ML14105A452

Staff Assessment of the Seismic Walkdown Report Supporting Implementation of Near-Term Task Force Recommendation 2.3 Related to the Fukshima DAI-ICHI Nuclear Power Plant Accident

ML14105A452
Person / Time
Site:	Duane Arnold
Issue date:	05/22/2014
From:	Mahesh Chawla Plant Licensing Branch III
To:	Richard Anderson NextEra Energy Duane Arnold
Mahesh Chawla, NRR/DORL 415-8371
References
TAC MF0121
Download: ML14105A452 (13)

Text

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON , D.C. 20555-0001 May 22, 2014 Mr. Richard L. Anderson Vice President NextEra Energy Duane Arnold , LLC 3277 DAEC Road Palo , lA 52324-9785

SUBJECT:

DUANE ARNOLD ENERGY CENTER- STAFF ASSESSMENT OF THE SEISMIC WALKDOWNREPORT SUPPORTING IMPLEMENTATION OF NEAR-TERM TASK FORCE RECOMMENDATION 2.3 RELATED TO THE FUKUSHIMA DAI -ICHI NUCLEAR POWER PLANT ACCIDENT (TAC NO.

MF0121)

Dear:

Mr. Anderson On March 12, 2012, the U.S. Nuclear Regulatory Commission (NRC) issued a request for information letter per Title 10 of the Code of Federal Regulations, Subpart 50 .54(f) (50.54(f) letter) . The 50 .54(f) letter was issued to power reactor licensees and holders of construction permits requesting addressees to provide further information to support the NRC staff's evaluation of regulatory actions to be taken in response to lessons learned from Japan's March 11 , 2011 , Great Tohoku Earthquake and subsequent tsunami. The request addressed the methods and procedures for nuclear power plant licensees to conduct seismic and flooding hazard walkdowns to identify and address degraded, nonconforming , or unanalyzed conditions through the corrective action program , and to verify the adequacy of the monitoring and maintenance procedures .

By letter dated November 27 , 2012 , NextEra Energy Duane Arnold , LLC (NextEra Energy Duane Arnold) submitted its Seismic Walkdown Report as requested in Enclosure 3 of the 50.54(f) letter for the Duane Arnold Energy Center. By letter dated September 13, 2013, NextEra Energy provided additional information on the completion of inaccessible items and the substitutions made to the list of inaccessible items in order to complete all walkdowns by the fourth quarter of 2014. By letter dated November 22, 2013, NextEra Energy Duane Arnold provided a response to the NRC request for additional information for the staff to complete its assessments .

The staff acknowledges that an updated walkdown report incorporating the results of the deferred walkdowns will be provided 90 days after the end of the next refueling outage scheduled for the fourth quarter of 2013, consistent with the regulatory commitment. The NRC staff reviewed the information provided and , as documented in the enclosed staff assessment, determined that sufficient information was provided to be responsive to Enclosure 3 of the 50 .54(f) letter.

R. Anderson If you have any questions, please contact me at 301 -415-8371 or by e-mail at Mahesh.chawla@ nrc.gov.

Sincerely, Mahesh Chawla, Project Manager Plant Licensing Branch 111-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-331

Enclosure:

Staff Assessment of Seismic Walkdown Report cc w/encl: Distribution via Listserv

STAFF ASSESSMENT OF SEISMIC WALKDOWN REPORT NEAR-TERM TASK FORCE RECOMMENDATION 2.3 RELATED TO THE FUKUSHIMA DAI-ICHI NUCLEAR POWER PLANT ACCIDENT NEXTERA ENERGY DUANE ARNOLD. LLC DUANE ARNOLD ENERGY CENTER DOCKET NO. 50-331

1.0 INTRODUCTION

On March 12, 2012, 1 the U.S. Nuclear Regulatory Commission (NRC) issued a request for information per Title 10 of the Code of Federal Regulations, Subpart 50.54(f) (50.54(f) letter) to all power reactor licensees and holders of construction permits in active or deferred status. The request was part of the implementation of lessons learned from the accident at the Fukushima Dai-ichi nuclear power plant. Enclosure 3, "Recommendation 2.3: Seismic,"2 to the 50.54(f) letter requested licensees to conduct seismic walkdowns to identify and address degraded, nonconforming, or unanalyzed conditions using the corrective action program (CAP) , verify the adequacy of monitoring and maintenance procedures, and report the results to the NRC.

The 50.54(f) letter requested licensees to provide the following :

a. Information concerning the plant-specific hazard licensing bases and a description of the protection and mitigation features considered in the licensing basis evaluation.

b. Information related to the implementation of the walkdown process.

c. A list of plant-specific vulnerabilities identified by the Individual Plant Examination of External Events (IPEEE) program and a description of the actions taken to eliminate or reduce them.

d. Results of the walkdown including key findings and identified degraded, nonconforming, or unanalyzed conditions.

e. Any planned or newly installed protection and mitigation features .

f. Results and any subsequent actions taken in response to the peer review.

In accordance with the 50.54(f) letter, Enclosure 3, Required Response Item 2, licensees were required to submit a response within 180 days of the NRC's endorsement of the seismic 1

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walkdown process. By letter dated May 29, 2012, 3 the Nuclear Energy Institute (NEI) staff submitted Electric Power Research Institute (EPRI) document 1025286, "Seismic Walkdown Guidance for Resolution of Fukushima Near-Term Task Force Recommendation 2.3: Seismic,"

(walkdown guidance) to the NRC staff to consider for endorsement. By letter dated May 31, 2012, 4 the NRC staff endorsed the walkdown guidance.

By letter dated November 27, 2012, 5 NextEra Energy Duane Arnold, LLC (the licensee) provided a response to Enclosure 3 of the 50.54(f) letter Required Response Item 2, for Duane Arnold Energy Center (DAEC) . By letter dated September 13, 2013, 6 the licensee provided an accelerated schedule and additional information on the completion deferred walkdowns for the inaccessible items, including substitutions in order to complete all walkdowns by the fourth quarter of 2014. In the NRC staff review of the walkdown report, the staff determined that additional supplemental information would assist in completing the review. In a letter dated November 1, 20137 , the NRC staff requested additional information to gain a better understanding of the processes and procedures used by the licensee in conducting the walkdowns and walk-bys. The licensee responded to the NRC staff request by letter dated November 22, 2013. 8 The NRC staff evaluated the licensee's submittals to determine if the information provided in the walkdown report met the intent of the walkdown guidance and if the licensee responded appropriately to Enclosure 3 of the 50.54(f) letter.

2.0 REGULATORY EVALUATION

The structures, systems, and components (SSCs) important to safety in operating nuclear power plants are designed either in accordance with , or meet the intent of Appendix A to 10 CFR Part 50, General Design Criteria (GDC) 2: "Design Bases for Protection Against Natural Phenomena;" and Appendix A to 10 CFR Part 100, "Reactor Site Criteria." GDC 2 states that SSCs important to safety at nuclear power plants shall be designed to withstand the effects of natural phenomena such as earthquakes, tornadoes, hurricanes, floods , tsunami, and seiches without loss of capability to perform their safety functions.

For initial licensing, each licensee was required to develop and maintain design bases that, as defined by 10 CFR 50.2, identify the specific functions that an SSC of a facility must perform, and the specific values or ranges of values chosen for controlling parameters as reference bounds for the design.

The design bases for the SSCs reflect appropriate consideration of the most severe natural phenomena that have been historically reported for the site and surrounding area. The design bases also reflect sufficient margin to account for the limited accuracy, quantity, and period of time in which the historical data have been accumulated.

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The current licensing basis is the set of NRC requirements applicable to a specific plant, including the licensee's docketed commitments for ensuring compliance with, and operation within, applicable NRC requirements and the plant-specific design basis, including all modifications and additions to such commitments over the life of the facility operating license.

3.0 TECHNICAL EVALUATION

3.1 Seismic Licensing Basis Information The licensee provided information on the plant-specific licensing basis for the Seismic Category I SSCs for DAEC in Section 2.0 of the walkdown report. Consistent with the walkdown guidance, the staff noted that the report includes a summary of the Safe Shutdown Earthquake (SSE) and a description of the codes, standards, and methods that were used in the design of the Seismic Category I SSCs for meeting the plant-specific seismic licensing basis requirements. The NRC staff reviewed Section 2.0 of the walkdown report, focusing on the summary of the SSE and the design codes used in the design.

Based on the NRC staff's review, the staff concludes that the licensee has provided information on the plant-specific seismic licensing basis and a description of the protection and mitigation features considered in the licensing bases evaluation consistent with Section 8, Submittal Report, of the walkdown guidance.

3.2 Seismic Walkdown Methodology Implementation Section 2, Personnel Qualifications; Section 3, Selection of SSCs; Section 4, Seismic Walkdowns and Area Walk-Bys; and Section 5, Seismic Licensing Basis Evaluations, of the walkdown guidance provide information to licensees regarding the implementation of an appropriate seismic walkdown methodology. By letter dated July 9, 2012,9 the licensee confirmed that it would utilize the walkdown guidance in the performance of the seismic walkdowns at DAEC.

The walkdown report dated November 27, 2012, did not identify deviations from the walkdown guidance.

The NRC staff reviewed the following sections of the walkdown methodology implementation provided in the walkdown report:

• Personnel Qualifications

• Development of the Seismic Walkdown Equipment Lists (SWELs)

• Implementation of the Walkdown Process

• Licensing Basis Evaluations and Results 9

ADAMS Accession No. ML12192A094

3.2.1 Personnel Qualifications Section 2, Personnel Qualifications, of the walkdown guidance provides licensees with qualification information for personnel involved in the conduct of the seismic walkdowns and area walk-bys.

The NRC staff reviewed the information provided in Section 3, Table 3-1, and Appendix A of the walkdown report, which includes information on the walkdown personnel and their qualifications. Specifically, the staff reviewed the summary of the background, experience, and level of involvement for the following personnel involved in the seismic walkdown activities:

equipment selection personnel, seismic walkdown engineers (SWEs), licensing basis reviewers, IPEEE reviewers, peer review team, and operations staff.

Based on the review of the licensee's submittals, the NRC staff concludes that those involved in the seismic walkdown activities have the appropriate seismic background, knowledge and experience, as specified in Section 2 of the walkdown guidance.

3.2.2 Development of the SWELs Section 3, Selection of SSCs, of the walkdown guidance provides information to licensees for selecting the SSCs that should be placed on the SWELs, so that they can be walked down by qualified personnel.

The NRC staff reviewed the overall process used by the licensee to develop the DAEC base lists, SWEL 1 (sample list of designated safety functions equipment), and SWEL 2 (sample list of spent fuel pool related equipment). The overall equipment selection process followed the screening process shown in Figures 1-1 and 1-2 of the walkdown guidance. Based on Appendix B of the walkdown report, DAEC SWEL 1 and 2 meet the inclusion requirements of the walkdown guidance. Specifically, the following attributes were considered in the sample selection:

• A variety of systems, equipment and environments

• IPEEE equipment

• Major new or replacement equipment

• Risk considerations Due to individual plant configurations and the walkdown guidance screening process followed to select the final SWEL equipment, it is possible that some classes of equipment will not be represented on the SWEL. The walkdown guidance recognizes this is due to the equipment not being present in the plant (e.g., some plants generate DC power using inverters and therefore do not have motor generators) or the equipment being screened out during the screening process (the screening process is described in Section 3 of the walkdown guidance). Based on the information provided, the NRC staff noted that a detailed explanation was provided justifying cases where specific classes of equipment were not included as part of the SWEL, and concludes that these exclusions are acceptable.

The NRC staff noted that no rapid drain-down items were included as part of the SWEL 2, as described in Section 3 of the guidance. In Appendix B of the walkdown report, the licensee stated that spent fuel pool (SFP) design does not have any penetrations that could rapid drain

down the SFP. Therefore, no items associated with SFP and rapid drain-down were identified. After reviewing the information provided in this section, the NRC staff concludes that the licensee provided adequate justification for not including rapid drain-down items as part of the SWEL2.

In order to complete the walkdowns of inaccessible items by the end of 2014, in letter dated September 13, 2013, the licensee stated that it needed to make two component substitutions and justification for not inspecting the internals of three components for the remaining six inaccessible SWEL items. The justification included other information , such as inspection results to similar items and other work that had been completed on the item in the past. For the substitutions, the licensee stated that the two substituted items represent equipment of a comparable condition, design and environment, and would be inspected in 2013 and 2014 rather than the original items which would not be accessible until a later date. After reviewing the licensee's proposed plans and justification, the NRC staff agrees that the substituted items are comparable to the previous ones and located in similar environmental conditions and that the justification for not verifying internals of three components is sufficient. In addition, the staff concludes that the diversity of the equipment classes represented in the original SWEL was maintained.

After reviewing SWELs 1 and 2, the NRC staff concludes that the sample of SSCs represent a diversity of component types and assures inclusion of components from critical systems and functions, thereby meeting the intent of the walkdown guidance. In addition, the NRC staff notes that the equipment selection personnel were appropriately supported by plant operations staff as described in the walkdown guidance.

3.2.3 Implementation of the Walkdown Process Section 4, Seismic Walkdowns and Area Walk-Bys, of the walkdown guidance provides information to licensees regarding the conduct of the seismic walkdowns and area walk-bys for each site.

The NRC staff reviewed Section 5 of the walkdown report, which summarizes the results of the seismic walkdowns and area walk-bys, including an overview of the number of items walked down and the number of areas walked-by. The walkdown report states that two Seismic Review teams, each of which included at least two qualified Seismic Walkdown Engineers (SWEs),

conducted the seismic walkdowns and area walk-bys. According to the walkdown report, main walkdown activities were conducted September 24-28, 2012, with additional walkdowns on October 12, 2012, to inspect selected electrical equipment and equipment in the primary containment. Based on the checklists, it appears that the SWEs discussed their observations and judgments with each other and the agreed on the results of their seismic walkdowns and area walk-bys before reporting the results of their review. Appendices C and D of the walkdown report provide the completed seismic walkdown checklists (SWCs) and area walk-by checklists (AWCs), documenting the results for each item of equipment on SWELs 1 and 2 and each area containing SWEL equipment. The licensee used the checklists provided in Appendix C of the walkdown guidance report without modification.

The licensee documented cases of potentially adverse seismic conditions (PASCs) in the checklists for further evaluation . Tables 5-2 and 5-3 of the walkdown report lists the PASCs

identified during the seismic walkdowns and the area walk-bys . The tables describe how each condition was addressed (e.g. , placement in the CAP) , its resolution , and current status.

Based on the initial review of the checklists, the staff was unable to confirm that all of the PASCs identified during the walkdowns were included in the walkdown report. By letter dated November 1, 2013, the staff issued two questions in a request for additional information (RAI) in order to obtain clarification regarding the process followed by the licensee when evaluating conditions identified in the field during the walkdowns and walk-bys. Specifically, in RAI 1 the staff requested the licensee to provide further explanation regarding how a field observation was determined to be PASC, and to ensure that the basis for determination was addressed using normal plant processes and documented in the walkdown report. In response to RAI 1, the licensee stated that based on the results of the visual inspections, the SWEs judged whether the condition was potentially degraded, non-conforming, or unanalyzed . The results of the visual inspection were documented on the SWCs and AWCs, 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 (LBE) was not necessary. If the condition was not possible to judge whether the condition was degraded , nonconforming, or unanalyzed, then it was entered into the CAP as a PASC. The licensee also stated that at the end of each scheduled walkdown day, a meeting occurred between the SWT and the NextEra Energy Duane Arnold Project Seismic Lead who also had a Licensing Basis Reviewer role, to discuss the progress made, provide responses to the SWT questions, provide additional plant design documents if needed, and plan the next day's walkdowns . In that meeting , a determination was made as to what observations by the SWT constituted a PASC. The results of these meetings were captured and documented in the SWCs and are provided in Appendix C of the walkdown report. Also, in response to RAI 1, the licensee confirmed that all issues identified during the walkdowns and walk-bys were addressed and included in Tables 5-2 and 5-3 of the walkdown report.

After evaluating the licensee's response and reviewing Tables 5-2 and 5-3 of the walkdown report , the NRC staff concludes that the licensee responded appropriately to RAI 1, PASCs were properly identified and documented, and summary Tables 5-2 and 5-3 is considered complete.

In addition to the information provided above, the NRC staff notes that anchorage configurations were verified to be consistent with existing plant documentation for at least 50 percent of the SWEL items, in accordance with Section 4 of the walkdown guidance.

The walkdown report indicates that the licensee opened some cabinets as part of the walkdowns . In addition, revised Table E-1 from the September 13, 2013, letter includes several cabinets that will be opened for internal inspections during the licensee's next refueling outage.

Since the licensee has opened and committed to open additional cabinets to verify their internal components and provided the schedules for performing these actions, the NRC staff concludes this is an acceptable approach.

The equipment and areas that were inaccessible during the 180-day period were initially discussed in Appendix E and listed in Tables E-1 of the walkdown report. A limited number of SWEL components (total of six) were inaccessible at the time of the initial walkdowns. As discussed above, the list was revised by the September 13, 2013, letter. The revised list of inaccessible items includes the condition which caused the delay of the walkdown . The licensee

committed to provide an updated submittal with the results of these walkdowns within 90 days after the end of the next refueling outage scheduled for the fourth quarter of 2014.

Based on the information provided in the licensee's submittals, the NRC staff concludes that the licensee's implementation of the walkdown process meets the intent of the walkdown guidance.

3.2.4 Licensing Basis Evaluations and Results Section 5, Seismic Licensing Basis Evaluations, of the walkdown guidance provides information to licensees regarding the conduct of licensing basis evaluations for items identified during the seismic walkdowns as degraded, nonconforming, or unanalyzed that might have potential seismic significance.

The NRC staff reviewed Section 6 of the walkdown report, which discusses the process for conducting the seismic licensing basis evaluations of the PASCs identified during the seismic walkdowns and area walk-bys. The licensee stated that the issues identified during the seismic walkdowns and area walk-bys were not determined to be PASCs based on evaluation within the CAP, because in all cases the anomaly or issue would not prevent the equipment from performing its safety-related function . Therefore, separate LBEs were not necessary and none were performed. The licensee indicated in Section 5 of the walkdown report that all potentially degraded, nonconforming, or unanalyzed conditions identified as a result of the walkdowns have been entered into the CAP. Evaluations of the identified conditions are complete and documented within the CAP.

The NRC staff reviewed the CAP entries and the description of the actions taken or planned to address potential deficiencies. The staff concludes that the licensee appropriately identified degraded, nonconforming, or unanalyzed conditions and entered them into the CAP, which meets the intent of the walkdown guidance.

3.2.5 Conclusion Based on the discussion above, the NRC staff concludes that the licensee's implementation of seismic walkdown methodology meets the intent of the walkdown guidance for personnel qualifications, development of SWELs, implementation of the walkdown process, and seismic licensing basis evaluations.

3.3 Peer Review Section 6, Peer Review, of the walkdown guidance provides licensees with information regarding the conduct of peer reviews for the activities performed during the seismic walkdowns. Page 6-1 of the walkdown guidance identifies the following activities to be conducted during the peer review process:

• Review the selection of the SSCs included on the SWELs

• Review a sample of the checklists prepared for the seismic walkdowns and area walk-bys

• Review the licensing basis evaluations

• Review the decisions for entering the potentially adverse conditions into the CAP

• Review the walkdown report

• Summarize the results of the peer review process in the walkdown report The NRC staff reviewed the information provided in Section 9.0 of the walkdown report, which describes the conduct of the peer review, and Appendix F of the walkdown report, which describes the results from the peer review including subsequent actions taken in response to the peer review. In addition , the NRC staff reviewed the response to RAI 2. In RAI 2, the staff requested the licensee to provide additional information on the overall peer review process that was followed as part of the walkdown activities. Specifically, the NRC staff requested the licensee to confirm that the activities identified on page 6-1 of the walkdown guidance were assessed and documented in the report. The licensee was also requested to confirm that any individual involved in performing any given walkdown activity was not a peer reviewer for that same activity. In response to RAI 2, the licensee confirmed that all the activities identified on page 6-1 of the walkdown guidance were included as part of the peer review process and referred to the results of the assessments and reviews documented in Appendix F of the walkdown report. The licensee further confirmed that the peer reviewers, were independent for all activities listed on Page 6-1 of the walkdown guidance and had no involvement in any other seismic walkdown-related activities.

The NRC staff reviewed the licensee's description of each of these activities in the walkdown report and RAI response, which included a discussion of the peer review team members' qualifications and level of involvement, the peer review findings, and resolution of peer review comments. After reviewing the licensee's submittals, the NRC staff concludes that the licensee sufficiently documented the results of the peer review activities and how these reviews affected the work described in the walkdown report.

Based on the discussion above, the NRC staff concludes that the licensee's results of the peer review and subsequent actions taken in response to the peer review meets the intent of Section 6 of the walkdown guidance.

3.4 IPEEE Information Section 7, IPEEE Vulnerabilities , of the walkdown guidance provides information to licensees regarding the reporting of the evaluations conducted and actions taken in response to seismic vulnerabilities identified during the IPEEE program. Through the IPEEE program and Generic Letter 88-20, "Individual Plant Examination of External Events for Severe Accident Vulnerabilities," licensees previously had performed a systematic examination to identify any plant-specific vulnerabilities to severe accidents.

The licensee discussed the IPEEE evaluation of DAEC and provided background information regarding their IPEEE program in Section 7 of the walkdown report. The licensee stated that the Seismic Margins Assessment defined in EPRI NP-6041 was used to examine seismic risk in the IPEEE. The potential vulnerabilities identified in the DACE IPEEE are listed in Section 7 of the walkdown report with a description of actions taken to eliminate or reduce the identified IPEEE seismic vulnerabilities. The licensee confirmed these actions were completed at the time of submittal of the DACE IPEEE to the NRC. The licensee also referenced another submittal to the NRC, which includes the documentation of the equipment outliers identified during the NRC

Unresolved Safety Issue A-46 implementation effort at DAEC. The final resolution of the eight outstanding outliers identified in that document was reported to the NRC, reviewed , and later documented in a safety evaluation.

Based on the NRC staff's review of Section 7 of the walkdown report, the staff concludes that the licensee's identification of plant-specific vulnerabilities (including anomalies, outliers and other findings) identified by the IPEEE program, as well as actions taken to eliminate or reduce them, meets the intent of Section 7 of the walkdown guidance.

3.5 Planned Upgrades The licensee did not identify any planned or newly installed protection and mitigation features in the walkdown report.

3.6 NRC Oversight 3.6.1 Independent Verification by Resident Inspectors On July 6, 2012,10 the NRC issued Temporary Instruction (TI) 2515/188 "Inspection of Near-Term Task Force Recommendation 2.3 Seismic Walkdowns." In accordance with the Tl, NRC inspectors independently verified that the DAEC licensee implemented the seismic walkdowns in accordance with the walkdown guidance. Additionally, the inspectors independently performed walkdowns of a sample of seismic protection features. The inspection report dated January 30, 2013,11 documents the results of this inspection and states that no findings were identified.

4.0 INACCESSIBLE ITEMS The equipment and areas that were inaccessible during the 180-day period were initially discussed in Appendix E and listed in Tables E-1 of the walkdown report. The schedule and list were revised by the September 13, 2013, letter which identified the remaining inaccessible items. The licensee committed to provide an updated submittal with the results of the deferred walkdowns within 90 days after the end of the next refueling outage scheduled for the fourth quarter of 2014.

The NRC staff concludes that the inaccessible equipment list was developed consistent with the walkdown guidance. The schedule for completion is consistent with the time to the next scheduled outage.

5.0 CONCLUSION

The NRC staff concludes that the licensee's implementation of seismic walkdown methodology meets the intent of the walkdown guidance. The staff concludes that the licensee, through the implementation of the walkdown guidance activities, and in accordance with plant processes and procedures, verified the plant configuration with the current seismic licensing basis; addressed 10 ADAMS Accession No. ML12156A052 11 ADAMS Accession No. ML13030A468

degraded, nonconforming, or unanalyzed seismic conditions; and verified the adequacy of monitoring and maintenance programs for protective features. Furthermore, the NRC staff notes that no immediate safety concerns were identified. The staff acknowledges that an updated letter will be provided within 90 days after the end of the next refueling outage scheduled in September of 2014 addressing the remaining inaccessible items consistent with the regulatory commitment. The NRC staff reviewed the information provided and determined that sufficient information was provided to be responsive to Enclosure 3 of the 50.54(f) letter.

R. Anderson If you have any questions, please contact me at 301-415-8371 or by e-mail at Mahesh .chawla@nrc.gov.

Sincerely, IRA!

Mahesh Chawla, Project Manager Plant Licensing Branch 111-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-331 Enclosure :

Staff Assessment of Seismic Walkdown Report cc w/encl: Distribution via Listserv DISTRIBUTION:

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