ML19212A723
| ML19212A723 | |
| Person / Time | |
|---|---|
| Issue date: | 07/31/2019 |
| From: | Office of Nuclear Regulatory Research |
| To: | |
| D. Stroup 415-1649 | |
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| Download: ML19212A723 (25) | |
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NRC-RES Fire PRA Workshop Module IV August 5-9, 2019 Rockville, MD NRC-RES/EPRI FIRE PRA METHODOLOGY:
Task 12 - Fire HRA Fire HRA Training Overview
Fire HRA Overview Slide 2 Fire PRA Workshop 2019, Rockville, MD Course Overview 1.
Introduction to HRA 2.
Overview of the EPRI/NRC Fire HRA Guidelines 3.
Identification and definition of fire human failure events 4.
Qualitative analysis 5.
Fire HRA Application Experience 6.
Quantitative analysis a) Screening b) Scoping c)
Detailed EPRI approach & ATHEANA (detailed) 7.
Recovery analysis 8.
Dependency analysis 9.
Uncertainty analysis
Fire HRA Overview Slide 3 Fire PRA Workshop 2019, Rockville, MD EPRI/NRC Fire HRA Guidelines Overview Purpose of the Fire HRA training course module Training objectives Background on the Fire HRA Guidelines Fire HRA development team, approach & timeline Fire HRA Guidelines, public review & path forward Summary of EPRI/NRC Fire HRA Guidelines scope & contents
Fire HRA Overview Slide 4 Fire PRA Workshop 2019, Rockville, MD EPRI/NRC Fire HRA Guidelines Purpose of Training Course Provide training on guidance from EPRI/NRC Fire HRA Guidelines (NUREG-1921/EPRI 1023001)
Opportunity for face-to-face, real-time interactions between authors and potential future users Opportunity to improve training
-It is important for us to get student/audience feedback for future presentations
Fire HRA Overview Slide 5 Fire PRA Workshop 2019, Rockville, MD Fire HRA Module Training Objectives 1:Be able to name the steps in the process for conducting a Fire HRA.
2:Be able to list the different categories of fire HRA human failure events.
3:Demonstrate a knowledge of ASME/ANS PRA Standard high level requirements related to HRA.
4:Be able to identify context and performance shaping factors used in the analysis of fire human failure events.
5:Be able to list the quantification methods available for HEPs.
6:Understand the concept and importance of addressing dependencies between fire HRA events.
Fire HRA Overview Slide 6 Fire PRA Workshop 2019, Rockville, MD Background on the Issue of Fire HRA Almost 50% of USA plants transitioning to NFPA-805
- Using NUREG/CR-6850 [EPRI 1011989] for the Fire PRA Guidance NUREG/CR-6850 [EPRI 1011989] addresses:
- Identifying human failure events (HFEs)
- Assigning conservative screening human error probabilities (HEPs)
- Fire performance shaping factor (PSF) information NUREG/CR-6850 [EPRI 1011989] does not:
- Describe a methodology for developing best-estimate HEPs (given fire related effects)
- Address the requirements of:
ASME/ANS RA-Sa-2009, Addenda to ASME/ANS RA-S-2008, Standard for Level 1 / Large Early Release Frequency Probabilistic Risk Assessment for Nuclear Power Plant Applications, Chapter 4 for fires Consequently, there was a need for fire-specific guidance for best-estimate HRA quantification in fire PRA
Fire HRA Overview Slide 7 Fire PRA Workshop 2019, Rockville, MD EPRI/NRC Fire HRA Guidelines High Level Objectives Through joint NRC and industry efforts, address the need for HRA guidance, especially for best-estimate quantification, for use in fire PRAs Address methodology Address guidance for implementing the methodology Develop a joint EPRI/NRC report (similar to NUREG/CR-6850 [EPRI 1011989])
Consider ASME/ANS PRA Standard requirements and user needs
Fire HRA Overview Slide 8 Fire PRA Workshop 2019, Rockville, MD Susan Cooper & Kendra Hill NRC-RES Project Manager Stuart Lewis EPRI Project Manager EPRI Jeff Julius (Lead)
Jan Grobbelaar & Kaydee Kohlhepp Erin Collins RES Susan Cooper (Lead)
John Forester Stacey Hendrickson & Mary Presley Independent Review Team NRC Reps Utility HRA Reps EPRI NRC EPRI/NRC Fire HRA Guidelines Development Team
Fire HRA Overview Slide 9 Fire PRA Workshop 2019, Rockville, MD Fire HRA Guidelines Development Approach 1)
Review of Generic Fire Literature and Data
Existing guidance & literature
Historical & experiential plant fire data 2)
Fire HRA Methodology & Guidelines Development
Examined HRA process & identified how process and tasks would change for the fire environment and accident response scenarios in response to a fire 3)
Fire HRA Review & Test
NRC and industry peer review team (7 people)
Two plants tested Scoping method flowcharts
Fire HRA Overview Slide 10 Fire PRA Workshop 2019, Rockville, MD 2010 Testing at BWR/PWR Pilot by PWROG Peer Review of 1st Draft Evolution of the Fire HRA Guidelines 2011 2009 initial draft revision revision Plant
Response
& FPRA Review Application of Fire HRA Guidelines to FPRA at Non-Pilot Plants NRC review Draft for public comment Public review &
comment Comment response
& report revision 2012 Technical Editing Final comment resolution ACRS PRA Sub-committee 2008 ACRS PRA Sub.,
then Full Committee Fire HRA Course 2007 Kick-Off Comb.
PRA Std Industry Peer Rvw 805 LAR Submittals First Draft Final Rpt July 2012
Fire HRA Overview Slide 11 Fire PRA Workshop 2019, Rockville, MD Fire HRA Guidelines Public Review & Comment NUREG-1921/EPRI 1019196 issued in November 2009 for public review and comment Prior to public review period, obtained comments during presentation to ACRS PRA Subcommittee Received 265 public comments (~75 editorial) from:
- PWROG
- BWROG Final report was revised to address public comments, etc.
- Approach is not fundamentally different, but
- Some important changes (e.g., reduced requirements for assessing feasibility of operator actions during screening and scoping analyses)
- Exelon
Fire HRA Overview Slide 12 Fire PRA Workshop 2019, Rockville, MD Fire HRA Guidelines Path Forward Final Guidelines document issued July 2012 It is anticipated that this guidance will be used by the industry as part of transition to NFPA 805 and possibly in response to other regulatory issues This is the first report addressing fire-related HRA for fire PRA that goes beyond the screening level As the methodology is applied at a wide variety of plants, the document may benefit from future improvements to better support industry-wide issues being addressed by fire PRA
Fire HRA Overview Slide 13 Fire PRA Workshop 2019, Rockville, MD Fire HRA Guidelines Summary Objectives and Scope Identify/analyze existing post-initiator HFEs
- Changes to previously modeled HFEs due to fire effects Identify/analyze post-initiator fire response HFEs
- New category of HFE to be analyzed Procedures, training, cues typically different from existing post-initiator HFEs
- Includes alternative shutdown (such as MCR abandonment due to habitability or transferring command and control to outside the MCR)
Identify/analyze post-initiator HFEs in response to spurious actuations and indications
- New category of HFE to be analyzed
Fire HRA Overview Slide 14 Fire PRA Workshop 2019, Rockville, MD Fire HRA Guidelines Summary Objectives and Scope (continued)
Implement post-initiator fire HEPs in fire PRA model(s)
- Initial quantification using screening or scoping approach
- Identification of risk significant events for later detailed HRA (e.g.,
to meet ASME/ANS Part 2 supporting requirement HR-G1, Capability Category II)
- Including dependency analysis Out of Scope
- Pre-initiators (per NUREG/CR-6850 [EPRI 1011989])
- Fire brigade response (except for impacts on fire PSFs)
Fire HRA Overview Slide 15 Fire PRA Workshop 2019, Rockville, MD Fire HRA Guideline Summary Standard HRA process used for Fire HRA modeling:
Based on other processes and guidance ASME/ANS PRA Standard NUREG-1792 Fire Manual Actions, NUREG-1852 SHARP1 ATHEANA Overall, NUREG-1921 [EPRI-1023001] captures the state-of-practice in HRA then advances the state-of-the-art for fire-specific PRA purposes
Fire HRA Overview Slide 16 Fire PRA Workshop 2019, Rockville, MD Fire HRA Process Steps 1.
Identification & definition of human failure events (HFEs):
Substantial guidance provided, including feasibility test
Feasibility Evaluation (Go / No-Go) example criteria Sufficient time available to complete action Procedures & cues exist Sufficient manpower 2.
Qualitative analysis
Iterative process that continues throughout quantification steps
Discussion includes tips & tools for information collection, &
interpretation, addressing important fire-specific topics, etc.
Comprehensive discussion of HFE feasibility under fire conditions
As fire PRA develops, fire HRA must consider additional fire scenario-specific details that become available
Fire HRA Overview Slide 17 Fire PRA Workshop 2019, Rockville, MD Fire HRA Process Steps (continued)
- 3. Quantification Methods - three levels
Screening Quantification Refinement/relaxation for areas identified in NUREG/CR-6850 [EPRI 1011989] implementation Typically used in NUREG/CR-6850, Task 7 first/screening quantification
Scoping Fire HRA method added (new):
Developed to address the majority of HFEs, thereby conserving HRA resources Simplified HRA quantification method with limited set of performance shaping factors (PSFs) to address Decision tree format (enhancing traceability)
Typically used during NUREG/CR-6850, Tasks 7 or 8, or early quantification of detailed fire scenarios in Tasks 11/14
Fire HRA Overview Slide 18 Fire PRA Workshop 2019, Rockville, MD Fire HRA Process Steps (continued)
- 3. Quantification (contd, 3rd of 3 methods)
Detailed Fire HRA Uses existing methods Performance shaping factors modified for the fire context:
EPRI Cause-Based Decision Tree & HCR/ORE; &
THERP NRCs ATHEANA HRA method Typically used in NUREG/CR-6850 [EPRI 1011989]
Tasks 11/14 quantification of detailed fire scenarios as needed
Fire HRA Overview Slide 19 Fire PRA Workshop 2019, Rockville, MD Fire HRA Process Steps (continued)
- 4. Recovery, Dependency, and Uncertainty Typically part of NUREG/CR-6850 [EPRI 1011989] Tasks 11/14 quantification of detailed fire scenarios In general, these tasks are not different than that for internal events PRA NUREG-1921 [EPRI 1023001] discusses fire-specific aspects of these tasks
Fire HRA Overview Slide 20 Fire PRA Workshop 2019, Rockville, MD Steps in the Fire HRA Process Screening Scoping Detailed analysis Identification and Definition Qualitative Analysis Quantitative Analysis Recovery Analysis Dependency Analysis Uncertainty Analysis
Fire HRA Overview Slide 21 Fire PRA Workshop 2019, Rockville, MD Mapping Fire HRA Process to Fire PRA Tasks NUREG/CR-6850
[EPRI 1011989] Task Fire HRA Process Step Task 2 - Component Selection Identification of previously existing HFEs &
potential response to spurious Task 5 - Fire-Induced Risk Model Identification and Definition of fire response HFEs Task 12 - Fire HRA Qualitative Analysis - context &
performance shaping factors Task 7 - First/Screening Quant.
Quantification - typically screening or scoping Task 8 - Scoping Quantification Quantification - typically scoping Tasks 11/14 - Detailed Scenario Quantification Quantification & Dependency could be screening, scoping or detailed HRA Task 15 - Uncertainty Uncertainty
Fire HRA Overview Slide 22 Fire PRA Workshop 2019, Rockville, MD Fire HRA Guideline Summary
NUREG-1921 [EPRI 1023001] also provides some additional tools & discussion that may be helpful to the analysis, e.g.,
Section 2.3, Relationship to Other Fire PRA tasks
More detailed discussion of relationship between HRA and fire PRA
Table 2-1 relates NUREG/CR-6850 tasks to ASME/ANS PRA Standard elements & HRA tasks Section 2.5, Fire-Induced Cable Failure(s) and Electrical Faults
Discussion of how fire PRA treats fire-induced cable failure(s)
Table 2-2 relates different types of fire damage to different fire PRA tasks & how this damage is addressed
Fire HRA Overview Slide 23 Fire PRA Workshop 2019, Rockville, MD Fire HRA Guideline Summary
NUREG-1921 [EPRI 1023001] also provides some additional tools and discussion (continued)
Section 4.3, Feasibility Assessment
Feasibility is defined & criteria are identified
Discussion of how feasibility assessments can be performed Section 4.6.2, Timing
Discussion of timing windows used in NUREG-1921 [EPRI 1023001] quantification methods
Discussion of how to develop timing information Section 4.11, Reviews with Plant Operations
Discussion on how to conduct talk-throughs & walk-throughs
Fire HRA Overview Slide 24 Fire PRA Workshop 2019, Rockville, MD Fire HRA Technical Overview Fire HRA Process Summary:
- Identification and Definition
- Qualitative Analysis
- Quantification Methods:
Screening Scoping Detailed
- Recovery, Dependency, & Uncertainty Each Fire HRA process step is further described in subsequent presentations
Fire HRA Overview Slide 25 Fire PRA Workshop 2019, Rockville, MD Questions?