ML20236K898

Comments Supporting Proposed Rule 10CFR50 Changing App K to Delete Requirements from Evaluation Model & Allow More Accurate Calculations

ML20236K898
Person / Time
Site:	Farley
Issue date:	08/03/1987
From:	Mcdonald R ALABAMA POWER CO.
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
References
FRN-52FR6334 NUDOCS 8708100038
Download: ML20236K898 (2)

Text

Alabama Power Con' pany Q f, 5)U"

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l 600 North 18th Streev l

Post Office Box 2641 i

Birmingham, Alabama 35291-0400 Telephone 205 250-1835 m

R. P. Mcdonald Senior Vice President Alabarlia Power the southem eitttre system l

l August 3, 1987

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l Docket Nos. 50-348 l

50-364 I

j U. S. Nuclear Regulatory Commission ATTN: Document Control Desk i

Washington, D. C.

20555 l

Gentlemen:

Joseph M. Farley Nuclear Plant - Units 1 and 2 Proposed Changes to 10CFR50.46 and Appendix K Alabama Power Company is pleased to comment on the proposed changes to 10CFR50.46 and Appendix K which appeared in the March 3,1987 Federal Register.

We support the proposed rule change which deletes the specific features and model requirements for an evaluation model (Section I of Appendix K to 10 CFR part S0) and allows more accurate, realistic calculations with sufficient supporting justification.

The more accurate calculations will also be useful for our operator training, accident management, and simulator response.

We agree that the current peak cladding temperature limit of 2200 F, the current oxidation limits, the core configuration for coolability requirement, and the requirements on long-term cooling should be retained.

These current limits preclude core temperatures which could result in significant fuel damage, and as such, provide additional conservat ism for the design basis accident as well as economic protection for the reactor.

The revised reporting procedure for code errors or changes and reanalysis requirements using a 50 F limit between small and larger changes is reasonable and does reflect a consideration of the financial burden to the utility that small changes in the evaluation model can cause.

We recommend that uncertainty analysis, which will be required for the proposed rule change, should not be prescriptive but should remain flexible. The evaluation of the uncertainties at a 95% probability level is adequate for the large break LOCA and is consistent with good I

engineering practice.

9 8708100038 070B03 PDR ADOCK 05000348 P

PDR

U. S. Nuclear Regulatory Commission Page 2 With regard to the specific comments for which the public was requested to respond to, our responses are given below:

We recommend that the current conservative ECCS evaluation method of Appendix K be permitted indefinitely. The current Appendix K method has been shown to be conservative, and the requirement of reanalysis using the methods of the proposed rule change would place an unfair financial burden cn those utilities which already have acceptable i

operating and ECC margins to the licensing limits and would not I

result in any improvement in safety, i

With regard to the concern on including an explicit amount of conservatism in the new rule change, we recommend no predetermined explicit degree of conservatism should be applied to the evaluation mode. The amount of conservatism that is applied and retained should be determined through the uncertainty analysis using the proposed model.

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With regard to potential power level increases, we believe that the research on fission product source term indicates that significantly lcwer amounts of fission products would be released than that currently used.

The 5 to 10 percent power uprating mentioned in the proposed rule change is well within the additional margin identified in the source term studies such that there is 10 calculated increase in risk to the public.

We also believe that a proposal for a rule change should not be tied i

to the resolution of all outstanding safety issues. The basis for the rule change is the significant amount of research and development which has been performed on ECCS performance, and the merits change should be judged by the research results.

With regard to the need for an independent review of the basis for the rule change, we recommend that the Advisory Committee (ACRS) and I

their consultants be the peer review body for the proposed rule change.

Again, we are pleased to comment on the proposed rule change, and if there are ony questions on our comments, please contact the undersigned.

r Respectfullysubiit(ed,

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ALABAMA PO ER COMPANY 0

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R. P. Mcdonald RPM /BHW: dst-D-T.S.2

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cc: Mr. L. B. Long Dr. J. N. Grace l

Mr. E. A. Reeves Mr. W. H. Bradford

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