ML19220B332

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Assesses Generic Implications of Fire in safety-related Motor Control Center at Tmi.Ie Circular Will Be Issued Instead of Bulletin
ML19220B332
Person / Time
Site: Crane Constellation icon.png
Issue date: 02/11/1977
From: Seyfrit K
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE)
To: Robert Carlson
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
References
NUDOCS 7904250644
Download: ML19220B332 (22)
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Text

{{#Wiki_filter:~ s-e e -[ s.. r FEB 111977 / Docket No. 50-320 hE40RMCUM FCR: R. T. Carlson. Chief, Reactor Construction and Engineering Support Eranch, RI FRCH: K. V. Seyfrit Chief, Reactor Technical Assistance Brancb, IE

SUBJECT:

PROPOSED ISSUANCE OF IE SblLETIM Ch A FIRE I:iSIDE A MOTCR CONTROL CENTER (MCC) AT TliREE MILE ISLUiD UNIT NO. 2 (TMI/2) MUCLEAR STATION (AITS F12106hl) This acorncu:2 is in answer to your request to assess the generic implications of the fire wnich occurred in a safety related MCC at Three Mile Island Unit 2 and to ceter:aine if the preposed draft IE Bulletin on this catser should be issued. This draft Bulletin also describes a similar fire which occurred on Maren 4,1976 at tne Trojan Nuclear Station. In each casa, the fire occurred in an ITE Series 5600 MCC. The cause for the fires was attributed to misaligned bus stabs of the assen!nlies connected to a ccabination circuit breaker starter unit. Because of the improper stab connection to the MCC vertical bus, an electrical arc developed igniting one of the vertical insulating barriers. In eaca incident, the fire subsequently rendered the affected MCC inoperative. We have examined the draft Berlietin and have detemined tnat the potential for MCC fires, at otter nuclear facilities has limited generic implications. In our review of this matter, we have had discussions with kneerleageable people frtzs several manufacturers of MCCs, the manufacturer of the vertical insulating barrier and tae licensees. As a result of these discussions, we conclude that issuance of a bulletin is not the best course of action to follow. Additional information supporting this finding was obtained during a special inpection of the HCC where the fire occurred at THI/2 Huclear Station by V. Tbc:sas IE:DQs on January 13, 1977. Our findings and r-M2tions are offered below, l. His-stabbing of HCC vertical bus bars has been a prooles for r.anufacturers of all McC's, however, recent design changes 7b--0G5 7904250f d o

FEB 11 1977 x.

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to vertical. bus barrier installations in taese units have virtually eaiminated the proclaa for cost manufacturers. 2. Tne - jor cause of the proposation of the MCC fires at both a Trojan anc T;il Unit 2 huclear Stations was the flawability characteristics of tne insulating materials usec for tne vertical and horizon +al bus carriers in certain ITE Series 5600 MCC's. These insulating materials are identified as Glastic "TSF" used for the vertical carrior insulation and ABS plastic used for the hori: ental barrier insulation. The "TSF" caterial is manufactured by the Glastic Corporation, Cleveland, Ohio, and the A55 plastic =aterial is manufactured by Borg Warner Corporation. 3. The Licensee of T!!I/2 Nuclear Station plans to replace the damaged W.C with a unit of improved aesign. A program nas also been initiatec to check. stab alignment cn similar ITE MCC's at this fac11 tty, using a test fixture supplied by the manufacturer. The ABS horizontal barrier insulating caterial will be replaced with a fire retardant caterial approved by UL and considered more suita le for this application. 4. For affected nuclear stations other than Three Mile Island, ITE plans to issue a technical letter alerting users of these MCC's of tne problem. ITE repcets that this letter will define the prob 1ts and provide corrective measures to resc1ve the si tuation. Copies of tne letter will be sent to the following nuclear plants: Arkansas huclear Plants, Units No. I and 2 Calvert Cliffs, Unit:No. 1' Cooper Nuclear Station, Unit No.1 Joseph M. Farley, Units No. I and 2 Femi II Three Mile Island, Units No. 1 and 2 TVA/ Watts Bar. Units No. 1 and 2 Yemont Yankee Washington Public Pcwer Supply System Unit No. 2 H. Zirmer Station, Unit No.1 Trojan Nuclear Stacion 5. Other r.anufacturers of McCs such as Westinghouse. General Electric. Allen Bradley, Scuare "D" and the like en: ploy insulating materials wnica nave excellent flame retarcant cnaracteristics ano, therefore, do not present the same potential for fires as the IlE un'its. W OGG

9 R. T. Carisca 3 FEB 11 1977 Ga tne bases of the atove findings, we do not plan w issue a cuiletin relatec to tnese fires. In view of tne pacential probles of c:is-staccin; associateu wi:n all tiCC's regaroless of manufacturer, we plan to restruc-ture your craft culletin and issue it as a non-response IE Circular to all nuclear pcwer reactors which are in operation or uncar cons:ruc-tion. e also suggest that assigned IE inspectors for the listed facilicies ascertain whether or not licensees receive the planned ITE technical letter and if appropriate reccmenced corrective measures are instituted. Enclosed for your information are copies of docunents containing pertinent supplemental information. Orignal sinea by, E.V. Seyfrit X. V. Seyfrit, Chief Reactor Technical Assistanca Branci; Office of Inspecticn and Enforcement

Enclosures:

1. GPU Interoffice Meco dd. ~12/16/75 2. GPU Interoffice Hec:o dd. 1/3/77 3. Ltr.. D. P. Rin olo, W to V.D. Thecas, IE ~ dd. 1/21/77 4. Ltr. D. P. Rinolo, W to V.D. Thoa:as, IE ~ 5. Technical Specifications for Insulating Materials Manufactured by Glastics Corporation (i.a., Graces TSF and UTS) 6. General Electric Company Specifications for Bus Support and Insulating Materials Used In GE NCCS 0 0 "g' t.) oIo:105S/R O CC ~ RTA: RIP:IE _RTA: RIP:IE.- o -'e =

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e fM87/C, aENERf L PURPOSEDEET STOCK ( FLAr.1E tests A suciect under current discussion in the plastics field is new to relate laccratcry ' ests of materials with Proof of Grade TSF Performance conditions in a full scale fire. and how to descrite the resuits to persons who may not te excerts in the field. It has been recem. Weight loss after 2000 C. aging 1/16' sheet mended that the feucwing statement be used as a caution: "The laboratory method c'escribed fo* flame tests an in-I f I dustriallaminates will not necessarily produce lnformation y with regard to performance of laminates under a full scale fire. This method. however. provides means of comparing l l materials under controlledlaboratory conditions." . ~. ' l C:mmecc:aav Avada e 5 -Oece ai Ps:cse c' ass vat i dELADE TSF {p M j ji Penester Sheet 5: ck l l.J An economy-priced, glass mat polyester laminate meet-g 2e ing NEMA GPO-1 specifications. Temperature index i = testing on this general curpose laminate resulted in 120' C electrical and 160* C mechanical ratings. Ex-b t: tensive field trials have proven TSF to be unique in ease "l , / ', of fabrication. Outstanding :unchability is experienced in the icwer thickness range with less halcing, recuced / I w w t2a m a dusting and powcering and greatly increased toci life

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particularly in high speed punching. Ang VALUES PRCPERTY CONDITION!NG TEST "ETH00 UNITS TSF Perpendac.!ar Cectne Strengtn, Shcrt Time, W" in air A l D-229 l veits/ Mil l 400 Perpen:!cular E ecn: Strerp. Sh rt Time, n'in air l A l D-229 l Vc:ts/ MJ l 500 r ;e

r Cectric Strerch, after heat. S.hcrt T;me, 200 hrs. 4 20C* C.

D4 Vcits/El 150 Paral!el E'enrie Stre-p :tes by ce;in air l A l D-229 l KV l a0 i Paradel E!ectne Strench after water, te; ty ne;in air l 043/50 l D-229 l KV l 15 At: Re::can:e l A l D 435 l sec:nds l 1:0 Car::n Tra:kMg ces:cance. n' l A l D-23:3 64T(D l rneutes i 1:0 P:w.r Fnt:r 50 Cic:e l A l D-li0-53T l 5 l 3.0 Tn;act Strerp l A l D-229 l Ft.-Lts. fin N:te-I 3.5 l F exural Stre-D j A l D-2:9 l Ps! l :0.0C0 l Flexural Strench tested 1130*0. l 1 hr. g 130*0. l D.23 l PSI l 12.C00 l F!exurai Streach after 9 eat. teste: 123*0. l

00 hrs. 4 20G*0.

l D-229 l PSI l 210C0 F!er.rai Strerg.h after Pest. 'nted 4 23*C; - - - - - - --} 650 hrs. @ 225*0.-- l D-2:9 - -l . PSI - l 7,5C0 - Cer;tes:ae Strerp l A l D-229 l PSI l 20.300 Water Ats r;t:c4 23*0., W" l 1 hr. @ 1C5*0. l D-229 l q in 24 hrs. l 14 Water Ats:r:acn a:ter test. W* 1000 his. 4 ;JC*C. l D-2:3 l % in :4 hrs. l 0.5 Water Ats:r;:,:n atter heat. W" 200 nrs. @ 2:5*0. l 0429 l 5 in 24 hrs. i 0.5 Thickne:s Retent.:n arter heat H hr. 4155*0. unter 15,030 ;u l 'J.S.T.C. No. 72249 l 5 l 97 We'get i:ss 200 hrs. 31E0*0. i 02:3 l 5 l 3.5 S;ec:r.c Oraury -- l A l D-732 - -- l - -- l 1.15 Cce fic:ent et Thermal Es;ans::n l A l C636 ' l P Int M/ *0. l 2.2 l l l ST.... [I l l 1.3 C177 Therrral Conductinty A g N.E.M.A. Grade Cespat:en l l l GPO 1 l Standard CcL:t l l l tan l Where testieg precedure is aconcacle, al! testing has :een done en %' thick material. AllM sph.h have teen taken from standard production runs. The preperty values shewn are consan,ative, cut because no warranty ts implied, test by the user shcold ce done to determine the t,est material fcr nis apphr.ation. 2

l ~ FLAI"IE RESISTAIS I -=plA-T>lu GENERAL FURPOSE SHEET STOCK l r M. ~ y eN oQo8-H. aw e' Oi cnA m urs ./ a ....r This UL reccgnized flame resistant glass mat (1 (~j i ../ a e o' pclyester laminate meets NEMA GPO 2 re i s quirements. Recent developments in mat con-l x * .e / , M- ', v struction pemiit cutstanding punching char. ' \\ 7 i x. Q.,. i acteristics. necognition ey UL ( 23cc5) of s t ~ general temoerature rating 130' C electrical, 160* C mechanical. This laminate offers de-gw g ej sign in applications where flame resistance is y. ,( (j ',.'l j mandatory, and higher retention of properties gs V( ;./ after heat aging is desired. ji 3 j

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N iY Ea! / M (QJ4 e U, n ASTM VALUES PROPERTY CONDITICNING TEST METHOD UNITS UTS Per;end:dar Cecr: ::rens*h. Shcrt I;r e. Mi* in air l A l D.229 l Vo;ts/ Mil l W Per;endcdar Eec.c S:renp. S'.:rt "ime. W in air l A l D.229 l Ve:ts, Mil l 5:0 Per;end.cdar E'e::nc S:tesp amer teat. Shcrt Time. Me":n a:r l 500 hrs. g 150*0. l D-229 l V:ttsMi l 253 Per;ent:dar Cecti c S:te: p af ter teat. Shcrt T;me. %s* in air l CC hrs. J ZG'C. l D-2:9 l V:Ps/ %I l DO ParaMel E.e:tn: Streap, s'e: ':y ces in air l A l D-229 l KV l 40 l Paradel Eecnc Streap amer water. Ste: ty Stes n air l 043/50 l D Z:9 l KV l 15 l Arc Retstance l A l D-435 l

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.D Car:on Dacung Ees:::ance, M* l A l D-2203-64T(!) l mm;tes l 25 P:wer fa;::r. :0 O de A .l D-150-53T l 5 l 2.5 f im;act 5:renp l A l D-C9 j Ft.-Lts.fln.N:!: s 3.5 Perural Streap A l D-229 l ?Si l l' Z0 l Pezural Strenp testes a 120' I hr. 4,120'0. l D29 l PSI l 2 Z0 l C:m;re:::ve Streap A l D-23 l PSI l 20.ZO Water Atscr; :en 3 23*0. Ma* l 1 hr. 4 ;C5*0. l D-229 l 5 in 24 hrs. l 3.75 l Water At: r;: n aner nest /..' l 1000 hrs 3150*0. l D 223 5 in 24 hrt. 1.0 l S;*cf:c Grav:ty l A l D-792 l l 1.75 U L S;tject it Pame M-tance. % an: ;p l l l l 3N 0 U.L Het Wire Igtt :n l A l UL l, secones l E0-U.L +gi Amp Arc Ig. men l A l UL l f ucc: ares j Z0-U.L W;n V:: tate Tracx Rate l A l UL l In.f%n. l 3 C:ef*ic:ent ;f T' ermai Ex:an:.:n l A l CE36 l 10-5 In/In/*C. l 2.') 0 11 Thermal C nduct v.ty A C177 y N.E.*A.A. Gra:e Ce::;na. ri i[$, @Q l GrCi i Standard C ::t l ) l l red Where testing procedure is acclica::la, all test:ng has been done on 2.ii' thick material. All test specimens have been taken from standard precuttien runs. The crc;erty va!ues sncwn are ccnse.vative, but because no warranty is implied, test by the user should be done to determine the test material for his application. 3

) f 1 V GPU SERVICE CORPORATION sys.a.,v s c-em w.c um.i.. co,x,u.o,, Subject CC - #2 Sus "aterial Location 3eadi 5 Date January 3, ic77 -. x To

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~-- a M As requested in ycur me c dated 12/21/76, Syste: Lab perfermed fla-aaility analyses on the three sa ples. All three sa ples vere identified as polyester reinforced fiberclass. T.2e pink slider cover appeared to be simile.r to the previcusly received pink sa=ple. One piece of the slider cover was ignited for e 30 seccnds, but that time proved to be tee severe for the sa ple. Ecvever, when this sa=ple was igrtted fcr 15 secends, it did self-extinguish. Tne pink sample received previcusly did not self-extinguish but since the current sample afforded a larger sr face ares, not as much of the sa:ple was consu=ed during the igniting period. See attached table and Picture I. Only cne sa=ple of the red hericental bus suppert was tested.

  • he sa ple was ignited for 30 seconds and C cst i mediately self-extinguished en re=cval of the fla=e.

See Ficture II. Tnree sa ples of the grey raterial vere ignited for 30 seconds each. ~ See O.c of the three sa ples self-extinguished al=cs' 4-ad'ately. =.< c +.,,.

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Ncne of the three sa ples seemed to support ec bustien, although the pink slider ecver was the easiest to ignite. If there are any questiens, please centact eicher of the undersigned. k.@. M R. M. Glass ) 4t/A u ?. S. Stener x s. r. m 12 c.s v i rt Ca* u'. C. '. a_' ' d '. .ma cre.4 vla File CC II. Flan = ability D ga-071 INTER-OFFICE ?.iE?.f 0R ANDUf.1

a a T MI UNIT *2 7 gy. I k l 6 _a i . _ _. c j t l. 4 j. t -1 m-l p ~. - .iyel4T Pl'Fl* Peri'T. el'e"'T'sl'T r"tT"1Te j '. 5.' el i i 2 I i 4 GPU SERV!CE CCFPCRAT CN e.. C';'-* SYSTEM t.AACIATCaf ~- ~~;i

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/ s PICTUP.3 Frem Top to 3cttc=: 1. Unburned slider ecver. 2. Slider cover ignited for 30 seconds. 3.&h. Slider ccVer istited fer 15 secends. T M I U N I T.S 2 __. u. ,.i--,<. _..., ~ -..,,. ,. ~ s. s .n e 4, m. = "1 t. ..J. - 1 y 3 . q .,q. Ll.,: _ ..- b-X h '~~ ', - CiP._ 'r; ;T"I'7"I'l'"'7'T' i E T'T'J'Y"lT'u' i.I ' J GFU SEP'.':CE CCFPCRAT CN ,e,,.., r. % r n.'.. C**-* $TSTIM LA8CaatCtf P T.C. w..wu Free Top to 3cttc=: '.. Unburned tus support. 2. Sus support idnited fer 2C secer.ds. rq _ nory 4 s) Ui4

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TT.T Fren Iop to Botte=: 1. Unburned bus barrier 2. Bus barrier ignited for 30 seccnds, total burn time 70 seconds. 3&h. Bus barrier ignited fer 30 secends, self-extinguished rapidly. NOTE: Sa:ple 2, 3 L L vere all ignited at the end en tne left side in this picture. TABLE MA-'I'IAL

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- r m.e...e.. - -V: - J IG'iTTION T3E TCTAL TDE (Tatal-Igniticn) Pink - Slider Cover 30 sec. 56 see. 26 sec. 15 sec. 22 see. 7 see. 15 sec. 17 see. 2 sec. Heri:ents_1 bus support 30 sec. 31 sec. 1 sec. (Red) Vertical bus barrier 30 sec. (Gray) 70 sec. 40 sec. 30 sec. 32 sec. 2 sec. i 30 see. 35 see. 5 sec. O 'ib 073 i e 1 I e

h 9 h GPU SERVICE CORPORATlON w~vscy/gu~,c-mn t ' a sdjm TMI-2 Plastic Materials Locaion Reading -p u t' tES Q , A) d Date December 16, 1976 - / SF j'y,s To J. Stoude q ) Syste= Laboratory received two sa=ples frc= nil-2 which were involved in a fire. The sa=ples were identified and checked for fla== ability. Using an infrared technique, the gray plastic wcs identified as an acrylonitrile-butadiene-styrene (A3S) plastic. The specific gravity of ABS should be between 1.01 - 1.07; the laboratory determination of the specific gravity of the gray plastic was 1.04. e This sa=ple was also tested for ignition te p The sample 105 - 110* d 'erature. ap,2ars to catch fire in the range of .aen this sample catches fire, it burns until totally consu=ed, leaving very little ash. The red =aterial was identified as a fiberglass impregnated with a polyester resia. This sa=ple did not catch fire as easily as the gray sample so a fla== ability test was perfer=ed. Strips of the material were ignited with a bunsen burner and ti=ed to see if they would self-extinguish. This procedure was modified frca ASni D-635. Three strips were exposed to the fla=c for 15 seconds. They burned for an average of 40 seconds before self-extinguishing. The sa=ple did not self-extinguish until the resin was totally consu=ed, leaving a carben coating on the fiberglass =at. (See Picture I) If there are any questions, please contact either of the undersigned. Qe) 7(,- 2 9' 0,$9 f "/ f D.P. RIZZCLO, PANAGER QUALITY ASSUR44CE I-CS I CC: hESTINGHCUSE ELECTRIC CCRPCRATICN CHICAGO GENERAL CCNTROL DIVISICN PR. M.D. MAYSACH MR. S. A. SPARIFF VR. G.P. KENNEDY PR. B.M. SHARTEEY I l t lls 07a'

Descr:ptive Builetin 12150 Page 3 h Type W Control Centers 600 Volts Maximum l ~ ing scly if cesirec) a 20-inen deeo struc-p-e-tu.e is used. Bern are free.stan:ing struc-L e b (;.qgg tures. Horizontal ::us in 15-ncn and 20-N lM% _ f

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,a ar inch ceep strue:ures are mcunted th'e ~ f',,,. I same distance frCm *Ne frOrt, so that Orm. d. 6 3. b binations of the two struC!ures can De l l uans er cus :rans.tien (see Figure 1). /g.73 front-ahgned witnou: s:ructura med.flCa-i gm .~ ~ ** {# ' t' i. i s I I s==

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Honzontal Bus kg,, , - se 4 I g,y ,y y, i je g Aquae 3. Veew of main hergentas bus snoeng 'eds E essia e A 6CO A. main non:cntal three-enase bus conections to.ernce bus. hato a:so swws now I' extenCs the C m lete :eng n of ea n struc-bus is sonced cetween two stancare contros cen-6 ture assemcly. It 's 'ccated ear :re tcp of 4L the structure. Hgrer ca:ac:tv a a'n cus. ue r== d r - 7 [. to 2500 amee'es. can te s,.

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e i ) w, 6 sucecrted by non 'ractng. ;iass remforcee j, e i s ! t, li 6 polvester insulators Anien are c;evous f jF 3 [ f [d to meis:ure and ciner ad.erse atmos;nenc y* g 'j, coeratng ceccidens. y; 'l ] i 4 G-% A "j - The bus assemcly es traced to witnstand ]. w U fault curren:s of 22.0C0 rms symmetncal b ,t j amceres. Accitenal bra::nq to witnstand ~ crr l* ( sgure 1. side view etn end co ers re-a 1 .t2.CCO rms amceres er hrgner can be acced T ',' iI j P ( moved. snow ng is..ncn structure coet) ] ^ l wn.ca accornmoca:es frent.n ci.ntea un,ts when tne cent 01 center is cor'nected to I.. i *.C g*, onfY. nn.ie 20-incas unit prev.ces sacs.fo. sys: ems carac!e Cf pr00uc:r g faults of in's ed back mounting. Location et norgental tus magn:tude. Atere cesared vertcal Ous from front is <centical for totn structures, isolaDon carriers can be proviced. Snich e can be remcvud for ::us inscecton without - - - [5 disrupting service. N t s They are ncrmally erectea '*;n Une." but .\\ l /.' by the use cf c:rrer sectens. *hev can te

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]Q / arrarged in "L" er "U" snacec assemenes. Incoming Cables ,-'-2 *n'* - 4. r=- w Incoming t.ne cacies entent'g ' rem tre ::p cr E l Two Stancard Structure Cecths bot:cm of the contrcl canter can te can. e nec:ed easily to sciceness L gs at e ther L ' 6-- {9 Westinghcuse Tvce W : ntrei canters ara a main breacer er tne main :: s. Tycica! [ j ~ previded in :wo s:andard ce::n structures. ar angements are snewn in F gure s For front-mcuntec ones criv. a 15-ncn 3 cec:al inc: ming hne arrangements inc:uc. ] p ceeo struc:ure ts ava iaele. nor uruts ing bus :uc: cennectens can ce cr:vtcea r p q'

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a / / / 7*" / - q, 'q _a,l j u J %: - / -- 1 a ~h t. r 7 ~ i s e t r d D ') l Q ' i O b,[- l ) e I w_ / f,. e i -j e p 6 a wL (i } } } } } } h ~ n y F<; Wa ps scrs er a::.t.crai cus at ett. ::ancard orac.no ior :leca -s seemeas y a suCOcris. VertCai Cus is Oraced cv tre amperes: at nqmt. aed.trenas oraeng for at:Co ems [/ J same M* ass-re'nt:rced OClves,*er irsulaters p! wirewn witn wiret e bracaets and uncostructed bot-used for :re main Ous. (see rgure s). tom,,nn,.,,ce. C I C2 Full-Decth Wi'eways Horizontal Winng Trough Full cecin vemcal wireways are avaif a le A nine inen scace is creviced at :Pe! cand rgure 7: cua,ter. turn rasteners (siot vemeai-open. in two typtis: bottCm Cf the structure f 0r Orcss-parel slot Moraontal-c!csed) provios gi.act and easy [ e incividual w:reway fcr each vertical winng. A winng trougn s located at :ne (0p ( accus to stanc un.ts. ccmplemy is: lated from tse nor.zontat compar: ment. bus. In cack-to-back des.gn a unng 7--- 3} M

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Centres canter. Wrewa<s are :Ove ed Oy AH unit coors rave f:rmed ed;es that cro-jq ? g, .. g f two Nrged :crs. eacn secured :y ;uarter ce ogic:tv. cresent f.r.4ned a:::earance. , :j, g [pi s f 'f .g turn fasterer:. FOr Osct TO-Ca:( Oesign, and ehmir'a:e snarD C:frer9 wniCN mignt ej COCrs are provicej :n COtn tre frCnt 3r'd tear. Cau!e d'urs. CCCrs are secured by ir0n- { C3tmg tyce Ouarter-tu"1 'asteaers 'Or Smce wint'Q aC:ess 50 'ndividual units raay cuiCK and easy aC ess. Harv'es are remov-F "'e a: ev emowns m scw from me uoew entet frem a':rar sice a "~'mmon urewav a le (by removing cr.e 3 re"w) as sn:wn S miage. tre coor is essav emoved wet $out J.sturning serves two.ert+ cal c racar:r ents.. nis in Figure 3. tn adow easy 000r removat otou units. inustrat.on snows pee raa..rrwo -

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ne mes:: e cact arrargement
  • nen ~arimum wert:ng access is Oesired.

aim accve voow singe. whde crowdmg c::: mum,vmng sca:e. pee Any deer mav ce remove: mircut cisturo-Figure 5). ,nq adpant decrs. (sN F cura 7.) Crawout Units Cutcuts are crc,<ded in the cecrs in all:w O'awout starter units witn eitner circuit Uncbstructed Ccnduit Space prosecten of tre cceratirg nancte are

reaner or fus.cle disconnects are sucched The c:er framewert :esign =revides man.

centret cewCes uren ec'rred. A tracket for meter s: art.ng cuty thrcugn NEM A size mum space fOr cordu:t entry at Octn tre weF!ed Cn thr. rear c' the 'OCr meC*.3-5. ach :s ces.gned into tas.C mcOular IC E9 and bcttom Of tne structure. Icaily interiCC..L ~~"i.1 b 4 N. N .Y[/ I -* g.M..,f L__. ; I a ~ 1 O ,_ vd ~ V h m u,e 2 2: Tn. m ner-two ucn can o. a y-g: W-t used to no.4 ene starter in tne %1 ciscon- ^*CT'd D8SCa-1 - 1'r* 6,*'S yy Egwre 9: T.cical dra.out unas *er motor control. }dO wo type VCP votor C.rcet Protectors. V.ew 6 14fjc snows contros ano caa wenng entenng rwi.ceptn i wire a sy. ' \\Y Agure 11: Typicas star ar unit (seae 1) witn tvoo VCP Voter Cacwt hotector Unit snown is .l , J., 3I NI III I} eqwooed mtn te<minal :.ocas for NEV A tvce 9 or C I Ag C,.,] g 8 construct:en. and witm start.s:op pusnbuttons and [ id'cmg 1.gnt. .jp_gg M C, s f - f m"L~iLF i m Ul. gFj-9 I .E hand cr aut ma:sc resett;ng features. Hand ,C' Off b y-- d resetting cf 3l1 centacts :s ac; rrChsrec OV a gv,) pushbutten thrcugn :ne Occr. E3ch line-l i- - i starter is ecwc:ec witn an internaily ured y-I inter 1CCk used f r ContaC:Cr seal-in. tutra i intericCks can te sucO!.td to crieet any Figure 13. The staner may be padlocked in g ,., g Contrel reqwremert. When scecif e10:n:rcl tne disconnected pos*on for saraty of per. -h _.'E M4 r MY transfctmers witn fused sec:ncary can ce net-I ~-~~~~'] O sucche1 All wirmg.s mace witn stranced L -#{ s-thermcClastic-insulated wue ratec 105'C. = / 8 Figure 10. Vagna Gno oNg-.n sta:s of craw-out POW'f Wihng 's Cla:t and of ade: Late S;;e unit.n fuit ccenectec rosmon with wenican Dus. No to C3rry tre maximum fullicad current fCr / q, % 4

h..}. ~ %. 7 3,

( stas ineg utenes.nto eus compartment. wnicn tre centac:Or is rate 1 Ac ::ntr:I 7.,33 winng is red, and Oc c ntrcl wiring ts ciue. 4 l '.f, J cacle connectens extencmg 'nsice each - I g unit. No stab winrg ex:encs Outs.ce its ' 0,' h.._..~,(%- &.. N enc!csure Guide Raiis ( Guice rads are secured to tre structure and i 1 located On eacn s:ce f tre ser*ical : m- - (P *f p c* N Starter Corroonents cartment near :ne :co cf each unit s ace gD Eacn starter is e:wc=ec witn a ::nmarv dis. Dese gwces are usec to sue: rt :ae uni as cennec*irg ewce-e'trer a Westingscuse wel as o abgn it re:erty witn :re ::us.

/L _ y 3

Shoui:er oms en eacn s:ce Of tre umt fm tre A i type MCP met:r : rtwt cratec:Or er a cuicx mate. cwcx bream us. ie-::ta:e rvce guides anc crecuce a minimum of fn:!.cn DS switen : m::med wi:n fusing 'ac: lit:es resistar ce wren cenrecting or ::scont ect. F-Jure 14: starter urut is essay nfted cat of.ts

  • *'N for use uth current.W. ting. re,ec:: rurt;e.

mg tre slacs etn tre cus. A t',cical gace NEMA class ' u uses. Acmties f r NEV A rad is snewn in Fgure 8. -] h,, \\ p_ }. j 6 class "W' fuses may te Or vicel Out in mcst cases el re:wre a f arger crawout l N I unit. The !:tal ava.lacie sncrt-c:rewt ca-Unit Latching and Removal i 1 aacity of :Pe s'. stem ic when.ra < Ontrci -:acn drawcut unit is ::rcinced witn a 1 c" enter fs cenrected must be c Ps.0ered.n sFreuced la!On (screw:nver ageratec) h I prccerly 3Cpf ying fuses and treamers. unich serves a dual Ourc:se. hrL to assure t [ _'.Y 8 / Octh r(ces Of distannec's are exteraally uit conrectec ::csi:icn cf :re unit !c tre l ~ bus and to ncid it secureiv.n tre cont ected ccerated by a Fan le mecnan:sm which is siten. secenc. :o assure M -isten re:*ed [ mcuntec cirec:!y On tre 1sc nnect. 0 siticn cf tre urit fr m tre cus arc to ncid Fgwe 15: 4r safety of ce'scaret. t. seamer nancia crav be acted.a tre O rt" sos.-

  • tandard hrestarters are ecw ced witn it securely in that 00 sit en witn Oa ::cbnq inree-ccle arabeat c:ra::ersated thermat fac.hties to assure a cermanent in-clace cvertoad relay assemCises with aclustacie safe position cunng maintenance.

r'O~080

f u-%)) / / 2 / i _s ' "- '7, Wesiinghause am cro c. m Electric Corporation 3r,w m sm C cm:ms EC532 . January 21, 1977 United States Nuclear Regulatory Commission Office of Inspection S Enforcement Washington, D.C. 20555 Atta: M. r. Vincent D. Thomas Subject-Motor Control Center fires related to plastic bus insulating materials t

Dear Mr. Thomas:

l i l This letter is in reference to our January 18th, telephone con-versation regarding the possibility of sustained fire in the ,e bus system of the motor control center during faults. I bring to your attention the fact that all the plastic components used j for supporting the bus bar system of the Five Star motor control } center conform to U/L Standard 94VE0 or 94VE1, and thus, would [ not sustain fire. To make it easier for you to get a clear idea of the bus system and various plastic components used in our control center, I am enclosing Descriptive Sulletin D3-12-155 and referring to the text or photos therein while describing the type of plastics used. The following are the details: Stabs Page 3. Sotto= two photographs. These photographs show the plug in type of contacts housed in the stab L'.ock. This stab block is molded of Noryl SE1/GTN-2. This is a thermoplastic manufactured by the G.E. Company and has a flammability rating of 94/E1 (self-extinguishing, non-dripping, Group 1). Vertical Sus Insulator Page 6. The vertical bus is neld t" the vertical bus insulators shown in the bottom photograph, page 5, whicle in turn are held by the steel l braces. Tha vertical sus insulators are melded from Rosite 3550FM thermoset polyester. This plastic is manufactured by Rostone .f VL 081

Mr. Vincent D. Thomas Page 2 Corporation and carries a flammability rating of 94VE0 (non-burning, non-dripping). Vertical Bus Isolation and Insulation Page 7 The vertical bus compartment is isolated from the unit compart-ment by a full height barrier. See page 7, top left hand photograph. This vertical barrier and the snap on covers and shutters are molded from UTS grade thermoset polyester. This plastic is manufactured by Glastic Corporation, and carries a flammability rating of 94720 (non-burning and non-dripping). i For Nuclear Power Plants, our standard practice is to supply the vertical bus with insulation as well as isolation. This is achieved by means of a labyrinth barrier. See photograph on page 7, top right hand side. This labyrinth barrier is molded from Rosite 3550FM thermose: polyester sheet molding compound. It is manufactured by Rostone Corporation and carries a flammabil-ity rating of 94VE0 (non-burning, non-dripping). Sleeving at the top of Vertical Bus Assemblies Page 7. Sottom Left photograph. Plastic sleeving is applied to the vertical bus in the area 8 where it crosses the horizontal bcs to insure proper electrical clearance. This sleeving is molded from Noryl SE1, is a thermo-plastic material manufactured by the G.E. Company and carries flammability rating of 94VE1 (Self extinguishing, non-dripping). a I Horizontal 3us Insulators Page 7. Sottom right photograph. The insulators holding the hori: ental bus are molded from Rosite 3550TM thermoset polyester. This plastic is manufactured by Rostene and carries a flammability rating of 94VE0 (non-burning, non-dripping). Thus, it can be seen that none of the plastic compartments will sustain combustion and a fault in the Five Starbus system is not likely to produce a fire hazard. If 'Je s tin gh ous e, Chicago General Control can be of any further help in your project, please contact me. Yours truly, cc: M.D. Maybach, i Chicago S.A.

Shariff,

'd G.P. Kennedy, 7 ,, /,,, 3.M. 3harteey,] p -N e n c.3 Donald P. Ri:/ Jo, Mai.ager ak Quality Assurance '/y. -()Q

Descriptive Bulletin _,(, 12-155 % '/ Page 3 Feeder Tap Unrts - -{ ' O II_ .~.', P --*'] Feeder tap units may contain eitner cirewt The CS switches are succlied with fusEg breakers or fussb!e switches. Craw-cut facilities for use wdh curren:Jimi ng or dual -"m ]. - breaker units irctuce tne fixed tric T,ce FS. element re:ection type. NEVA C: ass '*J" cr (e r--MJ w q j[ - -i singie or dual mcunted in rating: rreuen 150 "R" 'uses. Fac.l.t.es for N EMA C: ass "H" v) i I? amperes and the interchangeacie trio Ty::es fuses can also ce supplied. ~ .-(' [ [ [ ? W KS and LB singte mounted through 250 am-y peres and 400 amce es rescec ively Larger k j j), etcuit breakers are non draw-cut fixec g:.:f ~[ ' ' ("AJ' .O mcunted. Adlustacle seitronic treaker :s .-, _ w f' standard. Ratings to 2000 amceres are avail-i d, 4 a ble. ? (' y'*- " ~~'~~-- p ' Fusible feeder tao units utdize the Tyce CS d ~, b==L Switen thrcugh 200 amceres. Ncn auto ~ -- N breaters and fuses are furnished for 400 am-peres and acove. These switches

  • e mounted in draw-cut units thrcugh 400 am-peres with the 30 amcere and 60 amcere rat-ings avadacle in dual mounting. Ratings from 600 amperes thrcugn 1200 amceres are fixeJ mounted.

Terminal Biccks d' A new side mounted terminal block is stand-Standard track mounted terminal biccks in- [ -.a._. ard on units with NEMA Type B cr C wiring. c!uce the follcwing tyces: Standard Pressure j g. _j These terminal b!ccxs are mounted M knock. Ccnnector. Stardard Prescure Pull Acart. g f"' C outs on the wireway side cf the unit wracoer. Straight Ring or S::ade type for enmo termi-f- Eb This placement crr:vides greater access to nations. and Pull. Acar:R;ng or Scade type j) 7 cther com ponents within the unit. for crimp terminations. When mcunted in this 1 Q fashicn, a maximum of 20 c;rcuits can te [: The terminal bicck is available in three types; prcvided by the Standard Wes::rg hcuse A Standard Pressure Ccnnactor Pressure Pressure :yces and the Ring and S cade tyces. Full-Acart and Pull-Acart for ring or scade Wiring within each unit and tc the remnai type crimp terminations. The smal!est starter blocxs is mace witn '6 AWG strarded unit (2X or 12 inches nign) can acccmmcdate !hermcclast:c ir'sulated wire ra:ed 'C5'C. up to three of the new s,ce mounted terminal Power wiring is black and sized to carry the blocks providing a maximum of 21 circuits in maximism fuilicad c *ent of :ne un t. AC the standard pressure Wees and up to 13 cir-centrol wiring is red.ad DC centrol wiring is / cuits in the scade or ring tyce. Larger starter blue. ?'ugan tyce terminal biccus can c,: units can acccmmedate and;tional :erminal sucpiied for ai! con rcl wir:ng and icad wiring blocks.

hrcugh size 2 when soec:fied.

As an alternate. terminal biceks may be mounted across :he bottom front of the unit. Stab Assembly A newly designed two ecmcenent ecccer Four stab assemcly sizes are used: 50.

  • 50, a!!cy stab incerccrates ne uit: mate in 200 and 400 amceres to accurate'y match the mechanical simclic:ty to crevice prae:se con-efec:rical requirement of each unit.

%) trol of contact pressure on :ne tus. This as-l

  • [;.h

/ 4 sures a ocsitzve connec: en yet ::ermits easy A unit inser son and wondrawal. Seif angning m e Magna-Grio 3 s:a::s are mcunted in a g' ass [c ( .s-Y/g {w p y ; - *-- - . 3._ reinferted plast.c insu!aticn ciccx ansch :o-I.h, '# 4 4 g ,t -;s tally shrouds eacn stao and aosolutely en- , 4 ,1 I. ' ~,( M.$ sures ecsitive alignment Of the stats with the /- M , k* / ver:ical bus. The insulation biccx is also an in. V /

  • f. _

, ' j y-Nk D (N' f *, N tegral cart of the enase to :: nase isciation V.,,. A L;1 i sys:em. Power wirang s firmey weided to the y p stabs and is totally contained witnin tre unit y Q I 'r, D y g encicsure. This means :ne vert cal cus ccm. [ ~, ' - partment is ccmcie!e!y free of wiring for max-h' [h] b( s 6 mum safety and rehabsiity, L.

? / age 6 ? k I Units. Cc nt;nu ed il 8us S ystem Page(s) Vertical Sus.. 6-7 Nameplates N Horizontal Bus 7 Unit namectates are cf duracle anodized Neutral Bus 8 e N.7. ~ aluminum w:th '.'.ncn hign white let enng on Ground Sus.- 8 .?-- E a black bacr;rcuna. They are neat arc crack Centrol. Lead and incoming jy C q

y y_

resistant to ehminate the need for replace-Line Terminations. 8 1-l 1 -- *: !O Fpi ment. Nameolates are enounted with a pres- [' ~ jl 3 are sens.tive acheswe. Rivets or screws can N k-f ce used if specded. i l ll' i li i p t-q * ; [ y/ o n .i,,n Modifications I i t i. i tv Starter and feeder tap unitt. can be modifled I to meet a var:ety of scec:ficatien recuire-l N mitnts. Some tycical ccmconents which can N be added inctude; contrcl circu:t trans*or. h j. mers - fused or unfused; centrol relays. VCR i !( , p lj j j y [; y !.,1 ; { 1 (f0ccular overicadi relays. gecunegard re-4

  • ',: l

[' : J li. Iays, current transformers. extra e'ectricalin- _i terlocks. ::ushcuttens. se ector switenes in. dicating lignts, c:rcu.t breater shunt tric cr Ng ( undervcitage release and auxiiiary switenes. !i in most cases, these mod:8ications do not in - OE[ ]

  • ?

1.i crease starter unit size. j-j l Qj Additional E::uipment r In addition to mctor starter and feeder units i additional ecw;; ment can be succiied inc!ud. ing the fcllowing:

  • l N

l N Singfe chase dry tyce distribution transfor-mers in ratings of 3,5,7.5,10 and 15 <VA. l 7 I / i / Three phase dry ty;:e distr:butien transfor-mers in ratings of 9.15. 22.5. 20 and 45 KVA. Ughting pane!bcarcs with 12,18,24.20,26.

1. Bus System er 42 circu!ts w1:h euner plug ;n branch breakers or bc;t.on cranch breaxers.

Vertical Bus De vertical bus prevides three ;;hase pcwer Current h.miting reactors w!!h chmin va:ues of g g ...I J .01. 015. 02 and.025 and amcerage ratings cistr: button frem the m+.in horizcntal bus to 8 1 h { j of 600,800, tCCO and 1200. the ver*ucal compartmen s. The cus is a 41 j unicue angular configu atten witn an "L" or i ) { ,j Metenng ecuicment suen as voltmeter, "Z" shace cecencing en bus rating matenal h a 3 4 and wr ether the structure is cack to cack or / 1 jI ammete*s. aattmeters and pcwer facter 4 front mic. nted only. These snaces have the U meters-ij i s i in h ere,. rechanical strength to witnstar'd I { F L fault stressa. They also previce a smoctn --- stabbinc, surface for unit connection. ,j- %j g ' y .~. g N I Dl s b, } !! fj i P L L, - I ~ g.... s ~a Cut to the high strengtn c3C3bei:ty Of the bus bars, bus bracing at 42.000 RMS s vmmetrical amperes is standard. Cc cnal trac:ng is availab!e at 65.C00 and ICO.CCO AMS. Sus f braces are mt.1ed frem a glass re:cicrced ( polvester material wnich is non-tracking and impervious to meisture and cther adverse atmosphar c cperating conditions, t~E.- Lf\\pp (.-

? @Descrictive Bulletin 12 155 (iDi m .N Page 7 \\ Vertical Bus. C:nt.n u ed The exc:usive PCLYTET 50 crecess further and the barrier wNch minimizes air ;cchets.

mproves the corrosion res;stant cuaht es of This ;nsures ecmciiance utn *.EVA and UL p,-

~ ~ -.j i tin plated atumini.m wnen used in severe en-heat rise s:ardarcs. When tus Orac:ng cf vironments.lt also crovices a luencating ef. 101C00 PMS ameeres is sucched. the jf 8 -g ,i fect which prevents staes from galhng and tatyrinth carrier es provided as stancard. facilitates e asy removal and insertion of I' 'l [ W A ' i 7 I u nrts. - = - = - g 1-# I .b Isolation of the vertical bus ccmcartment j

  1. [-[f,

'l I' ........f. I from the unit compartments is accompusned j i ) i 9 f,,9 ^ g y g - [ by a full heignt carrier wnich :s creviced as t, i e standard. This :s a seg!e sneet of gtass-lJy,, - .f d )8 ( j reinf orced Ocivester with cut. outs to aucw ,/

  • s u. 6 l.-..

_1 the unit stats to engage the vertical tus. = T* ];,- [-- Snap in cov ers are in stad ed ove r unused cut-An automatic shutter mechan:sm is inc!uced .[ ,y[ 1 out coenings and are ava,lat e fer temcorary e 1 installation over used caenings to =rovice with the labyrinth carr:er to crov ce ccm :ete f

r v

- )[i. i isclation of the vertical tus. The snu: er ,t total isota;.on during maintenance crece. moves automatically to c=ver the s:ab ccen-d L dures. ings when a un.t is removed. This provices The vertical bus is availa fe in ratings of 3C0. When insulation and isolat:on of the vert: cat maintenance personnei witn mammum cro. SCO. SCO and 1200 3-peres for front r.icunted bus is rewired a lacyr' nth design barrier 's !ect:en since the verticzi bus is never ex. only, and 5C0 and 300 am eres fcr bc.ct to available. This barner is moided glass rein-Ocsed. As the unit is re:nseced ;n the ccm-back meurted. Stancard vertical bus bars forced colyester and fcrms a lacyrinth partment.the shutter movt:s sideways to un-arounc the bus tars to res:rict f ault Orcoa. cover the sta b openings in the carrier. through eC0 amceres are t n p:ated aluminum with the spec:al PCLYTET-50 ; recess. C ccer gation. This design provides maximum pro-bus is available as an cction in 3C0 and 6CO tectice rgainst enase to cnase insulation amperes and is s:andard in 800 and 1200 am-breandcwn. Thermal erfic:ency is maintain ed by a c!cse tolerance fit between the bus bars pere rating s-Horizontal 9us The main honz:ntal bus ;s rated at 6C0 am- ""N ~ / l',; {' g _,_I -dl b "a peres as stancard with ratings of 500. ICCO. ic L l l 1200.14C0.1600. 2000 and 2500 ameeres co- 'g tionally availatie. Tn-plated aluminum bus I.b, h j }

  • h i ars are succlied as stancard. Tn piated b

k l lI f aluminum or coccer is avadabie for ratmgs l g ~ b l fli iQ ~ ] Q! j s'~ ] up through 1:00 amperes. Above " 9 am. 7e[ ~ peres only cc=cer bus is sucched. ae exclu-I l l7 i sive PCLYTET-50 crocess is ap ded to all T ,1, lf [ ( e tin-plated aluminum honzental bus to further 't if 7 'f L l[i _L d. M U Q "E improve its corresicn resistant procert;es in I i, severe environments. i l" ~ T EJl, h The main honzontal bus crevices three chase The herizontal bus is rated at 55*C tempera-power distribut.cn frcm the meeming hne or ture rise in ccmcliance with NEMA standards. ~ k} ,, f ,, Q,, 2 pnmary cisconnect device to eacn vertcal A rat:ng of 50*C temcerature r:se to comony struc*ure in an assemciv. The ous cars are with UL Standards is avada:te as an ection. j mounted in a vertcai : lane. ecge to edge. j _ {; r-' 1, ! [ 1 This mounong crecuces an excepte.ity The henzontal main bus is.scle ted from :ne a ? strong assembiy acie to w,ths:and hign fauit too r'erizontal wireway compar+ ment Oy an j 1' isciation barner. Thisho crece s: eel barner l ctarrent stresses. 6* extends to the full wictn cf eacn vertcai d Standard herizontal bus tracmg is 42.000 structure. The two piece design ancas access p i, j RMS symme;ncsi am:eres. Cetional bracmg to bus connections m:nout the removai of _ _ Ms g .m_ is availabfe at 65.C00 ano NO.CCO RYS. Sus tne entire carner. fer acced mamtenance ~ braces are molded from a gass remf erced convenience. The tus car layaut permits polyester matenai with hagr. streagin *nich is frcnt access to all bus ccnnections. This al-non-trackmg and.mcervicus to moisture and !cws maintenance personnel to maae sonces other adverse atmoscnenc cperating conds-and ct'ect schce toit torques from the front -() d tions-of tne structure.

'm........u---...... e. Q L. &-0 Rd.y ^ G E N E R Al. 9) E i.E CT R I C b Proposition No. c o 11 P A N Y Spectricat. ions ,o. i ~ SPECIFICn. !CNS i BUS SU??CRT A!!D E SUI ATIC:T 1%TERIAL Eaterial used in 7700-Line l'.ctor Centrol Centers for 3us insulation and supports isla=inate c Grade UTS is a flame retardan: glastic grade LT'S r. terial. Laboratories under their reference specifications, and recognized by L'nden riters' at 150 degrecs C. I: =eets It is U/L cpproved as being fl,are resisten nu bcr E-23525 It was selected as effering :he best balance Cencral E1cetric specifica ica AlcE13-E. of required elec:rical and mechanical strength under various environ =ents and conditiens }'anufacturcrs are to subnit in trip'icat it t2ir,ht bc subjected to in this applica:ica. hat their materici has been tested to =ect our -certificates t This caterici is also used as barrier and support =aterial in our General Electric levcis. Before selecting it, the =aterial was Limita:p.' Centro 11er for 5000 vol: e have cxhaustively s:udied and tested in our Roanche and Philadelphia Laboratories. had no reports of any unsatisfactory perfor ance of this caterial in Limitamp controlle. Edison for their study. In additica, sa pics of this =aterial were subtit:cd to Detroit 5000 volt systets. - _Af ter review th2y accapted the Li=i:a=p centro 11ers for use en . This naterial is also used b'y our bedium voltage Switchgear and Distribution transfor= . Depart.=ents for si=ilar functions. FD ISII FOR S T.EL FJ.E'.!AIE A':D U TPAU IED ? ARTS A., Standard steel harduare and other unpainted steel parts are nine plated.0002" - .0003" thich and coaccd with a bronze colored chrc ate coating unich vill cc: }IIL SPEC QQ-Z-325A Class 3, Type II (100 hours 20" salt spray tes: before white corro'sive products occur). Publicity ncecplates bearing the Cencral Electric onor,r:= are anodized en brush- ~ B.. finished aluminum to =cet IIIL SPEC MIL-A-8625A Type. II (approxiestely 240 hours in,20% salt spray test). ~. a T 1 s 8~ e i ~ g .Y ^ Y ~.

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  • 4 e

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