ML18288A343
| ML18288A343 | |
| Person / Time | |
|---|---|
| Issue date: | 10/15/2018 |
| From: | Shivani Mehta NRC/NRR/DRA/APLB |
| To: | Casto G NRC/NRR/DRA/APLB |
| s n mehta | |
| References | |
| Download: ML18288A343 (6) | |
Text
October 15, 2018 MEMORANDUM TO: Greg A. Casto, Chief PRA Licensing Branch B Division of Risk Assessment Office of Nuclear Reactor Regulation FROM: Shivani N. Mehta, Engineer /RA/
PRA Licensing Branch B Division of Risk Assessment Office of Nuclear Reactor Regulation
SUBJECT:
SUMMARY
OF THE SEPTEMBER 25, 2018, CATEGORY 2 PUBLIC MEETING ON NATIONAL FIRE PROTECTION ASSOCIATION 805 AND FIRE PROBABILISTIC RISK ASSESSMENT FREQUENTLY ASKED QUESTIONS On September 25, 2018, the U.S. Nuclear Regulatory Commission (NRC) staff held a teleconference meeting with industry stakeholders and the public to discuss existing and new National Fire Protection Association (NFPA) 805 and fire probabilistic risk assessment (PRA) frequently asked questions (FAQs) and research projects.
The agenda included the discussion of the following six existing FAQs:
- NFPA 805 FAQ-18-0078: Insulation Materials
- FPRA FAQ-18-0014: Time to Detection is Zero for Manual Non-Suppression Probability Calculations
- FPRA FAQ-18-0017: Conditional Trip Probability for Modeling Operator Discretion
- FPRA FAQ-18-0015: More Realistic Contained Fire Duration Limits
- FPRA FAQ-18-0018: Electrical Non-Suppression Probability (NSP)
The industry brought forward questions on the endorsement of Nuclear Energy Institute (NEI) 00-01 Guidance for Post-Fire Safe Shutdown Circuit Analysis, NEI 04-02 Guidance for Implementing a Risk-Informed, Performance-Based Fire Protection Program Under 10 CFR 50.48(c), and NUREG/CR-7150, Volume 3 Joint Assessment of Cable Damage and Quantification of Effects from Fire (JACQUE-FIRE): Technical Resolution to Open Issues On Nuclear Power Plant Fire-Induced Circuit Failure, Final Report, Volume 3.
Enclosures:
List of Meeting Attendees NEI Clarifying Comments on FPRA FAQ 18-0017 CONTACT: Shivani N. Mehta, NRR/DRA 301-415-0860
G. Casto In regards to NFPA 805 FAQ 10-0059, the NRC staff indicated that it issued the closeout memo for this FAQ on August 7, 2018 (ADAMS Accession No.: ML18208A454).
For NFPA 805 FAQ 18-0078, the NRC Staff indicated that they do not see a need to clarify the term limited combustible as it relates to NFPA 805 design element 3.3.4 and the industry indicated that the FAQ will be withdrawn.
For fire probabilistic risk assessment (FPRA) FAQ 18-0014 ADAMS Accession No.:
(ML18198A366), the NRC staff and industry discussed staff comments (ML18263A104), and in particular focused on several technical issues related to treating detection under the approach described in the FAQ. The industry will provide an updated clarification to the FAQ for the staff to review. The staff plans to review industrys update and provide comments before the next FAQ meeting.
For FPRA FAQ 18-0017, the NRC staff (staff comments: ADAMS Accession No.:
ML18180A319) and industry discussed some of the clarifying statements on the FAQ intent and content recently provided by the industry (Enclosure 2). The industry indicated that it is looking for NRC to indicate whether there is agreement on the fundamental objective and clarifying statements. The staff indicated it would review those statements and provide any comments it has on those statements by the next FAQ meeting.
For FPRA FAQ 18-0015 (staff comments: ADAMS Accession No.: ML18180A290), the industry provided an updated FAQ prior to the meeting ADAMS Accession No.: (ML18277A208) with substantial changes made, including changes to the title and approach of the FAQ. The industry will assign the updated FAQ a new number and provide to the NRC. The NRC staff will provide comments on the new FAQ prior to the next public meeting.
For FPRA FAQ 18-0018 (ADAMS Accession No.: ML18198A387), the NRC staff and industry discussed technical issues related to the data being used for the methods suggested in the FAQ and the circumstances for which they apply. The industry requested the NRC staff provide the non-suppression data that it believes should be included in the FAQ method. This data includes all bins associated with NUREG-2169. The industry will provide an updated FAQ for NRC staff to consider including an update to all bins associated with NUREG-2169 with associated sensitivity analysis to justify the range factors postulated in the current FAQ. This analysis should also address the potential uncertainty associated with limited data sets from the proposed data ranges.
The Industry inquired as to the status of endorsement of NEI 00-01, NEI 04-02 and NUREG/CR-7150, Volume 3. NRC staff stated that there were no plans to endorse NUREG/CR-7150, Volume 3 as a whole report and advised that stakeholders request approval of techniques, methods, and information through other formalized NRC processes. The NRC staff is currently compiling comments on NEI 00-01 and plans to provide comments to the NEI in October of 2018, and predicts final endorsement through an updated Regulatory Guide in late 2019. The NRC staff requested an updated NEI 04-02 to include the information in the NFPA 805 FAQs.
Industry provided an update on a project for developing PRA credit for Very Early Warning Fire Detection Systems (VEWFDS). Industry stated that a team of 14 people and two NRC observers had been identified and that the team will meet at the Shearon Harris Nuclear Power Plant from November 13 -15, 2018, and will work towards developing the duration and frequency of incipient fires. A report with the findings is estimated to be issued through NEI by
G. Casto the end of 2018 and a broader document through the Electric Power Research Institute (EPRI) in late 2019.
As a Category 2 meeting, the public was invited to participate in the meeting by discussing regulatory issues with the NRC staff at designated points identified on the agenda. There were no public comments provided.
ML18288A343 NRR-106 Office NRR/DRA/APLB NRR/DRA/APLB NRR/DRA/APLB Name SMehta JHyslop GCasto Date 10/11/2018 10/12/2018 10/15/2018 NATIONAL FIRE PROTECTION ASSOCIATION 805 +
FIRE PROBABILISTIC RISK ASSESSMENT PUBLIC FAQ MEETING:
LIST OF MEETING ATTENDEES September 25, 2018 U.S. NUCLEAR REGULATORY COMMISSION STAFF Greg Casto Susan Cooper JS Hyslop Shivani Mehta Nicholas Melly Brian Metzger Charles Moulton Jay Robinson David Stroup INDUSTRY STAKEHOLDERS Victoria Anderson (Nuclear Energy Institute)
Leonard Robert Casella (Southern Company)
Robert Cavedo (Exelon)
Steven Dolley (SPG Global)
Rob Jackson (Jensen Hughes)
Greg Kvamme (Xcel Energy)
James Lechner (Jensen Hughes)
Jason LeMaire (Engineering Planning and Management (EPM), Inc.)
Ashley Lindeman (Electric Power Research Institute)
P. Shannon Lovvorn (Tennessee Valley Authority)
Laroy Martin (Dominion Energy)
Rodney Pletz (American Electric Power)
Jeff Quinn (Engineering Planning and Management (EPM), Inc.)
Marko Randelovic (Electric Power Research Institute)
Andy Ratchford (Jensen Hughes)
Frederick Charles Ross, Jr. (Tennessee Valley Authority)
Mark Schairer (Engineering Planning and Management (EPM), Inc.)
Thomas Shudak (Cooper)
Harold Stiles (Duke Energy)
MEMBERS OF THE PUBLIC John Boothroyd John Conly (Certrec Corporation)
Chris LaFleur (Sandia National Labs)
Keith Vincent (FPL)
Enclosure 1
NUCLEAR ENERGY INSTITUTE CLARIFYING COMMENTS ON FIRE PROBABILISTIC RISK ASSESSMENT FAQ 18-0017
- Some clarifying statements in response to the NRC comments on FAQ 18-0017:
- Some of the comments provided useful recommendations that would improve and strengthen the FAQ. But rather than responding to individual comments, these statements are intended to ensure a common understanding of the FAQ's purpose and approach.
o If there is agreement on the fundamental objective, then a revised FAQ can be pursued.
- FAQ 18-0017 describes a PRA technique for capturing risk insights for fire scenarios where no "plant trip" is required and without introducing overly conservative impacts to CDF/LERF.
o No required "plant trip" means fire-induced equipment failure would not: 1) cause an automatic trip, 2) prompt a manual trip, and 3) prompt a shutdown in less than (typically) 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />.
When no "plant trip" is required, NUREG/CR-6850 states that no initiator need be assigned, or the analyst may conservatively assign a "reactor trip" if in doubt.
To the extent that the operator has the discretion to shut down the plant beyond any such required plant trip, this technique represents a more realistic treatment than making an "all or nothing" assumption.
o As long as the condition trip probabilities yield cutsets but do not inflate CDF/LERF, the actual values are not important. But, the selected values (i.e., 0.1 and 0.01) are reasonable for typical screening purposes.
o In particular, this technique does not credit operator action to mitigate the consequences of the trip. The actions of the operator factor into the initiator.
o Under the conditions established in FAQ 18-0017, there can be no procedure requiring the operator to initiate a reactor trip. If one existed or was created, then this technique would not apply.
- The technique in FAQ 18-0017 is consider a good approach for capturing risk insights but is not mandatory. Analysts may continue either to assign no initiator or to assume a reactor trip and be in full compliance with NUREG/CR-685 Enclosure 2