ML19290D049
| ML19290D049 | |
| Person / Time | |
|---|---|
| Site: | Zion, 05000516, 05000517, Trojan File:ZionSolutions icon.png |
| Issue date: | 07/10/1976 |
| From: | Advisory Committee on Reactor Safeguards |
| To: | Advisory Committee on Reactor Safeguards |
| Shared Package | |
| ML19290C953 | List: |
| References | |
| ACRS-R-0725A, ACRS-R-725A, NUDOCS 8002150552 | |
| Download: ML19290D049 (3) | |
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Overpressurization Minutes of 106th ACRS Meeting Neting Intes: Ntober 9-11, 197:
A. System Overnreccurization J. Zion 1 and 2 J. Dyce discucced violationn.of technical cpecifications at Zion, D11ts 1 and 2.
We incidents similar in nature, occurred three ncnths j
apart. We incidents occurred during cold shutdesn. Upon icolation of l
'the RHR Systet to replace a Icaking suction relief in Qiit 1 valve, the ctx: tion valve to the RHR was chut, icolat.ing toth the relief valve and the syctre letdcw path. A centriftnal ch.2rging ptra was not chut off, causira the RCS preccure to rice over a short patiod of time.
La the niit 1 incident on June 3,1975, the pressure rose to if00 psig within 10 minutes. We temperature was appro.tirately 125 F.
We pump was cut off and the precsure was recuced to 150 psig in 18 minutes. In the thit 2 incident, spich occurred on.%ptember
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18, 1975, the pressure reached 1300 psig in la minutes dering a surveillance test. A pecccure switch, upon receving a signal
.of 450 lbs pressure, properly closed the RHR suction valvc, causing the equivalent siutation as ocurred in D1it 1.
At the ti.>a, Zion procedures did not specify securing t.ne. charginq pt_ p duri,3 shut-down; they do new. He noted that if the pressure had rea 7ed the safety setting of the relief valves at thc temperatur
- involved,
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the NDP curves of the pressure sessel would have been exc.;-ded (see Appendix XIX).
- 2. Trojan J. Dyer discusced an incident at Trojan resulting frc= an inadvertant icolation of the let dom path and the RHR Syc:cm during hot functional testir.g. Se isolation was cauced by clos :re of the RER suction valve with the charging pt=p still in operation.
We peak pressure tra.tsient, which lasted 10- 12 minutes, sns not greater than 3360 psig. We incident was ter=inated when the charging pu. p stalled out because of the. high discharge head.
Poc7 te: perature was appro.xi:ately 100"P.
Incpoctions by the licencee revealed no visual da= age or signs' of stress.
A successful hydrostatic test was completed the previous day at 3700 psig.
A Wstinghouce analysis of the transient has not been mde available to the IX'R Staff, yet.
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Hinutes of 107th AC<S n:cting Meeting Cutes,t Ibv. 6-0, 1975
- 5. CVerpressure Protection (Jamesport Nuclear Station - Open)
J. Cer:r.ak discucced Fcstinghounc's position on over pressure protection (sco Acpendix X.XXV111L r.oting that he believes this : ratter to be a new generic incue.
He noted that vinile presnurc/te:rporature li:aits are exceeded relative to the AS72 code, reactor cooling system integrity is not adversely affected by an overprecsure during the water solid condition and below relief valve settings.
F. Pluogge, NRC Staff, noted that ceven instances of overpres-surization transientn, cauced bf single-cporotor error or equipment malfunction, have occurtred since 1970.
IRC Staff believes that this typ2 of transient chould tra defined as an upset condition.
2crefore, pecccure/tc=perature li:.,its for upset conditions are clearly' defined in 10 CPR 50, Appendixes G and II.
2 c M r Staff also believes that modific-ations should i:e taade to cyntem decigns to preclude exceeding the heat-up and cool-do.m rates crecified in the technical cpecifications.
Minutes of 194th ACitS Meeting Meeting 7 ate : June'3-5, 1976 (Review of Zion Nuclear St'ation - Pcwer Inc.
.Open)
In ans or to a questIoq regarding t.o pressurization incidents 4
over a short p2riod of tic.c, Tc.61ing unid that the T. ion Station is making modifications to their primary tr.2ter systcf. to provide lcw pecccure relief viaencver the reactor is in cold chuth.c.
He noted that the Applicant ingan-in July of 3975 to re.irite and revicu all operating proceduren. %ece proceduren are currentir being tected.
In cddition, nc.i procedures have !)2en instituted following major maintenance v.ork, 9.hich requires a double check on all valves and operating equignent and electric lincups.
In answer to a question regarding the colonoid valve failures, T. Tanbling stated that the Applicant has cc:.~.nitted to an accelerated
. surveillance progran.
In acklition, new valvec are tcing cccured and installed..
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.2 t
linuten nf 194th ACIS Ideting
'!!ceting r:atec:.1une 3-5, 197G f-
%cre was no.ne di cu nion regarding g
the nu?.5er of incidents of op: ration outci,3c limitinq coaliticns.
Wp and the h'!C StaCC uss c;ucatione.:1 as to uhother the technical sp:cificationn :::i,3 t not !n unculf tight.
W. iii.Jgins stat 3 that h
f it is the MIC Staff's vicw that it is p3:Sible to operate Zion Plant within the technical specifications.
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Minutes of 195th ACRS Meeting Heeting Dates: July 8-10, 197'G C._overprecsuce Tiancients (Discussion with E00 - Closed Session)
I* Stollo, N r Staf f, discussed the proble:a of overpecccuro trancients in pecccurizeil water reactor vessels.
{!c noted that as e
a result of op rator crror, in certain instances, ~oreccuro has risen
, above. that p:rmitted in 10 CPR 50, Apinndix G.
Ilc noted that liconace-have inen informed of the problems, and that the N!C Staff is requirin.
corrective acticn.
Responto frc:n the utilitics ha3 W[1arvel Wilcox has alre favorabl I
lie noted that 0.abcoci:
steps to elle.:innte the problea.
Diccussions are In'ing held with tha
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vendprs of plant: currentlyintheconstructionanddesignjahanes' Se raain effort to date has ccccerned operating plants.
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