CNL-14-090, Response to NRC Request for Additional Information on the Proposed License Amendment for Browns Ferry Nuclear Plant, Unit 1

Response to NRC Request for Additional Information on the Proposed License Amendment for Browns Ferry Nuclear Plant, Unit 1

ML14167A407
Person / Time
Site:	Browns Ferry
Issue date:	06/13/2014
From:	James Shea Tennessee Valley Authority
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
CNL-14-090, L44 140613 005
Download: ML14167A407 (5)

Text

L44 140613 005 Tennessee Valley Authority, 1101 Market Street, Chattanooga, Tennessee 37402 CNL-14-090 June 13, 2014 10 CFR 50.4 ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, D.C. 20555-0001 Browns Ferry Nuclear Plant, Unit 1 Renewed Facility Operating License No. DPR-33 NRC Docket No. 50-259

Subject:

Response to NRC Request for Additional Information on the Proposed License Amendment for Browns Ferry Nuclear Plant, Unit 1 (TAC No. MF3260)

References:

1. Letter from TVA to NRC, Browns Ferry Nuclear Plant (BFN), Unit 1 -

Application to Modify Technical Specification 3.4.9, RCS Pressure and Temperature (P/T) Limits (BFN TS-484), dated December 18, 2013 (ADAMS Accession No. ML13358A067)

2. Electronic Mail from NRC to TVA, Request for Additional Information on the Proposed License Amendment for Browns Ferry Nuclear Plant, Unit 1, (TAC No. MF3260), dated April 23, 2014 By letter dated December 18, 2013 (Reference 1), the Tennessee Valley Authority (TVA) submitted a license amendment request (LAR) to revise the Browns Ferry Nuclear Plant, Unit 1, Technical Specifications (TS) for Limiting Condition for Operation (LCO) 3.4.9, RCS Pressure and Temperature (P/T) Limits.

By electronic mail dated April 23, 2014 (Reference 2), the Nuclear Regulatory Commission (NRC) transmitted a request for additional information (RAI) to support the review of the LAR.

The original due date for the response of May 30, 2014 was extended to June 13, 2014 by a teleconference with Andy Hon (NRC) on May 28, 2014. The Enclosure to this letter provides TVAs response to the NRC RAI.

Consistent with the standards set forth in Title 10 of the Code of Federal Regulations (10 CFR), Part 50.92(c), TVA has determined that the additional information, as provided in this letter, does not affect the no significant hazards consideration associated with the proposed application previously provided in Reference 1.

There are no new regulatory commitments contained in this submittal. Please address any questions regarding this submittal to Mr. Edward D. Schrull at (423) 751-3850.

U.S. Nuclear Regulatory Commission Page 2 June 13, 2014 I declare under penalty of perjury that the foregoing is true and correct. Executed on this 13th day of June 2014.

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Enclosure:

Response to NRC Request for Additional Information on the Proposed License Amendment for Browns Ferry Nuclear Plant, Unit 1 Docket No. 50-259 (TAC No. MF3260) cc (Enclosure):

NRC Regional Administrator- Region II NRC Senior Resident Inspector - Browns Ferry Nuclear Plant State Health Officer, Alabama State Department of Health

ENCLOSURE Response to NRC Request for Additional Information on the Proposed License Amendment for Browns Ferry Nuclear Plant, Unit 1 Docket No. 50-259 (TAC No. MF3260)

The Nuclear Regulatory Commission (NRC) staff has reviewed the proposed license amendment to modify Technical Specification 3.4.9 "Pressure and Temperature (PIT) Limits" submitted by Tennessee Valley Authority (the licensee, TVA) for Browns Ferry Nuclear Plant, Unit 1 (BFN-1 ), dated December 18, 2013 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML13358A067). The NRC staff has determined that additional information is needed to complete the evaluation pertaining to the request, as detailed below.

NRC RAI No.1 NEDC-33445P (Reference 1), Enclosure 2 to the proposed license amendment, lists the axial electroslag weld (ESW) as the limiting material for the development of the new PIT limit curves for BFN-1. Measured heat-specific Charpy and drop weight toughness data are not available. The initial RT NOT value in Tables B-2, B-4, and B-5 for the ESW is listed as 23.1 OF; Tables B-4 and B-5 use a value of 13°F for the standard deviation of the initial value to calculate the margin term based on Regulatory Guide 1.99, Revision 2. These values are based on previously approved submittals (Reference 2), which were initially presented in BAW-2258 for Dresden, Units 2 and 3 (Reference 3) and BAW-2259 for Quad Cities, Units 1 and 2 (Reference 4) from January 1996. The values came from the nil-ductility-temperature (T NoT) data contained in the weld procedure qualification records (PQRs) that were performed in the general time frame when the Quad Cities and Dresden reactor vessels were fabricated. This represented the best data available to characterize the unirradiated RT NOT for any ESW in the fleet at the time.

The submittal does not establish how the previously approved values of initial RT NOT (23.1 OF) and standard deviation (13°F) from PQRs for the ESWs at Dresden, Units 2 and 3 and Quad Cities, Units 1 and 2 is applicable to BFN-1.

Discuss the limited PQR database in BAW-2258 and BAW-2259 and explain how that database is relevant to the axial vessel welds at BFN-1. Include a summary of the plant fabrication records for the axial welds and any other newer test results that could be used to supplement the limited PQR database. Justify why the previously approved values can be used at BFN-1.

REFERENCES:

1. NEDC-33445P - Pressure and Temperature Limits Report Up to 25 and 38 Effective Full- Power Years, December, 2013.

2. U.S. Nuclear Regulatory Commission (NRC) staff's safety evaluation, dated February 28, 1997, to Dresden and Quad Cities concerning a revision of their Pressure-Temperature Limits, ADAMS No. ML021150615.

3. Evaluation of RT NoT, USE, and Chemical Composition of Core Region Electroslag Welds for Dresden Units 2 and 3, BAW-2258, January 1996, ML14091A387.

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4. Evaluation of RT NoT, USE, and Chemical Composition of Core Region Electroslag Welds for Quad Cities Units 1 and 2, BAW-2259, January 1996, ML14091A388.

TVA Response The materials and fabrication information for the Browns Ferry Nuclear Plant (BFN) Units 1, 2, and 3 reactor vessel core region components is summarized in BAW-1845 "Browns Ferry Core Region Materials Information (Units 1, 2, and 3)," dated August 1984 (Reference 1). BAW-1845 (full report) was previously submitted as an attachment in TVA to NRC letter, "TVA BFNP TS 191 Supplement 1," dated March 20, 1985. The report provides a beginning of life RT NOT for each of the seven welds and six plates that constitute the core region portion of the reactor vessels. The information provided is based on a review of quality assurance (QA) manufacturing records supplemented by information not available in the QA files.

No drop weight specimens were tested for the electroslag weld (ESW) metal. Three sets of Charpy impact toughness data exists for the surveillance welds, with 50 ft-lb temperatures of

+33aF, +1 oaF, and -21aF. With no other information available, a value of RT NOT= +OaF was estimated for the ESW metal for BFN Units 1, 2, and 3.

In TVA to NRC letter, "Browns Ferry Nuclear Plant (BFN), Sequoyah Nuclear Plant (SQN),

and Watts Bar Nuclear Plant (WBN) - Response to Generic Letter 92-01 (Reactor Vessel Structural Integrity)," dated July 7, 1992 (Reference 2) , TVA provided the requested chemistry and initial RT NOT information for the three BFN units. The ESW data was identical for the three units with a conservative initial RT NOT value of 1oaF. BFN Unit 1 received NRC approval in the Amendment No. 121 Safety Evaluation (SE), dated September 16, 1985 (Reference 3).

In NRC to TVA letter, "Request for Additional Information Regarding Reactor Pressure Vessel Integrity at Browns Ferry Nuclear Plant, Units 1, 2, and 3 (TAC Nos. MA 1179, MA1180, and MA1181)," dated June 10, 1998 (Reference 4), NRC staff requested a re-evaluation of the RPV weld chemistry values that had been previously submitted in light of bounding data included in BWRVIP-46 that included the recommendation to consider the Framatome Technology analysis of ESWs referenced in the Dresden and Quad Cities SE dated September 20, 1996 (Reference 5). TVA responded by letter dated September 8, 1998 (Reference 6) by addressing the limiting materials. The "best estimate" chemistry values approved in the Quad Cities and Dresden analysis were adopted for BFN Units 2 and

3. Because BFN Unit 1's ESW was not a limiting material, the "best estimate" chemistry values were not adopted. The response did not address the initial RT NOT values.

Consequently, the ESW RT NoT values for all three BFN units remained at 10°F.

In TVA to NRC letter, "Browns Ferry Nuclear Plant (BFN)- Units 2 and 3- Technical Specification (TS) Change No. 393, Supplement 1 -Pressure-Temperature (P-T) Curve Update," dated December 15, 1998 (Reference 7) , TVA addressed two issues raised by NRC staff. The issue relevant to this response was the applicability of additional generic initial RT NOT data reported by Framatome Technologies Inc. to the BFN Units 2 and 3 reactor pressure vessels. In light of the NRC SE for the Dresden and Quad Cities ESWs (Reference 5), NRC staff requested that TVA "...explain why it is appropriate for TVA to use a value of 10 *F for the BFN electroslag welds. This issue must be resolved in order to complete the review of the Browns Ferry P- T limits and the licensee 's response to Generic Letter 92-01, Supplement 1. " In response, the best estimate initial RT NoT value (23.1 oF) and E-2

associated standard deviation (13.0°F) reported by Framatome Technologies, Inc. (FTI) in the Quad Cities and Dresden reports were incorporated in the re-evaluation of the BFN Units 2 and 3 reactor pressure vessel ESWs.

In NRC to TVA letter, "Amendment Nos. 257 and 217 to Facility Operating Licenses Nos.

DPR-52, and DPR-68: Pressure and Temperature Limits- Technical Specification Change TS-393 (TAC Nos. MA1304 and MA1305)," dated January 15, 1999 (Reference 8), " ... the NRC staff verified that the licensee used the recommended initial RT NoT and sigma initial values of 23.1 oF and 13°F, respectively, for electroslag welds, as previously found acceptable ... "

The previously approved RT NOT and sigma initial values of 23.1 oF and 13°F are applicable to BFN Unit 1 based on the initial RT NoT estimation and generic chemistry information for BFN Units 1, 2, and 3 provided in BAW-1845 (Reference 1) and NRC's approval of the values for BFN Units 2 and 3 (Reference 7) based on the NRC SE (Reference 5) for the Dresden and Quad Cities ESWs.

References:

1. Babcock & Wilcox Report, BAW-1845 "Browns Ferry Core Region Materials Information (Units 1, 2, and 3)," dated August 1984.

2. TVA to NRC letter, "Browns Ferry Nuclear Plant (BFN), Sequoyah Nuclear Plant (SQN), and Watts Bar Nuclear Plant (WBN) - Response to Generic Letter 92-01 (Reactor Vessel Structural Integrity)," dated July 7, 1992.

3. Safety Evaluation for Amendment Nos. 121, 116 and 92 to License Nos. DPR-33, DPR-52 and DPR-68, dated September 16, 1985.

4. NRC to TVA letter, "Request for Additional Information Regarding Reactor Pressure Vessel Integrity at Browns Ferry Nuclear Plant, Units 1, 2, and 3 (TAC Nos. MA 1179, MA1180, and MA1181)," dated June 10, 1998.

5. NRC to Commonwealth Edison letter, "Issuance of Amendments (TAC Nos. M96898, M96899, M96900 and M96901)," dated February 28, 1997.

6. TVA to NRC letter, "Browns Ferry Nuclear Plant (BFN)- Units 1, 2, and 3- Generic Letter (GL) 92-01, Revision 1, Supplement 1, Reactor Vessel Structural Integrity-Response to Request for Additional Information (TAC Nos. MA1179, MA1180, and MA 1181 ),"dated September 8, 1998.

7. TVA to NRC letter, "Browns Ferry Nuclear Plant (BFN)- Units 2 and 3- Technical Specification (TS) Change No. 393, Supplement 1 -Pressure-Temperature (P-T)

Curve Update," dated December 15, 1998.

8. NRC to TVA letter, "Amendment Nos. 257 and 217 to Facility Operating Licenses Nos.

DPR-52, and DPR-68: Pressure and Temperature Limits- Technical Specification Change TS-393 (TAC Nos. MA1304 and MA1305)," dated January 15, 1999.

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