ML20210P053

Submits Evaluation of Util 870113 & 23 Submittals Re Adequacy of Reactor Containment Fan Cooler Heat Removal Capability.Coolers Adequate.Fsar Table 6.2-56 Should Be Updated.Addl Info Re Affect of Cooler Performance Requested

ML20210P053
Person / Time
Site:	Byron
Issue date:	02/06/1987
From:	Varga S Office of Nuclear Reactor Regulation
To:	Farrar D COMMONWEALTH EDISON CO.
References
NUDOCS 8702130287
Download: ML20210P053 (3)

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G February 6,1987 DISTRIBUITON Docket No. 50-455 w Docket File. J. Partlow NRC PDR N. Thompson local PDR B. Grimes PD#3 RDg. L. 01shan T. Novak C. Vogan OGC C. Tinkler Mr. Dennis L. Farrar E. Jordan ACRS(10)

Director of Nuclear Licensing Coninonwealth Edison Company Post Office Box 767 Chicago, Illinois 60690

SUBJECT:

BYRON UNIT 2, NRC EVALUATION OF REACTOR CONTAINMENT FAN COOLERS By letter dated January 13, 1987, you provided a discussion of the adequacy of the Reactor Containment Fan Cooler (RCFC) heat removal capability. This re-evaluation of the RCFC capability was necessitated by the discovery, upon com-pletion of preoperational testing, that all four of the fans produced a flow i rate lower than the design flow specified in the FSAR, (Table 6.7-56). The evaluation transmitted January 13, 1987 contended that diminished fan flow capacity was offset by increased effectiveness of the fan cooler coils as demonstrated by tests conducted at Wyle Laboratories. The staff, upon review of the discussion detennined that additional quantitative analysis was needed to provide sufficient justification for the conclusion of adequacy regarding the RCFC.

By letter dated January 23, 1987, you provided additional information demonstrating the installed RCFC heat removal capability exceeds the heat removal capability assumed in the containment integrity analysis. During the course of the review it was determined that the RCFC heat removal capability assumed in the containment analysis exceeded the original performance specified by the vendor, due to differences in the assumed cooling water flow rates and fan flow rates. It is the staff conclusion however, that the data obtained from tests of representative coils support the contention that the installed RCFC capability exceeds the relevant design requirement, i.e., the performance assumed in the containment integrity safety analysis. Therefore, the staff finds the Byron Unit 2 fan coolers to be adequate to perform their design function. The staff, also concludes as a result of this review, that the FSAR (in Table 6.2-56) should be updated to reflect the new minimum fan flow requirement of F4,000 cfm, based on the Wyle Laboratory testing as wgli as the heat removal requirement established by the safety analysis (143 x 10 ATV/HR) instead of the current inappropriate reference to earlier vendor specifications. We likewise observe that the FSAR should be modified to include a curve depicting the heat removal capability vs.

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! Finally, it is our position that Comonwealth Edison should provide additional information demonstrating that the enhanced performance of the RCFC, observed from testing, does not adversely affect the assumptions regarding RCFC perform-ance contained in the ECCS containment backpressure analysis. Alternatively, there may be a demonstration of acceptable consequences for the ECCS Appendix K evaluation. This additional information should be submitted for our review within 30 days of receipt of this transmittal.

Sincerely, Steven A. Varga, Director Proiect s Directorate #3 Division of PWR Licensing-A cc: See next page I

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Mr. Dennis L. Farrar Byron Station Commonwealth Edison Company Units 1 and 2 CC*

Mr. William Kortier Ms. Diane Chavez Atomic Power Distribution 528 Gregory Street Vestinghouse Electric Corporation Rockford, Illinois 61108 Post Office Box 355 Pittsburgh, Pennsylvania 15230 Regional Administrator, Region !!!

U. S. Nuclear Regulatory Commission Michael Miller 790 Roosevelt Road Isham, Lincoln & Beale Glen Ellyn, Illinois 60137 One First National Plaza 42nd Floor Joseph Gallo, Esq.

Chicago, Illinois 60603 Isham, Lincoln A Beale Suite 1100 Mrs. Phillip B. Johnson 1150 Connecticut Avenue, N.W.

1907 Stratford Lane Washington, D. C. 20036 Rockford, Illinois 61107 Douglass Cassel, Esq.

Dr. Bruce von Zellen 109 N. Dearborn Street Department of Biological Sciences Suite 1300 Northern Illinois University Chicago, Illinois 60602 DeKalb, Illinois 61107 Ms. Pat Morrisen Mr. Edward R. Crass 5568 Thunderidge Drive Nuclear Safeguards & Licensing Rockford, Illinois 61107 Sargent & Lundy Engineers 55 East Monroe Street Ms. Lorraine Creek Chicago, Illinois 60603 Rt. 1. Box 182 Manteno Illinois 60950 Mr. Julian Hinds U. S. Nuclear Regulatory Commission Ayron/ Resident Inspectors Offices 4448 German Church Road Byron, Illinois 61010 Mr. Michael C. Parker, Chief Division of Engineerinq Illinois Department of Nuclear Safety 1035 Outer Park Drive Springfield, Illinois 67704