ML18044A670
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l Docket No. S0-255 MEMORANDUM FOR:-
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SUBJECT:
_R. H.: Vo'1,~r *. Ass1s_tant-Director. for -Systems and
- . Projects, DOR
-~ R. P. Denise.* Acting Assis,tant* Director for Reattor
. Safety *.. DSS STAFF EVALUATION OF PALISADES RESPONSE RE:
.CONTAINMENT
- ovER~PRESSURIZATION POTENTIAL. DUE ro* AUXILIARY FEEDWATER Rµ~-OUT 'FLOW FOLLOWING.A MSLB
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- .B.}i'letter*d~t~d-Oecember.2_1~ :1979~,-Jhe*s~ajf requested 1;he Consumers* Power..
. Company. the licensee for the: PaHsades*-Nu~lear.P,ower. Platit 1_*:to provide certain
- ~4d1t1onal information *. -Sp~ifiea]Jy, the *consumers -Power Company* was to assess the* potential for. conta1*nment overpress.lirjzat;1on due to -the anticipated. continu-ous addit,on, at pump's.run-out flow, of auxf11ary feedwater to the affected steam generator :following a postulated mairi* steam line break (MSLB). acci'dent.-
The *staif1.s.in-~eres-t 1ri~this isslie_:~esulted. fro~-- the. Part 21 rC;po~t:f.il~d b; the Virginia Electric a.,d. Power Company (VEP*co) dated September 4. 1979 *. In that *report~ -the* NRC'was* fofonned*by' *vEPCO' tfo)t:overpressur1iati<)n.of* the :con-tainment* at.North Anna, Uni ts 3 and 4, _coi.ild occur 1n the event of a postulated MSLB jnslde containment~
VEPCO indi.cated that, due to the_***arit1c1p'ated con:t1m.i-
- ous addf tton *of aux-i.11 ary feedWater-*~.to. ttie* broken 1 oo'p s:te*am generator, at the *
- pump's, run~out flow corid1tfon-~* fo~lQyJ41119 a *M.SLB accident~. Jthe containment pres-
-~u~ wjll. }1!a~h. _the COl1~~moont ~esign"p~ssure in ab_out.l() m'nu~e~.*
In a Jetter:dated *:January *21,.1980, _*tfi~ _Cpns*um~r-S.- Po~e.(t~pany.responded to the st(lff~ s letter cited above arid indicated that '.the auxHiary -fee$ater system.*
utilizes run-out flow* control equipment *to *11rn~t flow *. The. 'flow Jim1t. has not yet been determined, but will probably -be *set at less *than 250 gpm to avoid*.
. water harrmers.in' the _ feedwater H rie ~
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In the*.original MSLB analysi$ no cotjs,~eratfon,was given.tto 'aux11,1a.ry fee.cjwater *
- pump rt.1n-out.
Combustion Engineering l)as perfonned* a_n analysis that.d~mon- -
-strates that the-addition of aux11iary*feedwater at the run-out flow.condition
. -w111 oot cau$e.containment pressure* ~o ri.se abovf;! ~he. initi:al *blowdown peak.
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..* 'The. staff concurs with. the Hcensee: thaf tbe peak containment pr-esst.ire wi-1'1 re-:
' main below the.contai.nment'-design pressure -with the addition of auxiliary f~ed-*
water at* run-out. fl ow.
An SER _on this *.matter was prepa~d by the eonta,i nment Systems Bra11cb aod ~s enclosed.*-. *.: :*.,* -*.*-:*
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. ' *1063 24 0 \\ \\ 2:'.
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NRC"FORM"318 (9-_76)"NRCM 0240
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. MAR 6
- 1980 e.
R. In the course of *our re'View of the _postulated MSLB with aux1l1ari feedwater pump,
run-out;.we noted that tt)e licensee ha*d riot considered the consequences of postu-1,ated single. failures 1f"! *th~ main feecfylater,. main steam. line isolation valves* and the auxiliary feedwater flow limi~ers. To satisfy present day*criteria, the MSLB-accident would have* to be re-a~alyzed assuming single active fai1ures*1n isola*'
- t1on valves and flow. limiters.
You. may wish to have this. ~atter reviewed at an.
- ().ppropri ate time..
Enclosure:
As stated*
cc: R. Mattson*
R. Tedesco R.* Silver o~ Ziemann.. ".
V.. Benaroya
- u. LeFave G. La1nas *.*
W. Butler w.-. Milstead
'J. Kudrick*
P. Heam Central files CSB Rdg NRR.Rdg
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- RDeni se *
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- ..... *Original Signed By
- .. Richard P.*Den'ise I
RiChard P.'_ Oe~ise,. Acting Assistant P1re~tor
.for Reactor Safety *..
- 01 vision of' Systems Saf~ty
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. NRC FORM 3J.8 19*76] NRC~;. Q;>.J0
".'.:-1.1.s, Gov:ER"-'E'-iT PR1r\\J:i:1NG oFF1cE: 1979-289'369.