ML20038A947

Part 21 Rept Re Slippage of Raceway Support Bolted Strut Fittings,Initially Reported 810807.Detailed Testing Program Being Prepared.Next Rept by 820601

ML20038A947
Person / Time
Site:	Seabrook, Washington Public Power Supply System
Issue date:	11/23/1981
From:	Sarsten G UNITED ENGINEERS & CONSTRUCTORS, INC.
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE)
Shared Package
ML20038A948	List: ML20038A947
References
REF-PT21-81, REF-PT21-81-518-000 PT21-81-518, PT21-81-518-000, NUDOCS 8111240494
Download: ML20038A947 (2)

Text

.

m 8

88m a constructorsinc.

sosro~

ECHELON 30 South 17th Street KNOXVILLE Post Office Box 8223 NILADELmlA VALLEY FORGE Philadelphia, PA 19101 50-443 November 13, 1981 ;,,y

- {, s l

j;

.i n I,Y Director l(

Office of Inspection and Enforcement fg g 0 00% h t-2 n

U.S. Nuclear Regulatory Commission 3;

u md /3 Q W n Washington, D.C.

20555 ce

{#y

,Q5 '

/N

Dear Sir:

b '

N g

Subject:

10 CFR 21 Report of a Potential Defect related to Public Service Company of New Hampshire -

Seabrook Station and Supply System -

WNP 1 and 4 On August 7,1981, UE&C submitted a report of a potential defect pertaining to slippage of raceway support bolted strut fittings.

In that report, we defined the corrective action that would be taken by the Power Division of United Engineers & Constructors Inc., and which was to be completed by November 15, 1981.

The purpose of this report is to inform you of the actions that have been taken to date and our progress toward obtaining a satisfactory resolution of the potential defect. The applicable details of the actions taken and the progress to date are contained in Attach-ment 1.

Attached also is a copy of the original report, (Attachment 2) and sketches of connections of major and minor concern.

(Attachment 3).

From Attachment 1, it should be noted that although firm corrective measures applicable to the present as well as the future installations with fittings of major concerns have been identified and are going to be implemented shortly, certain tests still are required to formally confirm the values of presently available data and to obtain final allowable loads for configurations of minor concern.

l

%N J

l

/ (

n111240494 81111 PDR ADOCK 05000 i

S P

l

[An.,in c

,)

Director November 13, 1981 U.S. Nuclear Regulatory Commission We are in the process of preparing a detailed testing program which will be implemented by a certified testing laboratory. We expect to be able to complete these tests and report to you the results, or inform you of the status thereof, by June 1,1982.

Very truly yours, y

A

,, l. f h,. l}%-W.O

<,., ' /

G. F/,Sa'rsten Vice President - Power Attachment copy: Regional Director USNRC - Region 1 Regional Director UShTC - Region 5 l

l i

l l

l l

l

...=

1 ATTAUIMENE 1 BOLTED STRUT FITTINGS SLIPPAGE FROBLP A.

ACTIONS TAKEN TO DATE i

1.

All applicable strut fitting configurations which are based on apparent incorrect load tables have.been identified as being of major or minor concern.

(A major concern fitting is i

defined to -be a fitting which has major usage and where dhe applied loading approaches the load carrying capacity.

All other fittings are defined to be of minor concern.)

4 l

2.

The strut vendors, Unistrut, Superstrut and Powerstrut were -

informally notified and the situation explained. Reliable loads for the configurations identified were solicited. However, no definite data could be obtained from the strut. vendors.

4_

3.

On the basis of limited available test information, UE&C i

{

chose a derating factor of 0.5 for the interLa period to allow for an immediate assessment of the implications of derated load allowables. This was done in parallel with dhe efforts to obtain vendor data in 4) below. The derated loads were utilized to identify the critical configurations, the number of supports possibly requiring corrective action, and the identification of special tests to be performed in support of the corrective action.

i

. A.

ACTIONS TAKEN TO DATE (Continued) 4.

Formal letters were sent to the strut vendors, requesting-either confirmation of originally assumed allowable loads or, their recommendations in lieu of these iaads. The responses to these inquiries were as follows:

Unistrut provided a written response providing applicable load allowables based on prior tests.

In some cases, the assumed allowable loads were confirmed and in other cases derated allowable loads were provided. Some of the derated values were derived by extrapolation and by analysis.

Powerstrut provided a written response. However, they neither confirmed the originally assumed allowable loads nor recommended alternative. allowable loads.

Superstrut did not provide a written response. However, their Chief Engineer visited UE&C and presented test data that had been performed for the Clinton Plant. In addition, he offered to make available to UE&C the use of his test stand so that the requested allowable load data could be established and corrective action evaluated.

i

. - A.

ACTIONS TAKEN TO DATE (Continued) 5.

Tests were carried out at Superstrut laboratory with UE&C participation to address the fittings of major concern.

For the WNP-1 plant, the fitting investigated was a 3 hole gusseted fitting used in a trapeze type support. In this configuration, two fittings are used to attach a vertical strut member to the building structural steel. The' fittings are welded to the structural steel and attached to the vertical strut by means of strut nuts and bolts, with 3 bolts per fitting.

For Seabrook Station, the fitting investigated was a 2 X 2 hole gusseted fitting used in a trapeze type support.

In this con-figuration, two fittings are used to attach a vertical strut i

member to a horizontal strut member, which in turn is welded to the brilding structural steel. The fittings are attached to the strut members by means of struc nuts and bolts, with 2 bolts in 1

each leg of the fitting.

In testing these connections, the effect of using the nut / bolt combinations from the various vendors were evaluated.

The results of these tests ehowed that the allowable loads for fittings were dependent upon:

a.

Hardness and geometry of nut teeth.

b.

Manufacturer of hardware c.

Load application and specific fitting configuration.

1 i,

a 4

W e,,,..~ww-en.~,--..e..m,-..

-w

-.-.,...-.y,-,-r-e nn are-c.

---,vn

,w.

9 A.

ACTIONS TAKEN TO DATE (Continued)

Specifically for the WNP-1 connection, a derating factor of 0.5 was adequate for the Powerstrut and Superstrut nut / bolt combination.

No derating factor was required for the Unistrut nut / bolt combination; the tests confirmed the allowable loais published by Unistrut.

Also, a limited number of tests were conducted using a high strength bolt with a nut by any vendor.

It was found that published shear capacities could be achieved by increasing the torque from the specified 50 ft-lbs to approximately 75 ft-lbs.

For Seabrook Station connections, the results were complicated by the fitting construction (the fitting corners may contain a welded or unwelded corner seam and the fitting has uneven leg lengths which may be instailed in either position). The worst case results occurred with the unwelded corner seam fitting installed with Superstrut nuts and bolts, and with the short leg of the fitting resisting the shear load.

For this configuration, the failure was due to the unfolding of the fitting which occurred at a value t.310w a 0.5 derated load.

The best case results occurred with the welded corner seam fitting installed with Unistrut nuts and bolts, and with the long leg of the fitting resisting the shear load. For this configuration, no derating factor was required.

-~

D

' A. ' ACTIONS TAKEN TO DATE (Continued) 6.

Based on dhe results of the tests described in (5) above, the following actions will be implemented for the present f

and future installations.

Present Installations All present installations will be re-evaluated. A limiting i

i load reduction factor of 0.5 will be annlied in these i

analyses to all the affected configurations since, in i

general, the manufacturer of the installed nuts and bol ts can not be identified.

For the WNP-1 plant, a systematic review of tray as-built drawings is underway. Ine review considers the derating factor identified above. Specific supports requiring corrective action will be identified so that appropriate corrections can i

i be made prior to start-up.

4 To date, our review of the as-built installations (approximately l

i 1/4 of the total number) show that less than 5% of the supports will require corrective action.

Possible corrective action may consist of:

Welding vertical fitting leg to strut member, or Replacing existing nuts and bolts with approved Unistrut nuts and bolts (or proven equivalent) or Replacing bolts only with high strength bolts and I

(

increasing the bolting preload, i

i

._.. _ _, _.._.,- ~.. _...

. A.

ACTIONS TAKEN TO DATE (Continued)

For Seabrook Station, all fittings of major concern with unwelded corner seam fittings, using Unistrut nuts and bolts, and the fitting long leg in the vertical position.

Future Installations Future installations are defined as those installed af ter:

January 4, 1982 for Seabrook Station 1 & 2 December 1,1981 for WNP 1 plant.

For the WNP-1 supports, only Unistrut (or proven equivalent) nuts and bolts will be used for installation.

For Seabrook Station supports, only fittings with welded corner seam, with Unistrut (or proven equivalent) nuts and bolts will be used for installation.

B.

REMAINING ACTIONS TO BE TAKEN 1.

Continue the tests with Superstrut laboratory to obtain preliminary data for the fitting types of minor conern.

(refer to Attachment 3) 2.

Obtain test data at an independent testing laboratory to confirm design allowable loads for several fittings which were not fabricated by the strut vendors.

3.

Perform tests at a certified testing laboratory to verify preliminary tests conducted to date.

4.

Complete all required modifications prior to plant start-up.

- -. ~, -

g mited engineers a--s~

30 Soutn 17th Street Post Office Box 8223

.%,viu s Philadelphia. PA 19101 amLADEL

'*A P

vAuty FonGE t.ugust 7, 1981 Ahhment 2 5...

Director e fa*

6'.' '

Of fice of Inspection and Enforcement j ',

U. S. Nuclear Regulatory Co:::tission j

Washington, D. C.

20555

Dear Sir:

Subjcet:

10CFR21 Report of a Potential Defcet related to Public Service Company of New Hampshire - Scabrook Station and Washington Public Power Sucolv System - WNP 1 and 4 This report describes a condition found during a routine engineering test program being performed on cable tray supports. The test results indicate that:

a.

Loa? capabilitics provided in strut vendor catalogues cannot be ccafirmed by tests by the vendor and Icad to wrong conclusions.

b.

UE6C criteria based on vendors published catalogue data do not provide acceptable margin.

Applicable details as required by 10CFR21, paragraph 21.21(b)(3) are con-tained in the attached report. This condition has been reported by Public Service Company of New Hempshire under the provisions of 10CFR50.55(e) and will be reported by Washington Public Power Supply System.

Very truly yours, A

,e

';. ~

e.;

.%G. E S'arsten Vice President - Power A c t.achmen t copy: Rezional Director p M).

USNRC - Region 1 i

Regional Director CSNRC - Region 5

\\

g

(

', O p..~ e- ]

s

w-.~-----..-----

. -...--.r - :- - -:-- -

. - - -- : :. : u----

~

g mited engineers.-sm 30 Soutn 17th Street Eo,,

Post Othee Box 8223 a orvut Philaoelphia. PA 19101

% Acat****

VALLEY FORGE t.ugust 7, 1981 AmcAment 2

• 4.;., ' ;..

'** i '*] *s,.

Director L

Office of-Inspection and Enforcement U. S. Nuclear Regulatory Co= mission Washington, D. C.

20555

Subject:

10CFR21 Repor: of a Potential Defect related to Public Seriice Co=pany of New Ha=pshire - Scabrook Station and Washington Public Power Suceiv System - WNP 1 and I.

This report describes a condition found during a routine engineering test program being performed on cable tray supports. The test results indicate that:

a.

load capabili:ics provided in stru: vendor catalogues cannot be ccafirmed by :es:s by the vendor'and lead :o wrong cenclusions.

b.

UI6C cri:eria based on vendors published catalogue data do not provide acceptable margin.

Applicable details as required by 10CFR21, paragraph 21.21(b)(3) are con-

ained in the attached repor:. This condition has been reported by Public Service Company of tie.v Mc=pshire under the provisions of 10CFR50.55(e) and will be reported by Washing:en Public Power Supply System.

Very truly yours, h h.;;..' :.

4.

o

.~

C.

7 ',

G. E S'ars ten Vice President - Power A c t.achmen:

copy: Regional Dirce:or q

USNRC - Region 1 gv

\\

Regional Director 7

iSNRC - Region 5 t,,

4(

e

[...~ - )

8

~ - ~ ~ ' ~ ~ '

~

-n,

,w

._g....~...__.

?

AME AND ADDRESS OF THE INDIVIDUAL OR INDIVIDUALS INFORMING Tr2 COMMISSION.

G. E. Sarsten, Vice President - Power United Engineers & tonstructors Inc.

30 South 17th Street Philadelphia; Pa.

19101 IDENTIFICATION OF TdE FACILIN, THE AC*IVI U, OR THE EASIC COMPONENT SUPPLIED FOR SUCH FACILIrf OR SUCH ACTIVITY WITHIN THE UNITED STATES TdICH FAILS TO COMPLY OR CONIAINS A DEECT.

Seabrook Station of Public Service Company of New Hampshire Nuclear Project Nos.1 & 4 - Washington Public Power Supply System The design of cable tray and conduit supports (struts) is based on the lead-carrying capabilities published in manufacturers design catalogues for struts, which cannot be suppor:ed by test results.

IDENTIFICATION OF THE FIRM CONSTRUCIING "EE FACILITY OR SUPPLYING Tr2 EASIC COMPONENT VHICH FAILS TO COMPLY OR CONIAINS A DEECT.

United Engineer: & Constructors Inc., architect, engineer, and construction manager.

Super Stru: Inc., Metal Framing Division, Midland Ross Corp.,

.0akland, California, manufacturers of " Super Strue" Power Stru: Division, Van Huffel Tube Corp., Warren, Chic,

=anufacturers of " Power Strut" NATURE OF Tr2 DEECT OR FAILUE TO COMPLY AND ~HE SAETY HAZARD Vd1CH IS CREATED OR COULD SE CREATED BY SUCH DEECT OR FAILURE TO COMPLY.

Tne stru: support syste= used for the cable tray and conduit supports could be subjec: to slippage at the bolted strut fit:ings at the publi:hed allouable loads when cultiple bolt fastening methods are used.

"te defect, if left uncorrected, could cause a failure of the cable tra/ and conduit supports to properly retain safety-related electrical cables during seismic events.

Tr2 DATE ON VdICH Tr2 INFOR'd.ATICN OF SUCH DEECT OR FAILURE TO COMPLY WAS OBTAINED.

Augus: 7, 1981.

1-B

.-_--n--...

,,r

-.-y

+--,w

-w

. - - +.

g.w-9-

-y-w y9

--+t g y

-y&>-

y.---~g y

--m -

7.__

IN IHE CASE OF A BASIC COMP 0HEh7 k'HICH C0biAINS A DEFECT OR FAILS TO COMPLY, DIE NUMBER AND 1.0CA!!ON OF ALL SUCH COMPONEhTS IN USE AT, SUPPLIED FOR, OR i

3EINC SUFFLIID FOR ONE OR MORE FACILITIES OR ACTIVITIES SUBJECT TO TdE REGU1.ATION IN TdIS PART.

This defec: applies to some cable tray and cenduit supports for

~

safety-related cables in the Seabrook Station and Washington Nuclear Projec: Nos. 1 and 4.

TdE CORRECTIVE ACTION WHICH HAS BEEN, IS BEING, OR WILL BE TA12N:

THE NAFI 0F THE INDIVIDUAL OR ORGANIZATION RESPONSIBLE FOR THE ACTION: AND THE LENGTd 0F TIE THAT HAS BEEN OR WILL BE TAIGN TO COMPLETE THE ACTION.

Corrective Action 1.

Identify all applicable stru: fitting configurations which are based on i= correct lead cabics.

2.

Determine appropriate applicable allowable loads for the con-figurations identified.

3.

Develop acceptance criteria and appropriate design modifications for the defective configurations, Name ef the Greanication Resnonsible for Corrective Action

?cwer Division of United Engineers & Constructors Inc.

Leneth of Time That Will Be Taken to Cemelete the Action

}

By Novc=ber 15, 1981 AL'Y ADVICE RE1ATED TO THE DE.=:CT OR FAILURE TO COMFLY A30UT THE FACILITY, ACTIVI Y, OR ?ASIC COMPONENT THAT HAS SEEN, IS BEING, OR WILL BE GIVEN TO FiRCH.uERS OR LICENTEES.

Public Se:vice Company of New Hampshire informed Region I on July 27, 1981 according to the provisions of 10CFR50.55(e).

Washington Fublic Pewer Supply System was advised by G. E.

Sarsten on August 7, 1981.

l.

a B

_n w

e gr s

n y

e m

+

r-

,-y 2-

-mm w

=

_=_,--.a..:_.._..

_a_.

~

ATTACHMENT 3 Fittings of major and minor concern with respect to allowable shear loads.

1.0 SUPPLY SYSTEM WNP 1&4 1.1 CONFIGURATION 1 N

/ w= AL 4.

/\\ %~/

\\htanal sW 4

,/-

\\

e

.I i

h

. " _-1I-_

r II s~

u T*

P l l

/

Il Ai2r.7.

MAJOR CONCERN UE ( e-Manu.hc% er Pht-i K3 o.

3/4 Um and Gomt A l?.c 2.

Picc* A Oirstru.t o

Ps-3c7.7.

b ec Strud Aizc ?

Supe,rsiru.i o

Unesdrud AS?.2%

Itwe,r Stra;t Sayfhad.

AB2.M5 Rs; snt T-et, censimy ates ( De. tails Mutu,/sprh Pion o -

Uni.itrat

(~ c PS-to-Its Peer Stut.

Aw-h" Sugar-Strset ttex wean HHcscsoite):G S nis h t ce :ceev Ps c:,ow

% =.;- sTrat 4.'-n.xt;{,"

E-62.vt a i-l, Supt-Steu.t 8

n..

-..+.~&

-w-wm

• ----r--

.c-

-e+

p pr 9-w p.

- - x. ~ a..

- - = -. - - - - - -..

= - - - - - - - = = - = = - - - = = = - - -

- - - - = =

1.2 CONFIGURATION 2 CONFIGURATION 2A

/

i/i v'

i :

A s2ar.

I I 8 1 4:2o7.

' I I i

_j l

l i ; -

2.

o l2 l

l

/

AI2G2.

l

.t sCRino ger g ! i.

T7P

( P l i s, I i i

= =4 ama

~l l

i. I l

ll i[i I i I

1 US-rC.

AAtJui:AcoRER. pag; e, B/M too, and umme,,

AItc7 P1001 Ortsdrud PS -2cl Power Sht ONC M A 12.c'2 Super stt u:i AB 213 /1 Pitti/ t Onetrud Ps-cooe.

%e *0%R AB-zit/4

.% pee'Stro.t A 5tG z.

Picc%

Undrd '

@ - M'21 Powt,r STrd A I"2 G7--

Suptr St c-u.t

.__._;-.u.~._

1.3 CONFIGURATION 3

/

.y.-

s E

I (TYP)

Mi,

Anst i

9 s:neu k.

A

'9 A

Nur e

AN A

B246 A

I f--

.f.

PLA9 VIEW 1 SEc riou A-A DE (c.

MAMAtTot.s R. PAR.T Ro.

~6/.M Me.

ond h3AME MINOR A 1247 PioesA Wis; RLJT CONCERN Ps-de17 Ptu.er-STed A%?

Supes-Strut Arzot.

Ptoo I Onestru.t Pstol be.v-Strid A17.o?.

Supr Sttu.t

'A3 24ee.

PD54h omstoct ber Stnd Asa+e,t s pr strat I

-. -.... - -. - ~

~~+e.

L, si =

~ s _, ' u n x: J

. _ -. ~. -

m sa 2.0 PSNH - SEABROOK 1&2 2.1 CONFIGURATION 1 l

f

)

Lm___ ___

______\\___J wu m s /-

X F ' f s f e,.

M l

s taverv%srum.

s l l 1I 33CA 130.H 33E"I erten L

l l cie)

M i

Pomi AT wu:::.4 t I v:5:st r l

DEFoRMAfrod W% I W 5-8

s Tc SF nm,

UE L C.'

MAWuFAGRGl: PAR:7 40 Slu uo.

AMD tem 1E SSAS P ioo%

vN:sta.s.tr 95 3072. PcWE1: STRUT A 17.G 7 Sde1ER srROf MAJOR 33A.O Piocc>

UN:5TRUT CONCERN PS-Zoo fcWst-STRUT A-Ito c SL*.ER STRdf M E.T P P. 3 1 LAt:STRQT 44-(,c$

POW 52. 57R07 A'6-7.S St.PL"?. STRVT utt3> ROT T

S3CA Picio PL io.E,5 PoA STR\\.T)

A sco-V:"

SUPE 2 STRot

~.e.3 CM uucscsc(toirG. UN FSGo4 7

.Pocce. sten E-t47.1/2s 1-5/lc.,5dPEe WRCT h

- ~ - -..

.----~,__m

2.2 CONFIGURATION 2

~

_ SEC l 10N A-A pug r r

~.

Pc:ssr n sec m v: stets cc:D2.,f% C O M

sic ac tJ:iG

- A

+i g g, gg O

s n

I a s-

.A j \\\\ '

A--

se.sMs M4

e r

/

?x vmN%

i McRTED ETWswos LOCA'-

COOCtJM PL AME 0f' ##h XI oi.7T CF Sz vi LC.,

Nguuf AC TURA pac ic, MINOR S/M Wo.

AN D NAtAs CONCERN SSAE Ficot NTM 4 '41 PouxR ST;n1T AP202 S@RSmtTT 33Di-Pnz7 t>nr.rRt/r FS-9ri-1 Poux2 57RtTI yr6 SM M

,-,,nw,.

....,_.n_... _ _. _. _ _.

=,u_--_._...

2.3

_CONFTGURATTON 3 l.

~

I%l gglr 33D4 35CA tzn.s -

,2, s L t.

O U"3 ;

T a3C4 O

A

.an.

nous 3 W>

i.,

Po M At w+C.A VISISLE' G3tS owon.ukTiot4 !.S in SC 23AC IUE1C MAROFACTORER PAR 1"WS.

EM 03.

AMD MAuf SSDR PIS24,. U 6 01"

.PS f 0/o PCWd. STROr

.I 2.4 CONFIGURATION 4 MINOR CONCERN g

soc:s 3-S 3g3 @

1

[%

---Gi o c'F t

pcs:r er m eH

• rM:-- %

V s:En r otycrb 4:fict3

~

89 15 7o EM@

3

\\

we

,i,l'-,

. 33p3 ife=r AL wn4 5: cts c5 23AS UELC MA40FACTURa PW No.

E M W D.

AuD NArAE' YM P172.fa VM':".ST'RVT Ps.srzo ece srRW Ae> 2.fo1 500m. sieur

r -

-.== = - - -. -

. = =.

-=------=-..-.;-.:-..

a -

2.5 CONFIGURATION 5 ams s a u utsI,L MINOR CONCERN

~

.[ l ll b 8

q\\

ii

,\\ ~

r me: Tron :s ro er wmic

_i t_.

V E & C.

MAh10FC02:si:. PA;;;r h30.

SM ub.

AMD MAMg

• 37Q PtoeA m TR0T Ps 7 2.1 Po*d2.srzor A 2.t?-

supct.en tty 1~

l

)

f f

9 0

~. - -.

- _ - - _ _ _ _. _ -.. -. - - -. -.