RS-14-213, Third Six-Month Status Report in Response to March 12, 2012 Commission Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events (Order Number EA-12-049)
| ML14248A240 | |
| Person / Time | |
|---|---|
| Site: | Quad Cities  |
| Issue date: | 08/28/2014 |
| From: | Kaegi G Exelon Generation Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| EA-12-049, RS-14-213 | |
| Download: ML14248A240 (22) | |
Text
smar- Exelon Generation Order No. EA-12-049 RS-14-213 August 28, 2014 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Quad Cities Nuclear Power Station, Units 1 and 2 Renewed Facility Operating License Nos. DPR-29 and DPR-30 NRC Docket Nos. 50-254 and 50-265
Subject:
Third Six-Month Status Report in Response to March 12, 2012 Commission Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events (Order Number EA-12-049)
References:
- 1. NRC Order Number EA-12-049, "Issuance of Order to Modify Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events," dated March 12, 2012
- 2. NRC Interim Staff Guidance JLD-ISG-2012-01, "Compliance with Order EA-12-049, Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events," Revision 0, dated August 29, 2012
Revision 0, dated August 2012
- 4. Exelon Generation Company, LLC's Initial Status Report in Response to March 12, 2012 Commission Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events (Order Number EA-12-049), dated October 25, 2012
- 5. Exelon Generation Company, LLC Overall Integrated Plan in Response to March 12, 2012 Commission Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events (Order Number EA-12-049), dated February 28, 2013 (RS-13-025)
- 6. Exelon Generation Company, LLC First Six-Month Status Report in Response to March 12, 2012 Commission Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events (Order Number EA 049), dated August 28, 2013 (RS-13-129)
- 7. Exelon Generation Company, LLC Second Six-Month Status Report in Response to March 12, 2012 Commission Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events (Order Number EA 049), dated February 28, 2014 (RS-14-015)
U.S. Nuclear Regulatory Commission Integrated Plan Report to EA-12-049 August 28, 2014 Page 2
- 8. NRC letter to Exelon Generation Company, LLC, Quad Cities Nuclear Power Station, Units 1 and 2 Interim Staff Evaluation Relating to Overall Integrated Plan in Response to Order EA-12-049 (Mitigation Strategies) (TAC Nos. MF1048 and MF1049), dated November 22, 2013 On March 12, 2012, the Nuclear Regulatory Commission ("NRC" or "Commission") issued an order (Reference 1) to Exelon Generation Company, LLC (EGC). Reference 1 was immediately effective and directs EGC to develop, implement, and maintain guidance and strategies to maintain or restore core cooling, containment, and spent fuel pool cooling capabilities in the event of a beyond-design-basis external event. Specific requirements are outlined in of Reference 1.
Reference 1 required submission of an initial status report 60 days following issuance of the final interim staff guidance (Reference 2) and an overall integrated plan pursuant to Section IV, Condition C. Reference 2 endorses industry guidance document NEI 12-06, Revision 0 (Reference 3) with clarifications and exceptions identified in Reference 2. Reference 4 provided the EGC initial status report regarding mitigation strategies. Reference 5 provided the Quad Cities Nuclear Power Station, Units 1 and 2 overall integrated plan.
Reference 1 requires submission of a status report at six-month intervals following submittal of the overall integrated plan. Reference 3 provides direction regarding the content of the status reports. References 6 and 7 provided the first and second six-month status reports, respectively, pursuant to Section IV, Condition C.2, of Reference 1 for Quad Cities Station. The purpose of this letter is to provide the third six-month status report pursuant to Section IV, Condition C.2, of Reference 1, that delineates progress made in implementing the requirements of Reference 1. The enclosed report provides an update of milestone accomplishments since the last status report, including any changes to the compliance method, schedule, or need for relief and the basis, if any. The enclosed report also addresses the NRC Interim Staff Evaluation Open and Confirmatory Items contained in Reference 8.
This letter contains no new regulatory commitments. If you have any questions regarding this report, please contact David P. Helker at 610-765-5525.
I declare under penalty of perjury that the foregoing is true and correct. Executed on the 28th day of August 2014.
Respectfully submitted, 7 7 Glen T. Kaegi Director - Licensing & Regulatory Affairs Exelon Generation Company, LLC
Enclosure:
- 1. Quad Cities Nuclear Power Station, Units 1 and 2 Third Six-Month Status Report for the Implementation of Order EA-12-049, Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events
U.S. Nuclear Regulatory Commission Integrated Plan Report to EA-12-049 August 28, 2014 Page 3 cc: Director, Office of Nuclear Reactor Regulation NRC Regional Administrator - Region III NRC Senior Resident Inspector Quad Cities Nuclear Power Station, Units 1 and 2 NRC Project Manager, NRR Quad Cities Nuclear Power Station, Units 1 and 2 Ms. Jessica A. Kratchman, NRR/JLD/PMB, NRC Mr. Jack R. Davis, NRR/DPR/MSD, NRC Mr. Eric E. Bowman, NRR/DPR/MSD, NRC Mr. Jeremy S. Bowen, NRR/DPR/MSD/MSPB, NRC Mr. Robert L. Dennig, NRR/DSS/SCVB, NRC Mr. John P. Boska, NRR/DPR/MSD/MSPB, NRC Illinois Emergency Management Agency - Division of Nuclear Safety
Enclosure Quad Cities Nuclear Power Station, Units 1 and 2 Third Six-Month Status Report for the Implementation of Order EA-12-049, Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events (18 pages)
Enclosure Quad Cities Nuclear Power Station, Units 1 and 2 Third Six Month Status Report for the Implementation of Order EA-12-049, Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events 1 Introduction Quad Cities Nuclear Power Station, Units 1 and 2, developed an Overall Integrated Plan (Reference 1 in Section 8) documenting the diverse and flexible strategies (FLEX) in response to Reference 2. This enclosure provides an update of milestone accomplishments since submittal of the last status report, including any changes to the compliance method, schedule, or need for relief/relaxation and the basis, if any.
2 Milestone Accomplishments Unit 1 Modification Development has been completed since the last update. U2 Modification Development has been completed since the last update. The FLEX storage building and Seismic Deep Well Modifications are in progress.
3 Milestone Schedule Status The following provides an update to Attachment 2 of the Overall Integrated Plan. It provides the activity status of each item, and whether the expected completion date has changed. The dates are planning dates subject to change as design and implementation details are developed.
The revised target completion dates impact the order implementation date. An explanation of the impact of these changes is provided in Section 5 of this enclosure.
Milestone Schedule Target Revised Target Milestone Completion Activity Status Completion Date Date Submit 60 Day Status Report Oct 2012 Complete Submit Overall Integrated Plan Feb 2013 Complete Contract with National SAFER Response Complete Center Submit 6 Month Updates:
Update 1 Aug 2013 Complete Update 2 Feb 2014 Complete Complete with Update 3 Aug 2014 this submittal Update 4 Feb 2015 Not Started Page 1 of 18
Quad Cities Nuclear Power Station, Units 1 and 2 Third Six Month Status Report for the Implementation of FLEX August 2014 Target Revised Target Milestone Completion Activity Status Completion Date Date Update 5 Aug 2015 Not Started Update 6 Feb 2016 Not Started Update 7 Aug 2016 Not Started See Section 5 of Submit Completion Report Not Started this enclosure.
Modifications Development &
Implementation':
Unit 1 Modification Development (All Feb 2014 Completed April 2014 FLEX Phases)
Unit 1 Modification Implementation (All Apr 2015 Started Mar 2015 FLEX Phases)
Unit 2 Modification Development (All Mar 2015 Completed FLEX Phases)
Unit 2 Modification Implementation (All Apr 2016 Not Started FLEX Phases)
Common Unit Modfication Development Started Mar 2015 (Building and Deep Wells)
Common Unit Modfication Implementation (Building and Deep Started Mar 2015 Wells)
Procedures:
Create Site-Specific Procedures Apr 2015 Started Mar 2015 Validate Procedures (NEI 12-06. Sect.
Apr 2015 Not Started Mar 2015 11.4.3)
Create Maintenance Procedures Apr 2015 Not Started Mar 2015 Perform Staffing Analysis Nov 2014 Started Storage Plan and Construction Apr 2015 Started Mar 2015 FLEX Equipment Acquisition Apr 2015 Started Mar 2015 Training Completion Apr 2015 Started Mar 2015 Page 2 of 18
Quad Cities Nuclear Power Station. Units 1 and 2 Third Six Month Status Report for the Implementation of FLEX August 2014 Target Revised Target Milestone Completion Activity Status Completion Date Date National SAFER Response Center Started Dec 2014 Operational Started See Section 5 of Unit 1 FLEX Implementation Apr 2015 this enclosure.
Started See Section 5 of Unit 2 FLEX Implementation Apr 2016 this enclosure.
Started See Section 5 of Full Site FLEX Implementation Apr 2016 this enclosure.
4 Changes to Compliance Method The Modification to the implementation plan for the use of two Deep Wells which was detailed in the February 2014 01P Six-Month update has been revised. Only one of the wells will be designed to withstand a seismic event. Neither well will be protected from high winds..
5 Need for Relief/Relaxation and Basis for the Relief/Relaxation Quad Cities Station submitted the request for relaxation to the NRC by letter dated February 27, 2014 (Reference 5). The NRC approved the Quad Cities Station relaxation request for full compliance of NRC Order EA-12-049 by letter dated April 15, 2014 (Reference 9).
6 Open Items from Overall Integrated Plan and Draft Safety Evaluation The following tables provide a summary of the open items documented in the Overall Integrated Plan (Reference 1) or the Draft Safety Evaluation (SE) (Reference 7), and the status of each item.
Section Overall Integrated Plan Open Item Status Reference Sequence of I. The times to complete actions in the Started Events (p. 4) Events Timeline are based on operating judgment, conceptual designs, and current supporting analyses. The final timeline will be time validated once detailed designs are completed and procedures are developed, and the results will be provided in a future six-month update.
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Quad Cities Nuclear Power Station, Units 1 and 2 Third Six Month Status Report for the Implementation of FLEX August 2014 Section Overall Integrated Plan Open Item Status Reference Sequence of 2. Issuance of BWROG document NEDC- Completed Events (p. 33771P, "GEH Evaluation of FLEX 4,5) Implementation Guidelines," on 01/31/2013 did not allow sufficient time to perform the analysis of the deviations between Exelon's engineering analyses and the analyses contained in the BWROG document prior to submittal of this Integrated Plan. This analysis is expected to be completed, documented on Attachment 1B, and provided to the NRC in the August 2013 six-month status update.
Sequence of 3. Additional work will be performed Completed Events (p. 6) during detailed design development to ensure Suppression Pool temperature will support RCIC operation, in accordance with approved BWROG analysis, throughout the event.
Sequence of 4. Initial calculations were used to Calculations have been approved. Action Events (p. 7) determine the fuel pool timelines. Formal Completed.
calculations will be performed to validate this information during development of the Spent Fuel Pool Cooling strategy detailed designs, and will be provided in a future six-month update.
Multiple 5. Procedures and programs will be Started Sections developed to address storage structure requirements, haul path requirements, and FLEX equipment requirements relative to the external hazards applicable to Quad Cities Programmatic 6. Quad Cities Nuclear Power Station will Started controls (p. 8) implement an administrative program for FLEX to establish responsibilities, and testing and maintenance requirements.
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Quad Cities Nuclear Power Station, Units 1 and 2 Third Six Month Status Report for the Implementation of FLEX August 2014 Section Overall Integrated Plan Open Item Status Reference Multiple 7. Detailed designs based on the current Started Sections conceptual designs will be developed to determine the final plan and associated mitigating strategies. Analysis will be performed to validate that the plant modifications, selected equipment, and identified mitigating strategy can satisfy the safety function requirements of NET 12-06.
Once these designs and mitigating strategies have been fully developed, Exelon will update the integrated plan for Quad Cities Nuclear Power Station during a scheduled six-month update. This update will include any changes to the initial designs as submitted in this Integrated Plan.
Maintain 8. Guidance will be provided to ensure that Started Core Cooling sufficient area is available for deployment Phase 1 and that haul paths remain accessible (P.13) without interference from outage equipment during refueling outages.
Maintain 9. Evaluation of the spent fuel pool area for Started Spent Fuel steam and condensation has not yet been Pool Cooling performed. The results of this evaluation Phase 1 and the vent path strategy, if needed, will be (p.32) provided in a future six-month update.
Safety 6.1.1 10. Habitability conditions will be Started Function evaluated and a strategy will be Support (p. developed to maintain RCIC
- 42) habitability Safety 6.1.2 11. Habitability conditions will be Complete. Duplicate of 3.2.4.6.A.
Function evaluated and a strategy will be Support (p. developed to maintain Main
- 42) Control Room habitability.
Safety 12. Battery Room Ventilation: Alternate Started Function ventilation will be provided to address Support (p. Hydrogen generation and cold weather, as
- 43) required.
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Quad Cities Nuclear Power Station, Units 1 and 2 Third Six Month Status Report for the Implementation of FLEX August 2014 Section Overall Integrated Plan Open Item Status Reference Safety 13. Fuel Oil Supply to Portable Equipment: Started Function A detailed fuel oil supply plan will be Support (p. developed.
- 43) 4. Provide alternate cooling to the RCIC Started 1A, Item 20 rooms. Procedure to be developed.
(P.59)
Section Interim Safety Evaluation / Audit Status Reference Questions Open Item 3.2.3.A SIGNIFICANT OPEN Item. Generic Complete. See February 2014 Six-Month concern related to adoption of Revision 3 to update.
the BWROG EPG/SAG [Emergency Procedure Guidelines/Severe Accident Guidelines] relating to potential detrimental effects on containment response.
3.2.4.6.A OPEN Item Licensee asserts 120 °F used Started for habitability in SBO is adequate for FLEX. Habitability of the control room should consider 110 degree F temperature limits of NUMARC 87-00 and MIL-STD-1472C.
3.3.2.A OPEN Item Control of equipment and Started connections for unavailability needs to be addressed.
3.4.B OPEN Item Details not provided to Complete. See February 2014 Six-Month demonstrate the minimum capabilities for update.
offsite resources will be met per NEI 12-06 Section 12.2.
3.1.1.2.A Confirmatory Item Studies for liquefaction Started and the effects on haul paths and storage location(s) are not complete.
3.1.1.2.B Confirmatory Item A postulated As discussed with the Second 6-month downstream dam failure from a seismic update Quad Cities Station will install two event is still being evaluated, independent full capacity wells which will be utilized for all makeup water for a seismic event which causes the downstream dam failure. Therefore, no further evaluation on the downstream dam failure is being performed. Complete.
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Quad Cities Nuclear Power Station, Units 1 and 2 Third Six Month Status Report for the Implementation of FLEX August 2014 3.1.1.2.0 Confirmatory Item Need to confirm Started implementation of strategy for power to move or deploy FLEX equipment and opening of doors.
3.1.1.3.A Confirmatory Item Plans for strategies have Started insufficient information to demonstrate alternate sources of instrument readings and adequate tolerances/accuracies if there is seismic impact to primary sources. Also, need identification of installed instrumentation location and power source.
3.1.1.3.B Confirmatory Item Need identification of The FLEX 480 VAC generators will be instrumentation used to monitor FLEX supplied by Cummins Power Generation.
electrical power equipment including The instruments supplied with the measurement tolerance/accuracy. generator will measure line to line and line to neutral voltage, phase current, and power output. Complete.
3.1.2.2.A Confirmatory Item A detailed fuel supply Started plan is to be provided in a future 6-month status update including what is needed, what is available, and how it will be transported.
3.1.3.2.A Confirmatory Item Completion of Started development of an administrative program to ensure pathways remain clear or compensatory actions will be implemented to ensure all strategies can be deployed during all modes of operation. Procedures and programs are to be developed.
3.1 .3.2.B Confirmatory Item Completion of Started assessment on the adequacy of the debris removal equipment and the effect on the timeline to assure the critical times are capable of being met. This will be tracked as an open item in the 6 month update.
3.2.1.1.A Confirmatory Item Need benchmarks to See Attachment 4 for responses to demonstrate Modular Accident Analysis MAAP4 information. Complete.
Program (MAAP)4 is the appropriate code for simulation of ELAP.
3.2. 1 .1 .B. Confirmatory Item The collapsed level See Attachment 4 for responses to must remain above Top of Active Fuel MAAP4 information. Complete.
(TAF) and the cool down rate must be within technical specification limits in the MAAP4 analysis.
3.2.1.1.C. Confirmatory Item MAAP4 must be used See Attachment 4 for responses to in accordance with Sections 4.1, 4.2, 4.3, MAAP4 information. Complete.
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Quad Cities Nuclear Power Station, Units 1 and 2 Third Six Month Status Report for the Implementation of FLEX August 2014 4.4, and 4.5 of the June 2013 position paper.
3.2.1.1.D. Confirmatory Item In using MAAP4, the See Attachment 4 for responses to licensee must identify and justify the subset MAAP4 information. Complete.
of key modeling parameters cited from Tables 4-1 through 4-6 of the "MAAP4 Application Guidance, Desktop Reference for Using MAAP4 Software, Revision 2" (Electric Power Research Institute Report 1 020236).
3.2.1.1.E. Confirmatory Item The specific MAAP4 See Attachment 4 for responses to analysis case that was used to validate the MAAP4 information. Complete.
timing of mitigating strategies in the integrated plan must be identified and available on thee-Portal for NRC staff to view. Alternately, a comparable level of information may be included in the supplemental response.
3.2.1.2.A. Confirmatory Item Questions remain Started unanswered regarding recirculation pump seal leakage rates. Aspects such as pressure dependence, leakage phase assumptions (single phase liquid, steam, mixed) are not discussed.
3.2.1.3.A. Confirmatory Item Need gap analysis Started between results of the licensee's analysis results and those of BWROG document NEDC-33771 P. Results are presented in 6 month update; however there is no analysis of the relevance of differences.
3.2.1,3.B. Confirmatory Item Licensee plans further Started review and analysis to ensure suppression pool temperature will support RCIC operation.
3.2.1.3.C. Confirmatory Item Need identification of Complete. See February 2014 Six-Month the minimum voltage required for the dc update.
buses and the basis of that determination.
3.2.1.4.A. Confirmatory Item Water quality issue and Started guidance on priority of water source usage need to be addressed.
3.2.1.4.B. Confirmatory Item Need completion of Started current evaluation of FLEX generator sizing calculation.
3.2.1.4.C. Confirmatory Item Need design and Started working pressure of hoses and fittings.
3.2.1.6.A. Confirmatory Item Licensee identified Started Page 8 of 18
Quad Cities Nuclear Power Station, Units 1 and 2 Third Six Month Status Report for the Implementation of FLEX August 2014 protection of equipment for Hardened Vent is to Order EA-13-109 (Reference 22).
Explain if this is equivalent to Order EA-12-049, as Order EA-13-109 does not require protection from external events.
3.2.2.A. Confirmatory Item The licensee identified Started modifications and procedures for SFP cooling are in development.
3.2.4.2.A. Confirmatory Item Modifications to restore Modification development has completed.
RCIC room cooling are being developed by the licensee.
3.2.4.2.B. Confirmatory Item Modifications to restore Modification development has completed.
ventilation to the battery rooms via use of the portable FLEX generators to address hydrogen and cold weather are being developed by the licensee.
3,2.4.4.A. Confirmatory Item Procedures for Started emergency lighting are to be developed for deployment of hands free flashlights.
3.2.4.4.B. Confirmatory Item Confirm upgrades to Started communication system that resulted from the licensee communications assessment.
(ADAMS Accession Nos. ML12306A199 and ML13056A135.)
3.2.4.5.A. Confirmatory Item Verify completion of Started drafted procedures for protected and internal locked area access.
3.2.4.6.B. Confirmatory Item Site industrial Complete. See February 2014 Six-Month procedures and identification of protective Update.
clothing, ice vests/packs, bottled water, etc.
is needed.
3.2.4.6.C. Confirmatory Item Need to address the use Started of appropriate human performance aids (e.g., component marking, connection schematics, installation sketches, photographs, etc.) which shall be included in the FLEX guidance implementing the FLEX strategies.
3.2.4.8.A. Confirmatory Item The licensee did not Started provide any information regarding loading/sizing calculations of portable diesel generators(s) and strategy for electrical isolation for FLEX electrical generators from installed plant equipment.
3.2.4.9.A. Confirmatory Item Need detailed fuel plan Started including fuel storage tank, truck, and day tank volumes and how fuel quality is Page 9 of 18
Quad Cities Nuclear Power Station, Units 1 and 2 Third Six Month Status Report for the Implementation of FLEX August 2014 maintained in the day tanks and in portable FLEX equipment.
3.2.4.10.A. Confirmatory Item Need detailed battery Started load profile for all mitigating strategies and a detailed discussion of loads that will be shed, how they will be shed, and what are the effects of the load shed.
3.4.A. Confirmatory Item Procedures for interface Started with the National SAFER Response Center need to be developed.
7 Potential Draft Safety Evaluation Impacts There are no potential impacts to the Draft Safety Evaluation identified at this time.
8 References The following references support the updates to the Overall Integrated Plan described in this enclosure.
- 1. Quad Cites Overall Integrated Plan in Response to March 12, 2012, Commission Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events (Order Number EA-12-049)," dated February 28, 2013.
- 2. NRC Order Number EA-12-049, "Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events," dated March 12, 2012.
- 3. NRC Order EA-13-109, "Issuance of Order to Modify Licenses with Regard to reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions," dated June 6, 2013.
- 4. Quad Cities Nuclear Power Station, Units 1 and 2 First Six Month Status Report for the Implementation of Order EA-12-049, "Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events," dated August 28, 2013.
- 5. Quad Cites Nuclear Power Station's Request for Relaxation from NRC Order EA-12-049, "Order Modifying Licenses With Regard To Requirements for Mitigation Strategies for Beyond-Design-Basis External Events" dated February 27, 2014.
- 6. RCIC Pump and Turbine Durability Evaluation Pinch Point Study, February 2013, 0000-0155-1545-RO, DRF 0000-0155-1541, Revision 0
- 7. Quad Cities Nuclear Power Station, Units 1 and 2 Interim Staff Evaluation Relating to Overall Integrated Plan in Response to Order EA-12-049 (Mitigation Strategies) (TAC NOS.MF 1048 and MF 1049), dated November 22, 2013.
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Quad Cities Nuclear Power Station, Units 1 and 2 Third Six Month Status Report for the Implementation of FLEX August 2014
- 8. Quad Cities Nuclear Power Station, Units 1 and 2 Second Six Month Status Report for the Implementation of Order EA-12-049, "Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events," dated February 28, 2014.
- 9. NRC Letter, Quad Cities Nuclear Power Station, Units 1 and 2 Relaxation of Certain Schedule Requirements for Order EA-12-049, "Issuance of Order to Modify Licenses with Regard to Requirements for Mitigation Strategies for Beyond Design Basis External Events," dated April 15, 2014.
9 Attachments Quad Cities Response to Confirmatory items 3.2.1.1 A-E (Answers derived from QC-MISC-014 Rev. 0)
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Quad Cities Nuclear Power Station, Units 1 and 2 Third Six Month Status Report for the Implementation of FLEX August 2014 Attachment Quad Cities Response to Confirmatory items 3.2.1.1 A-E 3.2.1.1.A Need benchmarks to demonstrate Modular Accident Analysis Program (MAAP)4 is the appropriate code for simulation of ELAP.
Response
Generic response provided by EPRI BWR Roadmap "Technical Basis for Establishing Success Timelines in Extended Loss of AC Power Scenarios in Boiling Water Reactors Using MAAP4,"
(EPRI Product ID 3002002749).
3.2.1.1.B The collapsed level must remain above Top of Active Fuel (TAF) and the cool down rate must be within technical specification limits in the MAAP4 analysis.
Response
The Quad Cities Integrated Plan states that the operators would commence a cooldown of the RPV after the RPV water level reaches +40" at a rate of 80°F/hr which is within the technical specifications limit of 100°F/hr. The following plot of the RPV pressure from the MAAP analysis uses a cooldown initiation setpoint of +40" water level in the RPV.
1200 1000 RPV PRESSURE (PPS), PSI 800 600 400 200 cAizzicav=;;Pcwcisit;zin4b1/444i;"ic 2 4 6 8 10 TIME, HOURS MAAP Calculation of RPV Pressure During RPV Depressurization Page 12 of 18
Quad Cities Nuclear Power Station, Units 1 and 2 Third Six Month Status Report for the Implementation of FLEX August 2014 For the representative MAAP run (Case 6), the collapsed RPV water level inside the shroud remains above TAF for the duration of the analysis. The plot below shows that the lowest RPV level, calculated by MAAP, was approximately -40" below instrument zero. (TAF is located at -142" relative to instrument zero, Instrument zero is at +503" above vessel zero.) As shown in the following plot, the collapsed RPV water level remains at least 8.5' above TAF for the duration of the analysis 80 (i) 60 0
co 40
-0 1 cc LLI u j 20
>N uj
..J 0
LLI
-20 0.
CC -40 0 20 40 60 80 TIME, HOURS MAAP Calculation of Collapsed RPV Water Level Inside the Shroud 3.2.1.1.0 MAAP4 must be used in accordance with Sections 4.1, 4.2, 4.3, 4.4, and 4.5 of the June 2013 position paper.
Response
MAAP analysis performed for Quad Cities was carried out in accordance with Sections 4.1, 4.2, 4.3, 4.4, and 4.5 of the June 2013 position paper, EPRI Technical Report 3002001785, "Use of Modular Accident Analysis Program (MAAP) in Support of Post-Fukushima Applications".
3.2.1.1.D In using MAAP4, the licensee must identify and justify the subset of key modeling parameters cited from Tables 4-1 through 4-6 of the "MAAP4 Application Guidance. Desktop Reference for Using MAAP4 Software, Revision 2" (Electric Power Research Institute Report 1 020236). This should include response at a plant-specific level regarding specific coding options and parameter choices for key models that would be expected to substantially affect the ELAP analysis performed for that licensee's plant. Although some suggested key phenomena are identified below, other parameters considered important in the simulation of the ELAP event by the vendor / licensee should also be included.
Page 13 of 18
Quad Cities Nuclear Power Station, Units 1 and 2 Third Six Month Status Report for the Implementation of FLEX August 2014
- a. Nodalization
- b. General two-phase flow modeling
- c. Modeling of heat transfer and losses
- d. Choked flow
- e. Vent line pressure losses
- f. Decay heat (fission products / actinides / etc.)
Response
- a. The reactor vessel nodalization is fixed by the MAAP code and cannot be altered by the user, with the exception of the detailed core nodalization. The Quad Cities MAAP 4.0.5 parameter file divides the core region into 5 equal volume radial regions (See NCHAN) and 13 axial regions (See NAXNOD). The axial nodalization represents 25 equal-sized fueled nodes (see NROWS), 1 unfueled node at the top (see NNFT), and 2 unfueled nodes at the bottom (see NNFB). The figure below, taken from the MAAP Users Manual, illustrates the vessel nodalization scheme.
SRV 0
4 to LOCA 4 Upper Head 4H-C=3 a LOCA 3 214- Key Standpipes Gas Flow Separators O PaM No.
at - A Heat Sink 4.1 Surface No.
5
- 4. 2 Sh-oud
}-noad Upper 1=1 Heat Sink Down-
,Z:k corner Genera2z1ed Openinti to Generalized Opening 2 Al Core cillower Generalized Downoomee 4. 7 7 - 1 Opening 3 8
Reciri LOCA Loop or 7 Lower Head v4' No: .Ne for GE bAiR's) f1/1944174.COR Page 14 of 18
Quad Cities Nuclear Power Station, Units 1 and 2 Third Six Month Status Report for the Implementation of FLEX August 2014 Containment nodalization is defined by the user. The standard nodalization scheme is used in the Quad Cities MAAP 4.0.5 parameter file and represents the following individual compartments:
- 1. Reactor pedestal region
- 2. Drywell
- 3. Drywell vents to torus
- 4. Torus (Wetwell)
The figure below illustrates the Quad Cities containment nodalization along with an identification of containment flow junctions.
Junction Description 1 Pedestal Door to Drywell 2 Drywell to Vents/Downcomers 3 Vents/Downcomers to Suppression Pool Drywell
--> Vent 4 Drywell Vent/Failure 5,6,7,8 Suppression
-7> Leakage Chamber to Vent Vacuum Breakers 9 Suppression Pedestal Chamber Vent/Failure
> Shell Failure 10 Drywell Leakage 1 2 33 Drywell Shell Failure Vents/
Down-corners
> Vent/Failure 5,6,7,8 Suppression Chamber 3
- b. General two-phase flow from the reactor vessel is described in the EPA! BWR Roadmap. In the case of the scenario outlined in the integrated plan, flow can exit the RPV via the open SRV(s) and from the assumed recirculation pump seal leakage. Flow from SRV will be single-phase steam and flow from the recirc pump seal or other RPV leakage will be single-phase liquid due to the location of the break low in the RPV with RPV level continued to be maintain above TAF. Upon exiting the RPV, the seal leakage will flash a portion of the flow to steam based on saturated conditions in the drywell, creating a steam source and a liquid water source to the drywell. As described in the BWR Roadmap (EPRI Product ID 3002002749) there are two parameters that can Page 15 of 18
Quad Cities Nuclear Power Station, Units 1 and 2 Third Six Month Status Report for the Implementation of FLEX August 2014 influence the two-phase level on the RPV. The following table confirms that the parameter values match the recommended values as outlined in the roadmap.
Value Used in the EPRI Parameter Name Quad Cities MAAP Analysis Recommended Value FCO 1.5248 1.5248 FCHTUR 1.53 1.53
- c. Modeling of heat transfer and losses from the RPV are described in the EPRI BWR Roadmap. The parameters that control these processes, as defined in the Roadmap, are provided below with the values selected to represent Quad Cities.
Value Used in the Parameter Name Quad Cities MAAP Analysis Comment QCO not-thru-insulation heat 3.90E6 BTU/hr Plant specific value based on transfer from RPV during drywell heat removal to normal operation. coolers during normal operation. Typical values range between 1-2 MW (3.4E6 to 6.8E6 BTU/hr).
FIN PLT number of plates in 8.0 Plant-specific value reflective insulation XTINS average reflective 0.2975 ft Plant-specific value insulation thickness At the request of the NRC, the following information, as used in the MAAP analysis, is provided.
Parameter Value Used in the Parameter Definition Name in MAAP Quad Cities MAAP Analysis Power level, MWth QCRO 2957 MWth Initial CST water volume, gal VCSTO (ft3) 345,977 gal Initial CST water temperature, F HCST (enthalpy) 95°F Initial suppression pool water Calculated from input 6,908,000 lbm mass, lbm Initial suppression pool water XWRBO(i), where i is node 14.0 ft Page 16 of 18
Quad Cities Nuclear Power Station. Units 1 and 2 Third Six Month Status Report for the Implementation of FLEX August 2014 level, ft number for wetwell Initial suppression pool water TWRBO(i), where i is node 92.5°F temperature, F number for wetwell Drywell free volume, ft3 VOLRB(i), where I is node 145,767 ft3 number for drywell Wetwell free volume, ft3 VOLRB(i) volume of 236,000 ft3 suppression pool water from initial pool mass Containment vent pressure, psia Refer to MAAP analysis 25 psia document RCIC max flow rate, gpm WVRCIC 400 gpm Max FLEX pump flow rate, gpm Refer to MAAP analysis 88.5 gpm document (into the suppression pool from 14.7 150 psia)
Lowest set SRV flow rate, lb/hr Derived from SRV area, 558,000 lb/hr ASRV Lowest set SRV pressure, psia PSETRV 1115.7 psia Recirc pump seal leakage, gpm Value that was used to 36 define LOCA area, ALOCA (18 gpm per pump)
Total leakage used in the Value that was used to 42 gpm transient, gpm define LOCA area, ALOCA
- d. Choked flow from the SRV and the recirculation pump seal leakage is discussed in the EPRI BWR Roadmap. The parameters identified that impact the flow calculation are listed below with input values identified.
Value Used in the EPRI Parameter Name Quad Cities MAAP Analysis Recommended Value ASRV effective flow area for 0.0639 ft2 Plant-specific value relief valve (based on rated flow at pressure)
ALOCA seal leakage area 5.8E-4 ft2 Plant-specific value (38 gpm at normal conditions)
FCDBRK discharge 0.75 0.75 coefficient for seal leakage Page 17 of 18
Quad Cities Nuclear Power Station, Units I and 2 Third Six Month Status Report for the Implementation of FLEX August 2014
- e. Vent line pressure loss can be represented in two ways. The actual piping flow area can be input along with a discharge coefficient (FCDJ). An alternative method would be to calculate the effective flow are given the estimated piping losses, and input a loss coefficient of 1.0. For the Quad Cities analysis, the vent area is input based on a 12" diameter pipe and a discharge coefficient of 0.5 was selected.
- f. Decay heat in MAAP is discussed in the EPRI BWR Roadmap (EPRI Product ID 3002002749). Input parameters used to compute the decay heat are identified in the roadmap and are listed in the following table along with their values used in the Quad Cities analysis.
Value Used in the EPRI Parameter Name Quad Cities MAAP Analysis Recommended Value FENRCH normal fuel enrichment 0.0408 Plant-specific value EXPO average exposure 20000 MW-day/ton Plant-specific value FCR total capture rate of U-238 / 0.324 Plant-specific value total absorption rate FFAF total absorption rate / total 2.37 Plant-specific value fission rate FQFR1 fraction of fission power 0.476 Plant-specific value due to U-235 and PU-241 FQFR2 fraction of fission power 0.437 Plant-specific value due to PU-239 FQFR3 fraction of fission power 0.087 Plant-specific value due to U-238 TIRRAD average effective 26280 hours Plant-specific value irradiation time for entire core 3.2.1.1.E The specific MAAP4 analysis case that was used to validate the timing of mitigating strategies in the integrated plan must be identified and available on thee-Portal for NRC staff to view. Alternately, a comparable level of information may be included in the supplemental response.
Response
The MAAP analysis performed in support of the Quad Cities Integrated Plan is documented in calculation QC-MISC-013 Rev. 2. This analysis is still in progress. The analysis will be made available to the NRC when it has been approved by the site. Case 6 was the specific MAAP run selected to represent the scenario as described in Attachment 1A of the integrated plan.
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