ML11095A073

Request for Additional Information Regarding a Request to Transition to Areva Fuel

ML11095A073
Person / Time
Site:	Browns Ferry
Issue date:	03/28/2011
From:	Gratton C Plant Licensing Branch II
To:	Krich R Tennessee Valley Authority
Gratton C
References
TAC ME3775
Download: ML11095A073 (6)

Text

OffiGial Use Only Proprietary Information J y" UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 March 28, 2011 Mr. R. M. Krich Vice President, Nuclear Licensing Tennessee Valley Authority 3R Lookout Place 1101 Market Street Chattanooga, TN 37402-2801

SUBJECT:

BROWNS FERRY NUCLEAR PLANT, UNIT 1 - REQUEST FOR ADDITIONAL INFORMATION REGARDING A REQUEST TO TRANSITION TO AREVA FUEL (TAC NO. ME3775)

Dear Mr. Krich:

By letter dated April 16, 2010 (Agencywide Documents Access and Management System (ADAMS), Accession No. ML101160153), as supplemented on February 23, 2011 (ADAMS Accession No. ML110590054), Tennessee Valley Authority (the licensee) submitted a request for a Technical Specification change to use AREVA fuel at Browns Ferry Nuclear Plant, Unit 1.

Based on our review of your submittal, the Nuclear Regulatory Commission (NRC) staff finds that a response to the enclosed request for additional information is needed before we can complete the review.

This request was discussed with Mr. T. Mathews of your staff on March 17, 2011, and it was agreed that a response would be provided within 45 days of the issuance of this letter. During the discussion, the licensee stated that the information requested in Question 1 was available in 6 of the April 16, 2010, application. The NRC staff agreed to delete the question, subject to a review of the attachment to ensure the information was available. The attached questions also include other editorial changes to the draft questions discussed during the call.

OffiGial Use Only Proprietary Information Uv

OffiGial Use Only Proprietal)' Information ~

R Krich -2 If you have any questions, please contact me at (301) 415-1055.

Sincerely,

~~

Christopher Gratton, Senior Project Manager Plant Licensing Branch 11-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-259

Enclosure:

Request for Additional Information cc: Distribution via Listserv OffiGial Use Only Proprietary Information f2J,r

OffiGial Use Only Proprietary Information Chr-REQUEST FOR ADDITIONAL INFORMATION REGARDING ANP-2908(P),

"BROWNS FERRY UNITS 1, 2, AND 3 105% OLTP LOCA BREAK SPECTRUM ANALYSIS" REQUEST TO TRANSITION TO AREVA FUEL AND SAFETY ANALYSIS METHODS TENNESSEE VALLEY AUTHORITY BROWNS FERRY NUCLEAR PLANT, UNIT 1 DOCKET NO. 50-259 By letter dated April 16, 2010, Tennessee Valley Authority, the licensee for Browns Ferry Nuclear Plant (BFN), Unit 1, requested approval of a license amendment supporting the use of AREVA fuel at BFN Unit 1. The Nuclear Regulatory Commission (NRC) staff requires the following additional information regarding ANP-2908(P), "Browns Ferry Units 1, 2 and 3 105% OLTP

[Original Licensed Thermal Power] LOCA [Ioss-of-coolant accident] Break Spectrum Analysis," to complete its review.

I. [Deleted]

II. Results - 0.25 If SF-BATTIBB Top-Peaked Axial

1) Explain what is causing (( )) immediately following the opening of the break.

2) Identify the reactor scram signal.

3) Explain whether main steam line isolation is modeled, the source of the isolation signal, the time of isolation, and the effect that steamline isolation has on the accident sequence.

4) The NRC staffs own analyses, as well as additional data gathered by the staff during the BFN power uprate reviews, have indicated that steady-state bundle exit void fractions are quite high. For core conditions matching the small break LOCA initial conditions, provide steady-state void fraction as a function of assembly elevation for a hot channel from XCORBA and indicate the limiting plane analyzed in HUXY. Justify any significant discrepancies between XCORBA and the RELAXlHUXY model.

5) Provide a plot of upper plenum liquid mass with higher resolution from 0-10000 Ib from the period between 300 seconds and the end of the transient. Provide similar plots (Le.,

increased resolution at the region of interest) of liquid mass for the core average, bypass, and hot channel regions and the lower plenum.

Enclosure Offisial Use Only Proprietary Information Cn..r

OffiGial Use Only Proprietary Information Qb

- 2

6) Identify the primary sources of increased lower plenum liquid mass from 350-450 seconds.

7) Provide a higher resolution plot of hot channel inlet flow rate from 350-500 seconds. Trace the zero line through the plot.

8) Explain the phenomena causing the ((

)) drop in temperature of the hot channel coolant. What are the sources and directions of liquid flow in this time period?

9) Explain what causes (( )) in the 50-75 second time frame.

10) Justify the selection of fuel channel nodalization.

11) Provide information concerning the thermal hydraulic characteristics of the bypass region (mixture level, liquid mass, quality).

III. Results - Break Spectrum, SF-BATTIBA, Pump Discharge

1) Explain why the predicted peak central temperature (PCT) ((

)) interval for the mid-peaked spectrum.

2) Explain similar trends on the top-peaked spectrum on the (( )) interval, and on the (( )) intervals.

3) Provide plots analogous to Figures 6.1 - 6.19 for each of the break sizes identified in 1 and 2 above to reinforce the discussion. Also provide tabulated sequences of events.

IV. Results - Break Spectrum, SF-BATTIBB Explain why the mid- and top-peaked power shape PCTs are inverted for the 0.45 ff break.

Provide plots for the (( )) breaks and justify the coarseness of the break spectrum. Also provide tabulated sequences of events.

V. Initial Conditions and Input Parameters

1) The emergency core cooling system fluid temperature has been reduced from 125 OF in previous analyses to 120 of. Explain and provide a justification for this change.

2) Provide a copy of ANP-2912(P) Revision 0, "Browns Ferry Units 1, 2 and 3 105 percent OLTP LOCA Parameters Document."

OffiGial Use Only Proprietary Information ~

OffiGial Use Only Proprietary InformationCh'

-3 VI. Fuel Thermal Conductivity Degradation Explain whether and how the RODEX2 fuel centerline temperature inputs to the RELAXlHUXY analyses are corrected for issues identified in NRC Information Notice 2009-23, "Nuclear Fuel Thermal Conductivity Degradation." If they are not corrected, explain why not.

OffiGial Use Only Proprietary InformationaL

Omsial Use Only ProprietaF}f Information CY R. Krich - 2 If you have any questions, please contact me at (301) 415-1055.

Sincerely, IRA!

Christopher Gratton, Senior Project Manager Plant Licensing Branch 11-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-259

Enclosure:

Request for Additional Information cc: Distribution via Listserv Distribution:

PUBLIC RidsNrrDorlLpl2-2 Resource RidsNrrDssSrxb Resource LPU2-2 R/F RidsNrrPMBrownsFerry Resource RidsNrrDoriDpr Resource RidsNrrlABClayton Resource RidsOgcRp Resource RidsRgn2MailCenter Resource RidsNrrAcrsAcnw_MailCTR Resource ADAMS Accession No'.. ML11095A073 *via email OFFICE NRRlLPL2-2/PM NRRlLPL2-2/lA NRRISRXBI8C NRR/LPL2-2/BC I NRRlLPL2-2/PM NAME CGratton BClayton TUlses* DBroaddus I CGratton DATE 03/23/11 03/23/11 03/11/11 03/28/11 03/28/11 OFFICIAL RECORD COpy Omsial Use Only Proprietary Informatio~