ML20138G740

Forwards 1996 Annual Rept of ECCS Evaluation Model Revs/Errors, Per 10CFR50.46(a)(3)

ML20138G740
Person / Time
Site:	Seabrook
Issue date:	12/27/1996
From:	Diprofio W NORTH ATLANTIC ENERGY SERVICE CORP. (NAESCO)
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
NYN-96090, NUDOCS 9701020237
Download: ML20138G740 (4)

Text

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

',)j Atlantic 0

se sreet. sii O3874 (603) 474-9521 The Northeast Utilities Systern l

December 27,1996 Docket No. 50-443 NYN-96090 '

l United States Nuclear Regulatory Commission

' Attention: Document Control Desk l Washington, D.C. 20555 l Seabrook Station ]

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' 10 CFR 50.46 Annual Renort l North Atlantic Energy Service Corporation (North Atlantic) has enclosed herein, pursuant to  !

10CFR50.46(a)(3), the 1996 Annual Report of Emergency Core Cooling System (ECCS) Evaluation

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l .Model Revisions / Errors. The enclosure includes a tabulation of the Large Break LOCA and Small Break i LOCA Peak Clad Temperature (PCT) margin allocations applicable to Seabrook Station. The PCT margin allocations reported in the enclosure represent permanent PCT margin allocations attributable to ECCS evaluation model revisions / errors and plant specific input assumption allocations through the period June 24,1996 as reported to North Atlantic by Westinghouse on July 8,1996 in NAH-96-220.

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Should you have any questions regarding this letter, please contact Mr. Anthony M. Callendrello, Licensing Manager, at (603) 773-7751.

Very truly yours, 1

NORTH ATLANTIC ENERGY SERVICE CORP.

e b 010051 liain A. dip fy' ~

Unit Director l

cc: H. J. Miller, Region I Administrator A. W. De Agazio, Senior Project Manager J. B. Macdonald, NRC Senior Resident inspector i

i ADDji 9701020237 961227 -

PDR ADOCK 05000443;.

F PDR '

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e ENCLOSURE TO NYN-96090 1

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Small Break Peak C8-d Temperature Margin Utilization ECCS EVALUATION MODEL REVISIONS / ERRORS 10CFR50.46 ANNUAL REPORT 1996 Eval. Model: NOTRUMP Fuel: 17 x 17 V511 FQ=2.5 FdH=1.65 SGTP=13%

Clad Temnerature A. ANALYSIS OF RECORD (8/93)

1. ECCS Analysis PCT = 1082 *F

2. Increased T,y, Uncertainty for PTD Bypass Elimination APCT= 8 F B. PRIOR PERMANENT ECCS MODEL ASSESSMt..- ' ' # APCT= 28 F C. 10CFR50.59 SAFETY EVALUATIONS

1. PSV/MSSV Setpoint Tolerance Relaxation' APCT= 5 'F D. 199610CFR50.46 MODEL ASSESSMENTS (Permanent Assessment of PCT Margin)

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1. SBLOCTA Fuel Rod initialization Error APCT= 10 'F E. OTHER MARGIN ALLOCATIONS e

1. EFW Actuation on SI Signal Only 5 'F LICENSING BASIS PCT = MARGIN ALLOCATIONS PCT = 1138 F

' NAH-94-202," North Atlantic Energy Service Corporation Seabrook Station,10CFR50.46, Notification and Reporting information," February 8,1994.

2 NAH-94-229," North Atlantic Energy Service Corporation Seabrook Station, SBLOCTA Axial Nodalization," October 27,1994.

3 NAH-96-204," North Atlantic Energy Service Corporation, Seabrook Station,10CFR50.46 Annual Notification and Reporting," February I?,1996.

• Amendment 15 to Facility Operating License NPF-86, September 3,1992.

8 NAH-96-220," North Atlantic Energy Service Corporation Seabrook Station,10CFR50.46 Small Break LOCA Notification and Reporting," July 8,1996.

6 NAH-95-230," North Atlantic Energy Service Corporation, Seabrook Station, Evaluation ofImpact of LOCA Related Analyses of EFW Start on SI Signal vs. Loss of Power Signal, November 17,1995.

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Large Break Peak Clad Temperature Margin Utilization ECCS EVALUATION MODEL REVISIONS / ERRORS 10CFR50.46 ANNUAL REPORT 1996 Eval. Model: NOTRUMP Fuel: 17 x 17 V5H FQ=2.5 Fdll=1.65 SGTP=13%

Clad Temperature A. ANALYSIS OF RECORD (8/93)

1. ECCS Analysis PCT = 1889 'F

2. Increased T ,, Uncertainty for RTD Bypass Elimination APCT= 5 'F B. PRIOR PERMANENT ECCS MODEL ASSESSMENTS'# APCT= 58* F C. 10CFR50.59 SAFETY EVALUATIONS APCT= 0 F D. 199610CFR50.46 MODEL ASSESSMENTS (Permanent Assessment of PCT Margin) APCT= 0 'F r

b LICENSING BASIS PCT = MARGIN ALLOCATIONS PCT = 1952 *F ,

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• Does not include Hot Leg Nozzle Gap Benefit (-142 F) reported in 1995, North Atlantic letter NYN-96086, dated October 26,1995.

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' NAll-94-204," North Atlantic Energy Sc.vice Corporation, Seabrook Station,10CFR50.46 Notification and Repodir.;; !nSr. nation," February 8,1994.

2 NAll-95-219," North Atlantic Energy Service Corporation, Seabrook Station, LOCA Axial Power Shape Sensitivity Model," August 14,1995.