ET 13-0039, Response to Request for Additional Information Associated with Near-Term Task Force Recommendation 2.3, Seismic Walkdowns
| ML13346A010 | |
| Person / Time | |
|---|---|
| Site: | Wolf Creek  |
| Issue date: | 12/02/2013 |
| From: | Broschak J Wolf Creek |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| ET 13-0039 | |
| Download: ML13346A010 (8) | |
Text
W$-1LF CREEK 'UCLEAR OPERATING CORPORATION December 2, 2013 John P. Broschak Vice President Engineering ET 13-0039 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555
References:
- 1) Letter dated March 12, 2012, from E. J. Leeds and M. R. Johnson, USNRC, to M. W. Sunseri, WCNOC, "Request for Information Pursuant to Title 10 of the Code of Federal Regulations 50.54(f)
Regarding Recommendations 2.1, 2.3, and 9.3, of the Near-Term Task Force (NTTF) Review of Insights from the Fukushima Dai-ichi Accident"
- 5) Letter dated November 1, 2013, from R. H. Beall, USNRC, to M. W.
Sunseri, WCNOC, "Request for Additional Information Associated with Near-Term Task Force Recommendation 2.3, Seismic Walkdowns"
Subject:
Docket No. 50-482: Response to Request for Additional Information Associated with Near-Term Task Force Recommendation 2.3, Seismic Walkdowns Gentlemen:
On March 12, 2012, the Nuclear Regulatory Commission (NRC) issued Reference 1 to all power reactor licensees and holders of construction permits in active or deferred status.
References 2, 3, and 4 provide Wolf Creek Nuclear Operating Corporation's (WCNOCs) response to Reference 1, Enclosure 3, "Recommendation 2.3: Seismic" for Wolf Creek Generating Station (WCGS). Reference 5, transmitted a request for additional information (RAI) associated to Recommendation 2.3 and requested a response within 30 days. The attachment to this letter provides WCNOC's response to the RAI.
P.O. Box 411 / Burlington, KS 66839 / Phone: (620) 364-8831 An Equal Opportunity Employer M/F/HCNET
ET 13-0039 Page 2 of 3 This letter contains no commitments. If you have any questions concerning this matter, please contact me at (620) 364-4085, or Mr. Michael J. Westman at (620) 364-4009.
Sincerely, John P. Broschak JPB/rlt Attachment cc: M. L. Dapas (NRC), w/a C. F. Lyon (NRC), w/a N. F. O'Keefe (NRC), w/a Senior Resident Inspector (NRC), w/a
ET 13-0039 Page 3 of 3 STATE OF KANSAS )
COUNTY OF COFFEY )
John P. Broschak, of lawful age, being first duly sworn upon oath says that he is Vice President Engineering of Wolf Creek Nuclear Operating Corporation; that he has read the foregoing document and knows the contents thereof; that he has executed the same for and on behalf of said Corporation with full power and authority to do so; and that the facts therein stated are true and correct to the best of his knowledge, information and belief.
By &2=
. Broschak icPresident Engineering SUBSCRIBED and sworn to before me this 2-rday of bemb ,2013.
-,&I, Notaroubli-c Public - State of Kansacj SNotaryi
'My A~i.-t. Expircs Expiration Date Eit Dae5
Attachment to ET 13-0039 Page 1 of 5 Response to Request for Additional Information On March 12, 2012, the U.S. Nuclear Regulatory Commission (NRC) staff issued Reference 1 requesting additional information per 10 CFR 50.54(f). Reference 1 requested that Wolf Creek Nuclear Operating Corporation (WCNOC) conduct seismic hazard walkdowns to verify the plant configuration with the current licensing basis (CLB). Reference 2 confirmed that the seismic walkdowns would be performed in accordance with Electric Power Research Institute EPRI-1025286, "Seismic Walkdown Guidance for Resolution of Fukushima Near-Term Task Force Recommendation 2.3: Seismic" (walkdown guidance). Following the NRC staff's initial review of the walkdown reports, regulatory site audits were conducted at a sampling of plants. Based on the walkdown report reviews and site audits, the staff identified additional information is necessary for the staff to complete its assessments (Reference 3). The specific NRC questions are provided in italics.
- 1. Conduct of the walkdowns, determination of potentially adverse seismic conditions (PASCs), dispositioningof issues, and reporting As a result of the audits and walkdown report reviews, the NRC staff noted that licensees' interpretations of the seismic walkdown guidance varied, which resulted in meaningful differences in the process used to disposition identified issues and in the documentation that was provided to the NRC staff In particular,the application of engineering judgment in determining what constituted a potentially adverse seismic condition (PASC), the threshold for conducting licensing basis evaluations (LBEs), and determining what information was to be reportedto the NRC staff varied.
The NRC staff intended that conditions initially marked No (N) or Unknown (U) in the field by the seismic walkdown engineers (SWEs) for which an analysis or calculation was performed would be considered as PASCs and that an analysis or calculation constituted an LBE. The walkdown guidance allows for analysis as part of engineering judgment; however, the intent was to allow for only simple analyses that could be readily performed in support of engineeringjudgment. Further,the walkdown activities were intended to allow for transparencyin the licensee's process to demonstrate that PASCs were appropriately identified, that they were addressed in an appropriatemanner, and the basis documented such that the current condition of the plant was clearly consistent with the CLB with regardto seismic capability.
During the audits, the NRC staff identified examples of field observations that were deemed not to be PASCs. However, the basis for the determination was not clearly recorded. In some cases, the field checklists were amplified by noting that the basis was engineeringjudgment. During site audit discussions, the staff was able to trace the basis for the engineering judgments and found that in many cases they were appropriate. It is expected that these situations would not be included in the walkdown report.
There were other situations that a PASC and LBE were not reported; however, the NRC staff found during the audit that a calculation, analysis (more than just simple), or evaluation was conducted but informally. An example is a confirmatory calculation performed to demonstrate that six anchor bolts out of eight was not a seismically adverse condition. Another example would be an analysis to demonstrate that an existing, slightly short weld was as seismically sound as the prescribed weld length in the plant design documentation. The staff expected these types of conditions and
Attachment to ET 13-0039 Page 2 of 5 evaluations to be captured in the licensee's normal plant processes (e.g., condition report or corrective action program (CAP)), and also reported in the walkdown report, since they were potentially adverse seismic conditions that requiredmore than applying judgment or simple analysis to address.
The NRC staff also found that the process that was used to deal with a field observation that was deemed to be a PASC was also not completely described or captured in the report. In many cases, the licensee reported that an LBE was not performed. However, during the audits, it was clear that an LBE (or an equivalent determination method) was performed and used in determining whether a PASC should be entered into the CAP.
The staff expects that these conditions would be reportedin the walkdown report.
On the whole, through the audits, the NRC staff found that it was able to conclude that the intent of the guidance was met when the licensee's overall process was completely explained, the information was updated to reflect the actual process, and results were updated. The self-assessments conducted by the licensees of the audited plants also identified the lapse in the description of the process used by the licensee to identify a PASC and disposition it.
Therefore, in order to clarify the process that was followed, please provide a description of the overall process used by the licensee (and its contractors) to evaluate observationsidentified in the field by the SWEs. The process should include how a field observation was determined to be a PASC or not and how the bases for determinations were recorded. Once a determination was made that an observation was a PASC, describe the process for creating a condition report (or other tracking mechanism),
performing the LBE (or other determination method), and the resultant action, such as entering it into the CAP, or documenting the result and basis.
Also, in order to confirm that the reportedinformation supports concluding that the plant meets the CLB, please follow one of the following three acceptable alternatives:
(a) Provide a supplement to the table or text from the originalwalkdown report, if needed, to include similar conditions as the above examples and situations and for conditions for which a calculation,analysis (if more than a simple analysis), or evaluation was used for a determination. The supplement should include a short description of each condition, how it was dispositioned and the basis for the disposition, as follows: 1) for each condition that was entered into the CAP, provide the CAP reference number, initiation date, and (if known) the planned completion date, or 2) for all other conditions, provide the result of the LBE (or other determination method), the basis for the result, and how (or where) the result was captured in the plant's documentation or existing plant process.
(b) Following the plant's standard procedures, confirm that a new CAP entry has been made to verify if appropriateactions were taken when reporting and dispositioning identified PASCs (including conditions for which a calculation, analysis (if more than a simple analysis), or evaluation was used for a determination). The eventual CAP closeout, including the process followed and actions taken, should be in sufficient detail to enable NRC resident inspectors to follow up.
Attachment to ET 13-0039 Page 3 of 5 (c) If no new conditions are identified for addition to the supplement or the CAP entry mentioned above is deemed not necessary, provide a statement of confirmation that all potentially seismic adverse conditions (including conditions for which a calculation, analysis (if more than a simple analysis),
or evaluation was used for a determination)identified during the walkdowns and walk-bys were addressed and included in the report to the NRC.
Response: This response follows alternative (c) from the above acceptable alternatives. No new conditions have been identified and entered into the Corrective Action Program (CAP). All potentially adverse seismic conditions (PASCs) identified during the walkdowns and walk-bys were addressed and included in the report to the NRC (References 5 and 6). The following paragraphs summarize how the overall process used by WCNOC for the seismic walkdowns conforms to the guidance of Reference 4 and is detailed in the submitted reports of References 5 and 6.
The Seismic Walkdown Team (SWT) for WCNOC consisted of 3 Seismic Walkdown Engineers (SWEs); 2 contractor engineers and 1 plant engineer, all of whom were qualified per the requirements of Section 2 of the EPRI guidance (Reference 4). The 2 contractor engineers were primarily responsible for the Seismic Walkdown Checklists (SWCs) and Area Walk-By Checklists (AWCs), with the plant engineer providing support. Additional plant personnel were included as needed for extra support.
While evaluating each component on a SWC or AWC, the contractor engineers discussed and collaborated until agreement was met. Any issue that could not be resolved by consensus of the SWEs during the walkdowns and easily determined to be acceptable was identified as a PASC on the SWC or AWC (as applicable). These PASCs were evaluated with respect to the CLB. All items concluded in the field to meet the CLB were denoted as "Y" with no further action required. All items readily concluded in the field to not meet the CLB were denoted as "N" and entered into the CAP. All items requiring further evaluation were denoted as "U". All field "N" and "U" items were entered into the licensing basis evaluation (LBE) process as PASCs and are detailed in the submitted reports (References 5 and 6), particularly the Appendix C tables, as per the EPRI guidance on page 8-4 (Reference 4). Furthermore, LBE items not readily concluded through the process to meet their CLB were entered into the CAP.
The conditions identified (PASCs) were evaluated with respect to the CLB and documented as LBEs (in accordance with Reference 4) and are listed in Appendix C of the submitted reports (References 5 and 6). Those PASCs that were later found to meet the plant's CLB were changed to "Y" for the final report. Although this approach varies slightly from the explanations in Reference 3 by changing the designation after the walkdown was completed, the intent of the guidance (Reference 4) is met because all PASCs initially identified in the field are included in the report sections and Appendix C of References 5 and 6 and have a full description of their LBE and resolution. The basis for engineering judgments used to reach a conclusion is clearly identified in the submitted reports (References 5 and 6).
- 2. Conduct of the Peer Review Process As a result of the walkdown report reviews, the NRC staff noted that some descriptions of the peer reviewers and the peer review process that was followed were varied and, in some cases, unclear. In some cases, the staff could not confirm details of the process, such as if the entire process was reviewed by the peer review team, who were the peer
Attachment to ET 13-0039 Page 4 of 5 reviewers, what was the role of each peer reviewer, and how the reviews affected the work, if at all, describedin the walkdown guidance.
Therefore, in order to clarify the peer review process that was actually used, please confirm whether the following information on the peer review process was provided in the original submittal, and if not, provide the following.
(a) Confirmation that the activities described in the walkdown guidance on page 6-1 were assessed as part of the peer review process.
(b) A complete summary of the peer review process and activities. Details should include confirmation that any individual involved in performing any given walkdown activity was not a peer reviewer for that same activity. If there were cases in which peer reviewers reviewed their own work, please justify how this is in accordancewith the objectives of the peer review efforts.
Also, if there are differences from the original submittal, please provide a description of the above information. If there are differences in the review areas or the manner in which the peer reviews were conducted, describe the actualprocess that was used.
Response: The overall process used by WCNOC for the peer reviews conforms to the guidance of Reference 4 and is detailed in Section 6 of the walkdown reports that were submitted to the NRC (References 5 and 6).
(a) The required peer review activities are specified on page 6-1 of Reference 4. A description of how WCNOC satisfied each of these requirements is included in the submitted reports (References 5 and 6). The review activities and the associated sections of the walkdown reports are listed below:
" Review the selection of the SSCs included on the SWEL - Section 6.2
" Review a sample of the checklists prepared for the Seismic Walkdowns and Area Walk-Bys - Section 6.3
- Review the licensing basis evaluations - Contained in Section 6.4 of the submitted reports (References 5 and 6)
- Review the decisions for entering the potentially adverse seismic conditions into the CAP process - Section 6.4
" Review the submittal report - Section 6.5
- Summarize the results of the peer review process in the submittal report -
Section 6.1 and following each Section 6 subsection (b) A complete summary of the peer review activities is detailed throughout Section 6 of References 5 and 6. None of the peer review engineers were involved in the seismic walkdown inspection process so that they could maintain their independence from the project. Thus, the peer reviewers were not reviewing their own work.
Attachment to ET 13-0039 Page 5 of 5
References:
- 1. Letter from E. J. Leeds and M. R. Johnson, USNRC, to M. W. Sunseri, WCNOC, "Request for Information Pursuant to Title 10 of the Code of Federal Regulations 50.54(f) Regarding Recommendations 2.1, 2.3, and 9.3, of the Near-Term Task Force (NTTF) Review of Insights from the Fukushima Dai-ichi Accident," March 12, 2012. ADAMS Accession No. ML12053A340.
- 2. WCNOC Letter ET 12-0015, "Wolf Creek Nuclear Operating Corporation's 120-Day Response to NRC Request for Information Pursuant to 10 CFR 50.54(f) Regarding the Seismic Aspects of Recommendation 2.3 of the Near-Term Task Force Review of Insights from the Fukushima Dai-ichi Accident," July 2, 2012. ADAMS Accession No. ML12192A543.
- 3. Letter from R. H. Beall, USNRC, to M. W. Sunseri, WCNOC, "Request for Additional Information Associated with Near-Term Task Force Recommendation 2.3, Seismic Walkdowns," November 1, 2013. ADAMS Accession No. ML13304B418.
- 4. Electric Power Research Institute Report 1025286, "Seismic Walkdown Guidance for Resolution of Fukushima Near Term Task Force Recommendation 2.3: Seismic," June 30, 2012. ADAMS Accession No. ML12188A031.
- 5. WCNOC Letter ET 12-0032, "Wolf Creek Nuclear Operating Corporation 180-Day Response to NRC Request for Information Pursuant to 10 CFR 50.54(f) Regarding Recommendation 2.3 (Seismic) of the Near-Term Task Force Review of Insights from the Fukushima Dai-ichi Accident," November 27, 2012. ADAMS Accession No. ML12342A252.
- 6. WCNOC Letter ET 13-0021, "Wolf Creek Nuclear Operating Corporation Supplement to 180-Day Response to NRC Request for Information Pursuant to 10 CFR 50.54(f) Regarding Recommendation 2.3 (Seismic) of the Near-Term Task Force Review of Insights from the Fukushima Dai-ichi Accident," June 20, 2013. ADAMS Accession No. ML13177A283.