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| | document type = E-Mail, Request for Additional Information (RAI) | | | document type = E-Mail, Request for Additional Information (RAI) |
| | page count = 3 | | | page count = 3 |
| | | project = TAC:ME5939, TAC:ME5940 |
| | | stage = Other |
| | }} |
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| | =Text= |
| | {{#Wiki_filter:From: Lynch, Steven Sent: Thursday, January 05, 2012 3:50 PM To: Schrader, Kenneth Cc: Lent, Susan; Burkhardt, Janet; Wang, Alan Subject: RAIs for DCPP Requested Revision to TS 3.8.1, 'AC Sources - Operating,' for TSTF-163 and Exception to RG 1.9 (TAC Nos. ME5939 and ME5940) |
| | Ken, |
| | |
| | By letter dated March 28, 2011 (Agencywide Documents Access and Management System (ADAMS) |
| | Accession No. ML110880202), Pacific Gas and Electric Company (PG&E) submitted PG&E Letter DCL-11-038, "License Amendment Request 11-03, Revision to Technical Specification 3.8.1, 'AC Sources - |
| | Operating,' for Traveler TSTF-163, Revision 2, and Exception to Regulatory Guide 1.9, Revision 0." |
| | PG&E submitted a request for revision to Facility Operating License Nos. DPR-80 and DPR-82, revising Technical Specification (TS) 3.8.1, "AC Sources - Operating," to incorporate Technical Specification Task Force (TSTF) Traveler TSTF-163, Revision 2. The proposed changes would also revise the Final Safety Analysis Report Update to identify an exception to Regulatory Guide 1.9, Revision 0. |
| | The U.S. Nuclear Regulatory Commission (NRC) staff has reviewed the information provided in your application and determined that the following additional information is required in order to complete its review. This request for additional information (RAI) was discussed with you on November 22, 2011. In a follow-up call with Alan Wang on January 5, 2012, it was agreed that a response to this RAI would be provided by January 31, 2012. If circumstances result in the need to revise the requested response date, please contact me at (301) 415-1524 or via e-mail at Steven.Lynch@nrc.gov. The NRC staff has determined that no security-related or proprietary information is contained herein. |
| | : 1) The licensee stated the following on page 15 of the enclosure to the license amendment request: |
| | The test data from the 1R5, 2R5, 1 R7, and 2R7 outages establish that there is adequate margin in the 4-second load timer interval to ensure there is no overlapping of loads and that the DG [diesel generator] |
| | is capable of starting and accelerating subsequent loads. |
| | |
| | For DGs 1-1 and 2-2 Bus H, the AFW [auxiliary feedwater] pump load is followed by the containment spray (CS) pump load. Since the AFW [auxiliary feedwater] pump motor is one of the largest loads sequenced on a bus (600 hp per FSAR [Final Safety Analysis Report] Update Table 8.3-5) and it has one of the longest start (acceleration) times, it is expected that the frequency recovery would require a longer interval than other ESF [engineered safety feature] loads. The frequency response for the AFW pump motors was compared to one another for available data from the 1 R5, 2R5, 1 R7, and 2R7 outages. The AFW pump response was consistent, indicating that the extended frequency recovery was not related to an unusual or degraded DG or AFW pump condition or DG overload. The test data demonstrates that the DG frequency consistently stabilizes within a nominal 2.2 to 2.3 seconds and that the DGs are capable of starting and accelerating the subsequent ESF loads. |
| | a) Provide a summary of the test data from the 1R5, 2R5, 1R7, and 2R7 outages to demonstrate that there is adequate margin in the 4-second load timer interval to ensure that there is no overlapping of loads, that the DG frequency consistently stabilizes within a nominal 2.2 to 2.3 seconds, and that the DG is capable of starting and accelerating subsequent ESF loads. |
| | |
| | b) Provide a discussion that demonstrates that all large loads are strictly dependant on sequencer permissive signals and that the loading sequence is not affected by process signals (e.g., system pressure, temperature, level, etc.), which could lead to overlapping or simultaneous actuation of loads. |
| | |
| | c) Clarify whether pumps were in recirculation mode or fully loaded during the testing period. If tested in recirculation mode, explain how the 4-second load time interval is adequate for worst case design basis accident loading conditions. |
| | |
| | d) The minimum steady-state frequency proposed in the LAR is 58.8 Hz. Provide details on the magnitude and duration of frequency variation that would be expected during sequencing of large loads when the DG is operating at this frequency. e) Provide a summary of the impact on EDG loading when operating at extreme values of the TS frequency range (i.e., 58.8 Hz and 61.2 Hz). Identify if operating time and performance capabilities of critical motors (pumps) or motor operated valves are affected. |
| | : 2) According to the Diablo Canyon Final Safety Analysis Report (FSAR) Update, the second level of undervoltage protection for each vital 4.16 kilo-Volt bus is set at approximately 3800 Volts (V). The second level undervoltage setpoint is typically the minimum acceptable voltage for operation of safety-related equipment. In the license amendment request, the licensee is proposing a minimum voltage of 3785 V for sequencing and steady-state operation of the DG. a) Provide a detailed discussion that demonstrates that equipment required for plant shutdown will perform within the design basis assumptions in the Diablo Canyon accident analyses when the DG is operating at the lowest allowable voltage and frequency. |
| | |
| | b) Confirm that the second level undervoltage relay does not have to be reset after actuation to allow the DG breaker to close. |
| | : 3) TABLE 8.3-8 of the Diablo Canyon FSAR Update contains the following note: Note 1: Original testing was done using a nominal 5-second load sequence time interval with the KWS relay installed. Since a nominal 4-second load sequence time interval is used in the design basis loading scenario and the EDG loading capability is demonstrated through computer simulation without KWS relays, the test results of Table 8.3-8 are of historical value. |
| | a) Provide details on how the computer simulation results are validated with actual operation of large loads, specifically as related to voltage and frequency variations during sequencing. |
| | Regards, Steve Lynch General Engineer Office of Nuclear Reactor Regulation Division of Operating Reactor Licensing, Plant Licensing Branch 4 Office: O-12F08 MS: O-12D20 Phone: 301-415-1524 |
| | |
| }} | | }} |
Letter Sequence RAI |
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TAC:ME5939, Minimum Vs. Steady State Voltage and Frequency, Add Action to LCO 3.3.6.1 to Give Option to Isolate the Penetration, Control Rod SCRAM Time Testing, Add New Condition B to LCO 3.6.2.3, RHR Suppression Pool Cooling (Approved, Closed) TAC:ME5940, Minimum Vs. Steady State Voltage and Frequency, Add Action to LCO 3.3.6.1 to Give Option to Isolate the Penetration, Control Rod SCRAM Time Testing, Add New Condition B to LCO 3.6.2.3, RHR Suppression Pool Cooling (Approved, Closed) |
|
MONTHYEARDCL-11-038, License Amendment Request 11-03 Revision to Technical Specification 3.8.1, AC Sources - Operating for Traveler TSTF-163, Revision 2, and Exception to Regulatory Guide 1.9, Revision 02011-03-28028 March 2011 License Amendment Request 11-03 Revision to Technical Specification 3.8.1, AC Sources - Operating for Traveler TSTF-163, Revision 2, and Exception to Regulatory Guide 1.9, Revision 0 Project stage: Request ML1110104912011-04-11011 April 2011 Acceptance Review E-mail, License Amendment Request to Revise Technical Specification 3.8.1, AC Sources Operating and TSTF 163, Revision 2, Minimum Vs. Steady State Voltage and Frequency. Project stage: Acceptance Review ML1200504972012-01-0505 January 2012 Request for Additional Information Email, Amendment Request to Revise Technical Specifications to Adopt TSTF-163, Rev. 2, Minimum Vs. Steady State Voltage and Frequency, and Final Safety Analysis Report Update Project stage: RAI ML1207903382012-03-29029 March 2012 Issuance of Amendment Nos. 211 and 213, Revise Technical Specifications to Adopt TSTF-163, Rev. 2, Minimum Vs. Steady State Voltage and Frequency, and Final Safety Analysis Report Update Project stage: Approval 2011-04-11
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Category:E-Mail
MONTHYEARML23334A0912023-11-30030 November 2023 NRR E-mail Capture - Diablo Canyon 1 and 2 - Audit Questions for License Amendment Associated with TSTF-505, Provide Risk-Informed Extended Completion Times - RITSTF Initiative 4b ML23335A1012023-11-0606 November 2023 OEDO-23-00350-NRR - Screen-in Email - 10 CFR 2.206 Petition from Mother'S for Peace and Change.Org Regarding Diablo Canyon ML23306A0422023-11-0202 November 2023 NRR E-mail Capture - Acceptance Review Diablo Canyon Request to Adopt 10 CFR 50.69, risk-informed Categorization and Treatment of SSCs ML23230A0702023-08-18018 August 2023 NRR E-mail Capture - Acceptance Review - Diablo Canyon Request to Revise Technical Specifications to Adopt TSTF-505, Revision 2, Provide Risk-Informed Extended Completion Times RITSTF Initiative 4b ML23165A2702023-06-14014 June 2023 NRR E-mail Capture - Acceptance Review - Diablo Canyon Revision to the Unit 1 Reactor Vessel Material Surveillance Program Withdrawal Schedule ML23157A2392023-06-0505 June 2023 Limited Appearance Statement from Nina Babiarz in the Matter of the Diablo Canyon ISFSI License Renewal Application ML23096A1792023-04-0606 April 2023 NRR E-mail Capture - Request for Additional Information Diablo Canyon Exemption Request Regarding Senior Reactor Operator License Application ML23094A1032023-04-0404 April 2023 NRR E-mail Capture - Acceptance Review - Diablo Canyon Exemption Request Regarding Senior Reactor Operator License Application ML23076A0932023-03-16016 March 2023 16-2023 Email - Estimate of Spent Nuclear Fuel in Tons ML23067A0202023-03-0808 March 2023 NRR E-mail Capture - Diablo Canyon Nuclear Power Plant Evacuation Time Estimate Analysis Review ML23046A1132023-02-13013 February 2023 Transmittal Email, Paul Bessette to Gibson, 2/13/23, Filing of Formal Opposition to PG&E Exemption Request ML23046A1042023-02-13013 February 2023 Transmittal Email, Diane Curran to Gibson, 2/13/23, Filing of Formal Opposition to PG&E Exemption Request ML23052A2042023-01-10010 January 2023 E-mail from Paul Bessette Dated 01/10/2023 Regarding Diablo Canyon ML22326A1632022-11-21021 November 2022 Licensee Comment Email on Post-Shutdown Emergency Plan Amendment ML22266A0012022-09-22022 September 2022 (External Sender) E-Mail Diablo Canyon Power Plant, Unit Nos. 1 and 2 - Total Amount of Spent Nuclear Fuel Stored in Tons ML22241A1142022-08-29029 August 2022 NRR E-mail Capture - Acceptance Review - Diablo Canyon Application to Revise Technical Specifications to Adopt TSTF-569, Revision of Response Time Testing Definitions ML22194A8872022-07-11011 July 2022 September 2022 Emergency Preparedness Exercise Inspection - Request for Information Email ML22187A2652022-07-0606 July 2022 NRR E-mail Capture - Request for Additional Information: Diablo Canyon Exemption Request for Part 73 force-on-force Training Due to COVID-19 ML22105A0702022-04-15015 April 2022 NRR E-mail Capture - Acceptance Review - Diablo Canyon Request to Revise Technical Specifications to Adopt TSTF 577, Revised Frequencies for Steam Generator Tube Inspections ML22090A0832022-03-31031 March 2022 NRR E-mail Capture - Acceptance Review - Diablo Canyon Request for Approval of a Certified Fuel Handler Training and Retraining Program ML22089A1672022-03-29029 March 2022 Email - Acknowledgement of NRC Receipt of Diablo Canyon ISFSI Renewal Application ML22087A0412022-03-25025 March 2022 NRR E-mail Capture - Acceptance Review - Diablo Canyon Request for Approval of Alternative Security Measures for Early Warning System ML22061A2192022-03-0202 March 2022 NRR E-mail Capture - Request for Additional Information - Diablo Canyon Proposed Changes to Emergency Plan for post-shutdown and Permanently Defueled Condition ML21323A0652021-11-19019 November 2021 NRR E-mail Capture - Acceptance Review - Diablo Canyon Revision of Emergency Plan for post-shutdown Condition ML21264A6722021-09-21021 September 2021 NRR E-mail Capture - Revised Schedule: Diablo Canyon Request to Revise Technical Specification to Reflect the Permanent Cessation of Reactor Operation ML21215A3432021-08-0303 August 2021 NRR E-mail Capture - Request for Additional Information - Diablo Canyon Request to Revise Technical Specification 3.8.1, AC Sources - Operating to Support Diesel Fuel Oil Transfer System Component Planned Maintenance ML21189A0462021-07-0707 July 2021 NRR E-mail Capture - Draft Request for Additional Information - Diablo Canyon Emergency Amendment Request to Revise Technical Specification 3.7.8, Auxiliary Saltwater (Asw) System ML21188A0382021-07-0707 July 2021 (External_Sender) DCPP Draft Emergency LAR - Asw DCL-21-046, Email for Emergency LAR for TS 3.7.8, Auxiliary Saltwater (Asw) System2021-07-0707 July 2021 Email for Emergency LAR for TS 3.7.8, Auxiliary Saltwater (Asw) System ML21189A0662021-07-0707 July 2021 NRR E-mail Capture - Additional Draft Request for Additional Information - Diablo Canyon Emergency Amendment Request to Revise Technical Specification 3.7.8, Auxiliary Saltwater (Asw) System ML21189A0442021-07-0707 July 2021 NRR E-mail Capture - Request for Additional Information - Diablo Canyon Emergency Amendment Request to Revise Technical Specification 3.7.8, Auxiliary Saltwater (Asw) System ML21124A0612021-05-0404 May 2021 NRR E-mail Capture - Acceptance Review - Diablo Canyon Request to Revise Technical Specification 3.8.1, AC Sources - Operating to Support Diesel Fuel Oil Transfer System Component Planned Maintenance ML21104A3642021-04-14014 April 2021 NRR E-mail Capture - Request for Additional Information - Diablo Canyon Proposed Technical Specifications and Revised License Conditions for the Permanently Defueled Condition ML21062A0642021-03-0202 March 2021 NRR E-mail Capture - Request for Additional Information for Diablo Canyon Generic Letter 2004-02 Submittal (L-2017-LRC-0000) ML21054A3112021-02-23023 February 2021 NRR E-mail Capture - Acceptance Review: Diablo Canyon Request for One-Time Exemption from Select 10 CFR 55.59 Requirements ML21012A4432021-01-12012 January 2021 NRR E-mail Capture - Acceptance Review - Diablo Canyon Request to Revise Technical Specification to Reflect the Permanent Cessation of Reactor Operation ML20328A3002020-11-23023 November 2020 Email from Cgnp to the NRC - Comment Diablo Canyon Nuclear Power Plant, Units 1 and 2 - Dcdep Public Meeting - November 24, 2020 ML20329A0692020-11-23023 November 2020 NRR E-mail Capture - Request for Additional Information: Diablo Canyon COVID-19 Exemption Request to Extend force-on-force Exercise ML20323A4532020-11-18018 November 2020 NRR E-mail Capture - Request for Additional Information: Diablo Canyon COVID-19 Exemption Request to Extend Firearms Requalification ML20261H4232020-09-17017 September 2020 NRR E-mail Capture - Request for Additional Information: Diablo Canyon Unit 2 Fall 2019 Steam Generator Tube Inspection Report ML20239A9492020-08-26026 August 2020 (External Sender) E-Mail Comment by D. Lochbaum Regarding Diablo Canyon Unit 1 AFW System Piping ML20239A7282020-08-24024 August 2020 (External-Sender) E-mail Comments on No Significant Hazards Determination for Diablo Canyon LAR ML20239A7752020-08-24024 August 2020 (External-Sender) E-mail Comments on No Significant Hazards Determination for Diablo Canyon LAR ML20240A2302020-08-23023 August 2020 (External-Sender) E-mail Public Comment by D. Lochbaum Regarding Diablo Canyon Safety Issue ML20234A2422020-08-20020 August 2020 NRR E-mail Capture - Diablo Canyon Additional Request for Additional Information: Exigent License Amendment Request for Application to Provide a New Technical Specification 3.7.5, Auxiliary Feedwater System, Condition G EPID: L-2020-LLA-017 ML20233A8592020-08-19019 August 2020 Mothers for Peace Public Comment on Exigent LAR to Modify TS 3.7.5, Auxiliary Feedwater System ML20233A3222020-08-18018 August 2020 Comment (4) e-mail from D. Lochbaum Regarding Diablo Canyon Exigent LAR ML20231A2372020-08-17017 August 2020 NRR E-mail Capture - Diablo Canyon Additional Request for Additional Information: Exigent License Amendment Request for Application to Provide a New Technical Specification 3.7.5, Auxiliary Feedwater System, Condition G EPID: L-2020-LLA-017 ML20232C6482020-08-17017 August 2020 Lochbaum Public Comment 1 on Exigent LAR to Modify TS 3.7.5, Auxiliary Feedwater System ML20230A0732020-08-14014 August 2020 NRR E-mail Capture - Diablo Canyon Request for Additional Information: Exigent License Amendment Request for Application to Provide a New Technical Specification 3.7.5, Auxiliary Feedwater System, Condition G 2023-08-18
[Table view] Category:Request for Additional Information (RAI)
MONTHYEARML24024A2072024-01-24024 January 2024 Inservice Inspection Request for Information IR 05000275/20240152023-10-10010 October 2023 Information Request for the Cybersecurity Baseline Inspection, Notification to Perform Inspection (050002752024015 and 050003232024015) ML23249A2782023-09-0606 September 2023 Inservice Inspection Request for Information ML23159A2382023-07-25025 July 2023 Request for Additional Information for the Technical Review of the Application for Renewal of the Diablo Canyon Independent Spent Fuel Storage Installation (Cac/Epid Nos. 001028/L-2022-RNW-0007) ML23159A2372023-07-25025 July 2023 ISFSI Renewal RAI Transmittal Letter Enclosure ML23096A1792023-04-0606 April 2023 NRR E-mail Capture - Request for Additional Information Diablo Canyon Exemption Request Regarding Senior Reactor Operator License Application ML23047A0062023-02-21021 February 2023 Request for Additional Information Alternative Security Measures for Early Warning System (EPID: L-2022-LLA-0029) (Public Version) ML23041A1862023-02-17017 February 2023 Request for Information Regarding Diablo Canyon Power Plant, Units 1 and 2 - December 8, 2022, Public Meeting ML22258A1112022-09-14014 September 2022 2022 Diablo Canyon PIR Request for Information ML22200A2572022-07-19019 July 2022 Notification of In-service Inspection (Inspection Report 05000323/2022004) and Request for Information ML22187A2652022-07-0606 July 2022 NRR E-mail Capture - Request for Additional Information: Diablo Canyon Exemption Request for Part 73 force-on-force Training Due to COVID-19 ML22152A1502022-06-21021 June 2022 Request for Additional Information Regarding License Amendment Request for Technical Specifications and Revised License Conditions for the Permanently Defueled Condition ML22122A1412022-05-0505 May 2022 .02 Doc Request ML22068A2312022-03-17017 March 2022 Notification of NRC Design Bases Assurance Inspection (Team) 05000275/2022011 and 05000323/2022011 and Initial Request for Information ML22061A2192022-03-0202 March 2022 NRR E-mail Capture - Request for Additional Information - Diablo Canyon Proposed Changes to Emergency Plan for post-shutdown and Permanently Defueled Condition ML21363A1692021-12-29029 December 2021 Inservice Inspection Request for Information ML22019A0412021-12-29029 December 2021 RFI ML21215A3432021-08-0303 August 2021 NRR E-mail Capture - Request for Additional Information - Diablo Canyon Request to Revise Technical Specification 3.8.1, AC Sources - Operating to Support Diesel Fuel Oil Transfer System Component Planned Maintenance ML21130A3642021-06-21021 June 2021 DC 2021401 Information Request ML21104A3642021-04-14014 April 2021 NRR E-mail Capture - Request for Additional Information - Diablo Canyon Proposed Technical Specifications and Revised License Conditions for the Permanently Defueled Condition ML21062A0642021-03-0202 March 2021 NRR E-mail Capture - Request for Additional Information for Diablo Canyon Generic Letter 2004-02 Submittal (L-2017-LRC-0000) ML20329A0692020-11-23023 November 2020 NRR E-mail Capture - Request for Additional Information: Diablo Canyon COVID-19 Exemption Request to Extend force-on-force Exercise ML20323A4532020-11-18018 November 2020 NRR E-mail Capture - Request for Additional Information: Diablo Canyon COVID-19 Exemption Request to Extend Firearms Requalification ML20301A2212020-10-27027 October 2020 Notification of an NRC Fire Protection Baseline Inspection (NRC Inspection Report 05000275/2021010 and 05000323/2021010) and Request for Information ML20261H4232020-09-17017 September 2020 NRR E-mail Capture - Request for Additional Information: Diablo Canyon Unit 2 Fall 2019 Steam Generator Tube Inspection Report ML20231A2372020-08-17017 August 2020 NRR E-mail Capture - Diablo Canyon Additional Request for Additional Information: Exigent License Amendment Request for Application to Provide a New Technical Specification 3.7.5, Auxiliary Feedwater System, Condition G EPID: L-2020-LLA-017 ML20230A0732020-08-14014 August 2020 NRR E-mail Capture - Diablo Canyon Request for Additional Information: Exigent License Amendment Request for Application to Provide a New Technical Specification 3.7.5, Auxiliary Feedwater System, Condition G ML20280A5432020-06-0303 June 2020 DC 2020 PIR Request for Information ML20041E6012020-02-10010 February 2020 NRR E-mail Capture - Diablo Canyon Nuclear Power Plant, Units 1 and 2 - Request for Additional Information for Post -Shutdown Decommissioning Activities Report (PSDAR) ML19262G7482019-08-0909 August 2019 Request for Information ML19149A6012019-05-28028 May 2019 NRR E-mail Capture - Request for Additional Information (Supplemental) - License Amendment Request (LAR) to Revise Emergency Plan Response Organization Staffing and Augmentation ML19123A2162019-05-0202 May 2019 NRR E-mail Capture - Diablo Canyon Nuclear Power Plant -Request for Exemption from Operator Written Examination and Operating Test - Request for Additional Information ML19084A2572019-03-21021 March 2019 NRR E-mail Capture - Request for Additional Information - License Amendment Request (LAR) to Revise Emergency Plan Response Organization Staffing and Augmentation ML19043A9452019-02-20020 February 2019 Notification of Inspection (NRC Inspection Report 05000275/2019002, 05000323/2019002 and Request for Information ML17306A9382017-11-0202 November 2017 NRR E-mail Capture - Request for Additional Information - Request for Approval for Application of Full Weld Overlay REP-RHR-SWOL, Diablo Canyon Power Plant, Units 1 and 2 ML17152A3192017-06-0101 June 2017 NRR E-mail Capture - Request for Additional Information (RAI)- Relief Requests NDE-SLH U2, NDE-LSL U2, NDE-LHC U2, NDE-LHM U2, and NDE-ONV U2 (CAC Nos. MF9386 Through MF9390) ML17102B6072017-04-12012 April 2017 NRR E-mail Capture - Request for Additional Information (RAI) - Revised Emergency Action Level Schemes Pursuant to Nuclear Energy Institute (NEI) 99-01, Revision 6 ML16347A0032016-12-0909 December 2016 NRR E-mail Capture - Request for Additional Information (RAI) - Diablo Canyon Power Plant License Amendment Request for Adoption of NEI 94-01 ML16326A3562016-11-21021 November 2016 NRR E-mail Capture - Request for Additional Information - License Amendment Request to Adopt Nuclear Energy Institute (NEI) 94-01, Revision 2-A for Diablo Canyon Power Plant, Units 1 and 2 - CAC Nos. MF7731 and MF7732 ML16048A2322016-02-17017 February 2016 NRR E-mail Capture - Diablo Canyon 1 and 2 - Met Data Second Round of Requests for Additional Information for License Amendment Request 15-03 to Adopt the Alternative Source Term Per 10 CFR 50.67 (TAC Nos. MF6399 and MF640 ML16011A3652016-02-0202 February 2016 Requests for Additional Information for the Review of the Diablo Canyon Power Plant, Units 1 and 2, License Renewal Application - Set 39 (TAC Nos. ME2896 and ME2897) ML16011A3172016-01-11011 January 2016 NRR E-mail Capture - Diablo Canyon 1 and 2 - Requests for Additional Information for License Amendment Request 15-03 to Adopt the Alternative Source Term Per 10 CFR 50.67 ML15358A0022015-12-23023 December 2015 Request for Additional Information Email (Follow-up Pra), Request to Adopt National Fire Protection Association NFPA 805, Performance-Based Standard for Fire Protection for LWR Generating Plants (2001 Edition) ML15357A3822015-12-23023 December 2015 Request for Additional Information, Round 4 - Amendment Request to Replace Digital Process Protection System for Reactor Protection System and Engineered Safety Features Actuation System Functions ML15295A3732015-11-0505 November 2015 Requests for Additional Information Related to the Diablo Canyon LRA Environmental Review ML15287A1652015-10-23023 October 2015 Requests for Additional Information Related to the Diablo Canyon LRA Environmental Review - SAMA ML15267A7742015-10-0101 October 2015 Request for Additional Information Associated with Near-Term Task Force Recommendation 2.1 Seismic Evaluations ML15217A4812015-09-24024 September 2015 Requests for Additional Information for the Review of the Diablo Canyon Power Plant, Units 1 and 2, License Renewal Application Set-38 TAC Nos. ME2896 and ME2897 ML15238B7742015-08-27027 August 2015 Request for Additional Information Associated with Near-Term Task Force Recommendation 2.1, Seismic Reevaluations ML15153A0332015-06-29029 June 2015 Request for Additional Information Associated with Near-Term Task Force Recommendation 2.1, Seismic Reevaluations 2024-01-24
[Table view] |
Text
From: Lynch, Steven Sent: Thursday, January 05, 2012 3:50 PM To: Schrader, Kenneth Cc: Lent, Susan; Burkhardt, Janet; Wang, Alan Subject: RAIs for DCPP Requested Revision to TS 3.8.1, 'AC Sources - Operating,' for TSTF-163 and Exception to RG 1.9 (TAC Nos. ME5939 and ME5940)
Ken,
By letter dated March 28, 2011 (Agencywide Documents Access and Management System (ADAMS)
Accession No. ML110880202), Pacific Gas and Electric Company (PG&E) submitted PG&E Letter DCL-11-038, "License Amendment Request 11-03, Revision to Technical Specification 3.8.1, 'AC Sources -
Operating,' for Traveler TSTF-163, Revision 2, and Exception to Regulatory Guide 1.9, Revision 0."
PG&E submitted a request for revision to Facility Operating License Nos. DPR-80 and DPR-82, revising Technical Specification (TS) 3.8.1, "AC Sources - Operating," to incorporate Technical Specification Task Force (TSTF) Traveler TSTF-163, Revision 2. The proposed changes would also revise the Final Safety Analysis Report Update to identify an exception to Regulatory Guide 1.9, Revision 0.
The U.S. Nuclear Regulatory Commission (NRC) staff has reviewed the information provided in your application and determined that the following additional information is required in order to complete its review. This request for additional information (RAI) was discussed with you on November 22, 2011. In a follow-up call with Alan Wang on January 5, 2012, it was agreed that a response to this RAI would be provided by January 31, 2012. If circumstances result in the need to revise the requested response date, please contact me at (301) 415-1524 or via e-mail at Steven.Lynch@nrc.gov. The NRC staff has determined that no security-related or proprietary information is contained herein.
- 1) The licensee stated the following on page 15 of the enclosure to the license amendment request:
The test data from the 1R5, 2R5, 1 R7, and 2R7 outages establish that there is adequate margin in the 4-second load timer interval to ensure there is no overlapping of loads and that the DG [diesel generator]
is capable of starting and accelerating subsequent loads.
For DGs 1-1 and 2-2 Bus H, the AFW [auxiliary feedwater] pump load is followed by the containment spray (CS) pump load. Since the AFW [auxiliary feedwater] pump motor is one of the largest loads sequenced on a bus (600 hp per FSAR [Final Safety Analysis Report] Update Table 8.3-5) and it has one of the longest start (acceleration) times, it is expected that the frequency recovery would require a longer interval than other ESF [engineered safety feature] loads. The frequency response for the AFW pump motors was compared to one another for available data from the 1 R5, 2R5, 1 R7, and 2R7 outages. The AFW pump response was consistent, indicating that the extended frequency recovery was not related to an unusual or degraded DG or AFW pump condition or DG overload. The test data demonstrates that the DG frequency consistently stabilizes within a nominal 2.2 to 2.3 seconds and that the DGs are capable of starting and accelerating the subsequent ESF loads.
a) Provide a summary of the test data from the 1R5, 2R5, 1R7, and 2R7 outages to demonstrate that there is adequate margin in the 4-second load timer interval to ensure that there is no overlapping of loads, that the DG frequency consistently stabilizes within a nominal 2.2 to 2.3 seconds, and that the DG is capable of starting and accelerating subsequent ESF loads.
b) Provide a discussion that demonstrates that all large loads are strictly dependant on sequencer permissive signals and that the loading sequence is not affected by process signals (e.g., system pressure, temperature, level, etc.), which could lead to overlapping or simultaneous actuation of loads.
c) Clarify whether pumps were in recirculation mode or fully loaded during the testing period. If tested in recirculation mode, explain how the 4-second load time interval is adequate for worst case design basis accident loading conditions.
d) The minimum steady-state frequency proposed in the LAR is 58.8 Hz. Provide details on the magnitude and duration of frequency variation that would be expected during sequencing of large loads when the DG is operating at this frequency. e) Provide a summary of the impact on EDG loading when operating at extreme values of the TS frequency range (i.e., 58.8 Hz and 61.2 Hz). Identify if operating time and performance capabilities of critical motors (pumps) or motor operated valves are affected.
- 2) According to the Diablo Canyon Final Safety Analysis Report (FSAR) Update, the second level of undervoltage protection for each vital 4.16 kilo-Volt bus is set at approximately 3800 Volts (V). The second level undervoltage setpoint is typically the minimum acceptable voltage for operation of safety-related equipment. In the license amendment request, the licensee is proposing a minimum voltage of 3785 V for sequencing and steady-state operation of the DG. a) Provide a detailed discussion that demonstrates that equipment required for plant shutdown will perform within the design basis assumptions in the Diablo Canyon accident analyses when the DG is operating at the lowest allowable voltage and frequency.
b) Confirm that the second level undervoltage relay does not have to be reset after actuation to allow the DG breaker to close.
- 3) TABLE 8.3-8 of the Diablo Canyon FSAR Update contains the following note: Note 1: Original testing was done using a nominal 5-second load sequence time interval with the KWS relay installed. Since a nominal 4-second load sequence time interval is used in the design basis loading scenario and the EDG loading capability is demonstrated through computer simulation without KWS relays, the test results of Table 8.3-8 are of historical value.
a) Provide details on how the computer simulation results are validated with actual operation of large loads, specifically as related to voltage and frequency variations during sequencing.
Regards, Steve Lynch General Engineer Office of Nuclear Reactor Regulation Division of Operating Reactor Licensing, Plant Licensing Branch 4 Office: O-12F08 MS: O-12D20 Phone: 301-415-1524