ML19309B050

Responds to Util Re Proposed Mods Eliminating Need for Operator Action in Event of Small Break in Discharge Piping from Reactor Coolant Pumps.Overall Concept Acceptable

ML19309B050
Person / Time
Site:	Rancho Seco
Issue date:	08/16/1978
From:	Reid R Office of Nuclear Reactor Regulation
To:	Mattimoe J SACRAMENTO MUNICIPAL UTILITY DISTRICT
References
NUDOCS 8004020526
Download: ML19309B050 (3)

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Docket No. 50-312 VStello BGrimes BReid t.._.

GZwetzig TAbernathy C-Glainis C "

JBuchanan Sacramento Municipal Pility District PCheck ACRS(16)

E ATTH: Mr. J. J. Mat; 3 RIngram Gray file

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Assistant Ge.-

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.==i.=j and Chief E, 6201 S Street DEisenhut j;l.g.g.]

P. O. Box 15830

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Sacramento, California 95813

}d F= E Gentlemen:

By letter dated July 20, 1978, you proposed certain modifications I.

at Rancho Seco Nuclear Generating Station to eliminate the need for operator action in the event of a small break in the discharge piping

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from the reactor coolant pumps. These prorosed modifications consisted Ei.. ?..

1) Maintaining the valves in the cross-tie line connecting the two

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High Pressure Injection (HPI) loops open whenever the HPI system is in service,

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2) Supplyino power to the HPI Loop A injection valves (one in 555 each leg) from the 125 volt DC, Class I, C battery and to

. -E the HPI Loop B injection valves similarly from the D battery, IC2.

3) Supplying power to the makeup isolation valve from the 125 f.[

volt DC, Class I, C battery, and p)))EE

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4) Supplying an "Open' sijnal to all four injection valves from I.'."..;

both Channels A and B of the safety features actuation system.

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Your submittal also presented a failure analysis of the proposed modified l;;;;=

system, and referenced an analysis which is stated to verify the adequacy z

of the battery capacity to power the valves and existing loads.

=r..s This is to advise you that based on our review of your submittal, we r-find the proposed modifications acceptable with respect to the overall 9"=,"

concept.

Lhether the rodifications will be fully acceptable in practice, r

howeJer, will depend upon the manner in which they are actually gf h

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Considerations bearing on this final acceptability L

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include: the environmental and seismic qualification of new compo-

.cs nents; the extent to which required operator action would differ from that required prior to discovery of the small break problem; the F = "i results of our review of the battery loading analysis; the proposed pre-operational test program; and conformance with other regulatory gufdance applied to safety-related systems of this type.

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Therefore, if you believe the proposed modifications, when implemented,

_...:d will meet regulatory requiremants, you should consider initiating pre-

'.. 3 parations for implementing the modifications as described, at an early gg date, and should submit information and/or comitments related to the jer...~ _

above considerations at least 60 days prior to implementation, r=~;;

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Sincerely,

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Robert W. Reid, Chief

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Operating Reactors Branch f4 mm; Division of Operating Reactors

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David S. Kaplan, Secretary and

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General Counsel

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6201 S Street Post Office Box 15830

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Sacramento, California 95813 Business and Municipal Department Sacramento City-County Library 828-I Street Sacramento, California 95814 g====.

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