ML16048A349

RAI Regarding License Amendment Request to Adopt National Fire Protection Association Standard 805, Performance-Based Standard for Fire Protection for Light Water Reactor Electric Generating Plants

ML16048A349
Person / Time
Site:	Robinson
Issue date:	03/02/2016
From:	Martha Barillas Plant Licensing Branch II
To:	Glover R Duke Energy Corp
Barillas M, NRR-DORL 415-2760
References
CAC MF2746
Download: ML16048A349 (9)

Text

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 IY13rdl 2, 2016 Mr. Richard Michael Glover Site Vice President H. B. Robinson Steam Electric Plant Duke Energy 3581 West Entrance Road, RNPA01 Hartsville, SC 29550

SUBJECT:

H. B. ROBINSON STEAM ELECTRIC PLANT UNIT NO. 2 - REQUEST FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST TO ADOPT NATIONAL FIRE PROTECTION ASSOCIATION STANDARD 805, "PERFORMANCE-BASED STANDARD FOR FIRE PROTECTION FOR LIGHT WATER REACTOR ELECTRIC GENERATING PLANTS" (CAC NO. MF2746)

Dear Mr. Glover:

By letter dated September 16, 2013 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML13267A211 ), Duke Energy Progress, Inc., (the licensee) submitted a license amendment request (LAR) for H. B. Robinson Steam Electric Plant Unit No. 2 (Robinson). This LAR would adopt a new fire protection licensing basis that complies with the requirements of Title 10 of the Code of Federal Regulations, Sections 50.48(a) and (c); the guidance in Regulatory Guide 1.205, Revision 1, "Risk-Informed, Performance-Based Fire Protection for Existing Light-Water Nuclear Power Plants"; and National Fire Protection Association (NFPA) 805, "Performance-Based Standard for Fire Protection for Light Water Reactor Electric Generating Plants" (2001 Edition).

By letter dated July 31, 2015 (ADAMS Accession No. ML15212A136), the licensee provided a response to a staff request for additional information (RAI). The NRC staff has determined that additional information is needed to complete its review related to probabilistic risk assessment (PRA). The enclosed RAls were e-mailed to the licensee in draft form on November 20, 2015 (ADAMS Accession No. ML15324A328). An RAI clarification call was held on December 7, 2015. The NRC staff also held an onsite audit February 9 - 10, 2016, to establish a proposed resolution of outstanding issues associated with the Robinson NFPA 805 review, including the the attached RAls. The audit plan, dated January 8, 2016, is available at ADAMS Accession No. ML15342A205.

During the audit, the licensee agreed to a schedule for providing RAI responses. By March 18, 2016, the licensee will provide responses to PR.A RAls 03.b.01, 05.c.01, and 30.02 and revised responses to FM RAI 01.b.01.02 and PRA RAls 1.c, 18.01, 23.a, 24.01, 24.b, and 24.c. By May 27, 2016, the licensee will provide responses to PRA RAls 03 and 16.01.01 and a revised response to PRA RAI 15.01.01.01. The licensee will also update the LAR submittal and

R. Glover - :2 -

Attachments C, G, H, J, M, S, V, and W, as applicable, by this date. The NRC staff agreed with these dates.

If you have any questions, please contact me at 301-415-2760 or Martha.Barillas@nrc.gov.

Sincerely, Martha Barillas, Project Manager Plant Licensing Branch 11-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-261

Enclosure:

Request for Additional Information cc w/enclosure: Distribution via Listserv

REQUEST FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST TO ADOPT NATIONAL FIRE PROTECTION ASSOCIATION STANDARD 805 "PERFORMANCE-BASED STANDARD FOR FIRE PROTECTION FOR LIGHT WATER REACTOR ELECTRIC GENERATING PLANTS" DUKE ENERGY PROGRESS. INC.

H. B. ROBINSON STEAM ELECTRIC PLANT UNIT NO. 2 DOCKET NO. 50-261 Probabilistic Risk Assessment (PRA) Request for Additional Information (RAI) 03.b.01 Confirm and modify as necessary the information in the following table that summarizes the resolution of the referenced RAls as requested in PRA RAI 03.b (Agencywide Documents Access and Management System (ADAMS) Accession No. ML14289A260). The following table includes (1) RAls referenced by PRA RAI 03, (2) RAls added based on the RAI responses, and (3) applicable follow-up RAls. The "Reference" column refers to the date of the RAI response.

As PRA RAI 03.b.01 is a supplement to PRA 03.b, a combined response to PRA RAI 03.b and PRA RAI 03.b.01 may be designated PRA RAI 03.b.01.

Note that the resolution of some referenced RAls includes performing confirmatory sensitivity analyses demonstrating that an issue is negligible with respect to transition or additional changes to the PRA should be proposed. In performing such sensitivity studies, synergistic impacts, as described in PRA RAI 03.b, must also be addressed. If the results of the sensitivity study cannot demonstrate that the associated issue is also negligible with respect to future self-approval, then provide an implementation item that resolves the unacceptable method.

These sensitivity analyses are identified with PRA RAI 01.c, PRA RAI 02.c, and PRA RAI 15.01.01.

RAI Reference* Resolution of referenced RAI in PRA PRA RAI 01.a January 22, 2015 RAI associated with Facts and Observations (F&Os) CF-A2-01 and FSS-E1-01. A description of what was done for addressing state of knowledge in the response to PRA RAI 03 should be provided.

If mean values will not be generated post-transition, the response to PRA RAI 03 should also clarify how parametric uncertainty, including the state-of-knowledge correlation, will be addressed in the self-approval evaluation of post-transition changes.

PRA RAI 01.b March 16, 2015 RAI associated with F&O CS-A 1-01. No change to PRA methods. Confirm PRA is updated consistent with referenced RAI response.

Enclosure

PRA RAI 01.c December 22, 2014 RAI associated with F&Os CS-A 11-01 and FSS-E4-01. Describe and complete the confirmatory sensitivity analysis.

PRA RAI 01.g March 16, 2015 RAI associated with F&O FSS-C7-01. No change to PRA methods.

PRA RAI 01.h December 22, 2014 RAI associated with F&Os FSS-D7-01 and FSS-F3-02. No change to PRA methods.

PRA RAI 01.i RAI associated with F&O FSS-G1-01. No change March 16, 2015 to PRA methods.

PRA RAI 01.j RAI associated with FSS-G6-02. No change to March 16, 2015 PRA methods.

PRA RAI 01.k.01 July 31, 2015 RAI associated with MCR abandonment methods.

No change to PRA methods.

PRA RAI 02.a March 16, 2015 RAI associated with F&O IE-C3-01. No change to PRA methods. Confirm PRA is updated consistent with RAI response.

PRA RAI 02.c March 16, 2015 RAI associated with F&O LE-E1-01. Describe and complete the confirmatory sensitivity analysis.

PRA RAI 04 March 16, 2015 See PRA RAls 05, 06, 11, 14, 16 and 18 as well as associated follow-up RAls: 05.a.01, 05.c.01, 06.01, 16.01, 16.02 and 18.01. Two issues are under review (refer to PRA RAls 05.c.01.01 and 16.01.01).

PRA RAI 05.a March 16, 2015 No change to PRA methods.

PRA RAI 05.a.01 April 1, 2015 RAI associated with Frequently Asked Question (FAQ) 14-0009 guidance. No change to PRA methods.

PRA RAI 05.b March 16, 2015 RAI associated with NUREG/CR-6850, "EPRl/NRC-RES Fire PRA Methodology for Nuclear Power Facilities, Volume 2: Detailed Methodology," September 2005 (ADAMS Accession No. ML052580118) and FAQ 08-0042 guidance. Confirm PRA method is changed consistent with the referenced RAI response.

PRA RAI 05.c March 16, 2015 RAI associated with FAQ 14-0009 guidance. No change to PRA methods with regard to motor control centers (MCCs). Confirm methodology is consistent with final FAQ 14-0009. For non-MCC cabinets, see PRA RAI 05.c.01.

PRA RAI 05.c.01 July 31, 2015 RAI associated with NUREG/CR-6850 guidance and the inapplicability of FAQ 14-0009 guidance.

This issue is under evaluation (refer to PRA RAI 05.c.01.01 ).

PRA RAI 06 January 22, 2015 RAI associated with FAQ 13-0004 guidance.

Confirm PRA method is changed consistent with the referenced RAI response.

PRA RAI 06.01 July 31, 2015 RAI associated with sensitive electronics outside of FAQ 13-0004 guidance. Confirm PRA method is changed consistent with the referenced RAI response.

PRA RAI 07 March 16, 2015 No change to PRA methods.

PRA RAI 10 January 22, 2015 RAI associated with FAQ 13-0006 guidance.

Confirm PRA method is changed consistent with FAQ 13-0006 guidance (as suggested by the referenced RAI response).

PRA RAI 11 March 16, 2015 No chanoe to PRA methods.

PRA RAIS 12 and January 22, 2015, RAI associated with guidance in Supplement 1 to 12.01 and NUREG/CR-6850. Confirm PRA method is July 31, 2015 changed consistent with the referenced RAI responses.

PRA RAI 14 December 22, 2014 RAI associated with Volume 2 of NUREG/CR-7150, "Joint Assessment of Cable Damage and Quantification of Effects from Fire," May 2014 (ADAMS Accession No. ML14141A129) guidance.

Confirm PRA method is changed consistent with the referenced RAI response.

PRA RAls 15, March 16, 2015, RAI related to fire probabilistic risk assessment 15.01, and April 1, 2015, and (FPRA) modeling associated with the lack of 15.01.01 July 31, 2015 breaker coordination. Consistent with the response to Part (a) of PRA RAI 15.01.01, PRA method is changed. This issue is still under evaluation (refer to PRA RA 15.01.01.01 ). Describe and complete any confirmatory sensitivity analysis.

PRA RAI 16 January 22, 2015 No change to PRA methods with regard to in-cabinet incipient detection credit. For area-wide and main control room (MCR) incipient detection credit, see PRA RAls 16.01 and 16.02, respectively.

PRA RAI 16.01 July 31, 2015 RAI associated with area-wide incipient detection credit. This issue is still under evaluation (refer to PRA RAI 16.01.01). Describe and complete any confirmatory sensitivity analysis.

PRA RAI 16.02 July 31, 2015 RAI associated with MCR incipient detection credit.

Confirm PRA method is changed consistent with the referenced RAI response.

PRA RAls 18 and March 16, 2015, and No change to PRA methods.

18.01 April 1, 2015 PRA RAI 19 March 16, 2015 No change to PRA methods.

PRA RAI 26 March 16, 2015 No chanoe to PRA methods.

PRA RAI 29 December 22, 2014 RAI associated with FAQ 09-0057 guidance. No change to PRA methods. Confirm PRA is updated consistent with RAI response.

PRA RAIS 30 and March 16, 2015, and RAI associated with Reactor Coolant Pump (RCP) 30.01 July 31, 2015 Shutdown Seals (SDS). Confirm PRA used in support of the License Amendment Request (LAR) is consistent with the response to PRA RAI 30 and PRA used in support of self-approval will be updated consistent with the implementation item proposed in the response to PRA RAI 30.01.

PRA RAI 34 March 16, 2015 RAI associated with use of fire ignition frequencies from Supplement 1 to NUREG/CR-6850.

Sensitivity analysis required. The results of the sensitivity study, which were requested in PRA RAI 34 but not provided in the March 16, 2015 letter, are to be included in the response to PRA RAI 03.

Fire Modeling (FM) July 31, 2015 RAI associated with fire propagation and zone of RAI 01.b.01.01 influence modeling changes to be updated in the FPRA. Describe and confirm the fire modeling update for the FPRA consistent with the RAI response.

FM RAI 01.b.01.02 July 31, 2015 RAI associated with a fire modeling method related to hot gas layer. Confirm that the acceptable method described in the supplement to FM RAI 01.b.01.02 and any follow-on FM RAls is included in the response to PRA RAI 03.

• ADAMS Nos. associated with RAI Responses in Table December 22, 2014 - ADAMS Accession No. ML15005A073 January 22, 2015 - ADAMS Accession No. ML15036A059 March 16, 2015 - ADAMS Accession No. ML15079A025 April 1, 2015 - ADAMS Accession No. ML15099A454 July 31, 2015-ADAMS Accession No. ML15212A136 PRA RAI 05.c.01.01 The response to PRA RAI 05.c.01 (ADAMS Accession No. ML15079A025) states that the treatment of well-sealed and robustly secured cabinets that are not MCCs is consistent with NUREG/CR-6850, as clarified by FAQ 08-0042. The response does not, however, appear to address the statement in Chapter 6 of NUREG/CR-6850 that indicates that for cabinets housing circuits of above 440 Volts (V), "an arcing fault could compromise panel integrity (an arcing fault could burn through the panel sides, but this should not be confused with the high energy arcing fault type fires)." Justify the Fire PRA's (FPRA's) treatment of such arcing faults for well-sealed and robustly secured cabinets that are not MCCs and that operate at 440V or greater.

- ,)i- -

PRA RAI 15.01.01.01 PRA RAI 15 (ADAMS Accession No. ML14289A260) requested information about how inadequate breaker fuse coordination was accounted for in the FPRA. The response to PRA RAI 15 (ADAMS Accession No. ML 15079A.025) did not mention secondary fires.

PRA RAI 15.01 (ADAMS Accession No. ML15057A403) requested clarification about how ignition of cables (secondary fires) is addressed and will be modeled in the FPRA. The response to PRA RAI 15.01 (ADAMS Accession No. ML15099A454) stated that the FPRA does not "currently" model these secondary fires. The response also stated that cable protection against overloads is a consideration in the general design criteria (GDC) but "is limited in application." The response did not state whether or not secondary fires will be modelled in the PRA.

PRA RAI 15.01.01 (ADAMS Accession No. ML15182A193) requested clarification if the GDC reference precluded secondary fires and, if not, requested that secondary fires be modeled in the FPRA. The response to PRA RAI 15.01.01 (ADAMS Accession No. ML15212A136) indicated that all secondary fires are not precluded by the GDC reference and stated that (1) the risk of secondary fires due to cables associated with "SSA [safe shutdown analysis] and FPRA equipment and other equipment important to plant operations" will be included in the updated risk results to be provided in response to PRA RAI 03 and (2) the risk of secondary fires due to cables associated with equipment "not identified as important for plant safety and operation" will be assessed as part of a separate sensitivity study using "bounding engineering analyses."

a) Please confirm that secondary fires are not caused by lack of breaker coordination.

b) Describe and justify the modeling approaches used to assess the risk of secondary fires for the FPRA and the supporting sensitivity study.

PRA RAI 16.01.01 The response to PRA RAI 16. 01 (ADAMS Accession No. ML15212A136) did not address the question related to the use of Appendix P. The response cites draft NUREG-2180, "Determining the Effectiveness, Limitations, ancl Operator Response for Very Early Warning Fire Detection Systems in Nuclear Facilities (DELORES-VEWFIRE)," for incorporating area-wide incipient detection credit into the FPRA. Therefore, currently, no acceptable method has been demonstrated for including area-wide incipient detection credit in the FPRA. The NRC staff requests the following information to evaluate for transition:

a. Provide the results of a sensitivity study (core damage frequency (CDF), delta (.0.) CDF, large early release frequency (LERF), .0.LERF), which removes credit for area-wide incipient detection although credit for the Halon system could be retained consistent with current acceptable guidance. If the FPRA credits the Halon system for this fire area, discuss the approach for modeling it consistent with acceptable guidance.

b. Provide an implementation item to update the FPRA with an NRC-accepted method prior to self-approval to credit area-wide incipient detection.

PRA RAI 30.02 The response to PRA RAI 30 (ADAMS Accession No. ML15079A025) revises Implementation Item 11 of LAR Table S-3 to reference Table S-2; however, while Table S-2 addresses planned modifications, it does not include procedure updates, which appear to be in Table S-3. Risk and change-in-risk results should be re-evaluated after both modifications and procedure updates are completed. Clarify that Implementation Item 11 will also include procedure updates as described in Table S-3.

R. Glover Attachments C, G, H, J, M, S, V, and W, as applicable, by this date. The NRC staff agreed with these dates.

If you have any questions, please contact me at 301-415-2760 or Martha.Barillas@nrc.gov.

Sincerely, IRA! Dennis Galvin for Martha Barillas, Project Manager Plant Licensing Branch 11-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-261

Enclosure:

Request for Additional Information cc w/enclosure: Distribution via Listserv DISTRIBUTION:

PUBLIC LPL2-2 R/F DGalvin, NRR RidsACRS_MailCTR Resource RidsNrrDorllpl2-2 Resource BMetzger, NRR RidsRgn2MailCenter Resource RidsNrrPMRobinson Resource SDinsmore, NRR RidsNrrLABClayton Resource RidsNrrDraAfpb Resource RidsNrrDraApla Resource JRobinson, NRR LFields, NRR AWu, NRR HBarrett, NRR DO'Neal, NRR AKlein, NRR ADAMS A ccess1on N o.: ML16048A349 *b1y e-ma1*1 OFFICE NRR/DORL/LPL2-2/PM NRR/DORL/LPL2-2/LA NRR/DRA/APLA/BC NAME DGalvin BClayton SRosenberg*

DATE 3/1/16 2/29/16 2/17/16 OFFICE NRR/DORL/LPL2-2/BC NRR/DORL/LPL2-2/PM NAME BBeasley MBarillas (DGalvin for)

DATE 3/2/16 3/2/16 OFFICIAL RECORD COPY