ML20024B988

LER 83-008/03L-0:on 830531,motor Driven Emergency Feedwater Pump Became Inoperable When Power Removed from Circuitry for Repair of Automatic Initiation Switch 2PS-388.Caused by Component Failure.Switch Replaced & recalibr.W/830630 Ltr

ML20024B988
Person / Time
Site:	Oconee
Issue date:	06/30/1983
From:	Petty J, Tucker H DUKE POWER CO.
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
References
LER-83-008-03L-02, LER-83-8-3L-2, NUDOCS 8307120093
Download: ML20024B988 (3)

Text

e s

A PPR u V N LY OM L

~

74 C FO ~ M 3.6 U.O. NUCt.7AT& CTULAT@t3Y CAMMISSIMM

"""* LICENSEE EVENT REPORT $",80s.3 o.e s

)

(PLEASE PRINT O N TYPE ALL REhUIREJ INFORMATION)

CONTROL BLOCK: l l l l l l @

l o j, l lS lC lN l E l E j 2 lgg 0 l 0[- l0 l 0 l 0 [ 0 [ 0l -l0 l0 lgl 4LICENSE l 1 lTYPEl j 1l 1lglSF CATl lg 7 a . b8CENSEE CODE 3. 85 LICENSE NUMBER 35 3. 3. S.

CON'T loll l aggg l 1.lgl 0 l 5 l 0 l 0l 0l 2 l7 l 0 l@l 0 l 5 l 3l 1l8 l 3 l@l 0 l 6l 3101813 l@

y g .. .3 DOCMETNUMBER .. .. EV ENT D ATE 7. 79 R EPORT D ATE ..

EVENT DESCRIPTION AND PROBABLE CONSEQUENCES h j o l2 l lOn May 31,1983 at 1553, the "2A" MDEFDW pump became inoperable when power was re- l l 013 l l moved from its circuitry so that the automatic initiation switch (for low dischnreel gg;4ggpressure) 2PS-388, could be repaired. While this pump was inoperable, the main l g , j 5 g lfeedwater system, the "2B" MDEFDWP, and the TDEFDWP and emergency feedwater frc.a l l ole llthe other two units, were available. The removal of the "2A" MDEFDWP was a planned l jol7ll action, and appropriate plans were made. Therefore, the health and safety of the l jolg[lpublic were not endangered. l

'3 '" 1*:: ,xmE CO M PO N E,,, C.. E S,c:::,;E Sun'E

[olg l [C lH j @ l E l @ [Ej @ j Il N11T l R ! U l O L.sj @ ! z! O

, . i. ,, ..

,. ORT e uE TVPE NO.

O '5,9,fEL L VEde?

,,8 13 I V El,A!R l01018I l/l laI3I

.. .. L.1J L.. J L..OJ u m 'Tx:  :::::, '=:::" N.. . @ ..EM,,,E. P...S... ..PPuE, .:::::,7,",'E.8 L,sAJS1 u zlO L1JO n

L:JO u

L2) 010101 L.<NJ@LU sr .. u S I Lu l@ Lc. I 7I 52Jn u

OAUTE DESCFt0T SON VJO CORHt.CTIVE ACTlONS h

@ Cl (Ibe oct cauce was_Sogp21 pent f.21:.lb. The nicch develone] c spil hole whim j -

l 1 l 1 j l allowed water in its circtiltry cmisine it to fail. To rennfr this switch. nower l l t l 2 l lhad to be removed from the pump, making the pump inoperable. The switch was re- l l 1 l 3 l lplaced, calibrated, and was determined to be functional. The "2A" MDEFDWP was l I t l 4 l l declared operable at 0955 on June 1,1983. l STAT $ 84 POW E R OTNEN ST ATUS IS C OV E R Y OlSCOVERY DE SCR sPTION l l,g3 l E g g l1,l 0 l 0 lgj NA l lB lglPlannedinoperability y l . u u a = =

, . . i.

NELE SED A E E AMOUNT OF ACTIVITY LOC ATION OF R ELE ASE l

'D M lilellZl@lZl@l n

, . . i. u l l l

NUMBER TTPE D E S C RIPTION I I l 71 l 0 l0 l0 [glz l@l NA l

,,;;,"::"" '"a"' :,PT,0N O NA l l l 1l 8 l l 0 ] 0] 0l@l ,

'fa,,oP oa =[,A;= , k'a P Ac'u'vg NA $ l l i1l9IL.z_J@l P

^

8307120093 830630 NR USE Om in 121 o l l l@l DESC=iPTiON(")

gE.u uciTv .

PDR ADOCK 05000270 l S PDR I I!IIllllll!!l ..

l

, . . i.

NAME OF PREPARER Jocelyn C. Petty pgone; (704) 373-8270

4 d s REGION ~1 Sh8ow1hi?G6MPANY P.O. DOK 33189 Clf.ARLOTTE, N.C. 28242 HALB. TUCKER , Teternoxa

"**"~*"

..:. ::=_ 83 JUL BJune A -

30, 1983 Mr. James P. O'Reilly, Regional Administrator U. S. Nuclear Regulatory Commission Region II 101 Marietta Street, NW, Suite 2900 Atlanta . Georgia 30303 Re: Oconee Nuclear Station Docket No. 50-270

Dear Mr. O'Reilly:

Please find attached Reportable Occurrence Report R0-270/83-08.- This report is submitred oursuant to Oconee Nuclear Station Technical Specification 6.6.2.1.b(2) which concerna operation in a degraded mode permitted by a liraiting ccndition for operation, and describes an incident which is considered tc. be. of no significance with respect to its effect on the health and safety of the puolic.

Very t.ruly yours, kb. bLt. '/gf h.l.B. Tucker JCP/php Attachment cc: Document Control Desk U. S. Nuclear Regulatory Commission Washington, D. C. 20555 INFO Records Center Suite 1500 1100 Circle 75 Parkway Atlanta, Georgia 30339 l

l Mr. J. C. Bryant

.. NRC Resident Inspector

! Oconee Nuclear Station L Mr. John F. Suermann Office of Nuclear Reactor Regulation U. S. Nuclear Regulatory Commission Washington, D. C. 20555 rfb gs,CT '

f:e #

-x ,

Duke Power Company Oconee Nuclear Station Report Number: R0-270/83-08 Report Date: June 30, 1983 Occurrence Date: May 31, 1983 Facility: Oconee Unit 2, Senees, South Carolina Identification of Occurrence: The "2A" MDEFDW Pump was made inoperable when power was removed to repair a switch.

Conditions ?rior to Occurrence: 100% FP Description of Occurrence: On May 31,1983 at 1553, the "2 A" Motor Driven Emergency Feedwater Pump (MDEFDWP) became inoperable when power was removed from its circuitry. Power was removed to facilitate repair of the "2B" Main Feedwater Pump Discharge. Pressure Switch 2PS-388.

While perfarming the moathly safety relat.ed functior.al test of the KDEFDWT initiation pressure switches, pressure switch 2PS-398 failed. This switch la part of the auto-initiation circuitry for the "2A" MDEEDWP. When this switch is inoperable, it would prevent the "2A" MDEFLWP from automatically starting on lov discharge pressure indication for both main feedwater pumps. To repair the switch, the breaker for the control circuitry for the su3 ject pump was removed. Thirc made the "2A" MDEFDiP im patable. and constituted operation in a degraded node per Technical Sp?cification 3.4.2(a).

Apparent Cause of Occurrence: The roct cause of this occurrence is a component failure. Because the switch failed, the "2A" MDEFDWP had to be made inoperable to repair the switch. and to restore the portion of automatic initiation capability that was lost back to the pump system. A small hole was found in the bellows of the switch which allowed water from the pressure line to get into the circuitry compartment causing it to fail when tested. During the previous monthly test, all of the "2A" MDEFDWP system met the required criteria.

Analysis of Occurrence: At the time "2A" MDEFDWP was inoperable, the main feedwater system was operable for decay heat removal and cooldown above 250*F.

Also available to meet the same requirements were the "2B" MDEFDW pump, the turbine driven emergency feedwater pump and emergency feedwater from the other two units. The removal of "2A" MDEFDWP was a planned action by Operations personnel. Appropriate plans for actions to be taken, if an event took place while "2A" MDEFDWP was inoperable, were made. Therefore, the health and safety of the public were not endangered.

Corrective Action: Pressure switch 2PS-388 was replaced with a new one. The new switch was calibrated and a functional test was made of the "2A" MDEFDWP auto-initiation circuitry. The "2A" MDEFDWP was declared operable at 0955 on June 1, 1983.