BSEP 16-0070, Response to Request for Additional Information Regarding License Amendment Request to Relocation of Specific Surveillance Frequency Requirements to a Licensee-Controlled Program

Response to Request for Additional Information Regarding License Amendment Request to Relocation of Specific Surveillance Frequency Requirements to a Licensee-Controlled Program

ML16238A152
Person / Time
Site:	Brunswick
Issue date:	08/15/2016
From:	William Gideon Duke Energy Progress
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
BSEP 16-0070
Download: ML16238A152 (5)

Text

~~DUKE William R. Gideon Vice President

~ ENERGY Brunswick Nuclear Plant P .0. Box 10429 Southport, NC 28461 o: 910.457.3698 August 1S, 2016 Serial: BSEP 16-0070 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20SSS-0001

Subject:

Brunswick Steam Electric Plant, Unit Nos. 1 and 2 Renewed Facility Operating License Nos. DPR-71 and DPR-62 Docket Nos. S0-32S and S0-324 Response to Request for Additional Information Regarding License Amendment Request to Relocation of Specific Surveillance Frequency Requirements to a Licensee-Controlled Program

References:

1. Letter from William R. Gideon (Duke Energy) to U.S. Nuclear Regulatory Commission, Application For Technical Specification Change Regarding Risk-Informed Justification for the Relocation of Specific Surveillance Frequency Requirements to a Licensee-Control/ed Program, dated December 21, 201 S, ADAMS Accession Number ML16004A249

2. NRC E-mail Capture, Brunswick Unit 1 and Unit 2 Request for Additional Information related to LAR to Relocation of Specific Surveillance Frequency Requirements to Licensee Controlled Program (GAG NOS. MF7206 and MF7207), dated June 1S, 2016, ADAMS Accession Number ML16167A174

3. Letter from William R. Gideon (Duke Energy) to U.S. Nuclear Regulatory Commission, Response to Request for Additional Information Regarding License Amendment Request to Relocation of Specific Surveillance Frequency Requirements to a Licensee-Controlled Program, dated July 13, 2016, ADAMS Accession Number ML 16029A22S Ladies and Gentlemen:

By letter dated December 21, 201 S (i.e., Reference 1), Duke Energy Progress, Inc., submitted a license amendment request (LAR) for the Brunswick Steam Electric Plant (BSEP), Unit Nos. 1 and 2. The proposed am,endment would modify the Technical Specificat.ions (TSs) by relocating specific surveillance freqtiencies to a licensee-controlled program with the implementation of Nuclear Energy Institute (NEI) 04-:10, "Risk-Informed Technical Specification Initiative Sb, Risk-Informed Method for Control of Surveillance Frequencies." Additionally, the change would add a new program, the Surveillance Frequency Control Program, to TS Section S.S, "Programs and Manuals." The changes are consistent with Nuclear Regulatory Commission (NRC) approved Technical Specification Task Force (TSTF) Standard Technical Specifications (STS) Change TSTF-42S, "Relocate Surveillance Frequencies to Licensee Control - RITSTF Initiative Sb,"

Revision 3.

U.S. Nuclear Regulatory Commission Page 2 of 3

. On June 15, 2016, by electronic mail (i.e., Reference 2), the NRG provided a request for additional information (RAI) regarding the LAR. The proposed questions were discussed by telephone with the NRG on June 13, 2016. It was agreed that a response would be provided within 30 days of receipt of the RAI, except for Question 4.c to which a response will be provided within 60 days. Duke Energy's 30-day response was provided on July 13, 2016 (i.e.

Reference 3). The 60-day response is provided in the Enclosure of this letter.

No new regulatory commitments are contained in this letter.

Please refer any questions regarding this submittal to Mr. Lee Grzeck, Manager- Regulatory Affairs, at (910) 457-2487.

I declare, under penalty of perjury, that the foregoing is true and correct. Executed on August 15, 2016.

• William R. Gideon MAT/mat

Enclosure:

1. Response to Request for Additional Information

U.S. Nuclear Regulatory Commission Page 3 of 3 cc (with. Enclosures):

U. S. Nuclear Regulatory Commission, Region II ATTN: Ms. Catherine Haney, Regional Administrator 245 Peachtree Center Ave, NE, Suite 1200 Atlanta, GA 30303-1257 U.S. Nuclear Regulatory Commission ATTN: Mr. Andrew Hon (Mail Stop OWFN 8G9A) (Electronic Copy Only) 11555 Rockville Pike Rockville, MD 20852-2738 U.S. Nuclear Regulatory Commission ATTN: Ms. Michelle P. Catts, NRC Senior Resident Inspector 8470 River Road

. Southport, NC 28461-8869 Chair - North Carolina Utilities Commission (Electronic Copy Only) 4325 Mail Service Center Raleigh, NC 27699-4300 swatson@ncuc.net Mr. W. Lee Cox, Ill, Section Chief (Electronic Copy Only)

Radiation Protection Section North Carolina Department of Health and Human Services 1645 Mail Service Center Raleigh, NC 27699-1645 lee.cox@dhhs.nc.gov

• BSEP 16-0070 Enclosure Page 1 of 2 Response to Request for Additional Information By letter dated December 21, 201S (i.e., Reference 1), Duke Energy Progress, Inc., submitted a license amendment request (LAR) for the Brunswick Steam Electric Plant (BSEP), Unit Nos. 1 and 2. The proposed amendment would modify the Technical Specifications (TSs) by relocating specific surveillance frequencies to a licensee-controlled program with the implementation of Nuclear Energy Institute (NEI) 04-10, "Risk-Informed Technical Specification Initiative Sb, Risk-Informed Method for Control of Surveillance Frequencies." Additionally, the change would add a new program, the Surveillance Frequency Control Program (SFCP), to TS Section S.S, "Programs and Manuals." The changes are consistent with Nuclear Regulatory Commission (NRC) approved Technical Specification Task Force (TSTF) Standard Technical Specifications (STS) Change TSTF-42S, "Relocate Surveillance Frequencies to Licensee Control - RITSTF Initiative Sb," Revision 3.

On June 1S, 2016, by electronic mail (i.e., Reference 2), the NRC provided a request for additional information (RAI) regarding the LAR. The proposed questions were discussed by telephone with the NRC on June 13, 2016. It was agreed that a response would be provided to Question 4.c within 60 days. Duke Energy's 60-day response to the RAI is provided below.

NRC RAI 4.c:

The following RA.ls apply to the internal fire F&Os reported in Table 3 of Enclosure 2 to the LAR:

c. Resolution to F&O 1-36 related to SR QU-B2,- QU-F2, QU-B3, FQ-B 1 and FQ-F1 states that effective truncation values of 1E-09/yr for CDF and 1E-1 O/yr for LERF are used for scenario quantification. It further states that the process for establishing truncation limits does not demonstrate that the overall model results converge and SR QU-B3 is assessed as 'Not Met'. Please provide the results from a sensitivity analysis that expands the truncation levels to those comparable for internal events, typically at least 1E-12 for CDF, as the necessary justification why the chosen truncation levels have no impact on the SFCP.

Response

The requested sensitivity analysis differs from the typical truncation study performed for an Internal Events Probabilistic Risk Assessment (PRA). Unlike the Internal Events PRA where the model would be quantified for Core Damage Frequency (CDF)/Large Early Release Frequency (LERF) at a particular truncation level, the Conditional Core Damage Probability (CCDP)/Conditional Large Early Release Probability (CLERP) for the Fire PRA is separately quantified for each of several thousand individual scenarios at various truncation levels, and the applicable scenario specific event frequency is applied to the cutsets in post-processing to obtain CDF/LERF. To retain the fire risk insights in the cutsets, the model was quantified using the ONEs solution. During qqantification of the Fi,re PRA, successively lowe(Jruncation levels were selected until either CCDP = 1 (i.e., at Which point, there is no reason to~lower 1

truncation) or the practical limitations of the software were reached (i.e., at which point, it is not possible to lower truncation). As a result, the scenario specific combinations of scenario event frequency and chosen truncation level result in a distribution of effective truncation levels. The effective truncation for most scenarios was less than 1E-9/yr for CDF and less than 1E-1 O/yr for LERF.

Because this was at least four orders of magnitude below the total risk, there was reasonable assurance that no significant accident sequence was inadvertently eliminated.

BSEP 16-0070 Enclosure Page 2 of 2 Since fire risk insights are not required for this sensitivity analysis, the Fire PRA was quantified using the TRUEs solution to demonstrate the truncation levels comparable to those used for the Internal Events PRA. For each risk metric, the cutset files from several thousand individual scenarios, each with a scenario specific effective truncation level, were merged to obtain a cutset file having a distribution of effective truncation levels. The effective truncation level for the merged cutset file for each risk metric was progressively raised to generate the following results.

BSEP 1 CDF BSEP 1 LERF BSEP 2 CDF BSEP 2 LERF Effective Truncation

1. cutsets Change #cutsets Change #cutsets Change #cutsets Change 1E-05/yr 0 0 0 0 1E-06/yr 2 1 4 1 1E-07/yr 32 76% 11 70% 40 56% 11 52%

1E-08/yr 345 44% 31 10% 286 31% 40 17%

1E-09/yr 2056 23% 107 4% 1652 16% 142 7%

1E-10/yr 10710 11% 685 4% 9521 8% 831 4%

1E-11/yr 52008 5% 4341 2% 47133 4% 4688 3%

1E-12/yr 235859 2% 24352 1% 212968 2% 25251 1%

The SFCP, therefore, is not affected by the chosen truncation levels because the fire PRA can be quantified at truncation levels where convergence is similar to internal events when the objective is to evaluate the risk impact of changes in surveillance frequency rather than to obtain fire risk insights.