ML020430044

Thirty-Day Report of Loss-of-Coolant Accident Evaluation Model Changes

ML020430044
Person / Time
Site:	Cook
Issue date:	02/04/2002
From:	Greenlee S Indiana Michigan Power Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
AEP:NRC:2046
Download: ML020430044 (5)

Text

Indiana Michigan Power Cumpany 500 Circle Drive Buchanan, MI 49107 1373 INDIANA MICHIGAN POWER February 4, 2002 AEP:NRC:2046 10 CFR 50.46 Docket No: 50-316 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Mail Stop O-P1-17 Washington, DC 20555-0001 Donald C. Cook Nuclear Plant Unit 2 THIRTY-DAY REPORT OF LOSS-OF-COOLANT ACCIDENT EVALUATION MODEL CHANGES to

Reference:

Letter from S. A. Greenlee, Indiana Michigan Power Company, U. S. Nuclear Regulatory Commission Document Control Desk, of "Donald C. Cook Nuclear Plant Units I and 2, Annual Report submittal Loss-of-Coolant Accident Evaluation Model Changes,"

C0801-19, dated August 31, 2001.

(I&M), the Pursuant to 10 CFR 50.46, Indiana Michigan Power Company a 30-day report licensee for Donald C. Cook Nuclear Plant (CNP), is submitting peak cladding of loss-of-coolant accident (LOCA) model changes affecting the 1 to this letter describes the temperature (PCT) for CNP Unit 2. Attachment analysis of record.

current assessments against the large break LOCA PCT value and Attachment 2 provides the large break LOCA analysis of record PCT value remains error assessments. Attachment 2 demonstrates that the specified in within the 2200 degree Fahrenheit ('F) PCT limit 10 CFR 50.46(b)(1).

analysis The overall change to the Unit 2 limiting large break LOCA (LBLOCA)

A is classified as significant in accordance with 10 CFR 50.46(a)(3)(i).

the sum of the significant change is defined as a cumulation of changes such that than 50'F. The absolute magnitudes of the temperature changes is greater transmitted in schedule for the reanalysis of the Unit 2 LBLOCA was previously the referenced letter and remains unchanged.

ý(DCA

U. S. Nuclear Regulatory Commission AEP:NRC:2046 Page 2 No new commitments are made in this submittal.

Should you have any questions concerning this subject, please contact Mr.

Gordon P. Arent, Manager of Regulatory Affairs, at (616) 697-5553.

Sincerely, S. A. Greenlee Director, Nuclear Technical Services Attachments

/jen c: K. D. Curry, w/o attachment J. E. Dyer MDEQ - DW & RPD, w/o attachment NRC Resident Inspector R. Whale, w/o attachment

ATTACHMENT 1 TO AEP:NRC:2046 ASSESSMENT AGAINST THE LOSS-OF-COOLANT ACCIDENT (LOCA)

ANALYSES OF RECORD Indiana Michigan Power Company (I&M) previously submitted an annual 10 CFR 50.46 report for Donald C. Cook Nuclear Plant (CNP) Unit 2 in a letter from S. A. Greenlee to Nuclear Regulatory Commission Document Control Desk, dated August 31, 2001. The reported analysis of record peak cladding temperature (PCT) values in Attachment 2 to this letter remain the same as stated in the previous submittal as no new LOCA analyses have been performed. New PCT assessments against the CNP Unit 2 large break LOCA (LBLOCA) analysis of record are described below. The new assessment is reflected in the PCT accounting in Attachment 2.

There is no new PCT assessment for the CNP Unit 2 small break LOCA analysis.

Assessment Against the LBLOCA Analysis of Record Cycle 13 ZIRLOTM Fuel Evaluation

Background:

The Unit 2 core will contain ZIRLOTM clad fuel rods beginning in Cycle 13. As a result, a new LBLOCA limiting case evaluation was performed to support this plant change. The LBLOCA evaluation incorporated ZIRLOTM cladding in the rod heat-up portion of the LBLOCA transient.

Estimated Effect:

As indicated in the PCT accounting in Attachment 2, the effect of the change to ZIRLOTM clad fuel is a 50-degree Fahrenheit ('F) benefit. As noted in Table 1 of Attachment 2, the LOCBART vapor film flow regime heat transfer error and cladding emissivity error previously reported have now been incorporated into the ZIRLOTM evaluation for which only the LOCBART code was actually re-run.

Containment Spray Temperature Reduction

Background:

A LBLOCA evaluation was performed to support a reduced containment spray temperature of 32 0 F.

Estimated Effect:

As indicated in the PCT accounting in Attachment 2, the effect of the reduced spray temperature is a 47 0 F penalty.

Conclusion These changes are effective at the beginning of Unit 2 Cycle 13. Thus, this submittal satisfies the 30-day reporting requirement of 10 CFR 50.46(a)(3)(ii).

ATTACHMENT 2 TO AEP:NRC:2046 DONALD C. COOK NUCLEAR PLANT (CNP) UNIT 2 LARGE BREAK LOSS-OF-COOLANT ACCIDENT PEAK CLAD TEMPERATURE (PCT)

SUMMARY

to AEP:NRC:2046 Page 1 TABLE 1 CNP UNIT 2 LARGE BREAK LOCA Evaluation Model: BASH FQ = 2.335 F1 = 1.6444 SGTP = 15% Break Size: Cd = 0.6 Operational Parameters: RHR System Cross-Tie Valves Closed, 3413 MWt Reactor Power' LICENSING BASIS Analysis-of-Record, December 19951 PCT = 20510 F MARGIN ALLOCATIONS (A PCT)

A. PREVIOUS 10 CFR 50.46 ASSESSMENTS

1. ECCS double disk valve leakage +80 F

2. BASH current limiting break size reanalysis to incorporate LOCBART spacer grid single phase heat transfer and LOCBART +580 F zirc-water oxidation error.

B. NEW 10 CFR 50.46 ASSESSMENTS

1. Cycle 13 ZIRLOTM fuel evaluation2 -500 F

2. Reduced containment spray temperature +47 0 F C. OTHER OOF D. LICENSING BASIS PCT + MARGIN ALLOCATIONS PCT = 2114°F

1. The power level used as the basis for PCT acceptance is 3413 MWt due to the reanalysis (see item A.2) to provide an integrated error effect on the limiting case. This reanalysis (Item A.2.) is not considered the analysis-of-record due to the spectrum of break sizes not being reanalyzed to ensure that the limiting break size at 3413 MWt with the errors incorporated would not change. Thus, the analysis-of-record remains as the 1995 analysis performed at a power level of 3588 MWt. The difference between the limiting case PCT (2051 °F) and the PCT from the power level used in the reanalysis is acceptable because it bounds the Unit 2 3411 MWt steady-state power limit in the operating license.

2. The LOCBART vapor film flow regime heat transfer error and cladding emissivity error previously reported have now been incorporated into the ZIRLOTM evaluation in which only the LOCBART code was actually re-run.