ML20210H899

Forwards Tabulation of Current LBLOCA & SBLOCA Peak Clad Temp Margin Utilization Tables Applicable to Seabrook Station

ML20210H899
Person / Time
Site:	Seabrook
Issue date:	07/27/1999
From:	Feigenbaum T NORTH ATLANTIC ENERGY SERVICE CORP. (NAESCO)
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
AR#97018883, NYN-99070, NUDOCS 9908040127
Download: ML20210H899 (5)

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North North Atlantic Energy Service Corporation P.O. Box 300 I

t Atlantic Seabrook, Nil 03874 (603) 474-9321 l

l The Northeast Utilities Systern l

July 27,1999 Docket No. 50-443 NYN-99070 l AR#97018883 United States Nuclear Regulatory Commission l Attention: Document Control Desk Washington, D.C. 20555 Seabrook Station North Atlantic Reporting of Changes to, or Errors in Emergency Core Cooling System Models or Applications In accordance with the requirements of 10CFR 50.46(a)(3)(ii), Enclosure 1 includes a tabulation of the current Large Break LOCA and Small Break LOCA Peak Clad Temperature (PCT) margin utilizatic,n tables applicable to Seabrook Station. The Large Break LOCA utilization table is consistent with the table provided in North Atlantic Energy Service Corporation's (North Atlantic) 199710CFR 50.46 Report, dated July 28, 1998. The Small Break LOCA utilization :able PCT total has been reduced by 5 F compared to the utilization table provided in North Atlantic's 199710CFR 50.46 Report, dated July 28, 1998. North Atlantic has been carrying 5 F PCT penalty as the result of a 1992 Technical Specification change relating to the relaxation in the Pressurizer Safety Valve and Main Steam Safety Valve (PSV/MSSV) setpoint tolerance to i 3%. The current licensing basis analysis for Seabrook Station already uses a t 3% uncertainty for the PSV/MSSV setpoint tolerance. IIence, a 5 F PCT penalty is not applicable.

By letter, dated April 14,1999, (NYN-99041), North Atlantic reported a temporary change in the PCT as the result of a turbine volumetric flow test. The temporary PCT penalty was applicable only during the performance of the test that commenced at 7:00 PM on March 25, 1999 and was completed at 5:30 AM on March 26,1999. Accordingly, this temporary PCT penalty is not included in the enclosure.

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s United States Nuclear Regulatory Commission NYN-99070 / Page 2

% s Should you have any questions regarding this report, please contact Mr. James M. Peschel, Regulatory Compliance Manager at (603) 773-7194.

Very truly yours, NORTil ATLANTIC ENERGY SERVICE CORP. ,

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Ted C. Feigenbaum /

Executive Vice President and Chief Nuclear Officer cc: 11. J. Miller, NRC Region 1 Administrator J. T. IIarrison, NRC Project Manager, Project Directorate 1-2 R. K. Lorson, NRC Senior Resident Inspector s

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ENCLOSURE TO NYN-99070 l

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• s Small Break Peak Clad Temperature Margin Utilization ECCS EVALUATION MODEL REVISIONS / ERRORS 10 CFR 50.46 ANNUAL REPORT Evaluation Akxlel:NOTRUMP Fuel: 17x17 V511 FQ=2.5 F A Ii=1.65 SGTP=13% 34II MWt Clad Temperature A. ANALYSIS OF RECORD (8/93)

1. ECCS Analysis PCT = 1082 F

2. ~ Increased T-AVG Uncertainty for RTD Bypass Elimination APCT= 8F B. PRIOR PERMANENT ECCS MODEL ASSESSMENTS APCT= 38 F C. 10 CFR 50.59 SAFETY EVALUATIONS APCT= 0F D. 199710 CFR 50.46 MODEL ASSESSMENTS APCT= 0F E. OTilER MARGIN ALLOCATIONS

1. EFW Actuation or, SI Signal Only APCT= 5F

2. +/- 5 *F T-AVG Window APCT= 40 F LICENSING BASIS PCT + MARGIN ALLOCATIONS PCT = 1173 F l

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Large Break Peak Clad Temperature Margin Utilization

! ECCS EVALUATION MODEL REVISIONS / ERRORS 10 CFR 50.46 ANNUAL REPORT Evaluation Model : NOTRUMP Fuel: 17x17 V511 FQ=2.5 F A 11=1.65 SGTP=13% 3411 MWt Clad Temperature A. ANALYSIS OF RECORD (8/93)

1. ECCS Analysis PCT = 1889 F

2. Increased T-AVG Uncertainty for RTD flypass Elimination APCT= 5F B. PRIOR PERMANENT ECCS MODEL ASSESSMENTS APCT= 58 F C. 10 CFR 50.59 SAFETY EVALUATIONS APCT= 0 F D. 199710 CFR 50.46 MODEL ASSESSMENTS (Permanent Assessment of PCT Margin)

1. Translation of Fluid Conditions from SATAN /LOCTA APCT= 15 F E. OTilER MARGIN ALLOCATIONS

1. +/- 5 F T-AVG Window APCT= 25 F LICENSING BASIS PCT + MARGIN ALLOCATIONS PCT = 1992 F I

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