NG-13-0407, NextEra Enerqy Duane Arnold, Llc'S Response to NRC Request for Additional Information Associated with Near-Term Task Force Recommendation 2.3, Seismic Walkdowns

NextEra Enerqy Duane Arnold, Llc'S Response to NRC Request for Additional Information Associated with Near-Term Task Force Recommendation 2.3, Seismic Walkdowns

ML13331A081
Person / Time
Site:	Duane Arnold
Issue date:	11/22/2013
From:	Richard Anderson NextEra Energy Duane Arnold
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
NG-13-0407
Download: ML13331A081 (6)

Text

NExTera EN ERGY*7-&-,

ý;ýARNOLD November 22, 2013 NG-1 3-0407 10 CFR 50.54(f)

U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Duane Arnold Energy Center Docket No. 50-331 Renewed Op. License No. DPR-49 NextEra Enerqy Duane Arnold, LLC's Response To NRC Request for Additional Information Associated with Near-Term Task Force Recommendation 2.3, Seismic Walkdowns

References:

1) NRC Letter, "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 Review of Insights from the Fukushima Dai-ichi Accident," dated March 12, 2012 (ML12073A348)

2) Letter, R. Anderson (NextEra Energy Duane Arnold, LLC) to NRC, "Response to NRC 10 CFR 50.54(f) Request for Information Regarding Near-Term Task Force Recommendation 2.3, Seismic," NG-12-0467, dated November 27, 2012 (ML12334A070)

3) NRC Letter, "Request for Additional Information Associated with Near-Term Task Force Recommendation 2.3 Seismic Walkdowns," dated November 1, 2013 (ML13304B418)

4) EPRI Technical Report 1025286, "Seismic Walkdown Guidance for Resolution of Fukushima Near-Term Task Force Recommendation 2.3: Seismic," dated June, 2012.

On March 12, 2012, the Nuclear Regulatory Commission (NRC) issued Reference 1 requesting information on several topics including information associated with Near-Term Task Force Recommendation 2.3 for a seismic walk down report. In Reference 2, NextEra Energy Duane Arnold, LLC provided the requested information. Reference 2 included a list of components selected for inspection and a list of those components that were not accessible for inspection.

NextEra Energy Duane Arnold, LLC, 3277 DAEC Road, Palo, IA52324

Document Control Desk NG-1 3-0407 Page 2 of 2 Subsequently, the Staff identified additional information, as documented in Reference 3, needed to complete its assessments. The Staff requested this information be submitted within 30 days.

The enclosure to this letter provides the information requested in Reference 3.

This letter makes no new commitments or changes to existing commitments.

If you have any questions or require additional information, please contact Ken Putnam at 319-851-7238.

I declare under penalty of perjury that the foregoing is true and correct.

Executed on November 22, 2013 T 4X.&5.Anders n Vice President, Duane Arnold Energy Center NextEra Energy Duane Arnold, LLC Enclosure

Enclosure to NG-13-0407 NextEra Enerqy Duane Arnold, LLC's Response To NRC Request for Additional Information Associated with Near-Term Task Force Recommendation 2.3, Seismic Walkdowns 3 pages follow

NextEra Energy Duane Arnold, LLC's Response To NRC Request for Additional Information Associated with Near-Term Task Force Recommendation 2.3, Seismic Walkdowns NRC Request 1: Conduct of the walkdowns, determination of potentially adverse seismic conditions (PASCs), dispositioning of issues, and reporting 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 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 CLB, 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 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 appropriate actions 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.

(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.

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NextEra Enerqv Duane Arnold Response to Request 1:

Based on the following, alternative (c) applies to Duane Arnold Energy Center.

The focus of the seismic walkdowns was on the seismic adequacy of the Seismic Walkdown Equipment List (SWEL) items and the potential for nearby Structures, Systems, or Components (SSCs) to cause adverse seismic interactions with the SWEL items. The seismic walkdowns focused on the following adverse seismic conditions: adverse anchorage conditions, adverse seismic interactions, and other adverse seismic conditions.

The observations and results of the seismic walkdowns by the Seismic Walkdown Team (SWT), and the issues for which additional information was needed were documented on the field copy of the Seismic Walkdown Checklist (SWC) provided in Appendix C of the EPRI guidance document, Reference 4.

At the end of each scheduled walkdown day, a meeting between the SWT and the NextEra Energy Duane Arnold Project Seismic Lead (who also had a Licensing Basis Reviewer role) occurred to discuss the progress made, to provide responses to the SWT questions, to provide additional plant design documents if needed, and to plan the next day's walkdowns. In that meeting, a determination was made as to what observation by the SWT constituted a Potentially Adverse Seismic Condition (PASC). The results of these meetings are captured and documented in the Seismic Walkdown Checklists included in the submitted report, Reference 2.

The approach used by the team to identify PASCs is detailed in Sections 5.2 of the submitted report, Reference 2, and is summarized below.

Based on the results of the visual inspection, the Seismic Walkdown Engineers judged whether the condition was potentially degraded, non-conforming, or unanalyzed. The results of the visual inspection were documented on the SWC, as appropriate. If there was clearly no evidence of degraded, nonconforming, or unanalyzed conditions, then it was indicated on the checklist and a licensing basis evaluation was not necessary.

However, if it was not possible to judge whether the condition was degraded, nonconforming, or unanalyzed, then the condition was entered into the Corrective Action Program as a potentially adverse seismic condition. Table 5-2 and Table 5-3 of the submitted report, Reference 2, provide a summary of the issues identified during the seismic walkdowns and the area walk-bys, respectively. Hence, all potentially seismic adverse conditions identified during the walkdowns and walk-bys were addressed and included in the report submitted to the NRC, Reference 2. No changes to the original submittal are required for this request.

NRC Request 2: Conduct of the Peer Review Process 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.

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(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, 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 actual process that was used.

NextEra Energy Duane Arnold Response to Request 2:

(a) The activities described on page 6-1 of the walkdown guidance, Reference 4, were assessed as part of the peer review process. The results of the assessments and reviews are documented in Appendix F (Peer Review Report) of the submittal report, Reference 2.

(b) A complete summary of the peer review process and activities is provided in Appendix F (Peer Review Report) of the submittal report, Reference 2. The peer reviewers, who reviewed/observed a sampling of the walkdowns and the area walk-bys were independent for all activities listed on Page 6-1 of the guidance document and they had no involvement in any other seismic walkdown-related activities.

Therefore, no changes to the original submittal are required for this request.

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