ML20136A907

Describes Decay Heat Removal Sys Proposed by Westinghouse to Back Up Existing Sys.Backup Sys Can Be Ready in 15 Days

ML20136A907
Person / Time
Site:	Crane
Issue date:	03/28/1979
From:	Office of Nuclear Reactor Regulation
To:	Harold Denton, Mattson R, Stello V Office of Nuclear Reactor Regulation
References
NUDOCS 7907180072
Download: ML20136A907 (5)

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Denton V.

S:tilo R. Mattson FRCM:

NRR T""m t CAL REVI EW TEAM

sti 9 ei.se is proser sild a DHR system to serve as a 5

'-:Lup to the existing i-em that ould be operative in a ar:xi. ately 15 efays.

I stem would at Sest Se of the sane slity of the c.<isting s-

nd vould not pr.+clude testage s i..; a f t.

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,,s s with -acFa,ical s.:11 s voul d ha used.

!r,7 ravi.ad the pr design and sugg,'st that it Se modified to pr:

h a system is 77ssible.

This would r quirc:

.selding of fisnged c pr es s r i z i ng Sci ce.:n s

.ard valve seals

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ENCLOSURE 1 PRO - V RHR DESIGN Timely Bac'.-Up Capability (15 Days)

One more'systus which buys additional time down the road for flow and cooling capability.

Skid concept buys HP advantage in installation and renoval.

CON - W DESIGN Not better and could be worse than existing system R.W.T.

Leakage (Mech, seals on pumps, valves with single packings (?),

and flanged connections) - potentially unacceptable offsite doses.

?5ysically large heat exchanger not needed for heat but for fl ow (ha rd to handle) (won't fit on skid),

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4 PRO - NRC ALTERNATIVE Leaktight system with inwerd leakage (wel ded ' connec t i ons ).

Longer term operability S-aller heat Rx with bypass loop could mount on one skid Simpler Installation Greater assurance of QA due to longer lead time Setter monitoring capabilities (l&C)

___?.i - !; R C A L T E.:.NA T I V E L:.,;er ti.me netdod to obtain (punos, valves)gassemble, and

'tbricate (T 20-30 days).

Additional piping (@ 3/4") needed for positive scaling Sooster pump needed to assure leakage in proper direction.

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GENERIC CONSIDERATIONS Additional loading on auxiliary building Timely clean-up of auxiliary building Functionability of RHR valves inside containment Tleing into existing lines Seismic Cons ideration 1

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.IN"LOSURE 2 TIME / DAYS ALL 0b'A % E L EAK RA TE I N GFM TO M E ET APPENDIX 1 PART 20 NN

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30 0.63 20 00 5.60 R0 I

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