ML19233A167
| ML19233A167 | |
| Person / Time | |
|---|---|
| Issue date: | 08/21/2019 |
| From: | Ed Miller Special Projects and Process Branch, PWR Owners Group |
| To: | Ed Miller Special Projects and Process Branch |
| References | |
| Download: ML19233A167 (43) | |
Text
NRR-DRMAPEm Resource From: Miller, Ed Sent: Wednesday, August 21, 2019 7:34 AM To: Miller, Ed
Subject:
Westinghouse Slides for Aug 21, 2019, public meeting Attachments: PA-RMSC-1647 - August 2019 NRC public meeting - Part I.pptx; PA-RMSC-1647 -
August 2019 NRC public meeting - Part II.pptx Attached are the Westinghouse slides for the August 21, 2019, public meeting on newly developed methods 1
Hearing Identifier: NRR_DRMA Email Number: 187 Mail Envelope Properties (BYAPR09MB27597304B32D53AB1B8CD3C0E9AA0)
Subject:
Westinghouse Slides for Aug 21, 2019, public meeting Sent Date: 8/21/2019 7:33:49 AM Received Date: 8/21/2019 7:33:52 AM From: Miller, Ed Created By: Ed.Miller@nrc.gov Recipients:
"Miller, Ed" <Ed.Miller@nrc.gov>
Tracking Status: None Post Office: BYAPR09MB2759.namprd09.prod.outlook.com Files Size Date & Time MESSAGE 105 8/21/2019 7:33:52 AM PA-RMSC-1647 - August 2019 NRC public meeting - Part I.pptx 1758435 PA-RMSC-1647 - August 2019 NRC public meeting - Part II.pptx 1361030 Options Priority: Standard Return Notification: No Reply Requested: No Sensitivity: Normal Expiration Date:
Recipients Received:
Global Expertise
- One Voice Newly Developed Methods NRC Public Meeting Date: August 21, 2019 P R E S S U R I Z E D WAT E R R E A C T O R O W N E R S G R O U P
Background/Purpose
- Develop process/requirements that allows the technical adequacy of a newly developed method to be accepted through the PRA Peer Review Process.
- Definitions, requirements and peer review process developed during multiple dedicated workshops (PWROG, BWROG, NEI, JCNRM, NRC)
- Three peer review pilots informed the final draft wording (requirements, report content, etc.)
- Results of the workshops are being transmitted to JCNRM for considerations for inclusion in the next edition of the standard (i.e., through the normal consensus process by JCNRM) 2 P R E S S U R I Z E D WAT E R R E A C T O R O W N E R S G R O U P
Products
Revision 0-A
- Dedicated to the NDM definitions, requirements and peer review process
- Revision 0
- Expected after this public meeting 3 P R E S S U R I Z E D WAT E R R E A C T O R O W N E R S G R O U P
Products
- PWROG-19019 - Revision 0-A
- Pilot peer review report for a NDM
- Documents the review of the EDG components Reliability Data method from PWROG-18026-P, Revision 0-B including tentative met/not met SRs and associated F&Os
- Documents the feedback for the process (captured in PWROG-19027-NP)
- Waiting for NRC comments
- Revision 0
- Expected after this public meeting 4 P R E S S U R I Z E D WAT E R R E A C T O R O W N E R S G R O U P
Products
- PWROG-19020 - Revision 0-A
- Pilot peer review report for a NDM
- Documents the review of the Room Cooling Screening Criteria Method from PWROG-18027-NP, Revision 0-B
- Documents the feedback for the process (captured in PWROG-19027-NP)
- Waiting for NRC comments
- Revision 0
- Expected after this public meeting 5 P R E S S U R I Z E D WAT E R R E A C T O R O W N E R S G R O U P
Newly Developed Methods
- Definition
- Supporting definitions 6 P R E S S U R I Z E D WAT E R R E A C T O R O W N E R S G R O U P
Newly Developed Methods in the PRA Update Process 7 P R E S S U R I Z E D WAT E R R E A C T O R O W N E R S G R O U P
NDM Peer Review Process
- Dedicated team with pre-requisites
- NDM review can be done together a PRA model review (where the NDM is implemented) or before implementation
- Not a spot-check but a detailed review
- Explicit statement on technical adequacy
- Minimal set of information available of a method that went through the NDM review process
- Review is performed against a new set of SRs that will be added to the Standard 8 P R E S S U R I Z E D WAT E R R E A C T O R O W N E R S G R O U P
New Standard Section1-7 and the NM Technical Element
- Section 1-7 will be dedicated to new methods 9 P R E S S U R I Z E D WAT E R R E A C T O R O W N E R S G R O U P
New NM SRs 10 P R E S S U R I Z E D WAT E R R E A C T O R O W N E R S G R O U P
NDM Peer Review Outcome 11 P R E S S U R I Z E D WAT E R R E A C T O R O W N E R S G R O U P
NDM with open F&Os
- Not ideal situation, but a method with open F&O can be used
- It takes away to the efficiency of the process
- Open F&Os should be dispositioned by the plant implementing the method
- Conceptually this is nothing different that everybody should be already doing when confirming applicability of a specific method to your own plant model
- Examples
- F&O is only a suggestion or on the documentation of the method
- F&O is on a part of the method that the plant has not used
- F&O is on a range of applicability of the method that is not the one used by the plant (e.g., F&O says this method is no good after 170F and the plant only uses it up to 130F).
12 P R E S S U R I Z E D WAT E R R E A C T O R O W N E R S G R O U P
NDM Peer Review Report
- Similar in structure to a normal Peer Review Report (SR assessment, F&Os)
- Main differences
- Explicit global assessment of the method Thumbs up/down from the review team
- Non proprietary appendix with minimal key information for public availability (e.g., on a method developer web site, in ADAMS, etc) 13 P R E S S U R I Z E D WAT E R R E A C T O R O W N E R S G R O U P
NDM Peer Review Report Non Proprietary Appendix
- Minimal set of information that can be shared to confirm that the method went through the NDM review process (and be referenced in future implementations of the method)
- Basic information
- Unique identification of the method
- Team composition
- SR met/not met
- F&O listing
- List of SRs to be peer reviewed in a plant PRA focused scope review following method implementation
- Explicit technical adequacy statement 14 P R E S S U R I Z E D WAT E R R E A C T O R O W N E R S G R O U P
Global Expertise
- One Voice www.pwrog.com
Backup Slides 16 P R E S S U R I Z E D WAT E R R E A C T O R O W N E R S G R O U P
New Standard Section1-7 and the NM Technical Element 17 P R E S S U R I Z E D WAT E R R E A C T O R O W N E R S G R O U P
New Standard Section1-7 and the NM Technical Element 18 P R E S S U R I Z E D WAT E R R E A C T O R O W N E R S G R O U P
New NM SRs 19 P R E S S U R I Z E D WAT E R R E A C T O R O W N E R S G R O U P
New NM SRs 20 P R E S S U R I Z E D WAT E R R E A C T O R O W N E R S G R O U P
New NM SRs 21 P R E S S U R I Z E D WAT E R R E A C T O R O W N E R S G R O U P
New NM SRs 22 P R E S S U R I Z E D WAT E R R E A C T O R O W N E R S G R O U P
New NM SRs 23 P R E S S U R I Z E D WAT E R R E A C T O R O W N E R S G R O U P
New NM SRs 24 P R E S S U R I Z E D WAT E R R E A C T O R O W N E R S G R O U P
Global Expertise
- One Voice Other PRA Standard Recommendations NRC Public Meeting Date: August 21, 2019 P R E S S U R I Z E D WAT E R R E A C T O R O W N E R S G R O U P
Background/Purpose
- Purpose
- Facilitate reaching an agreement on those topics
- Upgrade vs. Maintenance
- Screening requirements
- Use of the concept of risk-significance
- External hazards
- Assumptions and uncertainties
- Series of workshop between PWROG, NRC and other key stakeholders (BWROG, NEI, JCNRM) to address a number of topics related to the next edition of the PRA Standard
- Plan to submit the results of the workshops to JCNRM for considerations to be included in the next edition of the standard (i.e., through the normal consensus process by JCNRM) 2 P R E S S U R I Z E D WAT E R R E A C T O R O W N E R S G R O U P
Product
- PWROG-18056-NP - Revision 1-B
- Grand collection of all the workshop material on all the topics
- Detailed feedback to JCNRM (Section 4)
- Considerations on peer reviews (Section 5)
- Will be shared with JCNRM for their consideration of the recommended changes (September JCNRM meeting)
- Revision 1-C and then Rev. 2
- Expected after the October workshop 3 P R E S S U R I Z E D WAT E R R E A C T O R O W N E R S G R O U P
Key Definitions
- A number of key definitions have been revised (or added) in an attempt to reconcile definitions in ANS/ASME Standard, RG 1.200, NUREG-1855, ANS glossary
- Definitions for:
- PRA
- PRA Method
- PRA Upgrade
- PRA Maintenance
- Model
- Newly Developed Method
- State-of-Practice
- Consensus Method/Model
- Assumption
- Uncertainty
- Key Source of Model Uncertainty/Assumption 4 P R E S S U R I Z E D WAT E R R E A C T O R O W N E R S G R O U P
Key Definitions
- PRA Upgrade and Maintenance re-defined in a way that is less prone to vague conclusion
- Definition of key uncertainty/assumption in the context of application 5 P R E S S U R I Z E D WAT E R R E A C T O R O W N E R S G R O U P
Screening Criteria
- Objective was consistency in screening criteria
- Part 1-1.8 of the Standard will have a section on generic screening criteria an SR will reference as appropriate with consistent text
- Cleanup of use of the word screening 6 P R E S S U R I Z E D WAT E R R E A C T O R O W N E R S G R O U P
Other recommendations for JCNRM: Screening Criteria
- Individual parts will reference the Part 1 screening criteria adding specific information 7 P R E S S U R I Z E D WAT E R R E A C T O R O W N E R S G R O U P
Concept of Risk Significant
- Team concluded definition of risk significant in Part 1 is appropriate
- Risk significance in a single hazard and risk significance in overall risk profile
- A number of SRs use the definition inappropriately
- Long list of SRs with suggested re-writing 8 P R E S S U R I Z E D WAT E R R E A C T O R O W N E R S G R O U P
Uncertainties and Assumptions
- Team reached consensus on the structure of the SRs associated with assumptions and uncertainties
- You made and assumption you address the uncertainty associated with that assumption
- Four step process:
- IDENTIFY the assumption associated with a specific technical element (e.g., FSS)
- CHARACTRIZE the assumption within that technical element
- What is the basis
- Are there alternatives (is it actionable)
- How could you change the PRA to address the uncertainty associated with the assumption (e.g., what kind of sensitivities could be done, would you need to define al alternative flood propagation path, or al alternative operator action, etc)
- ASSESS the impact of the uncertainty on the overall plant risk profile (i.e., in CDF/LERF space) for the actionable assumptions. This is done in QU
- IDENTIFY the assumptions that are key based on the above 9 P R E S S U R I Z E D WAT E R R E A C T O R O W N E R S G R O U P
Uncertainties and Assumptions
- Each technical element to ensure that there is an SR for IDENTIFY/CHARACTERIZE the assumption/uncertainties and one for DOCUMENT them
- QU has a requirement to ASSESS the impact of the assumptions/uncertainties from ALL the Technical Element in CDF/LERF perspective
- Hazard specific QU need to ASSESS the impact of the assumptions/uncertainties for that hazard (i.e.,
fire Technical Elements) and for the internal events model used as basis for the hazard model.
- The above is nothing different than what PRA analysts are already expected to be doing 10 P R E S S U R I Z E D WAT E R R E A C T O R O W N E R S G R O U P
External Hazards
- Reached consensus on the relevance of the list of external hazards in the Standard (i.e., only a starting point)
- External hazard screened quantitatively to be retained as documented screening value in the plant risk profile (for a specific application) 11 P R E S S U R I Z E D WAT E R R E A C T O R O W N E R S G R O U P
PRA Upgrade/Maintenance Examples
- General recommendation is that Non Mandatory Appendix 1-A of the Standard be removed or greatly simplified
- Examples (too vague and ambiguously written) to be eliminated and put in a separate document where more details should be provided to allow a unique interpretation
- Details still to be worked out October workshop 12 P R E S S U R I Z E D WAT E R R E A C T O R O W N E R S G R O U P
Global Expertise
- One Voice www.pwrog.com
Backup Slides 14 P R E S S U R I Z E D WAT E R R E A C T O R O W N E R S G R O U P
Other definitions 15 P R E S S U R I Z E D WAT E R R E A C T O R O W N E R S G R O U P
Other definitions 16 P R E S S U R I Z E D WAT E R R E A C T O R O W N E R S G R O U P
Other definitions 17 P R E S S U R I Z E D WAT E R R E A C T O R O W N E R S G R O U P