ML19253B736
| ML19253B736 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 03/17/1972 |
| From: | Danielle Sullivan US ATOMIC ENERGY COMMISSION (AEC) |
| To: | Moore V US ATOMIC ENERGY COMMISSION (AEC) |
| References | |
| NUDOCS 7910180721 | |
| Download: ML19253B736 (5) | |
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UNITED STATES 1
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%n9 MAR 17 M2 P001 DRGINAL V. A. Moore, Chief Electrical, Ins trumentation and Control Sys tems Branch, DPS SITE VISIT, THREE MILE ISLAND NUCLEAR STATICN - UNIT 1; DOCKET NO. 50-2S9 I visited the Three Mile Island site on :: arch 9,1972, to review the ins trumentation, control and energency pctrer sys ters ins talled at Unit 1.
I was accompanied by !essrs H. Schier11ng and R. Cudlin of DRL and S. Folsca and T. Varella of C0:I.
The applicant was represented by the following persens:
R. W. Heward, Jr GPU W. T. Gunn CPU J. R. Thorpe GPU T. E. Hreczuch GPU J. H. Urigh t GPU D. H. Reppert GPU W. R. Schmauss GPU E. Stauf fer GAI W. F. Sailer GAI J. M. Smith GAI V. H. Willers GAI R. W. Liscom UE&C J. E. Hill B&W Sunnarv o f Outs tandir - Ite r-
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A.
There appear to be no cuality assurance procedures gove rnin g separation for tnat portion of the cable ins tallatien ber.ieen the control roca console and the cable spreading area in the room below.
B.
The separatica of ins talled redundant ESF signal cables appears to be inadequate.
C.
Several lighting fixtures of questionable seisnic integrity are suspended directly over the statica batteries.
D.
Proper separation of ins trumants, cables anc inculse lines to be located in centaic.en eculd not be verified since acne of this equip ant is
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1445 175 7910180 2
MAR 1 7 n72 V. A. Moore E.
Proper separation of the scram breakerr and associated cabling could
. e not be-verificd sin.e they are not yet ins talled.
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1.
Suitchvard We observed no deficineces. The transmissica lines converge on the site over tuo independent righ ts-of-way and te rminate at the suitch-yard which is arranced in a breaker-and-a-half configuration.
The two s tartup transf ormers are connected to the switchyard by tuo independent lines chich, respectively, terminate at the two switch-yard bus es.
2.
Control Roca The redundant reactor trip sys tcm cabinets will te located on opposite sides of the control roon (tuo on cae side and o.'o on the other). This is compatible with the tuo-ou:-of-four logic schene.
Vital equiprcnt and cables within the contr:1 console will be separated by thirty inches.
In one case (diesel generator controls) a steel fire barrier is also used.
Wiring runs to the reactor trip cabinets will be via floor mounted conduits, one fer each channel.
Since f our two-out-of-four relay matrices (to the scram breakers) are made up at thes e cabine ts,
there is sace, previously approved, intercennecting cabling beticen the four cabinets. This is also to be carried i floo r-moun ted conduit.
Wiring from the centrol console to the cable spreading area belcu is via vertical cabic runs ; i.e., horiscatal runs uithin the console are avoided.
Cur review indicated, hcwever, that there has been go site OA revieu of these vertical runs in terms of senaration of redundant syster cables.
3y centrast, there appears to be adequate control o-er the placement of switches, etc., at the console and over the rouring of cables into the spreading area.
The applicant was asked to perform an in-depth QA review over this portion of the cabling.
The scran brcahers uere not ins talled and, thus, could net be reviewed.
Also, the routing of cabics from the reactor trip panels 1445 176 11011DAl.
I E5 12 E72 V. A. Moore 7 4
to the breakers could not be revicued for the sane reason. The
.. cab.les co. the scram breaker.
- houl.d. b.e. run. in. four. indenendent trays or conduits.
I unders tand : :t Cc:71iance rill ve rify :ais item as well as the physical indepcndence of the breakers themselves.
3.
ESF Actuation Cabinets Our revie7 of the ESF actuation cabinets indicated that the schere for properly color cedin and separatina redundant ins truce-r signal wiring is not being implemented.
Uc were inforced that the sf.gnal
.viring was installed; hewever, there was no evidence.of three dis tinct (color coded) sets of ccaduit.
"e agreed to discuss this further at the enit intervieu.
During the exit intervieu ue were in.f.ormed that certain of the containment pressure suitch logic (tuo-out-of-three) was made up external to the ESF panels; thus, only two redundant signals (train A and B) uculd appear at these cabinets. This uas consis tent with the observed' tuo color sche =c (green and red).
However, ue were also infornad that the logic for the remaining signals uns made up in the cabiners; thus, three sets of conduit should have been observed.
The applicant was asked to pursue this matter further and to deter-uine what is actually being ins talled-at these cabinets.
The Compliance representatives were requested to follow this matter, including a review of the logic circuits uhich are external to the ESF cabine ts.
4.
Containment Aree None of the ins truments, cables, or impu3se lines have been ins talled. The Cenpliance representative were requested to follow and inspect the final ins tallatien.
5.
Diesel Generntors The tuo diesel ganararorc are located in separate rooms in a concre te s tructure. The coolin?, units are self centained.
Control and (output) pcuer tiring for the diesel generators are carried in separate underground ducts.
We observed no deficiencies.
V. A. Moore EE.I.1.? ;';72 i
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4160 Volt Motor Centrol Center
.The td.o 're, dun'dhnt ::CCs *.iere 'obs erved Eo '5'c idequately s~ebar~ated and m.
identificd. The ins talled redundant cenGuit was observed to be ade-quately identified (red and green colors) for the two etergency pcuer and ESF trains.
We cbserved no deficiencies.
7.
Batterv P.oors
' The tuo redundant sets of batteries and their distribution systems appeared to be adequately mounted, separated and ventilated. Ue observed, heuever, that several ligh tini fi.:tures of doub tful seistic integrity are suspended directly ove r the batteries.
Upon my return to Bethesda, I discussed this with Dave Lange who stated that he vill follou this iten.
8.
Control Red Patchine Panels We observed these panels costly to determine the potential for patching errors.
I remain convinced that there is censiderable pctential for caking these errors, and that the only adequate defanse is a careful cross-check with the hard uired " onc reference indicator" and the computer (also hard-wired) which displays the sane informatien as the zone reference sys tca.
Inasmuch as the zone reference sys tem and the computer comprise two
" standards" agains t which the patched rods could be conpared for patching accuracy, I asked if the acne 2nd co intar sys ters veuld 3e-cross-checked agains t each other during the,re-op tes ts. It would seem that such a cross-check eculd reveal ras e (through not all categories of) wiring errors.
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V. A. Moore IEAR 1 '.' l'72 This was discussed a uin at the c::it intervie'.i and my understanding is that the applicant a: reed to the sug3;es tipn, and.that.. the,
C6m;ilfance' re; ires eh'tla'tive's vill' fo'11c.,-uh on this iten.
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D. F. Sullivan Design Standards Branch Division of Reactor Standards cc:
S. Hanauer E.-Case P. Morris L. Low R. Minogue D. Knuth R. DeYoung R. Boyd D. Skovholt K. Kniel H. Schierling S. Folson (CO:I)
T. Varella (CO:I)
R. Cudlin D. Lange
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