ML15344A183

Report for the Audit of Duke Energy Carolinas, LLC Interim Evaluations Associated with Reevaluated Seismic Hazard Implementing Near-Term Task Force Recommendation

ML15344A183
Person / Time
Site:	Oconee, Mcguire, Catawba, McGuire
Issue date:	01/05/2016
From:	Nicholas Difrancesco Japan Lessons-Learned Division
To:	Duke Energy Carolinas, Duke Energy Corp
Wyman, Stephen NRR/JLD 415-3041
References
CAC MF3689, CAC MF3690, CAC MF3736, CAC MF3737, CAC MF3738, CAC MF3965, CAC MF3966
Download: ML15344A183 (20)

Text

To the Addressees on the Enclosed List UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 January 5, 2016

SUBJECT:

REPORT FOR THE AUDIT OF DUKE ENERGY CAROLINAS, LLC'S INTERIM EVALUATIONS ASSOCIATED WITH REEVALUATED SEISMIC HAZARD IMPLEMENTING NEAR-TERM TASK FORCE RECOMMENDATION 2.1 -

SEISMIC FOR: CATAWBA NUCLEAR STATION, UNITS 1 AND 2 (CAC NOS.

MF3965 AND MF3966); MCGUIRE NUCLEAR STATION, UNITS 1 AND 2 (CAC NOS. MF3689 AND MF3690); AND OCONEE NUCLEAR STATION, UNITS 1, 2 AND 3 (CAC NOS. MF3736, MF3737, AND MF3738)

By letter dated September 8, 2015 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML15226A185), the U.S. Nuclear Regulatory Commission (NRC) informed you of the staff's plan to conduct a regulatory audit of Duke Energy Carolinas, LLC's (Duke, the licensee) interim evaluations, also referred to as the Expedited Seismic Evaluation Process (ESEP), associated with reevaluated seismic hazards implementing Near-Term Task Force (NTTF) Recommendation 2.1 Seismic for the following plants:

Catawba Nuclear Station, Units 1 and 2 (Catawba)

McGuire Nuclear Station, Units 1 and 2 (McGuire)

Oconee Nuclear Station, Units 1, 2 and 3 (Oconee)

The audit was conducted in Rockville, MD via e-portal access provided by Duke. The audit was performed consistent with NRC Office of Nuclear Reactor Regulation, Office Instruction UC-111, "Regulatory Audits," dated December 29, 2008 (ADAMS Accession No. ML082900195). The NRC staff developed this report to document its audit observations and conclusions.

The audit provided the NRC staff with a better understanding of the ESEP interim evaluations associated with NTTF Recommendation 2.1 "Seismic" and allowed the NRC staff to evaluate Duke's implementation of the endorsed Electric Power Research Institute (EPRI) guidance1, as described by Catawba, Oconee and McGuire.

1 The EPRI ESEP guidance document can be found in ADAMS under Accession No. ML13102A142.

The audit supported the NRC staff review of the Catawba, Oconee and McGuire ESEP reports and related NRC staff requests for additional information. The NRC staff has completed its reviews based, in part, on information documented in this audit report. The NRC staff anticipates no further requests for additional information related to the Catawba, Oconee and McGuire ESEP reports. Additional information related to the audit is provided in the enclosure.

If you have any questions, please contact me at (301) 415-1115 or by e-mail at Nicholas. Difrancesco@ nrc. gov.

Enclosures:

1. Audit Summary

2. List of Addressees cc w/encl: Distribution via Listserv Sincerely, Nicholas J. DiFranc sco Hazards Managemen ranch Japan Lessons-Learned Division Office of Nuclear Reactor Regulation

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 NUCLEAR REGULATORY COMMISSION AUDIT REPORT OF DUKE ENERGY CAROLINAS. LLC INTERIM EVALUATIONS ASSOCIATED WITH RE-EVALUATED SEISMIC HAZARD IMPLEMENTING NEAR-TERM TASK FORCE RECOMMENDATION 2.1-SEISMIC FOR: CATAWBA NUCLEAR STATION, UNITS 1AND2; MCGUIRE NUCLEAR STATION, UNITS 1 AND 2; AND OCONEE NUCLEAR STATION, UNITS 1, 2 AND 3 BACKGROUND AND AUDIT BASIS:

On March 12, 2012, the U.S. Nuclear Regulatory Commission (NRC) issued a request for information pursuant to Title 10 of the Code of Federal Regulations (10 CFR) Part 50, Section 50.54(f) (hereafter referred to as the 50.54(f) letter) (Agencywide Documents Access and Management System (ADAMS) Accession No. ML12053A340). The purpose of that request was to gather information concerning, in part, the seismic hazards at operating reactor sites to enable the NRC staff to determine whether operating licenses should be modified, suspended, or revoked.

Requested Information Item (6) in Enclosure 1 to the 50.54(f) letter requests licensees to provide an interim evaluation and actions taken or planned to address the higher seismic hazard relative to the design-basis, as appropriate, prior to completion and submission of the seismic risk evaluation. By letter dated April 8, 2013 (ADAMS Accession No. ML13102A142), the Electric Power Research Institute (EPRI) submitted EPRI TR 3002000704 "Seismic Evaluation guidance; Augmented Approach for the Resolution of Fukushima Near-Term Task Force Recommendation 2.1: Seismic" (hereafter referred to as the ESEP guidance). The Augmented Approach (also called the Expedited Seismic Evaluation Process (ESEP), proposed that licensees would use a simplified seismic margins assessment process to provide additional assurance that key components of plant equipment in one safe shutdown pathway would be able to perform certain safety functions following a beyond-design-basis seismic event. By letter dated May 7, 2013, the NRC staff endorsed this guidance.

The NRC staff is conducting technical reviews on licensees' interim evaluations, to determine if the information provided meets the intent of the ESEP guidance, and if licensees responded appropriately to Requested Information Item (6) in Enclosure 1 to the 50.54(f) letter.

In December 2014, Duke Energy Carolinas, LLC (Duke, the licensee) submitted for NRC review its ESEP evaluations for Catawba Nuclear Station, Units 1 and 2 (Catawba), McGuire Nuclear Station, Units 1 and 2 (McGuire) and Oconee Nuclear Station, Units 1, 2 and 3 (Oconee). The corresponding ESEP report dates, and clarification question response dates, and respective ADAMS Accession Nos. are:

Catawba, Units 1 and 2, submitted December 31, 2014(ML15002A261 );

Clarification Question Responses submitted June 23, 2015(ML15175A457);

McGuire, Units 1 and 2, submitted December 17, 2014 (ML15005A085);

Oconee, Units 1, 2 and 3, submitted December 19, 2014 (ML14364A213);

Clarification Question Responses submitted April 24, 2015 (ML15120A017).

The NRC staff issued clarification questions to gain a better understanding of the information provided in the ESEP reports. The NRC staff reviewed the information provided by Duke for the review of Catawba, McGuire, and Oconee plants, and identified a number of instances where the approach taken for these three plants differ from the typical approach taken. In order to better understand the specifics of Duke's methodologies, and to assess the applicability of the ESEP conclusions using this alternative approach, the NRC staff conducted a regulatory audit of select supporting documentation for the ESEP evaluations, including the information provided in their responses. A summary of the findings from this regulatory audit is provided in this report.

REGULATORY AUDIT SCOPE AND METHODOLOGY:

The scope of the audit is limited to the information provided and referenced in the ESEP reports and in responses to the NRC staff clarification questions, including implementation of High Confidence of Low Probability of Failure calculations and fragility analysis performed for specific equipment. The purpose of the audit is to enable the NRC staff to gain a better understanding of the information used to support the licensee's submittals so that the staff can make an ESEP conclusion on whether the licensee's implementation meets the intent of the guidance, and if the licensee responded appropriately to Requested Information Item (6) in Enclosure 1 to the 50.54(f). Specific documents reviewed by the NRC staff through the electronic reading room access just prior to and during the audit are listed below.

DOCUMENTS PROVIDED FOR STAFF EXAMINATION:

Reports reviewed for familiarity in preparation for the audit Oconee Nuclear Station Individual Plant Examination of External Events (IPEEE) Submittal Report dated December 21, 1995, Duke Power, Seneca, SC.

Seismic Probabilistic Risk Assessment (PRA)/IPEEE Backup Calculations, Duke Energy, Seneca, SC, Rev. 0, 2011, OSC-10225.

Letter from W. R. McCollum Jr. to U.S. Nuclear Regulatory Commission, "Oconee Nuclear Station, Docket Nos.: 50-269, -270, -287; Oconee Supplemental IPEEE Submittal Report,"

dated December 15, 1997, Duke Power, Seneca, SC.

Reports used during the audit Duke Energy Report Number 030321.13.01-003, Rev. 2, Expedited Seismic Evaluation Process for Implementation of Seismic Risk Evaluations at Catawba Nuclear Station, Appendix D -

Calculations.

Duke Energy Report Number 030319.13.02.11-001, Rev. 1, Expedited Seismic Evaluation Process for Implementation of Seismic Risk Evaluations at McGuire Nuclear Station, Appendix E - Clipped Spectra Calculations.

Duke Energy Calculation OSC-11188, ONS Fukushima NTTF 2.1 Seismic Vendor Support Documents for GMRS [Ground Motion Response Spectra], Revision 2, Duke Energy, Seneca, South Carolina.

Specification for the Seismic Displacements and Response Spectra for the Turbine, Auxiliary, Reactor, and Standby Shutdown Facility Buildings, Duke Energy, Seneca, SC, Rev. 8, 2005, OSS-027B. 00-00-0002.

NRC AUDIT TEAM:

Title Branch Chief (NRC/NRO/DSEA)

Technical Lead (NRC/NRO/DSEA)

Technical Advisor (NRC/NRR)

Technical Reviewer (NRC/NRR)

Technical Reviewer (NRC/NRO)

Technical Reviewer (NRC/NRO)

Technical Reviewer (NRC/NRO)

Technical Support Reviewer (BNUConsultant)

Technical Support Reviewer (BNUConsultant)

Project manager (NRC/NRR/JLD)

AUDIT

SUMMARY

Applicable to Catawba. McGuire and Oconee Team Member Diane Jackson Nilesh Chokshi Kamal Manely Ian Tseng Tuan Le George Wang Richard Rivera-Lugo Nikolaos Simos Richard Morante Stephen Wyman A number of technical issues reviewed during the audit are applicable to the ESEP evaluations of all three plants. These were addressed by Paul Baughman, ARES Corporation, on behalf of Duke Energy. The presentation is included as Attachment 1 to this audit report.

There are three primary technical issues raised by the NRC staff regarding Duke's implementation of the interim evaluation guidance. Following a round of clarification questions and responses for each plant, as well as a teleconference held with the staff on June 9, 2015, the staff determined that an audit would be the most effective means to resolve the technical issues.

The three issues relate to screening of ESEP items using the screening levels detailed in Table 2-4, Summary of Equipment and Subsystems Screening Criteria for Seismic Margin Evaluation in EPRl-6041, Nuclear Plant Seismic Margin R-1. Duke, through its consultant ARES Corporation, developed and implemented an alternate screening methodology, which has not been reviewed or accepted by the NRG staff. As this methodology is for an interim evaluation, the NRG staff objective is not to render a technical determination on the future acceptability or applicability of Duke's alternate screening methodology. The NRG staff emphasis for the audit was to develop confidence that the ESEP conclusions by the licensee would apply if the ESEP interim evaluation guidance proposed by EPRI had been traditionally followed.

The first issue is the comparison of the In-Structure Response Spectra (ISRS) to 1.5 times the EPRI 6041 Table 2-4 screening levels (1.2g; 1.8g) for elevations below 40' above grade.

Normally the 5 percent damped Review Level Ground Motion (RLGM) spectra are compared to 1.0 times the EPRI 6041 Table 2-4 screening levels (0.8g; 1.2g) for these elevations. The alternate approach taken by the licensee is compatible with methods described in EPRI 1019200, Seismic Fragility Applications Guide Update, which is referenced in EPRI Technical Report 3002000704, Seismic Evaluation Guidance: Augmented Approach for the Resolution of Fukushima Near-Term Task Force Recommendation 2.1: Seismic, for use as the criteria for application of the screening tables in EPRI 6041 at elevations beyond 40' above grade, and were judged to be conservative in this specific implementation. The licensee further stated that using 1.2g vs. The RLGM at elevations within 40' of grade per EPRI 3002000794 instead of 1.8g vs. ISRS per EPRI 1019200 would not change the screening conclusions. On that basis, the NRG staff conceptually judges that the alternate approach to this issue is reasonable for the purposes of the interim evaluation.

The second issue is the use of raw, narrow-banded ISRS and peak clipping, whenever such spectra are available. The NRG staff's initial expectation was that the ISRS used in screening would be design-basis broadened ISRS, not raw narrow-banded ISRS. Broadened design ISRS would not be subject to significant peak clipping, whereas clipping factors approaching the lower bound value of 0.55 are fairly typical for narrow-banded ISRS. In support of this aspect of the licensee's screening methodology, the licensee indicated that peak shifting in lieu of peak broadening is permissible by EPRI 6041, and referenced EPRI 1019200 for the use of clipping factors calculated per EPRI 6041 Appendix Q. During the audit, the licensee presented an example for all three plants. The licensee stated that for these three cases, the conclusions reached by implementing the licensee's methodology are equivalent to what would have been reached by implementing the EPRI evaluation guidance. The NRG staff was satisfied with this explanation for the ESEP interim evaluation.

The third issue is the use of North-South (N-S)/ East-West (E-W) peak averaging (after clipping) to obtain the peak spectral acceleration, for comparison to the EPRI 6041 screening levels.

This issue is unique to the licensee's screening methodology, and the NRG staff noted that there is no precedent for this type of averaging. The licensee stated that this method is consistent with the philosophy in EPRI 6041, in that a single ground response spectrum is specified as the review level earthquake (i.e., RLGM in ESEP evaluations). The staff noted that typically N-S and E-W ground spectra are taken to be equal for the purpose of seismic design.

When using ISRS, filtered by the building structure, the peak spectral accelerations of the N-S and E-W ISRS can be significantly different. Averaging the ISRS peak accelerations can significantly reduce the numerical value that is compared to the EPRI 6041 screening levels. In response to the staff's concern, the licensee stated that the screening conclusions would be the same regardless whether the average or the higher of the two spectral peaks were used for comparison to the EPRI 6041 screening levels.

Applicable to Oconee In preparation for the audit, the NRC staff requested that the licensee make selected reference documents available prior to the audit through the licensee's ePortal. The intent was to enable the staff to focus on specific elements of the licensee's screening methodology, implementation, and results during the one-day audit. One document requested for Oconee was Duke Energy Calculation OSC-11188, "ONS Fukushima NTTF 2.1 Seismic Vendor Support Documents for GMRS," Revision 2. The Oconee ESEP submittal references Attachment 3 to OSC-11188 as the basis for screening all ESEP components in the Standby Shutdown Facility (SSF) and several ESEP components in the Auxiliary Building (AB) and Reactor Building (RB).

During initial staff review of Attachment 3, prior to the audit, the staff determined that the Oconee ESEP submittal lacked sufficient description of the Attachment 3 methodology. While the ESEP submittal identifies the SSF RLGM is equal to two times the SSF safe shutdown earthquake (SSE), Attachment 3 presents an assessment based on the GMRS, in lieu of the SSF RLGM, and a methodology that departed from the licensee's methodology, as discussed above. This became one of the focus areas for the audit.

During the audit, the NRC staff requested that the licensee provide a detailed description of the approach, and a technical justification for its validity. The licensee indicated that Attachment 3 had been prepared by its consultant, ARES Corporation, outside the scope of the ESEP. It was intended to address the large discrepancy between the newly defined Oconee GMRS and the Oconee plant design-basis SSEs (one for the AB and RB and a different one for the SSF). The consultant determined that it would be applicable to the ESEP screening evaluation, because the Attachment 3 assessment imposed a higher demand than an RLGM developed in accordance with the ESEP guidance. On this basis, screening/evaluation of all ESEP components in the SSF and selected ESEL components in the AB and RB rely on.

The licensee explained that the SSF SSE ISRS were multiplied by a factor of 2. 72 for comparison to the EPRI 6041 screening levels (1.2g; 1.8g), compared to a maximum factor of 2 based on the ESEP guidance. The 2. 72 factor is based on dominant horizontal mode scaling and averaging the N-S and E-W scale factors. In response to a staff question, the licensee referred to EPRI 6041, Section 4, p.4-17, as the technical basis for dominant mode scaling.

The staff reviewed EPRI 6041, Section 4, p. 4-17, and determined that it does address dominant mode scaling, but also specifies that the two response spectra (SSE vs. GMRS) should have similar shapes. This does not appear to be satisfied for Oconee. Therefore, the staff concentrated on the acceptability of the ESEP conclusions rather than on the acceptability of the methodology.

The NRC staff requested the licensee to submit a written description of the Attachment 3 methodology, and the technical basis for the use of the Attachment 3 results in addressing the ESEP. The staff reviewed a draft summary of the Attachment 3 methodology and results through the licensee's ePortal and considers it to be sufficient to make a final determination on the acceptability of the licensee's conclusions.

Summary As a result of the detailed discussions during the audit, the NRC staff gained an understanding of the licensee's screening conclusions for the ESEP interim evaluation. Given the interim status of the evaluation, the NRC staff's review is limited in scope and is not a licensing review.

The validity or future applicability of the alternate methodology used by the licensee was not addressed and would need to be reviewed separately. The focus of this audit was to determine whether the licensee's screening conclusions using an alternate approach, were acceptable within the scope of the ESEP. Based on the information reviewed during this audit, the NRC staff agrees with the licensee's statement that the conclusions made using the licensee's alternate approach are applicable to the screening of components for Catawba, McGuire, and Oconee within the scope of the ESEP, and meets the intent of the EPRI interim evaluation guidance.

Attachment:

ARES audit Presentation

ARES Audit Presentation ARES Seismic Demand vs. Capacity Methodology for Oconee, Catawba and McGuire ESEPs Agenda

• Seismic Demand (Scaling ISRS)

• Seismic Capacity (HCLPF Determination)

• Comments on 40 foot rule

• Peak Clipping

• Averaging

• Summary Seismic Demand for ESEP

• ARES approach:

- Seismic Demand for ESEP is Review Level Ground Motion (RLGM)

- RLGM is derived by linearly scaling the SSE by the maximum ratio of the GM RS/SSE between 1 and 10 Hz (not to exceed 2 times SSE)

- In-structure RLGM seismic motions derived using existing SSE ISRS scaled with the same factor

• This conforms exactly with EPRI 3002000704 ESEP Seismic Capacity

• ARES approach:

Used Deterministic Approach Performed initial screening1 using Table 2-4 of EPRI NP-6041-SL

• Since building foundations are control points for SSE, used basemat elevation as grade elevation

• Used EPRI 1019200 for elevations above basemat

• Used NP-6041-SL for basemat elevation (1.2g vs. RLGM)

- If screening not passed, calculated HCLPF using CDFM methodology in EPRI NP-6041-SL

• This agrees with EPRI 3002000704 See next slide for comments on 40 foot rule 1 Anchorage evaluated separately Comments on 40 Foot Rule EPRI 3002000704 statement on using Table 2-4:

Table valid up to 40 feet above grade (i.e., l.2g vs. RLGM)

Use EPRI 1019200 for locations more than 40 feet above grade EPRI 1019200 guidance on using Table 2-4 (Ref: summary, page 4-8)

For ground-mounted items, HCLPF = 1.1 *l.2g)

Use either free-field demand or peak-clipped ISRS for comparison For structure-mounted items, HCLPF = 1.5*1.2g)

Use peak-clipped ISRS for comparison Does not limit to more than 40 feet above grade ARES used EPRI 1019200 guidance as this is current SPRA practice.

At all locations less than 40 feet above grade, this was more conservative than l.2g vs. RLGM because ISRS amplification was more than 1.5 A review of results showed that using 1.2g vs RLGM within 40 feet of grade per EPRI 3002000794 instead of 1.8g vs ISRS per EPRI 1019200 would not change the screening conclusions EPRI 1019200 Guidance

• EPRI HCLPF training slide:

FPR! 101q/OO-Fr<1q11.rv Ap:il*<:dfHHl', C:;tJIW-'

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• L)QVQlop"d a ngw rm~thod to u~Q tt"IQ 1:µ~1 b0-11 !-.cammng 1<.lbl('s. based on m structure response compJrison:,

Av1w1" 1t11-1 nv1UPngP<> Of dC1<11i:>c.;o:;.1rKJ comrnnPnh 40 f' aboVP ef!OCUVI'::' grade

• !f ISRS are av.11!ab!e ~

JPCt.llllllJelKl 11s.1nq th*~ rnme IHl-'fll c1ppw.-u:n 1SR':.> ~,houlcl be c11pped bef(l(~ us1nq

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- Me(ilirn c.:;p;:ii:1tv

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• ARES used this methodology

- Note statement "if ISRS are available"

- Only applies to screening Peak Clipping EPRI HCLPF training slide:

Response Spectra Clipping (Appendix Q of EPRI 6041) Ncxed1flerrmtfromFraq1llty cllppmg t

• - "Q~

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• c

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=- 10 B :!: O.I

• Chpptng for TRS porformod in a s1m1lar marYler EPl2I ARES followed this procedure Raw spectra were used when available Smoothed/broadened spectra were used if raw spectra were not available Clipping with Separated Peaks

• EPRI HCLPF training slide:

Clipping Example - 2 Peaks Wide Separation Cippina ol N.rrow 5ped:r11I PHk:s

• ARES followed this procedure J.Mi 1.10 Ul 1.u EF'12t l Reduction limited to bottom of valley between peaks McGuire Example MCGUIRE NUCLtqR sr qTION

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lope indicated by SSE spectrum is 1.875 x 06E spectrum, therefore RLGM spectrum I

I

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C.xr~&-.qu.eitl HU.Pf Oppq: fxw- {EPlJ NP-6Gal. Ell Q-6) 11 11

SSE is [ '. RLGM Is 2 x [.

therefore RLGM ts 2 x 2.6,.. 5.2 tunes this curve

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fRCt-1 ~.alu&O".of,.M&.q...wy S.fipr.

(otr:alfi~_,

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RLE IRS

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1 SSt. spectrum J lb Averaging Horizontal ISRS

• ARES averaged the peak spectral accelerations of the clipped ISRS before comparing to the screening level in Table 2-4

- The reason was to be consistent with the basis for the screening level in EPRI NP-6041-SL

• EPRI NP-6041-SL says to use the average (Page 2-44)

- There are no statements about this in EPRI 3002000704 or EPRI 1019200

- Using the average vs. the maximum had no effect on the results

• Only applied to screening, not anchorage EPRI NP-6041-SL Guidance

• EPRI NP-6041-SL states that screening level in Table 2-4 should be compared to the average of peak spectral accelerations of the two horizontal directions

- Table 2-4 is for comparing to the ground response spectrum, which is assumed to be at grade

- This is consistent with development of the 1.2g screening level, which was derived from the average of the two horizontal ground spectra at the earthquake experience database sites

- It does not address averaging using ISRS; it only addresses ground response spectra Summary of ARES Approach

• Calculated RLGM ISRS by scaling SSE ISRS in accordance with EPRI 3002000704

• Compared RLGM to EPRI NP-6041-SL Table 2-4

- Used 1.2g vs. RLGM for basemat elevations

- Used 1.8g vs. clipped ISRS for elevations with ISRS

• Performed ISRS peak clipping in accordance with EPRI NP-6041-SL Appendix Q

• Averaged peak spectral accelerations of two horizontal ISRS for comparison to screening level

• Only applied to screening

Catawba Nuclear Station Duke Energy Carolinas, LLC Docket Nos. 50-413 and 50-414 License Nos. NPF.-35 and NPF-52 Mr. Kelvin Henderson Site Vice President Duke Energy Carolinas, LLC Catawba Nuclear Station 4800 Concord Road York, SC 297 45 McGuire Nuclear Station Duke Energy Carolinas, LLC Docket Nos. 50-369 and 50-370 License Nos. NPF-9 and NPF-17 List of Addressees Mr. Steven D. Capps Vice President - McGuire Site Duke Energy Carolinas, LLC McGuire Nuclear Station 12700 Hagers Ferry Road Huntersville, NC 28078-8985 Oconee Nuclear Station Duke Energy Carolinas, LLC Docket Nos. 50-269, 50-270 and 50-287 License Nos. DPR-38, DPR-47 and DPR-55 Mr. Scott Batson Vice President, Oconee Nuclear Station Duke Energy Corporation 7800 Rochester Highway Seneca, SC 29672-0752 The audit supported the NRC staff review of the Catawba, Oconee and McGuire ESEP reports and related NRC staff requests for additional information. The NRC staff has completed its reviews based in part on information documented in this audit report. The NRC staff anticipates no further requests for additional information related to the Catawba, Oconee and McGuire ESEP reports. Additional information related to the audit is provided in the enclosure.

If you have any questions, please contact me at (301) 415-1115 or by e-mail at Nicholas.Difrancesco@nrc.gov.

Sincerely,

/RAJ Nicholas J. DiFrancesco, Senior Project Manager Hazards Management Branch Japan Lessons-Learned Division Office of Nuclear Reactor Regulation

Enclosures:

1. Audit Summary

2. List of Addressees cc w/encl: Distribution via Listserv DISTRIBUTION:

PUBLIC JLD R/F RidsNRRJLD Resource SWyman, NRR MShams, NRR NDiFrancesco, NRR DJackson, NRR RidsNrrPMCatawba Resource RidsNrrPMOconee Resource RidsNrrPMMcGuire Resource RidsNrrDorllpl2-1 Resporce ADAMS Accession No.: ML15344A183

• via e-mail OFFICE NRR/JLD/JHMB/PM NRR/JLD/JHMB/LA NRO/DSEA/RGS/BC*

NRR/JLD/JHMB/BC NRR/JLD/JHMB/PM NAME NDifrancesco Slent DJackson MShams NDifrancesco DATE 12/10/2015 12/1/2015 12/3/2015 12/5/2015 1/5/2016 OFFICAL RECORD COPY