ML20212K740

Advises That Proposed Water Curtains Consisting of two- branch-line Wet Pipe Sprinkler Sys Installed Between Two Branch Lines on Each Elevation to Help Trap Heat from Anticipated Fires Acceptable

ML20212K740
Person / Time
Site:	Pilgrim
Issue date:	08/19/1986
From:	Zwolinski J Office of Nuclear Reactor Regulation
To:	Lydon J BOSTON EDISON CO.
References
TAC-60676, NUDOCS 8608250017
Download: ML20212K740 (3)

Text

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o UNITED STATES NUCLEAR REGULATORY COMMISSION

, y WASHINGTON, D. C. 20555 o8 August 19, 1986 Docket No. 50-293 Mr. James M. Lydon Chief Operating Officer Roston Edison Company 800 Roylston Street Boston, Massachusetts 02199

SUBJECT:

INSTALLATION OF WATER CURTAINS ON ELEVATIONS 23'-0" AND 51'-0" IN THE REACTOR BUILDING (TAC #60676)

RE: Pilgrim Nuclear Power Station By letter dated December 18, 1984, the staff granted Boston Edison Company (BECO) an exemption from Section III.G.2 of Appendix R to 10 CFR 50 from installing automatic fire suppression systems throughout elevations 23'-0" and 51'-0" in the Reactor Building. The exemption justifications were based partially on the proposed installation of water curtains used to separate fire zone 1.9 from fire zone 1.10 on elevation 23'-0" and senarate fire zones

, 1.11 from 1.12 on elevation 51'-0". The water curtains were the open sprinkler head deluge design type system.

In phone conversations and meetings with the NRC staff, BECO proposed to change the open-head deluge design to a closed head wet pipe sprinkler design. The staff had two major concerns with this proposal. First, the wet pipe system may not activate as far as the deluge system and second, if it does activate, the sprinkler heads at higher levels may activate before the sprinkler heads at a lower level. This would cool the lower sprinkler heads and possibly prevent them from activating.

By letters dated February 3, 1986 and June 17, 1986, BEC0 submitted the detailed design of the new proposed Water curtains. The new design consists of a two-branch-line wet pine sprinkler system. In addition, to promote rapid activation of the system, a draft curtain would be installed between the two branch lines on each elevation to help trao heat from anticipated fires. BECO also committed to installing metal shields over all lower level sprinkler heads to shield them from water spray from sprinklers installed at higher levels.

The staff has reviewed the new water curtain design and your additional commitments and has found that the concerns raised by the staff have been a608250017 e60319 PDR ADOCK 05000093 p PDR

I Mr. James M. Lydon August 19, 1986 resolved. The staff also concluded that the new water curtain design, together with the draft curtains and metal shields, will provide the same level of protection as the systems approved in the exemption. Your proposed modifications are therefore, acceptable.

Sincerely, ORIGINAL SIGNED BY .

John A. Zwolinski, Director BWR Project Directorate #1 Division of BWR Licensino cc:

See next page DISTRIBUTION rDocket File: E. Jordan J. Zwolinski OGC-Beth (Info only)

NRC PDR B. Grimes J. Stang Pilgrim file Local PDR J. Partlow P. Leech BWD1 Rdg N. Thompson C. Janerson R. Bernero R. Ferguson ACRS (10) 0FC :BWR:PD#1  : WR:PD# 3 :BWR:P :BWR:PD#1  :  :  :

_____:_________ _ ______ s__:_____

NAME :CJamerson- :Pleech :JSt a .# :JZwolinski :  :  :

DATE:08/l4/86 ,

08/13/86 :081///86 :08/\9/86  :  :  :

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OFFICIAL RECORD COPY

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Mr. James H. Lydon Boston Edison Company Pilgrim Nuclear Power Station cc:

Mr. Alfred E. Pedersen, Station Manager Boston Edison Company RFD #1, Rocky Hill Road Plymouth, Massachusetts 02360 Resident Inspector's Office U. S. Nuclear Reculatory Commission Post Office Box 867 Plymouth, Massachusetts 02360 Chairman, Board of Selectmen 11 Lincoln Street Plymouth, Massachusetts 02360 Office of the Commissioner Massachusetts Department of Environmental Quality Engineering One Winter Street Boston, Massachusetts 02108 Office of the Attorney General 1 Ashburton Place 19th Floor Boston, Massachusetts 02108 Mr. Robert M. Hallisey, Director Radiation Control Program Massachusetts Department of Public Health 150 Tremont Street, 2nd Floor Boston, Massachusetts 02111 Reatonal Administrator, Region I U. S. Nuclear Regulatory Commission 631 Park Avenue King of Prussia, Pennsylvania 19406 Mr. James D. Keyes Boston Edison Company 25 Braintree Hill Office Park Braintree, Massachusetts 02184 l

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