ML032450157

Technical Specification (TS) Change No. TS-02-13 - Robust Fuel Assembly (RFA)-2 Upgrade - Revised Page

ML032450157
Person / Time
Site:	Watts Bar
Issue date:	08/21/2003
From:	Pace P Tennessee Valley Authority
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
TAC MB7746, TS-02-13, TVA-WBN-TS-02-13
Download: ML032450157 (5)

Text

Tennessee Valley Authority, Post Office Box 2000, Spring City, Tennessee 37381-2000

'AUG 21 2003 TVA-WBN-TS-02-13 U.S. Nuclear Regulatory Commission 10 CFR 50.90 ATTN: Document Control Desk Washington, D. C. 20555 Gentlemen:

In the Matter of ) Docket No. 50-390 Tennessee Valley Authority )

WATTS BAR NUCLEAR PLANT (WBN) - UNIT 1 - TECHNICAL SPECIFICATION (TS) CHANGE NO. TS-02 ROBUST FUEL ASSEMBLY (RFA)-2 UPGRADE - REVISED PAGE (TAC-MB7746)

Reference:

TVA Letter to NRC, 'WBN - UNIT 1 - Technical Specification (TS) Change No.

TS-02 Revise Section 5.9.5 to Incorporate Analytical Methods for Robust Fuel Assembly (RFA)-2 Upgrade," February 14, 2003.

The purpose of this letter is to provide a revised replacement page for the referenced TS amendment request, as recently discussed with NRC Staff. The revised page is provided in the Enclosure and replaces Page 7-6 in the Attachment (Safety Evaluation) of the referenced letter. This revision removes the description of TPBAR impact on post-LOCA subcriticality (last paragraph of Section 7.5.2.3), since the RFA-2 with 1FM fuel product is independent of this analysis. This change does not impact the "No Significant Hazards Criteria Evaluation" provided in the referenced amendment request.

There are no regulatory commitments associated with this submittal. If you have any questions about this proposed change, please contact me at (423) 365-1824.

Pnnled wecn d pap

U.S. Nuclear Regulatory Commission Page 2

'AUG 2 1 2003 I declare under penalty of perjury that the foregoing is true and correct. Executed on this 21st day of August. 2003.

Sincerely, P. .e Manager, Site Licensing and Industry Affairs Enclosure Robust Fuel Assembly (RFA)-2 Fuel Upgrade - TS-02-13 (TAC-MB7746) - Replacement Page cc: Seepage 3

U.S. Nuclear Regulatory Commission Page 3

'AUG 21 2003 cc (Enclosure):

NRC Resident Inspector Watts Bar Nuclear Plant 1260 Nuclear Plant Road Spring City, Tennessee 37381 Ms. Margaret H. Chernoff, Project Manager U.S. Nuclear Regulatory Commission MS 08G9 One White Flint North 11555 Rockville Pike Rockville, Maryland 20852-2738 U.S. Nuclear Regulatory Commission Region II Sam Nunn Atlanta Federal Center 61 Forsyth St., SW, Suite 23T85 Atlanta, Georgia 30303

ENCLOSURE TENNESSEE VALLEY AUTHORITY WVATTS BAR NUCLEAR PLANT (WBN)

UNIT 1 DOCKET NO. 390 ROBUST FUEL ASSEMBLY (RFA)-2 FUEL UPGRADE - TS-02-13 (TAC-MB7746)

REPLACEMENT PAGE Remove Page 7-6, Revision 1, in the Attachment to TVA's February 14, 2003, Letter to NRC, and replace with the attached Page 7-6, Revision 2.

concentration was increased from 2400 ppm to 3500,ppm..--With the increases in minimum boron concentration in the RWST and accumulators, a new post-LOCA sump boron curve was calculated. This new curve will serve as the reload limit for future Watts Bar core designs.

The introduction of RFA-2 fuel has a negligible impact on the core reactivity and, therefore, has no effect on the post-LOCA subcriticality evaluation.

7.5.2A Hot Leg Switchover to Prevent Potential Boron Precipitation The hot leg switchover (HISO) procedure is initiated to preclude the possibility of boron precipitation in the reactor vessel core region following a LOCA. The key inputs to this calculation include:

• the maximum volumes and boron concentrations of the various sources of borated water which could arrive in the sump post-LOCA,

• the minimum volumes of various dilution sources which could arrive in the sump post-LOCA,

• the mixing volume of the core region in the vessel, and,

• the maximum core power level (prior to the LOCA).

For the implementation of TPBARs, the maximum RWST and accumulator boron concentrations were increased from 2700 ppm to 3800 ppm. With the increases in maximum boron concentration in the RWST and accumulators, a new HLSO time was calculated. The evaluation, which used the new RWST and accumulator boron concentrations and the Appendix K decay heat assumption, resulted in a HLSO time of 4.16 hours1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br />, which was reduced to 3.0 hours0 days <br />0 hours <br />0 weeks <br />0 months <br /> for further margin to the boron precipitation limit. The minimum flow requirements were evaluated at the new hot leg switchover time. It was determined that the minimum flow requirements were satisfied for a HLSO time of 3.0 hours0 days <br />0 hours <br />0 weeks <br />0 months <br />. This calculation is applicable to both V5H and RFA-2 fuel types.

7-6 Rev. 21