ML19165A017

Audit Plan License Amendment Request for Flood Protection Dike Modification

ML19165A017
Person / Time
Site:	North Anna
Issue date:	07/03/2019
From:	Geoffrey Miller Plant Licensing Branch II
To:	Stoddard D Dominion Energy Virginia
Miller G
References
EPID L-2018-LLA-0485
Download: ML19165A017 (11)

Text

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 July 3, 2019 Mr. Daniel G. Stoddard Senior Vice President and Chief Nuclear Officer Innsbrook Technical Center 5000 Dominion Blvd.

Glen Allen, VA 23060-6711

SUBJECT:

NORTH ANNA POWER STATION, UNITS 1 AND 2 -AUDIT PLAN RE:

LICENSE AMENDMENT REQUEST FOR FLOOD PROTECTION DIKE MODIFICATION (EPID L-2018-LLA-0485)

Dear Mr. Stoddard:

By letter dated November 19, 2018 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML18334A106), Dominion Energy Virginia (Dominion), submitted a license amendment request regarding the North Anna Power Station (North Anna), Units 1 and 2. The proposed amendment would revise the licensing basis of North Anna regarding a safety-related flood protection dike.

The U.S. Nuclear Regulatory Commission (NRC) staff will conduct a regulatory audit to support its review of the proposed license amendments. The audit is planned to be conducted on-site at North Anna to facilitate access to the licensee's computer models, documentation, and technical experts. The NRC staff intends to start the audit on July 15, 2019, and a detailed audit plan is enclosed. The logistics and scope of the audit was discussed with your staff on June 26, 2019.

If you have any questions, please contact me by telephone at (301) 415-2481 or by e-mail at ed.miller@nrc.gov.

G. Edward Miller, Project Manager Special Projects and Process Branch Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-338 and 50-339

Enclosure:

Audit Plan cc: Listserv

AUDIT PLAN FLOOD PROTECTION DIKE MODIFICATION AMENDMENT DOMINION ENERGY VIRGINIA NORTH ANNA POWER STATION, UNITS 1 AND 2 DOCKET NOS. 50-338 AND 50-339 I. BACKGROUND By application dated November 19, 2018 (Agencywide Documents Access and Management System (ADAMS} Accession No. ML18334A106, Dominion Energy Virginia, the licensee, requested the NRC staff review and approve a proposed amendment what would revise the North Anna Power Station (North Anna}, Units 1 and 2 current licensing bases regarding a safety-related flood protection dike.

A safety-related flood protection dike located west of the Unit 2 turbine building (TB} and service building, which provides flood protection to those buildings, was modified by a design change in 2013. Specifically, a non-safety-related fire protection water header and a non-safety related domestic water header were installed within the safety-related flood protection dike west of the Unit 2 TB.

The design change that implemented this change was evaluated per the criteria specified in 10 CFR 50.59 and was determined to not require prior NRC approval. During a recent NRC inspection (June 2, 2017-ADAMS Accession No. ML171578414) one aspect of the 2013 modification was determined to have required prior NRC approval.

The U.S. Nuclear Regulatory Commission (NRC} staff is performing a detailed review of the proposed license amendment request (LAR}. Due to the complexity of the proposed amendment, supporting calculations such as the slope stability analysis, external flood mitigation strategies, risk analysis, and completed design change modifications, the staff has determined that face-to-face interactions at the North Anna Power Station Units 1 and 2 site can resolve complex technical issues more quickly than several rounds of requests for additional information (RAI}. Face-to-face interactions will also allow the staff to review and assess physical aspects of the LAR at the site through field walkdowns.

The NRC staff has determined the need for a regulatory audit to be conducted in accordance with the Office of Nuclear Reactor Regulation (NRR) Office Instruction LIC-111, "Regulatory Audits" (ADAMS Accession No. ML082900195), for the NRC staff to gain a better understanding of the licensee's calculations and other aspects of the LAR.

11. REGULATORY AUDIT BASES A regulatory audit is a planned license or regulation-related activity that includes the examination and evaluation of primarily non-docketed information. A regulatory audit is conducted with the intent to gain understanding, to verify information and/or to identify information that will require docketing to support the basis for the licensing or regulatory decision.

Enclosure

The audit will consist of three parts. NRC initial review North Anna design change package on the associated electronic portal, on-site two and one-half day visit, and NRC final review of the North Anna design change package on the electronic portal.

NRC Regulatory Requirements The regulatory bases for the audit are described in North Anna Units 1 and 2 Updated Final Safety Analysis Report (UFSAR). Components comply with the Atomic Energy Commission (AEC) and Title 10 of the Code of Federal Regulations (10 CFR), Part 50, Appendix A, General Design Criteria for Nuclear Power Plants, as stated in North Anna UFSAR Sections 3.1

• Criterion 3 - Fire Protection

• Criterion 4 - Environmental and Missile Design Bases" Additional documents are listed below:

UFSAR Section 3.8.6, Flood Protection Dike UFSAR Section 9.2.3.1, Domestic Water System UFSAR Section 9.5.1, Fire Protection System UFSAR Figure 9.5.1, Fire Protection System Arrangement NAPS Technical Requirements Manual (TRM), Section 3.7.16, Flood Protection, The North Anna Technical Specifications (TS) or North Anna Fire Protection Program, as described in the North Anna TS are not involved, related, or part of the proposed LAR.

III. REGULATORY AUDIT SCOPE AND METHODOLOGY The purpose of this confirmatory audit is to determine if the design change modification related to the safety-related flood protection dike, previously installed in 2013, should be approved for North Anna. Specifically, the NRC staff will later in the LAR review process, determine based on input from this audit, if (1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2) there is reasonable assurance that such activities will be conducted in compliance with the Commissions regulations, and (3) the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the public.

To accomplish these objectives, the NRC staff:

Requests the licensee to provide an overview presentation and in-person walkdown of the flood protection dike; Requests the information listed in the section IV and the Attachment, Audit Questions, be made available in whatever format (e.g., electronic or paper) appropriate; and Requests the licensee to provide access to personnel familiar with North Anna to discuss the aforementioned information, as needed; The audit will be performed consistent with NRCs Office of Nuclear Reactor Regulation (NRR)

Office Instruction LIC-111, Regulatory Audits, dated December 29, 2008 (ADAMS Accession No. ML082900195).

IV. INFORMATION AND OTHER MATERIAL NECESSARY FOR THE REGULATORY AUDIT The licensee is requested to provide via an electronic portal, or during the audit, the following list of references related to the license amendment. The proposed list is a postulated list of North Anna Units 1 and 2 specific titles related to this proposed license amendment and actual titles may vary.

1. Design Change Modification Package related to the Flood Protection Dike, DCP 07-016, Fire Protection and Domestic Water System Modifications/North Anna/Unis 1 & 2.

2. Design Drawings, N-07016-0-1FB2A, Sheet 1, Fire Protection Arrgt Sh-1 North Anna Power Station.

3. Other physical arrangement drawings of the areas of the Protection Dike.

4. Calculation 25161-G-060, Slope Stability Analysis for Flood Protection Dike, Revision 1, Bechtel Power Corporation.

5. SAR Change Number NAPS-UCR-2013-004.

6. Bechtel Specification 25161-009-3PS-CE02-Q0001.

7. Field Completed work copy of Procedure: GMP-C-102, Excavation and Backfill.

8. Field Completed work copy of Procedure: GMP-C-174, Flood Wall Dike Repair.

9. Field Completed work copy of Procedure: 1-PT-9.3.

10. Design Drawing 11715-FY-8AG.

11. Calculation Package: DC 88-14-3.

12. Field Completed work copy of Procedure: GMP-C-102.

13. AMEC Report dated 2/1/2013 together with:

a- Location of the test locations b- Action taken when unsat. Was notified by the field test.

14. Drawing and/or sketch that is shown the actual location of the 12 and 2 pipe to the west slope and to the top of the slope.

Additionally, to support the at-site audit walkdown, please provide half-size drawings related to the license amendment and the associated modification.

Additional information needs, identified during the audit, will be communicated to the designated point of contact.

The information needed for the regulatory audit is listed in the Attachment. The audit team will not remove non-docketed information from the audit site.

V. AUDIT TEAM ASSIGNMENTS The NRC/NRR audit team onsite will consist of:

Larry Wheeler, Audit Team Lead, Technical Reviewer, Division of Safety Systems (DSS)/Containment & Plant Systems Branch (SCPB)

Dan Hoang, Technical Reviewer, Division of Engineering (DE)/ Structural Engineering Branch (ESEB)

Hosung Ahn, Technical Reviewer, NRO Division of Licensing, Siting, and Environmental Analysis (DLSE)/External Hazards Branch (EXHB)

G. Edward Miller, Project Manager, Division of Operating Reactor Licensing (DORL)/Plant Licensing Branch II-1, North Anna Power Plant The following additional NRC staff may support the audit from the NRC headquarters:

Jeff Circle, Technical Reviewer, Division of Risk Assessment, Licensing Branch DRA/APLA VI. LOGISTICS The NRC staff will conduct the audit on than July 15, 2019, on a mutually agreeable schedule and agenda. The NRC Project Manager will coordinate any changes to the audit schedule and location with the licensee.

VII. SPECIAL REQUESTS The NRC staff would like access to the following equipment and services:

Escorted or unescorted access within the protected area to germane locations of the plant (e.g., the flood protection dike);

Enclosed conference room (or comparable space) with a table, chairs, and white board sufficient to accommodate NRC participants and supporting licensee staff; and Computer access to any onsite electronic portal applicable for this audit.

VIII. DELIVERABLES At the conclusion of the audit, the NRC staff will conduct an exit briefing and provide a summary of audit results in each subject area defined in the audit scope, as well as discuss the projects next steps. Once the NRC audit team leaves the site, only new, post-site audit documents added to the electronic portal will continue to be reviewed and audited.

The NRC staff plans to prepare a regulatory audit summary within 60 days of the completion of the audit followed by a formal release of any RAIs at that time.

IX. REFERENCES

1. Sartain, Mark, Vice President, Virginia Electric Power Company (Dominion Energy Virginia), letter to U.S. NRC, "Virginia Electric and Power Company (Dominion Energy Virginia), North Anna Power Station, Units 1 and 2, letter to, Amendment for Flood Protection Dike Modification, dated November 19, 2018 (Agencywide Documents Access and Management System (ADAMS), Accession No. ML18334A106.

2. Bartley, Jonathan H., Chief, U.S. NRC, Letter to Daniel G. Stoddard, President, Dominion Energy, North Anna Power Station - NRC Evaluation of Changes, Tests, and Experiments Inspection Report 05000338/2017007 and 05000339/2017007, dated June 2, 2017, ADAMS Accession No. ML17157B414.

3. U.S. NRC Office Instruction, LIC 111 Regulatory Audits, dated December 16, 2008 (ADAMS Accession No. ML082900195).

Attachment:

Audit Questions

AUDIT QUESTIONS DOMINION ENERGY VIRGINIA NORTH ANNA POWER STATION, UNITS 1 AND 2 DOCKET NOS. 50-338 AND 50-339 Item# Regulatory NRC Question /Request:

Bases for the Audit Question?

1 Understanding From the LAR - The section of external flood protection dike of concern is and about 350 feet long. Is this the approx. length of the fire protection system Background (FPS) and domestic water system (DWS) lines, within the safety related (SR) dike. Provide a drawing detailing dimensions, if available.

Provide a general list of materials within the dike area - pipe fittings, valves, post indicating valves (PIVs), fire hydrants, thrust blocks, etc.

Provide as-built drawings showing that the new FPS and DWS lines are below the 5'0".

2 NFPA Code Provide documentation of FPS and DWS pressure testing after installation and ASME (within the dike area), and if possible, indicate what was the approx. test Code B31.1 pressures?

3 GDC 2 and DCP 07-016 (3.8, page 11/27) states that the FPS has been seismically SRP 3.2.1, reviewed. Provide calculations 11715-PX-1-HB, CE-1773, CE-1779 or Seismic other documentation acceptance of the review. Clarify whether the DWS Classification line have a seismic review/analysis since it was located within a seismically qualified dike.

4 SRP 18.0, DCP 07-016 (3.8 page 12/27) states that the dike is in the open and Human factors supports the PA fence which is continuously under surveillance and readily engineering observed and corrected before the FPS would fail from becoming unsupported by the solid in the dike. Is this true for the whole -350 feet of FPS line within the dike or just part of the buried lines?

5 SRP 18.0, DCP 07-016, Section 3.31, "training," did this section require non-licensed Human factors operators (outside rounds - NLO) and security patrols to now be aware of engineering possible leaking pipes in the area of the new FPS/DWS lines?

6 SRP 18.0, 10 CFR 50. 59 (page 15/17) states that if a failure of the DWS line would be Human factors reported to the main control room (MCR) in a timely manner - did the low engineering pressure alarm response get revised to state that a possible cause of low DWS pressure that a buried line in the SR dike has failed. Are there any immediate actions to begin walkdowns of the SR dike area first or ASAP?

Attachment

Item # Regulatory NRC Question /Request:

Bases for the Audit Question?

10 CFR 50.59/72.48 supplemental (page 5/7) -has good discussion of FPS/DWS of piping failures (double - ended breaks to small leaks.

- states that DWS piping would be identified quickly?

What directs operators to look in the area of the SR dike first?

Are isolation valves for the FPS and DWS indicated in any off normal instruction (ONI) for quick isolation to prevent damage to the SR dike?

7 SRP 2.4.10, Provide drawings that indicate where the dike is located on FSAR drawing flooding 9.5-1 and DCP drawing 2.1-1E.

protection requirements -

Drawing details missing from the LAR 8 SRP 18.0, From the LAR (break or leak timely identifications):

Human factors Security would notice significant differences (wetness or engineering pooling) in the appearance of the flood protection dike during routine patrols performed several times each day.

o How often are patrols directly over this FPS/DWS pipe, done with cameras, how close are the inspections done to the piping?

The flood protection dike is landscaped at least twice a year.

o Explain how is landscaping every 6 months considered here?

Small leaks of both pipe sizes would be detected during the annual flood protection dike inspection.

o How is inspection every 365 days considered here?

A fire protection system piping leak or rupture would result in increased cycling of the fire protection hydropneumatic tank level and pressure, which are monitored daily by Operations.

Furthermore, the pressure maintenance pump would be cycling to maintain the dropping tank pressure.

o Have alarm response procedures been revised to include looking in the SR dike area for leaks?

Significant leakage (>30 gpm) [gallons per minute] would auto start a main fire pump and alert the operators in the control room, triggering an investigation.

Operators perform quarterly and annual periodic tests which cycle the fire protection system valves at the ends of the flood

Item # Regulatory NRC Question /Request:

Bases for the Audit Question?

protection dike, which provides an additional opportunity to observe signs of leakage on the western bank of the flood dike.

o How is this considered?

The domestic water system usage is monitored monthly under a chemistry procedure and is trended by a System Engineer. A leak investigation would commence if the usage exceeds 600,000 gallons monthly (estimated to be equivalent to a 14 gpm leak based on normal usage).

o How is this considered?

9 GDC 2 LAR Att.1, Sec. 2.2 The attachment says that the dike slope stability analysis performed with the probable maximum flood (PMF) lake level of 264.2 ft mean sea level (MSL) shows adequate factors of safety. Generally, the dike slope stability analysis must also consider the effects of wave runup which are persistent during the lake flooding as the period of wave is much shorter than the period of flood (i.e., few seconds versus several hours). Therefore the NRC staff requests the following two items: (i) Present the dike slope stability modeling, including discussion of model setup, assumptions, and model input/output; (ii) Discuss the effects of the increased flood level due to the estimated wave runup of 3.1 ft (as reported in the UFSAR) on the dike stability analysis, or justify why the effects of wave runup is not applicable here.

10 SRP 2.4.10, LAR Att. 1, Sec. 3.0 flooding protection For PRA analysis on page 8, the applicant assumed that a failure of requirements - the fire protection pipe occurs within seven days of a significant Drawing rainfall event and that at least 15-inches of rain falls in less than details missing 72 hours3 days <br />0.429 weeks <br />0.0986 months <br />. However, the duration of design basis rainfall for the from the LAR. Lake Anna PMF outlined in the UFSAR is 9 days: 3 days for 40%

probable maximum precipitation (PMP) as a pre-storm, 3 days for no-rain, and then 3 days for PMP. Also, the 3-day PMP depth at the Lake Anna basin reported in the UFSAR is 30.65 inches. Address how this design basis PMP rainfall scenario changes the result of the PRA analyses.

(Risk Analysis, page 8): The leak condition could lead to a subsidence of the dike and in turn could create a rupture of 12 inches fire protection pipe and dike. In this case, rainfall and pipe failure events are dependent and the failure probability of this scenario would be increased compared to the applicants estimate under an independent assumption as described on page 10.

Please address the potential failure of the dike rupture followed by

Item # Regulatory NRC Question /Request:

Bases for the Audit Question?

a failure of drainpipe and fire protection pipe in a dependent manner during an extreme rainfall event, or justify why this type of combined failures is not plausible.

11 GDC 2 and Provide any documentation that the licensee has met: (1) Section 3.4 Fill SRP 3.2.1, Placement and Compaction Requirements and (2) Section 4.0, Quality Seismic Assurance and Testing Requirements of Specification No. NAI-003 ,

Classification Revision 1 dated September 21, 1989. As indicated in the Calculation package 25161-G-060, dated May 6, 2011, for 2011 modification works.

SRP 2.4.10, flooding protection requirements -

Drawing details missing from the LAR.

12 SRP 2.4.10, In the AMEC Report (dated 2/1/2013):

flooding There are 7 tests that appear to be missing in the report (28 -

protection 32, and 56 - 57). Please provide the missing test data requirements - There are 29 results that were outside of the test specified Drawing range - Please provide the corrective action, if any, that had details appear been taken by Dominion.

to be missing Please provide mapped out the test locations that were address from the LAR in the report 12 SRP 2.4.10, Please provide the dimension from the center line of the 12 FP piping to flooding the Westside of the dike.

protection requirements -

Drawing details missing from the LAR.

14 SRP 2.4.10, Please provide the original (hard copy) of DC 88-14-3 (proprietary) to flooding reviewed during the onsite audit protection requirements.

ML19165A017 *Via E-mail OFFICE NRR/DORL/LSPB/PM NRR/DORL/LPL2-1/LA NRR/DE/ESEB/BC NAME GEMiller KGoldstein BWittick DATE 6/26/19 06/26/19 6/26/19 OFFICE NRR/DSS/SCPB/BC NRR/DORL/LPL2-1/BC NRR/DORL/LSPB/PM NAME SAnderson MMarkley GEMiller DATE 7/3/19 7/3/19 7/3/19