ML20141E831

Forwards Request for Addl Info in Order to Continue Review of 850305 Submittal Re Ability of Control Room HVAC Sys to Meet Requirements of GDC 19 of App a to 10CFR50.Response Requested within 60 Days of Ltr Receipt

ML20141E831
Person / Time
Site:	Calvert Cliffs
Issue date:	04/11/1986
From:	Jaffe D Office of Nuclear Reactor Regulation
To:	Tiernan J BALTIMORE GAS & ELECTRIC CO.
References
GL-83-37, NUDOCS 8604220395
Download: ML20141E831 (3)

Text

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}L: C D)b Docket Nos. 50-317 April 11, 1986 and 50-318 Mr. J. A. Tiernan Vice President - Nuclear Energy Baltimore Gas & Electric Company P. O. Box 1475 Baltimore, Maryland 21203-

Dear Mr. Tiernan:

We are in the process of reviewing your March 5, 1985 submittal concerning the ability of the Calvert Cliffs control room heating, ventilating, and air condi'.ioning (HVAC) system to meet the requirements of General Design Cr;..crion 19 of Appendix A to 10 CFR Part 50. In the process of our review, we find it necessary to request additional information. Please provide your response to the enclosed request for information within sixty (60) days

-following receipt of this letter.

The reporting and/or recordkeeping requirements of this letter affect fewer than 10 respondents; therefore, OMB clearance is not required under P.L.96-511.

Sincerely, h/

David H. Jaffe, Project Manager PWR Project Directorate #8 Division of PWR Licensing-B

Enclosure:

As stated cc w/ enclosure:

See next page Docket File NRC & L PDRs Branch Files OELD ACRS 10 PKreutzer DJaffe '.

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Mr. J. A. Tiernan Baltimore Gas & Electric Company Calvert Cliffs Nuclear Power Plant cc:

Mr. William T. Bowen, President Regional Administratoi, Region I Calvert County Board of U.S. Nuclear Regulatory Commission Commissioners Office of Executive Director Prince Frederick, Maryland 20768 for Operations 631 Park Avenue D. A. Brune, Esq. King of Prussia, Pennys1vania 19406 General Counsel Baltimore Gas and Electric Company P. O. Box 1475 Baltimore, Maryland 21203 Jay E. Silberg, Esq.

Shaw, Pittman, Potts and Trowbridge 1800 M Street, NW Washington, DC 20036 Mr. M. E. Bowman, General Supervisor Technical Services Engineering Calvert Cliffs Nuclear Power Plant M0 Rts 2 & 4, P. O. Box 1535 Lusby, Maryland 20657-0073 Resident Inspector c/o U.S. Nuclear Regulatory Commission P. O. Box 437 Lusby, Maryland 20657-0073 Bechtel Power Corporation ATTN: Mr. D. E. Stewart Calvert Cliffs Project Engineer 15740 Shady Grove Road Gaithersburg, Maryland 20760 Combustion Engineering, Inc.

ATTN: Mr. R. R. Mills, Mana0er Engineering Services P. O. Bc 500 Windsor, Connecticut 06095 Department of Natural Resources Energy Administration, Power Plant Siting Program ATTN: Mr. T. Magette Tawes State Office Building Annapolis, Maryland 21204

REQUEST FOR INFORMATION ON CALVERT CLIFFS

• CONTROL ROOM VENTILATION SYSTEM

1. The basis for the temperature limitation of 104*F in the control room is equipment qualification. The location where this temperature is measured is important. BG&E should detail how the location they have selected adequately represents the point of maximum vulnerability for safety grade instrumentation and equipment during normal operation of the non-safety grade chiller system, during operation of the safety grade system and during a loss of ventilation or loss of chiller event.

2. In accordance with Generic Letter 83-37 the staff's position is that a technical specificr tion is necessary to periodically verify the leaktight-ness of the controi room. The technical specification for testing the leaktightness of the control room should be consistent with the test requirements specified in the sample technical specification provided by Generic Letter 83-37.

3. For the normal supply isolation damper, how does BG&E ensure that GDC 19 criteria is met in the event of a single failure of these dampers?

4. The cooling requirement for the control room is 116.5 tons while the capacity of the safety grade control room chiller unit is to be 96 tons.

During the period from July 16, 1980, through September 11, 1980, a total of five incidents occured (LERs80-034, 80-038,80-039, 80-049, and 80-051), in which the safety grade control room chillers tripped. In one case, a total loss of HVAC was experienced. In four of these LERs, the licensee stated that the system design was being reevaluated for additional cooling capacity and for reliability of the cooling portions of the control room HVAC system. BG&E's resolution to the problem was to install a new, 220 ton, non-safety grade chiller unit to cool the control room during normal operation. However, if the plant is required to operate the safety grade chiller unit for any reason such as during a loss of offsite power event, the system would still be susceptible to those same potential trips which were experienced in 1980 since nothing has been done to upgrade the safety grade chillers. Provide a justification as to why an upgrade of the safety grade chiller unit is not required.

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