ML20215G103

Summary of 861117 Meeting W/Util & Bechtel Re Seismic Adequacy of Plastic Tie Wraps as Cable Supports in Vertical Raceways.Attendance List,Article 300-19 of Natl Electric Code & Discussion of Issue as Contained in Module 22 Encl

ML20215G103
Person / Time
Site:	Vogtle
Issue date:	12/19/1986
From:	Mark Miller Office of Nuclear Reactor Regulation
To:	Office of Nuclear Reactor Regulation
References
NUDOCS 8612240287
Download: ML20215G103 (26)

Text

_ _.

'o UNITED STATES

! n NUCLEAR REGULATORY COMMISSION h WASHINGTON, D. C. 20555

\...../

. 1 9 DEC 1986 Docket Nos.: 50-424 and 50-42:

APPLICANT: Georgia Power Company FACILITY: Vogtle, Units 1 and 2

SUMMARY

OF MEETING ON PLASTIC TIE WRAPS AS VERTICAL CABLE SUPPORTS Cn November 17, 1986, the staff met with the applicant and its representatives to discuss the seismic adequacy of plastic tie wraps as cable supports in vertical raceways. This issue was identified during the staff's review of Readiness Review Module 22, " Independent Design Review." Participants are listed in Enclosure 1.

The independent design review (IDR) was conducted by Stone and Webster who identified the issue of plastic tie wraps for cable support based on guidance contained in Article 300-19 of the National Electric Code (NEC) (Enclosure 2).

Enclosure 3 contains the discussion of this issue as contained in Fbdule 22.

In its presentation, the applicant stated its belief that it followed industry practice in its use of plastic tie wraps and stated that there is no FSAR comitment related to cable tie wraps. Bechtel also stated that it does not refer to the NEC as a construction practice. The applicant indicated that the c tie wraps are used before and af ter corners in a horizontal run and on a

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horizontal to vertical transition of a cable tray run. The tie wraps are secured around metal brackets in the cable trays. The ties are spaced 4 ft apart on vertical cable runs. The cables are tied at the tie bar prior to entering the tennination panel and are also tied in the panel area.

The applicant also stated that construction specifications describe how to install the tie wraps, and crafts are trained in proper installation techniques.

The applicant explained that the NEC Code suggests securing conductor supports within the first 25 ft c.d then every 100 ft thereafter and that the Code does not specifically address cable.

The applicant's review of the Vogtle cable runs indicated that 10 out of 94 cable runs required the addition of a fitting over the siderail of the tray to take some weight off the cables. The 94 potential cable runs were identified through walkdowns perfonned by 1 to 2 engineers of 200 raceways. These 200 raceways were identified through a drawings review. The averace lenoth of a

, vertical drop of cable was 30 ft with the worst case between 40 and 60 ft.

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The applicant presented calculations showing how much load a cable tie can take before breaking. The applicant assumed that cable slippage is not a credible failure mode because of lateral deformation of cable under seismic conditions.

Shake table tests of the cable were also perfomed by ANC0 Labs. The tests involved 5 ft and 10 ft spacing of the tie wraps. Maximum accelerations were 2.2 g and 1.8 o in the horizontal direction and 2.2 g in the vertical direction. Acceleroneters measured data in three directions. Conclusions from the test data were (1) no cable slippage, (2) no calle tie breakage, and (3) no cable ejection from trays. The applicant also perfomed static tests of the following cable configurations: large single cable, small single cable, large bundle of cable, and small bundle of cable. The large bundle of cable test resulted in the lowest safety factor.

Following the applicant's presentation, the staff questioned the' number of tests performed, the performance of the tie wraps at higher temperatures, aging effects such as relaxation, safety factors assuming one tie wrap breaks, industry practice, and the installation process. The staff also requested that the applicant meet with Stone and Webster to determine whether the proposed resolution would satisfy Stone and Webster's original concern.

Ir1 portial response to some of these questions, the applicant indicated that a poll of ten Bechtel plants showed that all ten use plastic tie wraps for vertical cable support. The applicant also stated that NRC regional staff had looked at the use of plastic tie wraps at Hope Creek. The applicant comitted to meet with Stone and Webster, discuss resolutions, and obtain Stone and Webster's final conclusion in writing.

The applicant indicated that it would provide additional information to the staff within several weeks.

W 0.hl%

Melanie A. Miller, Project Manager PWR Project Directorate #4 Division of PWR Licensing-A

Enclosures:

As stated cc: See next page l

The applicant presented calculations showing how much load a cable tie can take before breaking. The applicant assumed that cable slippage is not a credible failure mcde ' :ause of lateral deformation of cable under seismic conditions.

Shake table tests of the cable were also performed by ANC0 Labs. The tests involved 5 ft and 10 ft spacing of the tie wraps. Maximum accelerations were 2.2 g and 1.8 g in the horizontal direction and 2.2 g in the vertical direction. Accelerometers measured data in three directions. Conclusions frcm the test data were (1) no cable slippage, (2) no cable tie breakage, and (3) no cable ejection from trays. The applicant also performed static tests of the following cable configurations: large single cable, snall single cable, large bundle of cable, and small bundle of cable. The large bundle of cable test resulted in the lowest safety factor.

Following the applicant's presentation, the staff questioned the number of tests performed, the performance of the tie wraps at higher temperatures, aging effects such as relaxation, safety factors assuming one tie wrap breaks, industry practice, and the installation process. The staff also requested that the aoplicant meet with Stone and Webster to determine whether the proposed resolution would satisfy Stone and Webster's original concern.

In partial response to some of these questions, the applicent indicated that a poll of ten Bechtel plants showed that all ten use plastic tie wraps for vertical cable support. The applicant also stated that NRC regional staff had looked at the use of plastic tie wraps at Hope Creek. The applicant consitted to ncet with Stone and Webster, discuss resolutions, and obtain Stone and Pebster's final conclusion in writing.

The applicant indicated that it would provide additional information to the staff within several weeks.

Pelanie A. Miller, Project Manager NiR Project Directorate #4 Division of PWR Licensing-A

Enclosures:

As stated cc: See next page R-A PWF WR-A i r/mac BJiu lood Ic/ 0 /86 12/j l6 1

, ..I MEETING

SUMMARY

DISTRIBUTION i

1. l!IidiiFF11FM ~

NRC Participants NRCPDR ~* M. Miller L PDR N. Romney NSIC. S. Chan 3 PRC System D. Jeng 'l PWR#4 Reading File G. Imbro Project Manager M. Miller R. Parkhill M. Duncan R. Ballard 0GC J. Partlow E. Jordan .

B. Grimes I ACRS (10) l I

I OTHERS f

l i

bec: Licensee & Service List

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. Nr.'d.P.0Reilly Georgia Power Company Vogtle Electric Generating Plant cc:

Mr. L. T. Gucwa Resident Inspector Chief Nuclear Engineer Nuclear Regulatory Commission Georgia Power Company P. O. Box 572 P.O. Box 4545 Waynesboro, Georgia 30830 Atlanta, Georgia 30302 Mr. Ruble A. Thomas Deppish Kirkland, III, Counsel Vice President - Licensing Office of the Consumers' Utility Vogtle Project Council Georgia Power Company / Suite 225 Southern Company Services, Inc. 32 Peachtree Street, N.W.

P.O. Box 2625 Atlanta, Georgia 30303 Birmingham, Alabama 35202 James E. Joiner Mr. Donald O. Foster Troutman, Sanders, Lockeman, Vice President & Project General Manager & Ashmore Georgia Pcwer Company Candler Building Post Office Box 299A, Route 2 127 Peachtree Street, N.E.

Waynesboro, Georgia 30830 Atlanta, Georgia 30303 Danny Feig Mr. J. A. Bailey 1130 Alta Avenue Project Licensing Manager Atlanta, Georgia 30307 Souttern Company Services, Inc.

P.O. Box 2625 Carol Stangler Birmingha'n, Alabama 35202 Georgians Against Nuclear Energy 425 Euclid Terrace Ernest L. Blake, Jr. Atlanta, Georgia 30307 Bruce W. Churchill, Esq.

, Shaw, Pittman, Potts and Trowbridge 2300 N Street, N.W.

Washington, D. C. 20037 Mr. G. Bockhold, Jr.

Vogtle Plant Manager Georgia Power Company Route 2 Box 299-A Waynesboro, Georgia 30830 Regional Administrator, Region II U.S. Nuclear Regulatory Commission 101 Marietta Street, N.W., Suite 2900 Atlanta, Georgia 30323 Mr. R. E. Conway Senior Vice President and Project Director Georgia Power Company 1 Rt. 2, P. O. Box 299A Waynesboro, Georgia 30830

4 Enclosure 1 Participants NRC Bechtel M. Miller A. Hadjuan N. Romney D. Jagannathan S. Chan R. Gross D. Jeng S. Hayter G. Imbro D. Monor

": !'OP Southern Company Services w.15ie/J2 k J. Bailey R. Thomas W. Ramsey

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,, NaflONAL ELECTRICAL CODE AR 318-CABLE TRAYS 70 183

-ee ut r r' (e) Equipment Grounding Conductors. Metal in cable trays. as

• "e'  % denned in Table 318-6(b) (2), shall be perir.itted to be used as equipment v a "r

• 6a e" . ,J grounding conductors in commercial and industrial establishments only.

Aaren C .here continuous maintenance and supervssion assure that only quali6ed

['x ,,'u ,jb8" j persons will service the installed cable tray system.

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(d) Hazardoue (Cteemifted) Locations. Cabic trays in hazardous (clas-g sined) locations shall conta's only tbc cable types permitted in Sections 8 vlees sho.c m Tat es Jao ev, 31470. 31481 and 3t482 m w r. 5014,50b4, and 503-1 Ns o$En "

Pimm.

i rs b$t$s"d7*10ed r en 318-3. Uses Not Perimetted. Cable tray w" - Ampacine, doen :n Tabies fc hoistways or where subjected to severc phys >, systems shall not be used cal damage.

310 77. 3l478. 31479 and 31444 *

'he tables are locaied in the outer ducts of the duct bank Ampacsuas b e mnce c'ecu e r tv r duct 318-4. Construction SpecJfications Cable trays shall comply with the bank ill have 10 be determined by speranj j, following:

• $ (a) Strength and meldtty. Shall have suitable stresgth and rigidity to -

p, provide adquate support for aD contained wiring.

ARTICLE 318 - CABLE TRAYS = (b) Smooth Edges. Shau not preacnt sharp edges, buirs, or projections A cable tray system is a unit or assembly of units or T injurious to the insulation or jackets of the wiring.

xhted 6ttqs made of metal forming a rigid structural (c) Corroe6on Protection. Shau be made of ccerosson-resistant mate i. l r;w ub;cs Flarne retardant nonmetalhc materials shah al or, if made of metal, shall be adequately protected against corrosion. I corienve areas ar ns alude Ide,'d it: areas requiring voltage isolation. (d) side name. Shall have side rads or equivalent structural members.

o "ctures. iraughs, channels, solid bottom trays, A I (e) Fittings. Shall include 6ttings or other suitable means for changes itent m direction and elevttim of ruet

.T t'a's . tit ck to require that cables be installed in $

is * ' L recognite tt c ue o all f conductors described in 4 3 93 5. betameGe4s.

i tray syer , for Zeneral siring. 1 mitteo '

(at Conspeete Systees. Cah,'t, tssys shall be instaued as a cx>mplete

'?"'" f*eW bMs a Mcetions shad be ao snade that 6e c!cedcal

'sec e.

Tr: . .>. g sai' bc rmated to tt installed in g continuity <4 the caWe t.sy system ww! su;TMt for the cables shall be

, u der d.e conditions described in the article for each: g maintainut.

J ue d. met: Wrhrd cable (Article 330); 2 armored ,

(b) Comp &eted BetMe :nstallattoo. Fach run of cable trsy sha!! be completed before the in.stauation of cables.

1,1 rnetal c'.d cable ( Artic!e 314); 4. power hmited tray

,5 a0L 5 ner. mets'Lc. sheathed cable (Article 336); 6. (c) Supporta. Sepparts shall be prtmded to revent stress on cables 4thc sheathed cable (Article 337); 7. multiconductor where they enter another raceway or amenosure frorn cable tray systems.

ble ( Article 338); 8 multiconductor underground feeder Covers. In portas obuns wkre shat potech b requhed cable (Article 339); 9 power and control tray cable < ***'* "'** F I I*S " # * ""'

Othes.fseto:y mernbied, multiconductor control, signal, ' compatible with the cable tray. .

. hah are specif ca:!) approved for installation in cable

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approved conduit or raceway with its contained (e) Mutticonductor Ca64es Rated 600 Volta or Lees. Multiconductor cables rated 600 volta or less shau be permitted to be installed in the same cable tray.

Estal;shm6nts in industrial establishments only, maintenance and supersition assure that only qualified (f) Cables Rated Over 600 Volta. Cables rated over 600 volts shall not be installed in the same cable tray with cables rated 600 volts or less.

thepermutes be hslalled cable tray system. any of the cables in (1) a he inf alled in ladder, ventilated trough. Exception No I: Where separated by a solidfixed barrier of a material l I ve ntsla*ed channel.:ype cable trays. compatsb!c wirA she cable tray. I ductor Single conductor cables shall be 250 MCM or g ,,,p g, y. Where cables are Type MC a a m hsted for use in cable trays. Where esposed to (g) Through PortJtions and Wans. Cable trays shall be permitted to 2n. cab es s .all be sunbght resistant. entend transversely through partitions and walls or verticalh through

tor. platforms and floors in wet or dry locations where the mstallations.

Multisonductor cables Type MV (Article 326)

'*ec' rs 3 < o r ,y, s,in shal' be sunhght resistant. complete with installed cables. are made'in accordance mith the require.

ments of Section 300 21.

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70 126 NATIONAL ELECTRtCAL COOE ARTICLE 300-W1 RING ME' Tam msway spaesnee to, coague,o, s*0R* carriel by the conductors are so small that the be ig sored where these conductore are placed u throagh metal.

Coopercias frPN) Because aluminum n not a magnetic metal asumanum c.,, , hy,teresis, however. induced currents will be present

% 18 Gru No 8 .Not greater than 100 feet 100 feet """"" *" "

No 6 - - '#" "# #"I thru No 0 .. 5 200 feet 100 feet t i C M thru 3 0.000 CM' '

.I 880 feet cet 80 feet 60 feet 300 21. Spread of Fire or Products of ComtN tions in hollow spaces, vertical shafts, and senti 350.001 C M thru 500 000 C M shall be so made that the possible s read of fire

]35['"

500.001 C M ibru 7505000 CM Abme 750.000 CM - - - w n t be suhtanMy increased pen (ngs at 85 feet f through Gre resistance rated walls, partitions.

firestopped using approved methods to maintair For SI units. one foot = 0 30a4 sieter.

(FPN): Firestorm may require decreasing the allow (b) Support mthods. One of the following methods of support shall 300 22. Wiring in Ducts, Plenums, and Other s be used. provisions of this section apply to the mstallatioi (1) By ciamping devices mastructed of or employtag insulating wedgcs and equipment in ducts, plenums, and othhr air inserted in the ends of thse Where clamping of insulation does not (FPN): See Article 424. Part F for Electric Duct n

adequately support the cable, the condactor also shall be clamped.

' (a) Ducts for Dust, Loose Stock, or va (2) By inserting boxes at tbc required intervals in which insulating systems of any type shall be installed in ducts i supports are installed and secured in a satisfactory amanner to withstand the stock, or flammable vapors. No winng system c weight of the conductors attached thereto, the boxes being provided with in any duct, or shaft containing only such duct' covert for ventilation of comrnercial type cooking equ (3) la junaton bones, by de&cting the cab!cs not less than 70 degrees (b) Ducts or Plenurne Used for Enviros and carrytag them horizontally to a dastance not less than twice the rnethods consisting of mineral insulated, mer diameter of the cabic, the cabica being carned on two or more insulating cable employing a smooth or corrugated impei supports, sad additWrtally secured thertso by tie wirts if desired. When this an overall sonmetallic covering electrical meta methof a md, cables shall be supported at intervals not greater than 20 tubing, intermediate metal conduit, or rigid me percert of thme nicadoned in the preceding tabuladon. in ducts or plenums used for environmental sie PIf Ty s aisehnd of egnal dermosames, liquidtight flexible metal conduit shall be pi exceed 4 feet (1.22 m), to connect physicall) 300 20. Induced Currents in nsetal s.ca o or getal Raceways, devices permitted to be in these ducts ar (a) Conductors Grouped Together. Where conductors carrying alter- connectors used with flexible metal conduit nating current are installed in metal enciosares or metal raceways, they openings in the connection. Equipment an shall be so arranged as to avoid besting the sacrounding metal by induction. within such ducts or plenum chambers only To acmmplish this, all phase conductors and, where used, the neutral anj i action upon, or sensing of, the contain str. ,

all equipmrst grounding enad=c'ars shall be grouped together ,_

are i stall d illu nation s n t2

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Exception No. I: As permined is Section 230-50. Exception for equipment grounding connectras. l~ (FPN): The above applies to ducts and plex transport environrr. ental sir.

ctPfion No. 2' As permitted is Sersios 427 47 for skin efect (e) Other Space Used for Environmental A metal sheathed cable. Type MC cable with (b) IndMdual Conductors. When a single cmductor of a circuit pssses covering, and Type AC cable, and other factoi through metal eith magnetic the indective cffect shall be control or power cable which is specifically lie minirmsed by (1) cutting slots in anetal between the individual holes for wiring in systems installed in other spacG through which the individual madarvars pass, or (2) passing all the Other cables and conductors shall be in conductors in the circuit through an inadating wall sufficiently large for all tubing, tible metallic tubing, intermediats

of the conductors of the ctreatt. conduit metal surface raceway or wirews Eaceptior In the case of cirndts sipplying vacuum or etearic. accessible or flexible metal conduit. Electric discharge lighting systenns or signr. or Xray apparatus, the currents within a building concealed space shall be pc 4

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• eW t'if) ays > hall be empmed aC ~ 5 ,

_ _ . . _ _ _ . _ _ _ _ _ 70-185 wrr' tr ' !y Sean '*"-C'*"" __

. ic,en- g , .e sha P he prouded and main. ^~ ~ 7' .

y fa) Cable Spieces.

, r. , , pe r ,- t  ; L gequue s ccu for insta!.'eg and ;g i,etF nh shall be permitted to be Icxated withm a ca e accesuble and do not project ahwe the ude raik e ey

$ }  ;

(b) Festaaed Securety, g L 1, n . Metalia sab,e trap which support electricai I< fastened secure 3y to transverse members of the cib roundet as required for condu6 tor enclosures in Artic e (c) Bushed Conduit.

A box shall not be re conductors u are installed in bushed conduit used fs quired where cables or

_.n Os a e Tray Systems. %.hera steel or alum num M dag support or for protection e ;se; as equipment groundmg conductors, all o t e shall be ccmplied with  ; M (d) Connected ew in PereHel.

3 d d a m m mW m Wd a pd mWhere single

. sn....ns and fitt ngs shall be identi6ed for grounding Section J10-4, abe conductors shall be installed in groups co more than one conductor per chase or ocutral, to prevent current u m the paraHeled conducton due to esductne reactana e anal cea V cab!c trays shall conform to 3 I d e At? M )(2) 3 t escessae movement due to fault current magnetic

, ses tar s sr4 htng s a,1! te lerbly and durably e E xceptwrt nu t 4rd : ea of M'a'in chann 1 t)pe Lable trays #

inple rid assembhrtMore sung!r enaductors are caled regether. snA as

, .a s c u raton e - ! 'h o's t ercos,ctimal eres o'

, Art o a 31S-R Number of Id.Jr y gb tyie aW w D u,7 g. Cabne Treys. cemductor C4caes, Ra'ed ?OOO V eita. Nc einal, or i

.e oa.

uunp. and cor ac;cd raceways shall be c . , t h Sec t ian 250 l' using hAcd mechanical .

voks, nominal, or Im, permitted in a smgle caHe tray c e

, me c.e4 r,

+.a'. / s1 in accordance witt rwurements aluminum andofcopyrr this wction The conduci st nres hernn apply m c<odt,ctort both t s) Any Mistura el Cabees.

e ,.e 11 H,i r,, t J, '

trays contam muloconduster power or lightmg ,

caMes or aWher ny m:sture of

,, u. . :teg.a e meste 'or Cab.e trare as f c warent Ground 8r's Conductors  ;

numbr r of cables shall conform to the follo*mgmula

-~ -

~ ~ ~ ~ O) Where all of the cables are 4/0 A% G or larger, the sum of the

.i

.o anaemum cros* 5+ctaaas' Am e' diameters shah be mstalled ofmallcables a single layershall not exceed the cab!c tras width, and tseias' e seare same (2)

' ' '~~ s, , ,

~~ -~' - r u.- tr a rs

- 43, 1! Where all of the cables are smaller than 4/C AWG ,

C*6 T'* r*

{I cross-sectional areas of au cables shall not etceed the ma cab lc hil area in Column I of Table 318 8, for the appropriate

• idth o yo c :0 0 aa O 'O 00 ]l (3) % here 4/0 AWG or larger cables are mstalled m the same n 20 ca ble i on tW" 0 ad areas of al! cables sma!Jer than 4 tray with cables -

ional smaller than 4 aHowaNe hD area resulting from/0 A% G sha!! not exceed the manimum O ']

- 0 $g 31u. for the appropriate cable tray widththe computatmn in Cofumn 2 of Tab g9

'me.

$ canes or them shah be mstaDed m a smgle layer and no ( der .'cables mm me m-e--m e g

=== (b) Waiticonductor Control and or Segnal Cab;ea Only. Where a

,N I. 7.Ys i 't m-  ! adder ides or vent: lated trough cable tray, haung aousaHef ti inude de

, . .ce> a a r...P ',pr csor Newe us umti mdi he us,i cab'e or%. the som of the crou secuonal m areas o seawrNe t rashal1 not citeed 50 percent of the interior crostsectional a ofthe are l s;, 7 5d'ehi T Ne*[

e Las a N.' re ca a

s .,

(

a ves *We intew (w sectional area of any cable tray insde depth of more than 6 inches (152 mm) I I

(' wh w <

~n . : y.3 } ~

n.,,e ma*'-_

/

t . .

,t, 'g

~

ny-m ym. , .+ .m. .

s, t - vv. <> # p' s n e && $ ^ - '

,.s, , 3 I

3 e-

1. 'D

{-g

.a . N: '2,#

- % ,y,w v f Y

.t m . ,' , ; . Q. *., ,_~t ;N ~d, , s %~.o. s e - ^ *;,, - s .,) { b 9

, gg .

M,,y '

.' " ' . a 4IDN w6%

,,y, v $ 5d M,$ehWMMW, .NINO's. ,. 4 5,A2M

.. s x _

Enclosure 3

.J ,

Observation'No. 22-F11 - Support of Cable in Vertical Runs Not Addressed General industry practice as identified in the National Electric Code requires that vertical runs of cable be supported as identified by configu-ration with proper grip type or wedge type supports. Design criteria (X3AR01) addresses only use of cable ties for support of cables. Addition-ally, cable ' supports where required must be accounted for. in the design of .

raceway supports.

Reference:

A) X3AR01 Sec. 9 B) NEC 0

l 5

E I

0895A-1522401-847 5.F11-1

. . .. 1 r

s , .

April 29, 1986

.s,...

11:00 A.v.

Observation No. 22-Fil:

Response

The findinM' addresses a concern that the industry practice (NEC) of using grip or wedge type sunoorts in long vertical runs of cable is not being imp.'emented on the project.. The finding also points out that cable supports, where required, must be accounted for in the design of raceway supports.

In order to properly address this concern, a review was"done i

, of the reasoning behind the industry practice for supporting vertical cable.

the subject. Section 300-19 of the NEC Handbook addresses The NEC criteria was established to address two primary concerns regarding long vertical cable runs:

1. Damage to insulation going over the upper vertical conduit edge due to cable weight.

2. Conductors being pulled out of the terminals.

The NEC criteria identifies several acceptable support methods which include the use of grips and wedges. The I criteria also allows any method of equal effectiveness.

The following summarises project design aspects that are considered as equally effective to those listed in NEC Section 300-19 for ensuring the adequacy of the cable system in vertical runs:

A. For cables routed in vertical trays, typically the support is provided by the horisontal to vertical z transition at the end of the horisontal run. Tray supports at this horizontal to vertical transition have

• been adequately designed to carry the weight of the vertical run of cable. The concern regarding raceway supports is addressed in the response to Readiness

! Review Finding 22-A02.

B. For cables routed in vertical conduits:

i

1. Manufacturers minimum bending radius is required to be maintained at the point where cables enter the vertical run from a horizontal tray, and verified by QC inspection.

2. Where required, tray edge protectors are used at points where cables exit to enter vertical conduits.

3. . Bushings are used at the top ends of vertical t

conduits.

5.r11-2A l

i

I Response 22-F11 Page Two J .

4. Cables do not enter safety-related equipment directly from long vertical runs. Longer conduit runs are generally in raceway riser areas.

5. . . . Cables are securely tied within panels, cabinets, etc. to avoid stress on termination points due to weight of terminated cables.

In general, the Vogtle project design does not include long d vertical runs of tray or conduit which could not be adequately i supported by the top horizontal-to-vertical raceway transition.

However, to enable a more definitive evaluation of the'

. adequacy of the project support requirmuuma, the project design criteria has been be revised to include the criteria of the National Electrical Code (NEC) article 300-19(a) for-supporting conductors in vertical raceways (reference DMCN 1809-3 dated March 21, 1986). In addition to supporting cables by use of wedges, grips or clamps the horizontal-to-vertical transition fitting will be oomsidered adequate top support for the cable provided there is sufficient . length of horizontal cable-run to support the vertical run cable

. loading. This will be demonstrated by analysis. If exist-l ence of sufficient horizontal length is not justified, then appropriate retraining devices will be added to vertical cable run. The tray and supports system will be evaluated

, as necessary to demonstrate their support capability for the 1 weight of the vertical run of cable length. In selected

, cases, where required, deviations to the EBC criteria will be allowed af ter engineering analysis verifying compliance to vendor's parameters for the cable.

+

For the tray system, this criteria will not be included in the construction specification to avoid possible misinter-pretation by construction due to its complexity in implemen-

! tation, but rather engineering will evaluete compliance to the above criteria by review of project raceway drawings and/or jobsite walkdowns. As a result of the review, should j = additional cable support be required, the specific support i requirements will be added to project design drawings.

' ' However, for conduit systems, the requirement for comc11ance I with NEC Article 300-19(a) will be added to construction l, specification X3AR01, Section E9.

With respect to the specific concern regarding adequacy of tray edge protection for cables leaving tray over tray siderail or and where drop-out filling has not been pro-vided, an engineering analysis will be performed to demon-strate conformance to cable vendor performance criteria (e.g., cut thru and/or crush limits). If these limits are exceeded, appropriate vertical supports will be provided.

4 5.Fil-25

. Responso 22-F11 a . Page Three Associated Reports:

None Root Cause Unique use'of an equal but subjective criteria in lieu of a industry accepted criteria for support of cabla.

Action Taken to Prevent Recurrance:

None. No similar use of an alternative less definitive ~~

criteria is known to exist on project nor has Readiness Review shown amothat similar observation.

Future Conunitaants:

Revise construction specification X3AR01, Section E9 to include sequirements of NEC Articla 300-19(a) for conduit systems by May 15, 1986.

Engineering review of project tray drawings (including any necessary analysis) fpr compliance to NEC Art.icia 300-19(a) to be completed by Nay 15, 1986.

Completa review of tray edge protmetion analy. sis by May 15, 1946.

E 1

9 5.F11-2C

Obse rva. tion No. 22-Fil JDR Assessment The project support response of. catale addresses in vert the IDR observation regarding the lack of seal runs.

certain de' sign features such as While the project has indicated that 4 tray edge protectors or pushings provided some degree project consitment of vertical cable support, the IDR acceptance is based on ther l article 300419 in project to include the design criteria criteria of National DC-1809 and Electric Code13AK01 specification (NEC) i ,

g  :

to satisfy the requirement for addressing vertical cable run support. The l project additionally has committed a) to perform an analy.s.is whenever a; horizontal and sufficienttray to vertical tray transition is considered as the top support';

vertical tray length of cable exists in the horizontal run to support the loading,. b) to analyze deviations from the NEC criteria verifying compliance with vendor's cable parameters, c) to evaluite com-

! pliance with the criteria for tray application, by review of project raceway drawings and/or field walkdowns and revision to project drawings where required to add specific support requirements, d) to revise construction

)

specification for conduit systees,X3AR01 section E9 to include compliance with NEC requirements

e) to perform an analysis of adequacy of tray edge i protection to demonstrate conformance to cable vendor performance criteria. ,

During the response assessment, the IDR team reviewed the physical plant and identified locations where the claimed design features such as tray edge protectors and drop out fittings were not in place as specified and cables were noted resting on sharp edges of trays.

The IDR team concurs that the progras committed to by the project should resolve the issue of support of cable in vertical raceway runs.

}

The IDR tese concurs with the project identification of the root cause to be

the use of a subjective criteria in lieu of an industry accepted criteria.

The design of vertical cable support is a unique issue and the IDR concern l

' is limited to this issue.

s The IDR team considers that wedge or clean.. type vertical cable support in accordance with the NEC article 300-19 is adequate to resolve this observation.

bas committed If to any deviations from the NEC criteria are taken, the project 8

documenting the basis for acceptance. The method of j justifying deviations from NEC was not available prior to the completion of this assessment.

I f

4 l

i 0895B-1522401-84T $J11-3 l -

l BECURING 6 SUPPONflMG CABLES IN CABLE TRAYS .

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FIGURE I )V FIGURE 2

i i.

1 i

I CABLE TIE SEISMIC ADEQUACY l

POTENTIAL FALURE MODES:

e CABLESUPPAGE e STRENGTH 3

• TENSEE CAPACITY I

LATCHING MECHANISM k -

e l

a

• O lla ry

BECHTEL VERTICAL CABLE TRAY DYNAMIC TESTS A VERTICAL CABLE TRAY SYSTEM WAS NSTALLED ON THE SHAKE TABLE AND SUBJECTED TO THREE-COMPONENT EARTHQUAKE MOTION TO INVESTIGATE ITS DYNAMIC BEHAVIOR.

l THE VERTICAL CABLE TRAY SYSTEM CONSISTED OF A VERTICAL SECTION OF CABLE TRAY,18'-10" LONG, WITH 90 ELBOWS AT THE TOP AND BOTTOM. CABLE TRAY SUPPORTS WERE SPACED AT APPROXIMATELY 8'.

CABLES RANGNG IN WEIGHT UP TO 1.57 LBS/FT WERE PULLED INTO THE CABLE TRAY AND TIED INDMDUALLY OR N BUNDLES OF APPROXIMATELY 4" IN DIAMETER DIRECTLY TO THE CABLE TRAY. THE CABLE TES WERE STANDARD PANDUIT BLACK NYLON AND INST.M I m AT 5' AND 10' SPACING.

TWO SERES OF INCREASING AMPLITUDE EARTHQUAKE-LIKE TESTS WERE PERFORMED ON THIS TEST CONFIGURATION. THE FIRST SERES OF TESTS UTILIZED THE 5' NOMINAL CABLE TE SPACING AND THE SECOND SERES UTILIZED A 10' NOMINAL CABLE TE SPACING.

1 ACCELERATIONS AS HIGH AS 2.2G,1.8G AND 2.2G ZPA WERE ACHEVED FOR l THE X, Y AND Z (VERTICAL) DIRECTIONS RESPECTIVELY.

. NO CABLE SLIP, CABLE TE BREAKAGE OR CABLE EJECTION OCCURRED DURING THESE HIGH LEVEL EARTHQUAKE TESTS.

l l

! MODEL HYPOTHESIS 1

1 I e CABLE SLIPPAGE IS NOT A CREDIBLE FAILURE MODE, BECAUSE OF THE i

l LATERAL DEFORMATION OF THE CABLE UNDER SEISMIC CONDITIONS 1

l \ INmAL CONFIGURATION l )u  !

SAsLE Tis

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)pDISPLACEp CONFl4URATION (VEMY FLEXBLE LATETiA ~ ,. ,

)9 CADLE Tip -

( / , , 7= .

'/ ,

d

~e THE LOAD ON A CABLE TIE CAN THEREFORE BE CALCULATED BASED ON l- ' i E THE TRIBUTORY LENGTH CONCEPT -

i 2 1 LOAD - (WElGHT/FT) x (TE SPACNG) x (ACCEL.:VALUE) .

a-i $l; CABLE ' . ,s j j:

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. e STANDARD SEISMIC DESIGN PRACTICE: INERTIA LOADS D;5TRIBUTED . ,.

BY TRIBUTARY AREA FOR FLEXIBLE ELEMENTS

- ~7

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u. 2 2 . ;

j -: _.

BECHTEL DYNAMIC TESTS RESULTS e MAXIMUM ACCELERATIONS-(2.2G,1.8G,2.2G)ZPA e NO CABLE SUPPAGE e NO CABLE TIE BREAKAGE e NO CABLE ERCTION i

l i

I 1

p 0 $

l

__ m_ _ _ ___..___ _ _ _ _ _ _ _ . _ _ _

--- - -_ _._= _ _ _ _ _ _ _ _ __ ___

CONSIDERATIONS FOR TEREE COMPONENT EARTHQUAKE EFFECTS 2

a R[ + %

r j'  ;

V '

[

j

, , ,,%= V x 2 + y '

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f DISTRIBUTION OF SEISMIC LOADS AND TEST SET-UP CABLE TIE i

APPLIED CABLE TRAY g DYNAMOMETER

' ' APPLIED LOAD

$__ __ . _TRI8UTAE

\ CABLE

. . ' LENGTH' ~ ~ '

i STATIC TEST CONFIGURATION i

UTAR CABLE WElGHT CABLE PER FOOT JRWElGHT{

\v \v v . < v CABLE TIE

.. y ..........v

- ~

I ACCELERATION x UNIT CABLE WElGHT x TRIBUTARY LENGTH

=

N

• $ ll0 l

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% M \

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• i i i 1 O & 3 i en e 6 @e f h e $ U 5 &

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CETEAM\NATtoN cf .5AFE TT FAC.Ycets

$A n?LE CAL 40LATions

94. CA%E 4049'E (5 091 L&s/FT)

VMIMATE AxtAL. loa D - 7,cp Las LATEitAL LDAP s .}3 x 5 097 LSS -  !

t. .

TEST RE5WTAMT a (g,,)b (g,p g,,91 =284.fe(55 o n.tc.a u *o n a s.T a r

(,SA5E D ou PtAn Acc.5 Le etATf ew 5)

-QOM \ ;

OBE: (y a oW3 A g = o.W g  :

R (S 0M LS5/FT') (5 fT) .(\4p.W)hkh*+o.4.(*

I = Y'7*T LSS

.5AFETT FAcTeg s N41 #-=4%

1 sss ; 4 =

4 a > sq. g 0 6'? 3 R,. (,S 94 9 (.5) [Q4 o7h) hko 5')Y+(* 87) = 5W sog.b SAfeTT FACTcit- = -

3 Lo t l 1

s44 .. .

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VOGTLE S'TATIC TESTS

, RESULTS i

, CABLE TIE CAPACITY FAILURE LOAD

- ~

CABLE SIZE AND TYPE 12' TEST SPAN

• 17' TEST SPAN

• 81L 350 MCM (LARGE CABLE) 115 LBS 100 LBS 34 - CABLE BUNDLE 200 LBS 200 LBS (LARGE BUNDLE)

A27 2/C**14 (SMALL CAM F) 50 LBS -

4 - CABLE BUNDLE 105 LBS 120 LBS (SMALL BUNDLE)

• TO ACCOUNT FOR LOADING FROM ONE AND TWO HORIZONTAL SEISMIC COMPONENTS

- . CAPACITY ESSENTIALLY INDEPENDENT OF LATERAL LOADING FROM HORIZONTAL SEISMIC COMPONENTS

^

8l $lI

CONSERVATISMS TESTIN4 e CABLE TIE CAPACITY IS BASED ON STATIC EOAEMNe e MAXIMUM LOADINGS FROM THREE COMPONENTS OF EARTHQUAKE ASSUMED TO ACT SIMULTANEOUS e PEAK ACCELERATIONS OF RESPONSE SPECTRA USED e APO)Tt0NAL TtEs usED AT BLocKouTS, PANEL , Tis.S !f T 10.5 AT F ITTle K95 , .

' 4 t

O J $ Y

' ,,f-

. RB44tftE M6NTS A P,5:

4 0 ((',#]3 O '".

- - - - - - - - - - - - - --