TENNESSEE VALLEY AUTHORrTY CHATTANOOGA. TENNESSEE 3740t

5515S7B okout Pla~b. AUG 2 P : 23 WoD-5-390/86-27 AN 19 N$

WND-50-391/86-23

U.S. Iuclear Regulatory Coarission Region II Attention: Dr. J. elsnn Grace, Regional Administrator 101 iMrietta Street, WI, Suite 2900 Atlanta, Georgia 30323

Dear Dr. Grn'•e

WATTS BAR EUCLEAR PLABT - JITS 1 AID 2 - FLEXIBLE CONDUIT IOT IISTALLED TO CO4MHPSATF FOR THERMAL AID SEISHIC MOVBENITS - WBRD-50-390/86-27, WBRD-50-391/86-23 - FINAL REPORT

The subject deficiency was initially reported to ERC-Region II Inspector Bob Carroll on January 14, 1986, in accordance with 10 CFV 50.55(*) as MC WI 6529 for unit 1. NCR 6569 was later written to document the deficiency for unit 2. Interia reports were submitted on February 27 and June 6, 1986. IBclosed is our final report.

If you have any questions, please get in touch with J. A. McDonald at (615) 365-8527.

Very truly yours,

TEBUaSSEE VALLaY AUTHORITY

R. L. Gridley Director losure uclear Safe and Licensing

Enclosure cc (Enclosure):

Mr. James Taylor, Director Office of Inspection and Enforcement U.S. Iuclear Regulatory Commission Washington, D.C. 20555

Records Center Institute of Nuclear Power Operations 1100 Circle 75 Parkway, Suite 1500 Atlanta, Georgia 30339

8609030394 860019 PDR ADOCK 05000390

PDR

'1An Equal Opportunity Employer

Mmi Mit WCLEiR m. WE 1 MO 2 yatmwr "a COMIMER Mr mar rMW=I 2

0 oAgmU t 0mm rL AM s-rE Wnvmg 1-D-5-390/f-27, I sD-590-3s1/-23

CR IW 6529-8 (Ur 1) SCm WI 6569-6 (OIr 2)

10 CM 50.55(e) HmmL 8 *MPO

Iasci$4o of Defitiommv

A ample of 100 flexible conduit instaUlltions ma ubenmd for adequat displa em provisions and lengths per the theal consideration requl t of Tble 3.2.6-1 in General Construction Specification -40.

tn e*vluation of this ampl reveald three nouoeformsa t emditions Mhich re onewrnd in the scope of this report.

1. lexible conduit to class 1 pipe monted devices (uch ua mtor-operated valves, olmnoid-opeated valws and t prtture wtchs) ma not istalled to adequately ropnar for cianed thermbl/sami c

ovements. The displac nts ad lngth of flexible conduit installations provided inide the unit I reactor building nre found to be inadequate per the requimmir s for therml considerations in 0-40, osetion 3.2.6.3, for electrical conduit systm.

2. Minijm bend radius of the flexible conduit at connetions to the pipomounted deices ms violatod. Minirm bend radii are specified in the Electrical Design Standard 0-313.1.7 which is referencod in -40. This condition has since been identified by the MC as unresolved item 391/85-53-02.

3. loiable conduit to class 1I floor-munted equipmet mn not installed with specifiod lateral displae nt to cmprnsat for sei•aic memats. to smple also identified two installation in the unit 1 auxiliary building where conduit displemeonts did not moet speifications for seismic considerations of 6-40, section 3.2.6.2.

All of the above conditions renut from sonmpliance with the existing a-40 spoeification. nomwvr, frlible conduit reuiremnts for soismic/therml Mamnsts and miniam bond radii mre not added to a-40 until October 21, 190, at hdich tine tho ajority of Usttf Nar uclear Plant (6W) flexible conduit had boon desined and installod. Alo, desig draings did not identify any flexibl conduits to pipeO-ountd devices which should allow for therm1 sovemnts. Drawings did require a on-inch disploe-m t at seismically qualified, floor-mountd equipment for the reactor building and intake pmping station, thus prevnting simic nonconformance for thes

reso. Howeor, design drawings did not require this same displcmen- t eonsideration in other aore• with seismielly qualified clss 1I equipmnt.

TWA hs subsequently issued significant condition report (SCR) VW 6569-8 to documet a similar deficiency for installation of unit 2 floxibleo onduit. As indicated abovo, this roport covers both •iCs WE 6529-S (unit 1) and 6529-1 (unit 2).

Flesible conduit for class 11 electrical devices on meoeanical system bhich reqpire provislons for thermal ovemat and clss It seismicaye ualified floor-mounted equipimn which las installd with inedequate

aloMmcen to compesate for espension or contraction could fail due to hem l/seismi moemaets. This condition could reult in conductors

baminn shorted due to moisture intrusion or breakin/puLling may from their terminal points cannsqunFt reultins in failure of the associated afety-related equipmnt to peform its intended function(s). This

condition could adverely affect the safe operations of the plant.

Coractive Action

TWA's Division of maclesr tinnering (DME) has reevaluated the raquirments and specifications govrnin the relationship of flexible conduit to electrical pipe-ounted devices subject to combined therml/seismic movie ts and to floor-mounted equipment subject to seismic nvemnts. Specification Revision Notiee Sn8-C-40-11 to G-40 Ms issued May 22, 1986 to clarify and further define the intent of these installations and the requirements for displcement, minimm length, and bend radius. Calculation has been issued to support the criteria end posiions set forth. This revision of G-40 will provide criteria nucss ry for inspectlon of class 18 flexible conduits which must be verified for proper installation.

Corrective ations for flexible conduit instl lations involving pipe-mounted and floor-mounted devices re as follow:

1. Conduits to Pipe-Mounted Devices

UE has provided to T A's Division of auclear Construction and MI Operation a list for units 1 snd 2 of the flexible conduits to Class 11 pipe-mounted devices which must be inspected to assure these installations adequately copensate for cobined thersl/seismic movemnts. These lists, which will be domented by design calculations, wre developed from computer data and verified by cross-reference to desin drwings. The combined therml/seismic

oveemnt for each device shown on the list will be provided nd each existing flexible conduit length will be inspected to determine if this movement can be *rcommodted. If conduit installations do not meot the requirements for ininmu conduit length and minimuo bend radii specified, they will be replaced or evaluated by D3 and dispositloned on a case-by-case basis. VA will document finding, variances to 0-40, and actions which establish acceptability of them conduits.

WieerinS chabM notice (feo) 6129 for unit 1 and 6269 for unit 2 ave been immed for preperatio of drawings aed amlcltine

mecmry to support the orrective action described abowe. rlutot and required modification will be completed before fuel

lead of the repective unit.

2.- Conduits to Fleor-4unted Devices

_ rFlible oeaduit connected to Class 1I equi mnt of sheet metI sestru tl01 (i.e., notor ceontrol ceters and suitchger) nd ast or forged Clas 15 uipmnt (i.e., motors) is required by -40 to be at least 18 inche in lunath, except ere variances have been approd by D. Previous field inspections per quality Control Procedure (QCW) 3.03 and IMdifications and Additions lntrution (MAI)-13

nsum that existig installation met th requirments of C-40. tFlible, caduits greater than or equal to 18 ioebs in leath (or lo where approved by DME) will adequately compensate for movemants operieaced during a design bsis seimic event. Therefore, thew existing conduit installations are cceptable for ue-es-is.

Aceptance of existing nstallations are basd upon the evaluation of effects due to seismic ad therMl aemnts as documente by design calulations. design site inspections. end the inhrent ability of flexible conduit to acc date mervemnts such that damge should not occur to the equipment or conduit.

The rWevilun to 0-40 ad rvisions to the design drawings will prevent recurrence of the subject nonconfornces on future installations of flexible conduits. To ensure that field inspections clearly reflect the changes to C-40, revisions will be mde to M I-13 md QCP 3.03. Upon request, DK will exmine criteri and allow emptions or make recommdations on a case-by-case basis for existing and future flexible conduit irstallations for lass I1 equipm t.

M063