ML19339A952

Forwards NRC Position Re Application of Cladding Swelling & Rupture Models for LOCA Analyses.Requests Supplemental Calculations Described in Encl & Schedule for Response

ML19339A952
Person / Time
Site:	Perry
Issue date:	10/17/1980
From:	Tedesco R Office of Nuclear Reactor Regulation
To:	Davidson D CLEVELAND ELECTRIC ILLUMINATING CO.
References
NUDOCS 8011060054
Download: ML19339A952 (3)

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o, UNITED STATES i

, r,( ( h NUCLEAR REGULATORY COMMISSION

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Docket Nos. 50 440

.and 50-441 fir. Dalwyn R. Davidson Vice President, Engineering The Cleveland Electric Illuminating Company P. O. Box 5000 Cleveland, Ohio 44101

SUBJECT:

STAFF POSITION ON CLADDING SWELLING AND RUPTURE MODELS FOR LOCA ANALYSES Enclosed is the staff position concerning the application of the cladding swelling and rupture models for loss of coolant accident analysis. We request that you provide the supplemental calculations described in the second paragraph of the enclosure.

Please advise us of the schedule for your response.

If you require any clarification, contact the staff's assigned licensing project manager.

Sincerely.

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Ro rt L esco Assistant Director for Licensing Division of Licensing

Enclosure:

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As stated cc w/ enclosure:

See next page i

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Mr. Dalwyn R. Davidson Vice President, Engineering The Cleveland Electric Illuminating Company P. O. Box 5000 Cleveland, Ohio 44101 cc: Gerald Charnoff, Esq.

Shaw, Pittman, Potts & Trowbridge 1800 M Street, N. W.

4 Washington, D. C.

20036 Donald H. Hauser, Esq.

Cleveland Electric Illuminating Company P. O. Box 5000 Cleveland, Ohio 44101 U. S. Nuclear Regulatory Commission Resident Inspector's Office i

Parmly at Center Road Perry, Ohio 44081 1

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ENCLOSURE The NRC staff has been generically evaluating three materials models that

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are used in ECCS evaluations. Those models predict cladding rupture temperature, cladding burst strain, and fuel assembly flow blockage. We have (a) discussed our evaluation with vendors and other industry repre-sentatives (Reference 1), (b) published NUREG-0630, " Cladding Swelling and Rupture Models for LOCA Analysis (Reference 2), and (c) required licensees to confirm that their ocerating reactors would continue to be in conformance with 10 CFR 50.46 f f the NUREG-0630 models were substituted for the present, materials models in their ECCS evaluations and certain other compensatory model changes were allowed (References 3 and 4).

Until we have completed our generic review and implemented new acceptance criteria for cladding models, we will require that the ECCS analyses in your FSAR be accompanied by supplemental calculations to be perforr.ed with the materials models of NUREG-0630. For these supplemental calculations Only, we will accept other compensatory model changes that may not yet be approved by the NRC, but are consistent with the changes allowed for the confirmatory operating reactor calculations mentioned above.

REFERENCES 1.

Memorandum from R. P. Denise, NRC, to R. J. Mattson, " Summary Minutes of Meeting on Cladding Rupture Temperature, Cladding Strain, and Assembly Flew Blockage," November 20, 1979.

1 2.

D. A. Powers and R. O. Meyer, " Cladding Swelling and Rupture Models for LOCA l

Analysis

• NRC Report NUREG-0630, April 1980.

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Letter from D. G. Eisenhut, NRC, to all Operating Light Water Reactors, dated November 9,1979.

4 Memorandum from H. R. Centon, NRC, to Commissioners, " Potential Deficiencies in ECCS Evaluation Models," November 26, 1979.

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