ML17310A848

Forwards Rept Re Transfer of High Burnup Fuel Rods,As Part of Fuel Performance program.Site-specific Data Will Ultimately Be Used to Support Efforts to Achieve Economic Benefits of Higher Burnup Fuel Cycles Consistent W/Approval

ML17310A848
Person / Time
Site:	Palo Verde
Issue date:	11/19/1993
From:	Conway W ARIZONA PUBLIC SERVICE CO. (FORMERLY ARIZONA NUCLEAR
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
102-02736-WFC-R, 102-2736-WFC-R, NUDOCS 9312100052
Download: ML17310A848 (10)

Text

ACCELERATED DI ~BUTION DEMONS TION SYSTEM REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)

ACCESSION NBR:9312100052 DOC.DATE: 93/11/19 NOTARIZED:

NO DOCKET FACIL:STN-50-528 Palo Verde Nuclear Station, Unit 1, Arizona Publi 05000528 AUTH.NAME AUTHOR AFFILIATION CONWAY,W.F.

Arizona Public Service Co.

(formerly Arizona Nuclear Power RECIP.NAME RECIPIENT AFFILIATION Document Control Branch (Document Control Desk)

SUBJECT:

Forwards rept re transfer of high burnup fuel rods, as part of fuel performance program. Site-specific data will ultimately be used to support efforts to achieve economic benefits of higher burnup fuel cycles consistent w/approval.

DISTRIBUTION CODE:

AOOID COPIES RECEIVED:LTR

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ENCL

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SIZE:

TITLE: OR Submittal:

General Distribution R

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NOTES:STANDARDIZED PLANT 05000528 RECIPIENT ID CODE/NAME PDV LA HOLIAN,B INTERNAL: ACRS NRR/DORS/OTSB NRR/DRPW NRR/DSSA/SRXB OC DCB G FI 01 EXTERNAL NRC PDR COPIES LTTR ENCL 1

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1 RECIPIENT ID CODE/NAME PDV PD TRAN,L NRR/DE/EELB NRR/DRCH/HICB NRR/DSSA/SPLB NUDOCS-ABSTRACT OGC/HDS1 NSIC COPIES LTTR ENCL 1

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D NOTE TO ALL"RIDS" RECIPIENTS:

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PLEASE HELP US TO REDUCE WASTE! CONTACT THE DOCUMENT CONTROL DESK, ROOM P 1-37 (EXT. 20079) TO ELIMINATEYOUR NAMEFROM DISTRIBUTION LISTS FOR DOCUMENTS YOU DON'T NEED!

TOTAL NUMBER OF COPIES REQUIRED:

LTTR 24 ENCL 22

WILLIAMF. CONWAY EXECUTIVEVICEPRESIDENT NUCLEAR Arizona Public Service Company P.O. BOX 53999

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PHOENIX. ARIZONA85072-3999 102-02736-WFC/RAB/GAM November 19, 1993 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Mail station P1-37 Washington, D.C. 20555

Reference:

Letter from A. C. Thadani, NRC, to A. E. Scherer, Combustion Engineering Inc., Generic Approval of C-E Topical Report CEN-386-P, "Verification of the Acceptability of a 1-Pin Burnup Limit of 60 MWD/kg for Combustion Engineering 16X16 PWR Fuel," (TAC No. M82192), dated June 22, 1992.

Subject:

Palo Verde Nuclear Generating Station (PVNGS)

Unit 1 Docket No. STN 50-528 Fuel Rod Transfer File: 93-056-026 Arizona Public Service Company (APS) and ABB Combustion Engineering have been collaborating in an ongoing fuel performance program at PVNGS.

This program is designed to help APS achieve higher fuel rod burnups by evaluating the oxide film thickness of standard and improved fuel rod cladding compositions that have been subject to reactor coolant temperatures and water chemistry at PVNGS. This site-specific data will ultimately be used to support efforts to achieve the economic benefits of higher burnup fuel cycles consistent with the generic NRC approval for higher burnups described in the referenced letter.

As a part of the fuel performance program, 15 fuel rods with several Zircaloy-4 cladding variants were transferred from a D fuel assembly to an E assembly during the Palo Verde Unit 1 fourth refueling outage.

These 15 fuel rods were irradiated for three cycles in the D fuel assembly, and will be irradiated for one additional cycle in the E assembly.

The purpose of the rod transfer is to demonstrate acceptable corrosion resistance of the cladding to exposures up to 60,000 megawatt-days per metric tons of uranium (MWd/MTU) rod average burnup.

This burnup is greater than the 52,000 MWd/MTU described in section 4.3.1.1 of the PVNGS Updated Final Safety Analysis Report.

However, safety and design analyses have shown that the performance of the transferred fuel rods is non-limiting and is bounded by the results of the Unit 1 Cycle 5 safety analysis.

In accordance with 10 CFR 50.59, no unreviewed safety question is involved.

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'PDR ADQCK 05000528 P

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Nuclear Regulatory Commission

-ATTN: Document Control Desk Fuel Rod Transfer Page 2 Enclosed is a description of the rod transfer.

This rod transfer has been evaluated as part of the Unit 1 Cycle 5 reload using NRC approved methodologies, with predicted performance bounded by the safety analysis results.

This letter is being provided to the NRC for information; no response is requested.

Should you have any questions, please contact Richard A. Bernier at (602) 393-5882.

Sincerely, WFC/RAB/GAM/kl Enclosure cc:

B. H. Faulkenberry J. A. Sloan

C I+I p

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ENCLOSURE TRANSFER OF HIGH 8URNUP FUEL RODS IN PVNGS UNIT 1

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. Transfer of Hi h Burnu Fuel Rods in PVNGS Unit 1 A small number of fuel rods (15) in PVNGS Unit 1 that have been irradiated in Fuel Assembly P1D001 for three cycles were transferred into Assembly P1E001 during the Palo Verde Unit 1 end-of-cycle-four (EOC-4) refueling outage.

Assembly P1E001 has been returned to the Unit 1 core for irradiation during Cycle 5.

These 15 fuel rods are clad with several different Zircaloy-4 cladding variants.

The purpose of the rod transfer is to demonstrate acceptable corrosion resistance of the fuel rod cladding to exposures up to 60,000 megawatt-days per metric ton of uranium (MWd/MTU)rod average burnup.

The rod average burnups of the 15 fuel rods from P1D001 transferred to P1E001 will exceed 52,000 MWd/MTUduring Cycle 5 and a few of these rods will approach 60,000 MWd/MTU.

All 15 fuel rods from P1D001 transferred to P1E001 were visually examined and measured for oxide thickness during the Unit 1 EOC-4 refueling outage, with the results confirming expected performance.

Twelve of these same 15 fuel rods had also been measured for oxide thickness during the.EOC-3 refueling outage.

Non-linear regression analysis was used to estimate the projected oxide thicknesses on these 15 fuel rods at the end of Cycle 5. The analysis determined that, based upon the measured and projected oxide thicknesses for these fuel rods, corrosion on the 15 rods through Cycle 5 is expected to be lower than 120 microns.

Safety and design analysis of the 15 transferred rods has shown no impact on the results contained in the Unit 1 Cycle 5 safety analysis. Afuel performance calculation performed using FATES3B (References 1-1, 1-2 and 1-3) shows that predicted results for fuel rod internal pressures, fuel temperatures, and power to fuel centerline melting for these 15 rods are bounded by the results calculated for the rest of the core. Also, LOCA and non-LOCA transient analysis results remain bounding and applicable for these 15 rods.

Furthermore, the mechanical performance ofthe cladding, considering allowable cladding

stresses, strains,

fatigue, and cladding, collapse, was found to be acceptable.

Consequently, the performance of this'mall number of fuel rods is non-limiting and is bounded by the results in, the Unit 1 Cycle 5 safety analysis.

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References:

1-1.

CENPD-139-P-A, "C-E Fuel Evaluation Model," Combustion Engineering,

Inc, July, 1974.

. 1-2. 'EN-161-(B)-P-A, "Improvements to the Fuel Evaluation Model," August 1989.

1-3.

CEN-161-(B)-P-A, "Improvements to the Fuel Evaluation Model," August 1989, Supplement 1-P-A, January 1992.

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