ML20101M268
| ML20101M268 | |
| Person / Time | |
|---|---|
| Site: | Seabrook  |
| Issue date: | 07/01/1992 |
| From: | Feigenbaum T NORTH ATLANTIC ENERGY SERVICE CORP. (NAESCO) |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NYN-92092, NUDOCS 9207080139 | |
| Download: ML20101M268 (5) | |
Text
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1-P.O. Box 300 Seabrook, NH 03874 Telephone (603)474 9521 Facsimile (603)474 2987 Energy Service Corporation Ted C. Felgenbaum Senior Vice President and Chief Nuclear Officer NYN-92092 July 1,1992 United States Nuclear Regulatory Commission Washington,- D.C.
20555 Attention:
Document Control Desk
Reference:
Facility Operating License No. NPF-86, Docket No. 50-443
Subject:
10CFR50.46 Annual Report Gentlemen:
North Atlantic Energy Service Corpm ation (North Atlantic) has enclosed herein, pursuant to.10CFR50.46(a)(3), the 1992 Annual Report of Emergency Core Cooling System (ECCS) Evaluation Model Revisions. The enclosure includes a tabulation of the limiting Large Break LOCA and limiting S.nall Break LOCA Peak Cladding Temperature (PCT) margin t.llocations applicable to Seabrook Station. The PCT margin allocations reported in the enclosure represent-permanent PCT margin allocations attributable to ECCS evaluation model revisions and plant specific inpu. assumption revisions through the period of June 1992 as reported to North Atlantic by Westinghouse on June 23, 1992.
North Atlantic notes that the PCT margin allocations reported herein include the PCT increases associated with the climination of the RTD Bypass System which was propo,.ed in License Amendment Request 92-01 and Supplement 1 thereto on June 19, 1992.
The proposed Reactor Coolant System (RCS) temperature measurement system design yields an increase in the uncertainty value for RCS average temperature from z 4 *F to e 5 'F.
Tbc attendant PCT increases are 4 "F for the large break LOCA and 8 'F for the small break LOCA. The current PCT values reported herein are 2052.2 *F for the large break LOCA and 1981.2 'F for tne small break LOCA.
The enclosure demonstrates North Atlantic's compliance with the requirements of 10CFR50.46 and thus no additional analyses or further actions are requiicd. Should you have at:y cluestions regarding this letter, please contact Mr. James M. Peschel, Regulatory Compliance Manager at (603) 474-9521 extension 3772.
Very truly yours, l
Ted C Fei <enbaum l
TCF: A LL/act Enclosure t
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. United. States Nuclear Regulatory Commission July 1,1992 Attention:
Document Control Desk '
Page two l. --
cc:
Mr. Thomas T. Maiiin Regional Administrator U. S. Nuclear. Regulatory Commission Region I 475 Allendale Road King of Prussia, PA -19406 Mr.= Gordon E. Edison, Sr. Project ' Manager
. Project Directorate 1-3
-~ Division of Reactor Projects
-U.S. Nuclear Regulatory Commission L Washington, DC 20355
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Mr.' Noel Dudicy
'NRC Senior Resident inspector P.O. Box 1149 '
Scabrook, NH -03874
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ECCS EVAIUATION MODEL REVISIONS 10CFR50.46 ANNUAL REPORT 1992 PEAK CLAD TEMPERATURE (PCT) MARGIN ALLOCATION LARGE BREAK LOCA-A.
Analysis of Record PCT = 1965.2 *F (Updated Final Safety Analysis Report, Rev. 1, May 1992, Sec. 15.6*)
B.
ECCS Evaluation Model Revisions (thru 6/92 as reported in Westinghouse. letters dated 6/20/91 and 6/23/92) a.
Fuel Rod Initial Condition a PCT = +25.0 *F Inconsistency b.
Steam Generator a PCT = +40.0 *F Seismic /LOCA Assumption C.
Plant Specific Input Assumption Revisions a.
Chamfered Pellet a PCT = +10.0 *F b.
Tube-Plugging a PCT = +8.0
- F**
c.
RTD Bypass Elimination a PCT = +4.0
- F***
Analysis of-Record' PCT + 6 PCT Marnin Allocation = 2052.2 "F The Large Break-LOCA analysis was performed utilizing the February 1979 version of the Westinghouse Large Break Evaluation Model The 1991 10CFR50.46 Annual Report specified a 1 *F PCT margin allocation for steam generator tube plugging based on the number of tubes plugged in the as-shipped steam generators for Unit 1.
Currently, less than
.25% of the tubes are plugged in the steam generator with maximum plugging. Westinghouse allocates 8 *F for each 1 % of steam generator tubes plugged.
For conservatism.
8 'F is reported herein.
License Amendment Request 92-01 and Supplement 1 thereto dated June 19, 1992 proposed.Seabrook Station Technical Specification changes relating to the proposed elimination of the RTD Bypass System.
The proposed Reactor Coolant System temperature measurement system uncertainty value for Reactor Coolant System average temperature increases from i 4 *F to 1 5 *F.
The attendant increase in PCT is reported herein.
1
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-s; ECCS EVALUATION HODEL REVISIONS 10CFR50.46 ANNUAL REPORT 1992-PEAK CLAD TEMPERATURE (PCT) MARGIN ALLOCATION SM.S.LL BREAK LOCA A.
Analysis of Record PCT - 1790.0 *F (Updated _ Final Safety Analysis Report, Rev. 1, May 1992, Sec. 15.6*)
B.
ECCS Evaluation Model Revisions (thru 6/92.as reported in Westinghouse letters dated.
6/20/91 and-6/23/92) a.
Fuel Rod Initial Condition a PCT - +37.0 *F Inconsistency C.
Plant Specific Input Assumption Revisions-2.
Chamfered Pellet A PCT - +10.0 *F b.
. Emergency Feedwater o PCT - &l36.2 *f Enthalpy Switchover c.
RTD Bypass Elimit.ation A PCT - 48.0 "F**
Analysis of Record PCT + 6 PCT Marnin Allocation = 1981.2 F The Small Break LOCA analysis was performed utilizing the October 1975 version of the Westinghouse ~ECCS Small Break Evaluation Model License Amendment Request 92-01 and Supplement 1 thereto dated June 19, 1992 proposed Seabrook Station Technical _ Specification changes relating to the proposed elimination of the RTD Bypass System, The proposed Reactor Coolant System temperature measurement system uncertainty value
.for Reactor Coolant System average temperature increases from 4 *F to i 5 *F.
The attendant increase in PCT is reported herein.
.