LIC-99-0036, Submits Annual Rept of 1998 Loca/Eccs Models Per 10CFR50.46. Small & Large Break LOCA PCT Values Continue to Remain Less than 10CFR50.46(b)(1) Acceptance Criterion of 2200 F

Submits Annual Rept of 1998 Loca/Eccs Models Per 10CFR50.46. Small & Large Break LOCA PCT Values Continue to Remain Less than 10CFR50.46(b)(1) Acceptance Criterion of 2200 F

ML20206D760
Person / Time
Site:	Fort Calhoun
Issue date:	04/28/1999
From:	Phelps R OMAHA PUBLIC POWER DISTRICT
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
LIC-99-0036, LIC-99-36, NUDOCS 9905040233
Download: ML20206D760 (3)

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' Omaha PubicPower DeWf 444 South lah SteetMet Omahn, Nebraokn 681#2247 April 28,1999 LIC-99-0036 U.S. Nuclear Regulatory Commission l Attn: Document Control Desk l Mail Station PI-137 l Washington, D. C. 20555 l

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References:

1. Docket No. 50-285 l

2. WCAP-13027-P," Westinghouse ECCS Evaluation Model for Analysis of CE-NSSS," dated July 1991

3. Letter from OPPD (T. L. Patterson) to NRC (Document Control Desk), l dated August 21,1996 (LIC-96-0119) l

4. Letter from OPPD (S. K. Gambhir) to NRC (Document Control Desk),

dated April 30,1997 (LIC-97-064)

5. Letter from OPPD (S. K. Gambhir) to NRC (Document Control Desk),

dated April 6,1998 (LIC-98-0053) e

SUBJECT:

Annual Report for 1998 Loss of Coolant Accident (LOCA)/ Emergency Core l Cooling System (ECCS) Models Pursuant to 10 CFR 50.46 l 1

In accordance with 10 CFR 50.46(a)(3)(ii), the Omaha Public Power District (OPPD) is submitting the annual 10 CFR 50.46 summary report for 1998. This summary report updates all identified changes or errors in the LOCA/ECCS codes and methods used by Westinghouse Electric Corporation (B to model Fort Calhoun Station (FCS) Unit No. I as provided in Reference 5. Reference 2 describes the methodology utilized by W to model Combustion Engineering plants, such as FCS.

OPPD has reviewed the W 10 CFR 50.46 report for 1998 regarding this subject. There were no reportable Peak Clad Temperature (PCT) impacts for the NOTRUMP (small break) and BART (large break) Evaluation Model analyses for FCS. The steam generator (S/G) orifice plates were removed during the spring 1998 refueling outage. Therefore, the Reference 4 penalties of 100*F for the small break LOCA and 98*F for the large break LOCA, for the presence of the (S/G) orifice plates, have been deleted. The attachment summarizes the calculated PCT values for small break LOCA and large break LOCAs. Removal of the above noted 98 F and 100 F penalues associated with the steam generator orifice plates is not considered a significant change /crror per 10 CFR 50.46(a)(3)(i) because it represents the removal of temporary penalties previously reported as a significant change / error in Reference 3. f

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U. S. Nuclear Regulatory Commission LIC-99-0036-

' Page 2 The penalty values, reported in Reference 3, represented extremely conservative initial estimates. l These estimates were revised with final values reported in Reference 4. Small and large break

' LOCA PCT values continue to remain less than the 10 CFR 50.46(b)(1) acceptance criterion of 2200 F.

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Please contact me if you have any questions. '

Sincerely, ,

i 4 .19 99 R. L. Phelps .

j Division Manager - Nuclear Engmeenng j DDD/ddd Attachment j c: E. W. Merschoff, NRC Regional Administrator, Region IV j L. R.- Wharton, NRC Project Manager W. C. Walker, NRC Senior Resident Inspector Winston & Strawn

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Attachment LIC-99'0036 1998 SMALL BREAK PEAK CLAD TEMPERATURE MARGIN UTILIZATION FORT CALHOUN STATION UNIT NO.1 A. Analysis of Record (8/91) PCT =1444 F B. Prior Pennanent ECCS Model Assessments APCT = -4*F C.10 CFR 50.59 Safety Evaluations APCT = 6F*

D.199810 CFR 50.46 Model Assessments - None APCT = 0F E. Temporary ECCS ModelIssues-None APCT = 0F F. Other Margin Allocations -None PCT = 0F ]

LICENSING BASIS PCT + MARGIN ALLOCATIONS PCT = 1446 F 1998 LARGE BREAK PEAK CLAD TEMPERATURE MARGIN UTILIZATION FORT CALIIOUN STATION UNIT NO.1 A. Analysis of Record (8/91) PCT =2066*F B. Prior Permanent ECCS Model Assessments APCT = -30 F C.10 CFR 50.59 Safety Evaluations - None APCT = 0F*

D.199810 CFR 50.46 Model Assessments - None APCT = 0F E. Temporary ECCS ModelIssues-None APCT = 0F F. Other Margin Allocations - Ncne PCT = 0F LICENSING BASIS PCT + MARGIN ALLOCATIONS PCT = 2036*F

• Previous penalty for steam generator (S/G) orifice plates has been deleted with removal of the S/G orifice plates. A 6 F penalty for the use of annular fuel pellets in the small break LOCA PCT has been determined and factored into the margin utilization calculation.