follow Up Assessment Letter ML23190A0012023-07-0909 July 2023 Special Report 2023-003 Inoperable Radiation Monitoring Instrumentation Channel ML23187A5092023-07-0606 July 2023 Request for Federal Emergency Management Agency Consultation on the Dominion Energy Proposal to Consolidate the Emergency Operations Facility for the Virgil C. Summer Nuclear Station Unit 1 ML23178A1682023-06-26026 June 2023 2022 Annual Report of Emergency Core Cooling System (ECCS) Model Changes Pursuant to the Requirements of 10 CFR 50.46 ML23173A1052023-06-22022 June 2023 Special Report 2023-002 Inoperable Loose-Part Monitoring System Channel ML23163A2352023-06-12012 June 2023 Request to Use a Later Edition of the ASME Boiler and Pressure Vessel Code, Section XI, for the SPS Sixth Inservice Inspection (Isi) Intervals and VCSNS Fifth ISI Interval ML23159A2332023-06-0808 June 2023 License Amendment Request - Emergency Response Organization Augmentation Time Change, Emergency Operations Facility Relocation and Other Emergency Plan Changes ML23156A3092023-06-0505 June 2023 Requalification Program Inspection Virgil C. Summer Nuclear Station Unit 1 - 05000395/2023003 2024-02-07
[Table view] Category:Request for Additional Information (RAI)
MONTHYEARML23270B8712023-09-27027 September 2023 NRR E-mail Capture - Draft RAIs for License Amendment Request (LAR) to Revise the Virgil C. Summer Nuclear Station (VCSNS) Unit 1 Emergency Plan (L-2023-LLA-0083) ML22263A0502022-09-19019 September 2022 NRR E-mail Capture - Draft Request for Additional Information for Proposed Alternative Request RR-4-26 Extension of Steam Generator Primary Inlet Nozzle Dissimilar Metal Weld Inspection Interval V.C. Summer Unit 1 ML22194A9422022-07-13013 July 2022 NRC 50.59 Inspection (IP 71111.17T) Information Request ML22075A0482022-03-16016 March 2022 V.C. Summer Nuclear Station - Information Request for the Cyber-Security Baseline Inspection, Notification to Perform Inspection 05000395/2022401 ML21333A1892021-11-29029 November 2021 NRR E-mail Capture - Draft RAI for Summer LAR Relocate Surveillance Frequencies to Licensee Control - RITSTF Initiative 5b, (TSTF-425) ML21253A1352021-09-0808 September 2021 Document Request for VC Summer Nuclear Station - Radiation Protection Inspection - Inspection Report 2021-04 ML21154A2792021-06-0303 June 2021 Requalification Program Inspection 05000395/2021003 - Virgil C. Summer Nuclear Station, Unit 1, ML21145A0222021-05-24024 May 2021 003 Radiation Safety Baseline Inspection Information Request ML21131A0402021-05-11011 May 2021 NRR E-mail Capture - V.C. Summer, Unit 1 - Final RAI for the Spring 2020 RFO Sgtir Review ML21020A0562021-01-20020 January 2021 Email Capture Upcoming V.C. Summer POV Inspection (IP71111.21N.02) Information Request ML20342A1822020-12-0707 December 2020 NRR E-mail Capture - Final RAI for Summer LAR - TS 3.6.4 ML20342A3822020-12-0707 December 2020 NRR E-mail Capture - Final RAIs for Summer Fs LOCA LAR ML20321A2112020-11-16016 November 2020 NRR E-mail Capture - Summer, Unit 1 - Final RAIs for the SG Tube Inspection Report Review ML20196L7782020-07-13013 July 2020 Notification of Virgil C. Summer Nuclear Station Design Bases Assurance Inspection U.S. Nuclear Regulatory Commission Inspection Report 05000395/2020010 ML20106E8902020-04-15015 April 2020 Program Inspection RFI ML20056E3042020-02-25025 February 2020 VC Summer 2020-002 Radiation Safety Baseline Inspection Information Request ML19211D5102019-07-30030 July 2019 NRR E-mail Capture - Virgil C. Summer Nuclear Station, Unit No. 1 - Request for Additional Information LAR-16-01490 NFPA-805 (Supplement to PRA RAI 03) ML19179A1262019-06-27027 June 2019 NRR E-mail Capture - Virgil C. Summer Nuclear Station, Unit No. 1 - Request for Additional Information LAR-16-01490 NFPA-805 Program Revisions ML19095A6532019-04-0404 April 2019 NRR E-mail Capture - Virgil C. Summer Nuclear Station, Unit No. 1 - Request for Additional Information NFPA-805 Program Revisions LAR ML19072A1442019-03-13013 March 2019 NRR E-mail Capture - Virgil C. Summer Nuclear Station, Unit No. 1 - Request for Additional Information LAR-16-01490 NFPA-805 Program Revisions ML19009A1052019-01-0909 January 2019 NRR E-mail Capture - Virgil C. Summer Nuclear Station, Unit No. 1 - Request for Additional Information LAR-10-02395, TS 3.8.2, D.C. Sources - Operating ML18249A1932018-09-0505 September 2018 TS 4.3.3.6 SR LAR - Request for Additional Information ML18225A0932018-08-13013 August 2018 Notification of Inspection and Request for Information ML18218A2622018-08-0101 August 2018 Emergency Preparedness Program Inspection Request for Information ML18066A0002018-03-0808 March 2018 Request for Additional Information Integrated Leak Rate Test Peak Calculated Containment Internal Pressure Change ML18023B0692018-02-15015 February 2018 Request for Additional Information Relief Request (RR-4-13), Use of Risk-Informed Process as an Alternative for the Selection of Class 1 and Class 2 Piping Welds ML17095A2842017-05-11011 May 2017 Request for Additional Information License Amendment Request for Implementation of TSTF-411 (WCAP-15376-P-A), Revision 1 ML17067A5322017-03-0808 March 2017 Notification of Radiation Protection Baseline Inspection and Request for Information ML17059C5382017-02-23023 February 2017 Notification of Inspection and Request for Information ML16302A1252016-11-0808 November 2016 Request for Additional Information License Amendment Request for Implementation of TSTF-411 and WCAP-15376-P-A, Revision 1 RC-16-0112, NRC Request Information Baseline Radiation Safety Inspection2016-07-0707 July 2016 NRC Request Information Baseline Radiation Safety Inspection ML16111A0912016-05-0303 May 2016 Request for Additional Information Regarding the Station Physical Security Plan, Revision 14 ML16097A0812016-04-0808 April 2016 Request for Additional Information ML16064A0332016-03-0303 March 2016 NRR E-mail Capture - Request for Additional Information Related to the March 1, 2016, Exigent Amendment Request ML16042A4712016-02-18018 February 2016 Request for Additional Information ML15320A3382015-12-0101 December 2015 Request for Additional Information Regarding License Basis Changes in Steam Generator Tube Rupture Analysis RC-15-0177, Submits LAR-12-04269, License Basis Changes in Steam Generator Tube Rupture Analysis Response to Response for Additional Information2015-11-0505 November 2015 Submits LAR-12-04269, License Basis Changes in Steam Generator Tube Rupture Analysis Response to Response for Additional Information ML15261A0512015-09-22022 September 2015 Request for Additional Information Regarding License Basis Changes in Steam Generator Tube Rupture Analysis ML15118A4592015-05-19019 May 2015 Request for Additional Information Regarding Alternative Request ML15118A3802015-05-0505 May 2015 Request for Additional Information Regarding Snubber Program Alternative Request ML15076A1182015-04-13013 April 2015 Request for Additional Information Regarding License Basis Changes in Steam Generator Tube Rupture Analysis ML15079A0992015-03-26026 March 2015 Request for Additional Information ML14339A0302015-01-0909 January 2015 Request for Additional Information Regarding License Basis Changes in Steam Generator Tube Rupture Analysis ML14268A5162014-10-23023 October 2014 Request for Additional Information Associated with Near-Term Task Force Recommendation 2.1, Seismic Re-evaluation Related to Southeastern Catalog Changes ML14226A2552014-08-29029 August 2014 Request for Additional Information ML14182A4732014-07-11011 July 2014 Request for Additional Information Regarding License Amendment Request to Adopt National Fire Protection Association Standard 805 ML14071A1692014-03-24024 March 2014 Request for Additional Information ML14023A7402014-01-30030 January 2014 (VCSNS) - Request for Additional Information ML13347B0492013-12-19019 December 2013 (VCSNS) - Request for Additional Information ML13340A3772013-12-11011 December 2013 (VCSNS) - Request for Additional Information 2023-09-27
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UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 February 15, 2018 Mr. George A. Lippard, Ill Vice President, Nuclear Operations South Carolina Electric & Gas Company Virgil C. Summer Nuclear Station Post Office Box 88, Mail Code 800 Jenkinsville, SC 29065
SUBJECT:
VIRGIL C. SUMMER NUCLEAR STATION, UNIT NO. 1 - REQUEST FOR ADDITIONAL INFORMATION RE: RELIEF REQUEST (RR-4-13), USE OF RISK-INFORMED PROCESS AS AN ALTERNATIVE FOR THE SELECTION OF CLASS 1 AND CLASS 2 PIPING WELDS (EPID NO. L-2017-LLR-0133)
Dear Mr. Lippard:
By letter dated October 30, 2017, South Carolina Electric & Gas Company (SCE&G, the licensee) submitted an alternative request for Virgil C. Summer Nuclear Plant, Unit 1. The proposed alternative requests the use of a risk-informed process as an alternative for the selection of Class 1 and Class 2 piping welds in lieu of the inspection and examination requirements specified by the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code (BPV),Section XI, "Rules for inservice inspection of nuclear power plant components," Tables IWB-2500-1 and IWC-2500-1.
The U.S. Nuclear Regulatory Commission (NRC) staff has reviewed the licensee's submittal and determined that additional information is needed to continue its review. As discussed with Ms. Dalick, please respond within 45 days of the date of this letter. Please note that the NRC staff's review is continuing, and further requests for information may be developed.
G. Lippard If you have any questions, please contact me at 301-415-1009 or Shawn.Williams@nrc.gov.
Sincerely, Shawn A. Williams, Senior Project Manager Plant Licensing Branch 11-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-395
Enclosure:
Request for Additional Information cc w/enclosure: Distribution via Listserv
REQUEST FOR ADDITIONAL INFORMATION RELIEF REQUEST (RR-4-13) FOR USE OF A RISK-INFORMED PROCESS AS AN ALTERNATIVE FOR THE SELECTION OF CLASS 1 AND CLASS 2 PIPING WELDS SOUTH CAROLINA ELECTRIC & GAS COMPANY VIRGIL C. SUMMER NUCLEAR STATION, UNIT NO. 1 DOCKET NO. 50-395 By letter dated October 30, 2017 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML173036183), South Carolina Electric & Gas Company (SCE&G, the licensee) submitted a relief request (RR) for Virgil C. Summer Nuclear Plant, Unit 1 (VCSNS).
The licensee proposed the use of Risk-Informed lnservice Inspection (RI-ISi) Program as an alternative to the selection of Class 1 and Class 2 piping welds in lieu of the inspection and examination requirements specified by the American Society of Mechanical Engineers (ASME)
Boiler and Pressure Vessel (BPV) Code,Section XI, "Rules for inservice inspection of nuclear power plant components," Tables IWB-2500-1 and IWC-2500-1.
The U.S. Nuclear Regulatory Commission (NRC) staff has determined that the following requests for additional information (RAI) are required to complete its review.
RAI No.1 Regarding the risk metrics provided in the RR, please clarify the following:
- a. On page 7 of the RR, the licensee states:
The revised program represents an overall reduction of plant risk of -9.83E-09 for CDF [core damage frequency] and -4.0BE-09 for LERF
[large early release frequency].
Please clarify that the negative value of the CDF and LERF risk metrics represent risk reductions and not "negative reductions," in which a reduction of a negative value as provided in the license amendment request (LAR) could imply an increase in risk.
- b. On page 8 of the RR in the table "VCSNS Risk Impact Results", the change in LERF for each system is approximately 40% of the corresponding change in CDF, which is consistent with the overall change in CDF and LERF as provided on page 7 of the LAR.
However, the changes in LEAF for the Emergency Feedwater (EF) and Feedwater (FW) systems have the same values as their corresponding changes in CDF, which does not appear to be consistent with the rest of the systems, where the change in LERF is always less in magnitude than the corresponding change in CDF, and the overall results.
Please clarify why the changes in CDF and LERF for the EF and FW systems are equal and not consistent with the other results.
Enclosure
RAI No. 2 According to Regulatory Issue Summary 2007-06 (ADAMS Accession No. ML070650428), the NRG staff expects that licensees fully address all scope elements with Revision 2 of Regulatory Guide (RG) 1.200 (ADAMS Accession No. ML090410014) by the end of its implementation period (i.e., one year after the issuance of Revision 2 of RG 1.200). Revision 2 of RG 1.200 endorses, with exceptions and clarifications, the combined American Society of Mechanical Engineers (ASME)/American Nuclear Society (ANS) Probabilistic Risk Assessment (PRA) standard (ASME/ANS RA-Sa-2009).
On page 3 of Attachment 1 of the LAR, the licensee states:
Independent PRA peer reviews were conducted under the auspices of the Pressurized Water Reactor Owners Group (PWROG) following the Industry PRA Peer Review process in 2002 and 2016.
The licensee further explains a PRA model update was completed in 2016 and a full scope peer review was performed. Please confirm the following items in regard to the 2016 full scope peer review:
- a. Please confirm the full scope peer review was reviewed against the 2009 ASME/ANS PRA standard, as endorsed by RG 1.200, Revision 2. If not, identify any gaps between the peer review and the guidance in RG 1.200, Revision 2.
- b. For the disposition of SR IE-A5/A6 in Table 1 of the LAR, the licensee states:
The initiating event list in the VCSNS PRA was based on a review of other risk assessments, plant operating history, and plant design. This included a review of support systems."
The guidance in RG 1.200, Revision 2 specifies the systematic evaluation of each system, including support systems, needs to be performed "down to the subsystem or train level where necessary." Please confirm if the review of the support systems was provided down to this level, and provide justification if it was not.
RAI No. 3 In Table 1 of Attachment 1 of the RR, for the disposition of SR IE-C1, the licensee cites performance of a sensitivity study to address the Finding, in which a change in consequence from MEDIUM to HIGH was due to a near factor of four increase in medium loss-of-coolant accident (LOCA) frequency. The disposition further questions the basis for this increase, stating the difference may be based on binning or expert elicitation, and, therefore, concluding that the data used in the current PRA model are "sufficient for medium LOCA." Please explain the reasons for the increase in frequency other than how the data, which may include recent updates, have been processed. Please provide justification for taking exception to the factor of four increase in the medium LOCA frequencies and/or include an evaluation of the effect from the sensitivity study of the factor of four increase in the medium LOCA frequencies on the risk metrics applicable to this application.
RAI No. 4 In Table 1 of Attachment 1 of the LAA, for the disposition of SR SY-A4, the licensee states:
Walkdowns of recent system modifications have been done in support of Fire PAA human reliability.
The licensee's National Fire Protection Association (NFPA) 805 "Performance-Based Standard for Fire Protection for Light Water Reactor Electric Generating Plants" LAA (ADAMS Accession No. ML14287A289) was submitted on November 15, 2011, and the Amendments issued on February 11, 2015 (ADAMS Accession No. ML14287A289). Based on the walkdowns, referenced in Table 1 of the LAA, walkdowns were performed six or more years ago. Please provide justification that these walkdowns are adequate to be representative of the as-built, as-operated status of the plant for the version of the PAA used in this application.
RAI No. 5 In Table 1 of Attachment 1 of the RR, for the disposition of SR HR-G7, identify the joint Human Error Probability (HEP) floors that were used. Please confirm that none were < 1E-6 for internal events. If any were <1 E-6 for internal events, please provide the basis and the results of a sensitivity evaluation using 1E-6, and include any effects on the "small" impact statement under the "Impact" column in Table 1.
RAI No. 6 In Table 1 of Attachment 1 of the LAA, for the disposition of SR IFEV-A7, the licensee states:
Limited on-line maintenance makes human induced flooding less significant and it should not affect the failure probability or consequence for any piping welds.
Although on-line maintenance is limited, it is not eliminated and, therefore, there may be risk from human induced flooding. Please justify with a bounding quantification the statements that human induced flooding should not affect the risk, and the likely impact on RI-ISi risk is small and will not add significance.
RAI No. 7 In Table 1 of Attachment 1 of the RR, for the disposition of SR QU-D2 / AS-AS, the licensee cites conservatism in the PAA model and that the risk impact is expected to be small. On the basis that conservatism may underestimate the risk increase or overestimate the risk reduction of the application, provide the following information:
- a. When citing conservatism in the PAA model, please confirm that calculation of the differential risk for this application is also conservative (i.e., the risk estimated for the before versus after condition uses the same assumptions, etc., except for the change to any basic event values affected by the application, ensuring that the before value is not overestimated such that subtracting it from the after value could underestimate the risk increase).
- b. Please provide quantitative justification with a bounding evaluation, crediting the available recovery options, that the expected impact is small, as stated in the "Impact" column.
RAI No. 8 VCSNS Unit 1 is currently already in its Fourth 10-Year ISi interval, which started on January 1, 2014, and is scheduled to end on December 31, 2023. The licensee implemented its regular ISi program for ASME Code Class 1 and Class 2 piping welds for the first period of the Fourth 10-Year ISi interval. Relief Request RR-4-13 states that the licensee will use its RI-ISi Program for the balance of the Fourth 10-Year Interval (i.e., second and third periods), and "prorate" for examinations it already performed in the first period.
In its submittal, the licensee did not provide any specific information on the weld examinations already performed for the first period, or how these examinations will be "prorated" for the Fourth 10-Year Interval. Additionally, it is not clear if all risk significant examinations that would have been completed during the first period of a RI-ISi Program at VCSNS Unit 1, were performed.
In its submittal, the licensee provided summary tables that include the total weld population in the scope of the VCSNS Unit 1 proposed RI-ISi Program. Please provide the ASME Code classifications (i.e., ASME Class 1 or 2) of the piping welds in the tables. Additionally, confirm that risk significant examinations that should have been performed during the first period of the RI-ISi program were performed during the first period as part of the regular ASME ISi, or will be performed as part of the RI-ISi Program consistent with the requirements of Table IWB-2411-1.
According to ASME Code Case N-578-1, "Risk-Informed Requirements for Class 1, 2, or 3 Piping, Method B, Paragraph -2420 (a), "Successive Inspections," the sequence of piping examinations established during the first inspection interval using the risk-informed process shall be repeated during each successive inspection. Thus, please confirm that the sequence of the piping examinations for periods 2 and 3 of the Fourth 10-year RI-ISi interval will be consistent with the sequence of examinations for 2 and 3 of the Third 10-year RI-ISi interval.
ML180238069 *via email OFFICE DORL/LPLll-1/PM DORL/LPLll-1/LA NRR/DRA/APLA/BC*
NAME SWilliams KGoldstein SRosenberg DATE 02/13/18 02/09/18 02/02/18 OFFICE NRR/DMLR/MPHB DORL/LPLI 1-1 /BC DORL/LPLll-1/PM NAME DAIiey MMarkley SWilliams DATE 02/05/18 02/15/18 02/15/18