ML20028F513

Informs That Steam Condensing Mode Deleted as Operating Mode of RHR for All Normal Plant Operations.No Design Basis Transients of Accidents for Mitigation Require Use of Steam Condensing Mode of RHR Sys

ML20028F513
Person / Time
Site:	Shoreham File:Long Island Lighting Company icon.png
Issue date:	01/28/1983
From:	James Smith LONG ISLAND LIGHTING CO.
To:	Harold Denton Office of Nuclear Reactor Regulation
References
SNRC-824, NUDOCS 8302020027
Download: ML20028F513 (2)

Text

. - _____ ____________ _____________ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

. .s s .

,  :=ewm.am sa.n.co.--v.-

l 6 LONG ISLAND LIGHTING COMPANY

$ 4 g SHOREHAM NUCLEAR POWER STATION l

d% r~, wax.4 mew.wj P.O. BOX 618, NORTH COUNTRY ROAD e WADING RIVER, N.Y.11192 Direct Dial Number January 28, 1983 SNRC-824 a

Mr. Harold R. Denton, Director Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, D.C. 20555 Humphrey Concerns 3.3 and 3.4 Shoreham Nuclear Power Station - Unit 1 Docket No. 50-322

References:

(1) Robert L. Tedesco letter to M.S. Pollock, dated July 8, 1982 (2) J.L. Smith letter to H.R. Denton, SNRC-808, dated December 9, 1982

Dear Mr. Denton:

Reference (1) requested that Long Island Lighting Company provide a proposed program to respond to the subject concerns that were identified as being potentially applicable to Shoreham.

In Reference (2), LILCO transmitted its responses to those items, with the exception of items 3.3 and 3.4. Reference (2) committed to a submitta? in January of 1983 relative to these two items.

Since the tire that Reference (1) was transmitted, continued analyti-cal investigation has been conducted by Stone & Webster Engineering Corporation into the submerged structure loads and piping / pipe support loads . associated with RHR heat exchanger relief valve dis-charge events during the Steam Condensing mode (SCM) of RHR system operation. This analysis is complex due to: a): the various poten-tial modes of system failure, and b) the response characteristics of system components. To'date, we have been unable to demonstrate that the existing piping, supports, and structures can withstand the present conservatively predicted loadings which may be imposed by this event.

Sool 8302020027 830120 PDR ADOCK 05000322 A PDR ,

FC-8935.1

a

~ ,

SN RC-824 *

- ' January 28, 1983 Page 2 As a result, LILCO has elected to delete the SCM as an operating mode of RHR, for all normal plant operations. This would allow LILCO to utilize available engineering resources more efficiently for-the purpose of completing construction and supporting the current schedule for fuel load.

Accordingly, a standing order will be issued to operating personnel prohibiting the use of SCM during normal plant operations. Addi-tionally, manual isolation valves which isolate RHR system pressure control valves lEll*PCVOO7A, B, level and-pressure controllers lEll*

LTOO2A, B and lEll*PTOO3A, B respectively. and upstream manual isola-tion valves which isolate RHR system pressure control valves lEll*PCVOO3A, B will be maintained normally closed and administratively controlled to preclude inadvertent operation in the SCM. The Station Test Pro-cedure for SCM operation will not be conducted until an analytical justification has been developed.

A review of the Shoreham licensing application was conducted and it has been determined that there are no design basis transients or accidents which, for the purpose of mitigation, require the use of the SCM of the RHR aystem.

However, for non-design basis eventa involving multiple failures (e.g.

Station Blackout), the SCM flow path of the RHR system will be retained as an available option for use by operating personnel when all other means of core / containment cooling have been exhausted. For such an event, reactor pressure would be less than the relief setpoint of 450 psig and the system would only be operated in a local manual mode.

It is our belief that, given the above commitments, this issue is removed as a licensing concern, with the understanding that LILCO may conduct an engineering effort in the future to demonstrate the ability of the RHR system to withstand the potential loads while operating in the SCM.

If you should have any questions concerning this matter, feel free to contact this office.

Very truly yours, q)(. L/

. L. Smith Manager, Special Projects Shoreham Nuclear Power Station DWD/jpb cc: All Parties J. Higgins, Site NRC