ML18107A560

Submits 30-day Fuel Clad Temp Rept,Iaw 10CFR50.46.Rept Describes Changes to Calculated Peak Clad Temp (PCT) for Salem Generating Station Large & Small Break LOCA Analyses

ML18107A560
Person / Time
Site:	Salem
Issue date:	10/18/1999
From:	Eric Simpson Public Service Enterprise Group
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
LR-N990450, NUDOCS 9910260250
Download: ML18107A560 (4)

Text

Public Service Electric and Gas Company E. C. Simpson Public Service Electric and Gas Company P.O. Box 236, Hancocks Bridge, NJ 08038 609-339-1700 Senior Vice President - Nuclear Engineering ocr1e 1999 LR-N990450 United States Nuclear Regulatory Commission Document Control Desk Washington, DC 20555 Gentlemen:

SALEM LOSS OF COOLANT ACCIDENT PEAK CLAD TEMPERATURE MARGIN TRACKING DAY NOTIFICATION SALEM GENERATING STATION UNIT NOS.1AND2 DOCKET NOS. 50-272 AND 50-311 In accordance with the requirements of 10CFR50.46, Public Service Electric and Gas (PSE&G) hereby submits the 30-day fuel clad temperature report. This report describes the changes to the calculated Peak Clad Temperature (PCT) for the Salem Generating Station* (SGS) Large and Small Break Loss of Coolant Accident (LB LOCA and SB LOCA) Analyses.

In the last report to the NRC of April 27, 1999 (Ref. LR-N990200), the following Loss of Coolant Accident (LOCA) peak clad temperatures (PCTs) were identified.

S 1C131ast report Large Break LOCA-PCT = 2029°F S 1C131ast report Small Break LOCA-PCT = 1652°F S2C 11 iast report Large Break LOCA-PCT = 2053°F S2C 11 iast report Small Break LOCA-PCT = 1662°F As a result of a reanalysis performed by Westinghouse to assess the PCT impact on a plant-specific basis of three newly-identified errors, a benefit to the LB LOCA PCT of 12°F was assessed. These three errors are as follows.

1. Accumulator Line/Pressurizer Surge Line Data Discrepancy Review by Westinghouse of various geometric data related to the accumulator lines and pressurizer surge lines revealed discrepancies between current plant configuration and LOCA analysis models. The impact on the Large and Small

. Break LOCA-PCTs of this error was determined on a plant-specific basis using the corrected geometric data.

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001'181999 Document Control Desk LR-N990450

2. LOCBART Spacer Grid Single-Phase Heat Transfer Error The Yao-Hochreiter-Leech correlation is used in the LOCBART code to compute single-phase heat transfer enhancement for axial elevations located downstream of spacer grids. An error was discovered in the length-averaging logic for heat transfer coefficient calculations in the LOCBART code. The impact on the Large Break LOCA-PCT of this error was addressed on a plant-specific basis using a code version with the corrected length-averaging logic.

3. LOCBART Zirc-Water Oxidation Error A logic error in the LOCBART code caused the Baker-Just metal-water reaction calculations to be performed three times per timestep. Correcting this error was found to reduce the total cladding oxidation while increasing the heat deposition in the cladding. The impact on the Large Break LOCA-PCT of this error was determined on a plant-specific basis using a code version with the corrected zirc-water oxidation logic.

The plant-specific impact of these three errors is a 12°F benefit for the Large Break LOCA-PCT and no change for the Small Break LOCA-PCT. Thus, the current Large and Small Break LOCA-PCTs for Salem Unit 2 are:

S2C11~urrent Large Break LOCA-PCT =2041°F S2C11 current Small Break LOCA-PCT =1662°F In addition, the LB and SB LOCA-PCTs for Salem Unit 1 Cycle 14 are expected to change from the last report to the NRC.

For Small Break LOCA, 10°F generic PCT penalty will be assessed due to the impact of fully enriched annular pellets.

For Large Break LOCA, three changes to the Analysis of Record (AOR) PCT are being implemented as part of this report. First, the last "Analysis of Record" was re-evaluated through plant-specific analysis using the latest computer codes for the evaluation model incorporating the effects of Robust Fuel Assembly Features and updates to the evaluation model as was detailed in LR-N990200 letter for Unit 2 yielding a 25°F PCT penalty with respect to the AOR PCT of 1978°F. Second, a generic transition core PCT penalty of 50°F will be assessed for Unit 1 to account for the effects of a partial core with Intermediate Flow Mixers (IFMs) as was detailed in LR-N990200 letter for Unit 2.

Third, the errors identified above yield a 12°F PCT benefit. Thus, the current Large and Small Break LOCA-PCTs for Salem Unit 1 are:

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Document Control Desk . . LR;*N990450 S1C14current Large Break LOCA-PCT =2041°F S 1C 14current Small Break LOCA-PCT = 1662°F At the present time it is expected that initial criticality of Unit 1 cycle 14 (S1 C14) will occur on October 26, 1999. Therefore, submitting a PCT report to the NRG within 30 days of initial criticality of S1 C14 will meet the 30-Day reporting requirements induced by the sum of the absolute values of each ~PCT for the Unit 1 Large Break LOCA exceeding 50°F .. Although the sum of these errors (25°F + 50°F + 12°F = 87°F) is greater than 50°F, a re-analysis is not necessary to demonstrate compliance with 10 CFR 50.46 because the PCT assessments for errors identified were made using plant-specific data and the latest computer codes for the evaluation model. The evaluations were in essence a re-analysis. Thus, a schedule for re-analysis is not required.

Should there be any questions regarding this submittal; please contact Mr. T. K. Ross of my Staff at (856) 339-1222.

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Document Control Desk LR-:N990450 Attachments C Mr. Hubert J. Miller, Administrator - Region I U. S. Nuclear Regulatory Commission 475 Allendale Road King of Prussia, PA 19406 Mr. P. Milano, Licensing Project Manager - Salem U.S. Nuclear Regulatory Commission One White Flint North 11555 Rockville Pike Mail Stop 14E21 Rockville, MD 20852 Mr. S. Morris - Salem (X24)

USNRC Senior Resident Inspector Mr. K. Tosch, Manager IV Bureau of Nuclear Engineering 33 Arctic Parkway CN 415 Trenton, NJ 08625