ML18039A658

Forwards Supplements Info to Support NRC Review of Proposed TS Change TS-393,revising pressure-temp Curves to Extend Validity of Curves to 32 EFPY

ML18039A658
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Site:	Browns Ferry
Issue date:	12/15/1998
From:	Abney T TENNESSEE VALLEY AUTHORITY
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
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NUDOCS 9812240163
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ACCESSION NBR: 9812240163 DOC.DATE: 98/12/15 NOTARIZED: YES DOCKET Browns Ferry Nuclear Power Station, Unit 2, Tennessee 05000260 ¹'ACIL:59'-260 50-296 browns Ferry Nuclear Power Station, Unit 3, Tennessee 05000296 AUTH. NAME AUTHOR AFFILIATION ABNEY,TLE. Tennessee Valley Authority RECIP.NAME RECIPIENT AFFILIATION Records Management Branch (Document Control Desk)

SUBJECT:

Forwards supplements info to support NRC review of proposed TS change TS-393,revising pressure-temp curves to extend validity of curves to 32 EFPY.

DISTRIBUTION CODE: D030D COPIES RECEIVED:LTR TXTLE: TVA Facilities - Routine Correspondence j ENCL I SIZE: 9 4~

NOTES.:

RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL PD2-3 1 1 PD2-3-PD 1 1 DEAGAZIO,A 1 1 INTERNAL: ACRS 1 1 IL CENTER 01 1 1 OGC/HDS3 1 0 RES DE SSEB SES 1 1 EXTERNAL: NOAC 1 1 NRC PDR 1 1, NOTE TO ALL "RIDS" RECIPIENTS:

PLEASE HELP US TO REDUCE WASTE. TO HAVE YOUR NAME OR ORGANIZATION REMOVED FROM DISTRIBUTION LISTS OR REDUCE THE NUMBER OF COPIES RECEIVED BY YOU OR YOUR ORGANIZATION, CONTACT THE DOCUMENT CONTROL DESK (DCD) ON EXTENSION 415-2083 TOTAL NUMBER OF COPIES REQUIRED: LTTR 9 ENCL 8

E Tennessee Va! ley Authority, Post Office Box 2000, Decatur, Alabama 35609-2000 December 15, 1998 TVA-BFN-TS-393, Supplement 1 10 CFR 50.90 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D.C. 20555 Gentlemen; In the Matter of ) Docket Nos. 50-260 Tennessee Valley Authority ) 50-296 BROWNS FERRY NUCLEAR PLANT (BFN) UNITS 2 AND 3 TECHNICAL SPECIFICATION (TS) CHANGE NO. 393, SUPPLEMENT 1 PRESSURE-TEMPERATURE (P- T) CURVE UPDATE The enclosures provide supplemental information to support the NRC si aff's review of proposed technical specification change TS-393. TVA submitted TS-393 to NRC by letter on March 3, 1998 to revise the BFN Units 2 and 3 P-T curves to extend the validity of the curves to 32 effective full power years (EFPY). The enclosed information addresses two issues raised by the staff: 1) The acceptability of the fluence used by TVA which was partially based upon flux wire data, and 2) the applicability of additional generic initial RTNpT data reported by Framatome Technologies Inc. to the BFN Units 2 and 3 reactor pressure vessels.

To resolve these issues TVA has re-evaluated the proposed P-T curves utilizing a conservative analytical fluence and has incorporated the generic Framatome initial RTNDT data. The re-evaluated Units 2 and 3 P-T curves are identical tc the curves "e8i2240163 921215 PDR ADOCK 05000260, P PDR,'~

v t )I UiS. Nuclear Regulatory Commission Page 2 December 15, 1998 submitted by the March 3, 1998, letter with the exception that the proposed P-T curves are valid to 16 EFPY and 20 EFPY respectively. TVA has adopted the Framatome data and methodology in order to facilitate NRC review, since the Framatome data and methodology have previously received NRC approval for Commonwealth Edison P-T curve updates. Use of the Framatome methodology for this licensing action does not preclude future re-assessments of the BFN initial RTNpT data using other NRC-approved methodology. It is TVA's expectation that this supplemental information will enable the staff to complete its reviews. The Unit 2 curve is projected to expire on February 5, 1999, therefore, expedited NRC review is requested.

The information contained in the Enclosures reflects clarifications of the issues as discussed with the NRC staff during telephone calls on November 24, 1998 and December 8, 1998.

There are no new commitments contained in this letter. If you have any questions about this change, please telephone me at (256) 729-2636.

S'ncere T. E. Abney Manager o icens ng and Ind stry Affa'rs Enclosures cc: See page 3 Subscribed and sworn to before me on is 15th day of December 1998.

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U.S. Nuclear Regulatory Commission Page 3 December 15, 1998 Enclosures cc (Enclosures):

Chairman Limestone County Commission 310 West Washington Street Athens, Alabama 35611 Mr. Harold O. Christensen, Branch Chief U.S. Nuclear Regulatory Commission Region II 61 Forsyth Street, S. W.

Suite 23T85 Atlanta, Georgia 30303 NRC Resident Inspector Browns Ferry Nuclear Plant 10833 Shaw Road Athens, Alabama 35611 L. Raghavan, Project Manager U.S. Nuclear Regulatory Commission One White Flint, North 11555 Rockville Pike Rockville, Maryland 20852 State Health Officer Alabama Department of Public Health 434 Monroe Street Montgomery, Alabama 36130-1701

ENCLOSURE 1 TENNESSEE VALLEY AUTHORITY BROWNS FERRY NUCLEAR PLANT (BFN)

UNITS 2 AND 3 PROPOSED TECHNICAL SPECI FICATION (TS) CHANGE TS 393 ~ SUPPLEMENT 1 RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION ln TVA's submittal of March 3, l998, TVA indicated that the ini tial RTjqpp value for the Browns Ferr'y Units 2 and 3 electroslag welds is 20'. By NRC Safety Evaluation dated February 5, 1997, the staff generically addressed the IRTNpg value for the Dresden and Quad Cities electroslag welds (also addressed in BAN-2258 and 2259). CONED determined the mean value of the ini tial RTNp> to be 23.2'. with a standard deviation of 23 F. for the Dresden and Quad Cities electroslag welds. The staff found these values to be acceptable. In light of this review, explain why of'0'. it is appropriate for TVA to use a value for the Browns Ferry Units 2 and 3 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 92-02, Supplement 2.

How would TVA propose to resolve this issue?

TVA has re-evaluated the proposed Unit 2 and 3 pressure-temperature (P-T) limits submitted by Reference 1 utilizing updated best-estimate chemistry, best-estimate initial RTN>>

values, and a conservative end-of-life reactor pressure vessel (RPV) peak surface fluence. The results of this re-evaluation are reflected on the revised ART tables contained in Enclosure 2 and revised TS P-T limits for Units 2 and 3 contained in . Enclosure 3 contains marked pages describing the proposed changes in relation to the current Units 2 and 3 Improved Technical Specifications.

The best estimate initial RTN>> value (23.1'.) and associated standard deviation (13.0'.) reported by Framatome Technologies, Inc. (FTI) in the Reference 2 and 3 reports were incorporated in the re-evaluation of the BFN Unit:s 2 and 3 RPV longitudinal electroslag welds (ESW). The longitudinal ESWs are t: he limiting material for the Units 2 and 3 P-T curves. TVA has previously adopted the best-estimate chemistry documented in the Framatome reports by Reference 5. Accordingly the corresponding chemistry

ENCLOSURE 1 factors presented on the revised ART tables in Enclosure 2 reflect the Framatome data. Previous NRC review and acceptance of the Framatome best-estimate chemistry and best-estimate initial RT>>T values are documented in Reference 4:

In addition, the re-evaluation of Units 2 and 3 P-T limits utilized a conservative, calculated 32 EFPY RPV peak surface fluence of 1.07E18 n/cm'ultiplied conservatively by 1.05 factor to account for the effects of a 5 percent power level uprat:e.

This fluence value was previously submitted to NRC by Reference 6 for inclusion in the Reactor Vessel Integrity Database. Imposing an increase in fluence to the proposed P-T curves decreased the period to which the curves are valid. Fluence values (interpolated from the 32 EFPY peak RPV fluence) at various periods were used to recalculate the ART for the beltline plate and weld materials. The objective of the re-evaluation was t:o determine the EFPY in which the ART values were equal to or less than the ART values associated with the P-T curves originally submitt:ed in Reference 1. As a result, new EFPY have been applied to the Reference 1 curves. This analysis supports a P-T curve validity of 16 EFPY for Unit 2 and 20 EFPY for Unit 3.

TVA has reviewed the Reference 1 submittal'nd has determined that the conclusions of the previously submitted safety analysis, proposed finding of no significant hazards considerations and environmental impact consideration remain valid.

E1-2

ENCLOSURE 1 REFERENCES

1. Letter from TVA to NRC dated March 3, 1998, Units 2 and 3 Technical Specification (TS) Change No. 393 Pressure-Temperature Limits.

2. "Evaluation of RT~DT, USE, and Chemical Composition of Core Region Electroslag Welds for Dresden Units 1 and 2," Framatome Technologies, BAW-2258, January 1996.

3. "Evaluation of RT>DT, USE, and Chemical Composition of Core Region Electroslag Welds for Quad Cities Units 1 and 2,"

Framatome Technologies, BAW-2258, January 1996.

4. NRC letter to Commonwealth Edison dated February 28, 1998, Issuance of Amendments.

5. TVA letter to NRC dated September 8, 1998, Generic Letter 92-Ol, Supplement 1, Reactor Vessel Structural Integrity to NRC Request for Additional Information. 'esponse

6. TVA letter to NRC dated March 27, 1995, Units 1, 2, and 3 Generic Letter 92-01, Reactor Vessel Structural Integrity Update To The Initial Reference Nil-Ductility Temperature (RT~DT), Chemical Composition and Fluence Values.

E1-3

ENCLOSURE 2 TENNESSEE VALLEY AUTHORITY BROWNS FERRY NUCLEAR PLANT (BFN)

UNITS 2 AND 3 PROPOSED TECHNICAL SPECIFICATION (TS) CHANGE TS-393, SUPPLEMENT 1 RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION REVISED ART TABLES See attached.

BELTLINE ART VALUES FOR BROWNS FERRY UNIT 2 AT 16 EFPY CONSIDERING POWER UPRATE Low-Int Shell Low-Int Shell:

Thickness = 6.13 inches 32 EFPY Peak I.D. fluence = 1.1E+18 n/cm 32 EFPY Peak 1/4 T fluence = 7.8E+17 n/cm Lower Shell Lower Shell:

Thickness = 6.13 inches 32 EFPY Peak I.D. fluence = 1.1E+18 n/cm 32 EFPY Peak 1/4 T fluence = 7.8E+17 n/cm INITIAL 16 EFPY SIGMA 16 EFPY 16 EFPY COMPONENT I.D. HEAT %Cu %Ni CF RTndt Del ta RTndt'IGMA I Delta MARGIN SHIFT ART PLATES:

Lower Shell 6-127-14 . C2467-2 0.16 0.52 112 -20 28.5 14.3 28.5 57.1 37.1 Lower Shell 6-127-1 5 C2463-1 0.17 0.48 117 -20 29.8 14.9 29.8 59.6 39.6 Lower Shell 6-127-17 C2460-2 0.13 0.51 88 0 22.4 11.2 22.4 44.9 44.9 Low-Int Shell 6-127% A0981-1 0.14 0.55 98 -10 ~ 25.0 12.5 25.0 50.0 40.0 Low-Int Shell 6-127-16 C2467-1 0.16 0.52 112 -10 28.5 14.3 28.5 57.1 47.1 Low-Int Shell 6-127-20 C2849-1 0.11 0.50 73 -10 18.6 9.3 18.6 37.2 27.2 WELDS:

Longitudinal 0.24 0.37 141 23.1 35.8 13.0 17.9 44.3 80.1 103.2 D55733 ESW'ircumference 0.09 0.65 117 -40 29.8 0 14.9 29.8 59.6 19.6 ESW chemistry based on BAW-2258/2259.

Specific weld heat chemistries are not available.

'ased on fluence interpolations from 32 EFPY.

BELTLINE ART VALUES FOR BROWNS FERRY UNIT 3 AT 20 EFPY CONSIDERING POWER UPRATE Low-Int Shell Low-Int Shell:

Thickness = 6.13 inches 32 EFPY Peak I.D. fluence = 1.1E+18 n/cm 32 EFPY Peak 1/4 T fluence = 7.8E+17 n/cm Lower Shell Lower Shell:

Thickness = 6.13 inches 32 EFPY Peak I.D. fluence = 1.1E+18 n/cm 32 EFPY Peak 1/4 T fluence = 7.8E+17 n/cm INITIAL 20 EFPY SIGMA 20 EFPY 20 EFPY COMPONENT I.D. HEAT %Cu %Ni CF RTndt Del ta RTndt'IGMA I Delta MARGIN SHIFT ART PLATES:

Lower Shell 6-145M C3222-2 0.15 0.52 106 10 30.6 15.3 30.6 61.1 71.1 Lower Shell 6-145-7 C3213-1 0.13 0.58 90 -20 25.9 13.0 25.9 51.9 31.9 Lower Shell 6-145-12 C3217-2 0.14 0.66 101.5 -4 29.3 14.6 29.3 58.5 54.5 Low-Int Shell 6-145-1 C3201-2 0.13 0.60 91 -20 26.2 13.1 26.2 52.5 32.5 Low-Int Shell 6-145-2 C3188-2 0.10 0.48 65 -20 18.7 9.4 18.7 37.5 17.5 Low-Int Shell 6-145-6 B7267-1 0.13 0.51 88 -20 25.4 12.7 25.4 50.7 30.7 WELDS:

Longitudinal ESW* 0.24 0.37 141 23.1 40.5 13 20.3 48.2 88.7 111.8-Circumference D55733 0.09 0.66 117 40 33.7 0 16.9 33.7 67.5 27.5

• ESW chemistry based on BAW-2258/2259.

• Specific weld heat chemistries are not available.

'ased on fluence interpolations from 32 EFPY.