BWROG - RCIC (AFW) Expanded Operation Performance Band - Overview and Status

Transcription

1 BWROG - RCIC (AFW) Expanded Operation Performance Band - Overview and Status Randy Bunt (SNC) - BWROG RCIC Expanded Operating Band Committee Chairman Lesa Hill (SNC) - BWROG Chairman Nuclear Strategic Issues Advisory Committee Meeting October 15, 2015 Washington, DC Copyright 2015, BWR Owners Group, All Rights Reserved

2 Value Statement Reduce and Deter Costs: Provide an improved transition to portable FLEX equipment by expanding Terry Turbine operational margin; potential avoided costs Expand the high temperature and low pressure Terry Turbine operational bands by improved operational guidance during low speed operation Reduce Risk of Operations: Update the EPGs to reduce the likelihood that any beyond-design basis event will progress to core damage Establish the technical basis for the steam driven systems operational changes that prevent events from progressing to core damage (reduce CDF and plant risk) Simplify Plant Operations: Add flexibility to respond to events by examining RCIC operational conditions identified in the Fukushima accidents; Terry Turbine selfregulation with water level (this can be a game changer similar to feed and bleed identified after TMI for PWRs) Addresses Flood and Seismic Mitigating Strategies Assessments (MSA) in response to Mitigating Strategies Rulemaking and NTTF Reevaluated Hazards per 50.54(f) criteria Copyright 2015, BWR Owners Group, All Rights Reserved October 15,

3 Organizational Contribution to Project Organization Percent Type of Participant Notes U.S. Industry ~ 1/3 Nuclear Operator o o o o o BWROG EPRI NEI PIM PWROG BWROG - Research participant, subject matter experts and meeting logistics EPRI Project Management and leveraged research NEI - Level of effort in support role PIM - Equipment Industry support of test equipment is listed below, but would be coordinated here. Operational and event data is part of this support. Equipment costs distributed among industry participants U.S. DOE ~ 1/3 International ~ 1/3 PWROG - Level of effort consistent with consequences for PWR fleet Modeling and Research participant Modeling and Research participant Operational and event data is part of this support US National Laboratories and Universities with DOE HQ oversight Japan (IAE / METI) Copyright 2015, BWR Owners Group, All Rights Reserved October 15,

4 Rough Estimate of Costs by Phase Phase Estimated Costs Deliverable Estimated Duration Phase 1, Plan Development $ K Project Plan containing: Detailed benefit, cost, schedule including off-ramps, resource options, project QA/QC aspect 3 months Phase 2, First Principle Analytical Modeling (Modeling will continue throughout other phases to refine scope in those phases) Decision (off-ramp) for next Phase $750 1,500K Phase 3, Prototype Testing $750 3,000K Decision (off-ramp) for next Phase Phase 4, Small Scale Testing $ M Decision (off-ramp) for next Phase Phase 5, Large Scale Testing $12 20M Test results Model revisions, analyses, and input to the prototype and small scale testing designs Testing results to influence small and large scale testing Test results to provide anticipated benefits of some enhancements Testing results to influence large scale testing Test results to provide anticipated benefits of some enhancements 3-6 months 3 months for setup 6-9 months for test May include step wise approval of next phase 4-6 months for setup 9-15 months for tests Will include step wise approval of next phase months for setup 60 months for tests Copyright 2015, BWR Owners Group, All Rights Reserved October 15,

5 Questions Utilities working with stakeholders to improve fleet wide performance Copyright 2015, BWR Owners Group, All Rights Reserved October 15,

6 Global Expertise One Voice Nuclear Strategic Issues Advisory Committee Meeting PWROG Update Jack Stringfellow PWROG Chairman and COO October 15, 2015

7 Agenda Status of GSI 191 Submittal NRC Acceptance Review October 20 ACRS Meeting Status of PWROG Filtering Strategies work Focus of current activities Industry Coordination 2

8 GSI 191 Program Objectives The PWROG in-vessel debris program has been established and funded to: Improve upon the in-vessel debris limits defined in WCAP Revision 2 for PWROG member utilities pursuing final closure of GSI-191 using a deterministic approach (SECY , Option 2A) Support plants pursuing closure by risk informed methods (Option 2B) The program demonstrates that LTCC requirements are satisfied due to the fact that adequate core cooling is available through alternate flow paths and mixing continues to occur between the core and lower plenum in the presence of specified amounts of debris 3

9 WCAP Status WCAP submitted on July 17, 2015 Post-submittal review meeting with the NRC on August 6, 2015 NRC review schedule is 12 months from submittal date contingent upon WCAP acceptance 4

10 NRC Acceptance Review NRC Acceptance Review is in process NRC has identified the need for additional information with respect to the Cold Leg Break Methodology PWROG has performed "brine testing" to demonstrate continued core mixing with accumulated debris 5

11 NRC Acceptance Review Due to resource limitations, the brine test report was not finalized at the time of the WCAP submittal. PWROG supported an NRC audit of the cold leg break methodology, including the brine test results, on October 5 to identify exactly what additional information was needed by NRC to complete their acceptance review. 6

12 NRC Acceptance Review NRC Audit on Cold-Leg Break Method Confirmed significant margins and conservatism for the WCAP CLB limit NRC acknowledged that no single test provides a quantitative basis for the established value NRC will continue with the acceptance review contingent upon receiving supplemental information by November 30, 2015 NRC recommends moving ahead with the ACRS meeting on October 20,

13 ACRS Meeting October 20, 2015 ACRS Meeting Identify and stress program differences between WCAP and WCAP Program objectives Technical approach Balance between phenomenological understanding and application Present testing program results and evidence supporting revised methodology 8

14 PWR Filtering Strategies 9 BWR Containment Protection and Prevention of Radiological Release (CPPR) is nearing completion Engineered Filters for BWR Mark 1 & 2 Plants have been deemed as not cost effective BWR Strategy is to provide Severe Accident Capable Hardened Vents in conjunction with Severe Accident Water Addition/Management PWROG (PA-RMSC-1135 was issued June 2015 to identify preliminary PWR insights PA-RMSC-1365 is focused on enhancing existing SAMG containment protection strategies and will continue to follow NRC activities

15 PWR Filtering Strategies - Insights Containment venting may be necessary before 24 hours for ELAP events. Wet versus dry cavity designs may pressurize containment differently and these effects must be further investigated. Core/concrete interactions may also result in long term containment pressurization. The most effective means to preventing the need for venting and a radiological release is having steam generator feed at the start of the accident scenario. FLEX reactor vessel injection and steam generator heat removal, post core damage, may preclude reactor vessel failure and subsequent containment challenge 10

16 PWR Filtering Strategies Industry Coordination PWROG will continue work as necessary to support SAMG implementation. PWROG is participating in industry Filtering Strategies Working Group along with the BWROG. A cross-license agreement is being finalized to facilitate sharing information between EPRI and the PWROG. In parallel, discussions are underway between EPRI and PWROG regarding scope, schedule and deliverables for further analysis. 11

17 Global Expertise One Voice

18 PWR Filtering Strategies - Insights Containment spray may delay reaching the containment venting set point but will subsequently pressurize containment to failure earlier than without sprays. The behavior is sensitive to the timing of operating the spray. Hydrogen igniters alone are not expected to provide any benefit for large dry containments (the containment will be steam inert) but could be important for ice condenser containments. Passive autocatalytic recombiners could prove useful. PWR SAWA may provide scrubbing and filtering effects similar to what is seen in BWRs, though a severe accident capable vent may be required. 13