RNP-RA/13-0125, Response to Request for Additional Information Regarding the Seismic Hazard Walkdowns Associated with Near-Term Task Force Recommendation 2.3, Seismic Walkdowns
| ML13346A426 | |
| Person / Time | |
|---|---|
| Site: | Robinson  |
| Issue date: | 11/26/2013 |
| From: | William Gideon Duke Energy Carolinas |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| RNP-RA/13-0125 | |
| Download: ML13346A426 (8) | |
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Serial: RNP-RA/13-0125 N0V 2 6 2013 ATTN: Document Control Desk U. S. Nuclear Regulatory Commission Washington, DC 20555-0001 N. 8. ROBINSON $TEAM ELECTRIC PLANT, UNIT NO. 2 DOCKET NO. 50-261 I RENEWED LICENSE NO. DPR-23
Subject:
Response to Request for Additional Information Regarding the Seismic Hazard Walkdowns Associated With Near-Term Task Force Recommendation 2.3, Seismic Walkdowns 0-NAC.UL *Requet rxifoiit~maigA "Pwaut* torTft1210of the code of Federa
- Rgutatleis 50. 541V REgai*h, mn.t , 2.3, and 9.3, of theNear-Term Task Force Review of Insights from the Fukushima Dai-IchiAccident, dated M"4d 12,12, ADAMS Accession No. ML12053A340
- 2. Electrical O er storch Institute (EPRI) Seivmic Wakdwn Guidance, ForResolution of Fukushima Neo-Term Task Pe Rocomrrierhtlo7 23: Seismic, EPRI Report 1025286, dated 2012, ADAMS Accession No. ML12188A031
- 3. Duke Energy Letter, H. B. Robinson Steam Electric Plant, Unit No. 2 Response to Recommendation 2.3 "Seismtc Walkdown of the Near-Term Task Force Review of Insights from the Fukushima Dai-ichiAccident, dated November 27, 2012, ADAMS Accession No. ML123410131
- 4. NRC Letter, Request for Addtmal InformationAssociated with Near-Term Task Force Recommondation 2.3, Seism*tb Alkdowns dated NOvember 1, 2013, ADAMS Accession Ladies iad'Gieii"mef:
On MaA 12012, hN ere ,to',mis."n (NIC)$staff issued a letter requesting iforrmeon p4'11le0 to *ri- C&* iflideIýZb* "?, ,ection 50.54(f) (Referenc 1). The letter requested licensees to conduct seismic hazard walkdowns to verify current plant WoAr with the current licensing basis (CL0).
Serial: RNP-RAI1 3-0125 Page 2 of 3 Duke Energy Progress, Inc., (Duke Energy) conducted the requested wallkdowns using the NRC endorsed, Electric Power Research Institute (EPRI) guidance (Reference 2). Duke Energy submitted the walkdown report for H. 8. Robinson Steam Electric Plant (HBRSEP) by letter dated November 27, 2012, (Reference 3). The NRC has requested additional information related to the seismic walkdowns by letter dated November 1, 2013, (Reference 4). The Duke Energy response for HBRSEP Is enclosed.
This letter contains no new regulatory commitments.
Ifyou have any questions regarding this submittal, please contact Mr. Richard Hightower at (843) 857-1329.
I declare under penalty of perjury that the foregoing is true and correct. Executed on Sincerely, W. R. Gideon Site Vice President WRG/shc
Enclosure:
H. B. Robinson Steam Electric Plant Response to the NRC Request for Additional Information Regarding Seismic Walkdowns xc (with enclosures):
V. M.McCrea, Region IIAdministrator U.S. Nuclear Regulatory Commission Marquis One Tower 245 Peachtree Center Avenue NE, Suite 1200 Atlanta, GA 30303-1257 S. P. Lingam, NRR Project Manager (HBRSEP, Unit No. 2)
U. S. Nuclear Regulatory Commission 11555 Rockville Pike Mail Stop 8 G9A Rockville, MD 20852-2738 K. M.Ellis, Senior Resident Inspector H. B. Robinson Steam Electric Plant, Unit No. 2
Serial: RNP-,AI13-0125 Page'3 of 3 bxc:
Chris Nolan David Llewellyn Greg Robison Jeff Thomas Richard Hightower Christine Caudell (For HBRSEP Licensing/Nuclear Records Files)
Mark Vansicklen Mike Janus File: (Corporate)
Ms. Sue Perkins-Grew (spganei.org)
Untd States Nulew ReOUiwy.ComnrAnml Enciows to Serial: RNP-RA.13-0125 5 Pages with Cover Page Enclosure H.S.RobiOn Stem Eletri Pln Responslo the Nt Request for Additional lnfona Regdng SeismicWaV*downs
Enclosure to Serial: RNP-RA/13-0125 H.. 1. Robinson fmt" Mctric Plant Response to ths #RC Request for Additional Information Reagpardi Seismoic Weskdowns.
NRC Question 1: Conduct of the walkdowns, determination of potentatly adverse ismic conditions (PASC), dispositloning of Ihsss, and reportng 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 (LBEA), and determining what Information was to be reported to 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 end 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 engReering judgment.
Furthe, the walkdown activities were intended to allow for transparency in the licensee's process to demonstrate that PASCs were appropriately identified, that they were addressed in an appropriate manner, and the basis documented such-that the cret condition of the plant was clearly consistent with the CLB with regard to 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 cleady recorded. In some cases, the field checklists were amplified by noting that the basis was engineering judgment.
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 wulkdown report.
There were other situations that a PASC and LBE were not reported; however, the NRC staff found during the audit thatsa calculation, analysis (more than just simple), or evaluation was conducted but informally. An example is a conrmatory 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 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 required more 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 L13E 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 reported In the walkdown report.
Enclosure to Serial: RNP-RI13-0125 H. B. Robinson Steam Ekletrc Plant RIsponse to thw NRC Reqtes for Addtona Infomutlon Reording Selmwki Wulkdowns On the whole, through the audits, the NRC staff found that itwas 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 overafl process used by the licensee (and its contractors) to evaluate observations identified 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 reported information supports concluding that the plant meets the CLS, please follow one of the following three acceptable alternatives:
(a) Provide a supplement to the table or text from the original walkdown 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 Itwas dispositioned and the basis for the disposition, af 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 Ifappropriate actions were taken when reporting and dispositioning identified PASCs (Includi 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.
(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.
Enclosure to Serial: RNP-RA/13-0125 H.8.. obln"on Stewm EJcklc Plant Reepons to fte NRC Request for Addlkow hnmnatlon Regrdn Seimk Welkdowns Rn e to Guestion1:
This response is in accordance with NRC Question 1(c), therefore, there are no new Potentially Adverse Seismic Con'dItions (PASC) to report because all PASC Items were addressed and included inthe prior submittal.,
Any condition that was a potential adverse seismic condition (PASC) waslfurther evaluated for' its ability to meet its seismic design basis requirements and put into the plant Corrective Action Program (CAP), if necessary.
The SWEs used engineering judgment, based on their experience and tra ning, to identify PASCs. After active discussion of observations and judgments, all Issues that were not resolved by consensus of the SWE* were further evaluated as described In Section 5.0 of the EPRI Seismic Walkdown Guidance, EPRI 1025286 (Cover Letter Reference 2). Walkdown results, Including observations and PASCs, are documented on the Seismic Wakdown Checklists, and area walk-bys on Area Walk-By Checklists.
The seismic walkdowns focused on Identifying PASCs for the SSCs listed on the SWEL using criteria for adverse anchorage conditlons, adverse seismic spatial interactions, or other adverse seismic conditions as described in Secton 4 of Referencel.
The key examination factors for area walk-bys Included: anchorage conditions, significantly degraded equipment in the area, a visual assessment of cable/conduit raceways and HVAC ducting, housekeeping items that could cause adverse seismic interaction, seismically Induced fire and flooding/spray interactions. Thes Inspections are further described Inthe report submitted on November 27, 2012, (Cover Letter Reference 3).
When conditions were identified during the inspection that were not readily determined as acceptable, they were documented along with an evaluation of the condition using available design information and based on the SWEs experience. SSCs may have been determined to be I PASC at the time of the inspection and noted as such on the checklist, or the condition may have been documented and further discussion completed before determining if it was a PASC.
Non-PASC conditkins found durng the Inspections are those evaluated and determined to not affect the ability of the item to perform its intended safety function during or after design basis ground motion as noted in the Current Licensing Basis. FOr those tems not readily evaluated to meet that criterion, the Item was entered into the CAP for resolution. Licensing basis evaluations were performed for all items entered in the CAP and are included with the CAP items.
Non-PASC evaluations are included on the Seismic Walkdown Checklists or Area Walk-by Checklists. These evaluations typically credit engineering judgment by the Seismic Wakdown Engineer team or existing analyses where a condition was previously evaluated to comply with design basis requirements.
No new PASCs have been identified. All PASCs were addressed and included In the report
Enclosure to Serial: RNP-RI3-0125 H. B. Robinson Stem Electric Plant Response to the NRC Request for Additional Information Regarding Seismic Walkdwns WRC Question 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 Ifthe entire process was reviewed by the peer review team, who were the peer reviewers, what was the role of each peer reviewer, and how the reviews affected the work, Ifat all, described In 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 accordance with the objectives of the peer review efforts.
Also, ifthere are differences from the original submittal, please provide a description of the above information. Ifthere are differences in the review areas or the manner in which the peer reviews were conducted, describe the actual process that was used.
Response to Question 2:
The information requested is contained in Reference 3. The submittal included a separate peer review report organized to emphasize activities identified In Section 6 (Page 6-1) of Reference 2 and was provided as Attachment 8 of Reference 3. A complete summary of peer review activities Is contained in that Attachment 8. As described in Section 3 of Reference 3, the Peer Review Team had no duties regarding other seismic walkdown-related activities.