ML21321A042
| ML21321A042 | |
| Person / Time | |
|---|---|
| Site: | Columbia  |
| Issue date: | 12/13/2021 |
| From: | Mahesh Chawla Plant Licensing Branch IV |
| To: | Sawatzke B Energy Northwest |
| Chawla M | |
| References | |
| EPID L-2021-LRM-0102 | |
| Download: ML21321A042 (5) | |
Text
December 13, 2021 LICENSEE:
Energy Northwest FACILITY:
Columbia Generating Station
SUBJECT:
SUMMARY
OF OCTOBER 22, 2021, TELECONFERENCE MEETING WITH ENERGY NORTHWEST REGARDING PROPOSED LICENSE AMENDMENT REQUESTS TO ADOPT TSTF-505 AND 10 CFR 50.69 CATEGORIZATION PROGRAM FOR COLUMBIA GENERATING STATION (EPID L-2021-LRM-0102)
On October 22, 2021, an Observation public teleconference was held between the U.S. Nuclear Regulatory Commission (NRC) and representatives of Energy Northwest. The purpose of this meeting was to discuss the licensees plans and schedule for the following two proposed license amendment requests (LARs) for Columbia Generating Station to adopt (1) Technical Specifications Task Force (TSTF) Traveler TSTF-505, Provide Risk-Informed Extended Completion Times - RITSTF [Risk-Informed TSTF] Initiative 4b; and (2) to adopt Title 10 of the Code of Federal Regulations Section 50.69 (10 CFR 50.69), Risk-informed categorization and treatment of structures, systems and components for nuclear power reactors.
The meeting notice and agenda, dated October 6, 2021, are available in the Agencywide Documents Access and Management System (ADAMS) at Accession No. ML21280A133. A list of attendees is enclosed.
The licensee presented meeting slides, which can be found in ADAMS at Accession No. ML21292A141. The meeting slides included the scope of the LARs. The licensee will be requesting NRC approval to implement 10 CFR 50.69 using the processes for categorization and will include references to different probabilistic risk assessment (PRA) models used as well as Arkansas Nuclear Ones passive categorization method. The licensee intends to follow Nuclear Energy Institute (NEI) 00-04, 10 CFR 50.69 SSC [Structure, System, and Component]
Categorization Guideline, with no exceptions for categorization of SSCs.
For TSTF-505, the licensee will utilize the same PRA models and PRA maintenance process as described in the 10 CFR 50.69 LAR. Application of risk-informed completion times will be limited to 30 days. The TSTF-505 LAR will be consistent with TSTF-505, Revision 2, and NEI 06-09 (Revision 0)-A, Risk-Informed Technical Specifications Initiative 4b Risk-Managed Technical Specifications (RMTS) Guidelines, with minimal variations from TSTF-505, which will not impact TSTF-505 applicability. The licensee also stated that the 10 CFR 50.69 LAR is expected to be submitted in the first half of November 2021, and TSTF-505 is expected to be submitted in the second half of November 2021.
For Columbia, the internal events PRA model was peer-reviewed for technical adequacy using Regulatory Guide (RG) 1.200 Revision 2, An Approach for Determining the Technical Adequacy of Probabilistic Risk Assessment Results for Risk-Informed Activities, dated March 2009 (ADAMS Accession No. ML090410014) and the fire PRA model used in RG 1.200 Revision 3, Acceptability of Probabilistic Risk Assessment Results for Risk-Informed Activities, dated December 2020 (ADAMS Accession No. ML20238B871). The use of either revision to support the SSC categorization program is acknowledged in the LaSalle County Station, Units 1 and 2, 10 CFR 50.69 Safety Evaluation dated May 27, 2021 (ADAMS Accession No. ML21082A422). The licensee stated that its seismic PRA was also peer-reviewed for technical adequacy using RG 1.200 Revision 2. The NRC staff provided feedback that, based on available information, the licensees seismic PRA was developed using the Code Case for seismic PRAs and peer-reviewed using the guidance in NEI 12-13 External Hazards PRA Peer Review Process Guidelines. The NRC staff clarified that neither the Code Case nor NEI 12-13 were endorsed in RG 1.200, Revision 2, but rather both were accepted for use in licensing applications via a publicly available memorandum.
The NRC staff discussed with the licensee that the future LARs should consider the following items as part of the upcoming submittals:
The licensee identified three systems that are included in the Diverse and Flexible Coping Strategies (FLEX) that they intend to credit in the proposed risk-informed application. NRC staff has previously issued a request for additional information regarding information needed for the NRC staff to review and assess the adequacy of the FLEX modeling used for credit in the PRAs for other submittals. It is recommended that the licensee review the precedent and include a brief description of its FLEX modeling that captures all elements outlined in the FLEX guidance for permanently installed and portable equipment.
The LAR should be clear in providing sufficient information in the submittal so that the NRC staff can discern that Revision 1 of NUREG-1855, Guidance on the Treatment of Uncertainties Associated with PRAs in Risk-Informed Decisionmaking, dated March 2017 (ADAMS Accession No. ML17062A466), was applied appropriately.
The licensee provided an example of the percentage change in core damage frequency and large early release frequency that could trigger an update to its PRAs. The NRC staff stated that there is precedence regarding the appropriateness of this approach for use in the 10 CFR 50.69 process. For SSC categorization, importance measures are used, and changes can impact or mask the importance of other SSCs, thereby, impacting the categorization of an SSC. The licensee should include sufficient information for the NRC staff to determine that the thresholds used will not adversely impact SSC categorization (i.e., importance measures).
The NRC staff pointed out a slight disagreement between the TSTF-505, Revision 2, Standard Technical Specification (STS) mark-ups and the associated model safety evaluation with respect to STS 5.5.15 (Risk Informed Completion Time Program),
paragraph e. Paragraph e describes the risk assessment approaches and methods acceptable to the NRC. The NRC staff noted that the language in the model safety evaluation is clearer than that in the STS markups.
The NRC staff also discussed an item that is typically included in TSTF-505 LARs (i.e.,
Table E1-1, In Scope TS/LCO Conditions to Corresponding PRA Functions). This table includes a discussion of the design success criteria as it relates to each TS condition and action. The NRC staff indicated that more information provided in this table lessens the chance of ambiguity. The NRC staff also indicated that the information needed for the design success criteria column is the minimum equipment required to meet that safety function given the TS condition (i.e., inoperable equipment).
The licensee should provide the reference to the generation of the boiling-water reactor STS and the NUREG used for its submittal and describe the plant specific differences in preparation of the LAR.
The licensee stated that the LARs would address the comments and concerns raised by the ML21321A042NRC staff in this teleconference.
No regulatory decisions were made as a result of this teleconference. Members of the public were in attendance. Public Meeting Feedback forms were not received.
Please direct any inquiries to Mahesh.Chawla@nrc.gov or contact at 301-415-8371.
/RA/
Mahesh L. Chawla, Project Manager P Plant Licensing Branch IV Division Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-397
Enclosure:
List of Attendees cc: Listserv
Enclosure LIST OF ATTENDEES OCTOBER 22, 2021 PRE-SUBMITTAL TELECONFERENCE WITH ENERGY NORTHWEST REGARDING PROPOSED LICENSE AMENDMENT REQUESTS TO ADOPT TSTF-505 AND 10 CFR 50.69 FOR COLUMBIA GENERATING STATION U.S. Nuclear Regulatory Commission M. Chawla J. Hughey E. Torres A. Rezai A. Hiser A. Russell D. Widrevitz G. Bedi J. Wilson C. Li C. Jackson J. Cintron-Rivera K. Hsu K. Tetter K. West M. Li M. Yoder P. Klein S. Vasavada R. Pettis K. Quinlan E. Kleeh S. Wyman J. Hyslop N. Iqbal B. Grenier T. Hilsmeier A. Brown J. Dixon-Herrity J. Robinson Energy Northwest M. Armenta D. Stephens D. Wolfgramm D. Clymer R. Garcia T. Collis A. Maysam W. Layne H. Shtaih B. Smith M. Rice Enercon J. Wheat N. Johnson L. Swenzinski T. Sande Pacific Northwest National Laboratory S. Short Public R. Burg (Engineering Planning Management (EPM), Inc.)
V. Khanchadourian (EPM Inc.)
Meeting Notice, ML21280A133 Meeting Summary, ML21321A042
- via e-mail OFFICE NRR/DORL/LPL4/PM* NRR/DORL/LPL4/LA* NRR/DRA/APLA/BC* NRR/DRA/APLC/BC*
NAME MChawla PBlechman w/comment RPascarelli SRosenberg DATE 12/10/2021 11/18/2021 11/18/2021 12/9/2021 OFFICE NRR/DEX/EEEB/BC*
NRR/DEX/EICB/BC*
NRR/DEX/EXHB/BC* NRR/DSS/STSB/BC*
NAME WMorton MWaters BHayes VCusumano DATE 12/9/2021 12/9/2021 11/18/2021 12/10/2021 OFFICE NRR/DORL/LPL4/BC* NRR/DORL/LPL4/PM*
NAME JDixon-Herrity MChawla DATE 12/13/2021 12/13/2021