ML20043G605

LER 90-008-00:on 900517,unit at Power Permissive Circuit Actuated on Train a of Solid State Protection Sys.Caused by Procedural Deficiency in That Switch Rotation Not Specified. Procedure revised.W/900614 Ltr

ML20043G605
Person / Time
Site:	Braidwood
Issue date:	06/14/1990
From:	Querio R, Wagner J COMMONWEALTH EDISON CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
BW-90-0636, BW-90-636, LER-90-008-03, LER-90-8-3, NUDOCS 9006200478
Download: ML20043G605 (4)

Text

-- _

• l f' m ) Commonwealth Edison N

Braidwood Nucl: r Poti:t St: tion i

\'q,c".-

Route 01. Box 64 Braceville, Illinois 60407 j

Telephone 815/458-2801 June 14,1990 l BW/90-0636 l J

l U. S. Nuclear Regulatory Commission I Document Control Desk Washington, D.C. 20555

Dear Sir:

The enclosed Licensee Event Report from Braidwood Generating Station is being transmitted to you in accordance with the requirements of 10CFR50.73(a)(2)(iv) which requires a 30-day written report.

This report is number 90-008-00: Docket No. 50-457.

Very truly yours,

+f.

h R. E. Querlo Station Manager.

Braidwood Nuclear Station REQ /JDW/sjs (7126z)

Enclosure:

Licensee Event Report No. 90-008-00 cc: NRC Region 111 Administrator .

NRC Resident inspector INPO Record Center CECO Distribution List b

o006200478 900614 DR ADOCK0500gg7 f

[i ,

~

LICENSEE EVENT REPORT (LER)

I;cility Name (1) Docket Number (2) _tagt (3)

_BIAldEQDL2 015! Ol_0lJjJ1J17 1lof!_0 J.

Title (4) $purious Actuation of the Unit at Power Fermissive Circuit During Cold $hutdown Activities due to Procedural Deficiency.

,,1tenLp31gj$J.___ LER Number (6) ltPAE.LElle (7) 01htr Facilitits InvohtdjB)

Month Day Year Year //jj / Sequential /// Revision M nth Day Year _[311111336!nti._ .00Clti_NM.t ri s )

7 u/

1H 1&tr UL Jntr_.

OllLDLQ1JI I I

~

_0llLQLol 01 I l_

~

al s 117__ JJO_ J1D 0._101B 0_LD _ _ 016 114 91 0 THl$ REPORT l$ $UBMITTED PUR$UANT 10 THE REQUIREMENi$ OF 10CFR (CitiLDat or_ more _RLihtl0llswIng) (11) 9 3

_.__ 20.402(b) 20.405(c) 2. 50.73(a)(2)(tv) 73.71(b)

POWER .__. 20.405(a)(1)(1) __ 50.36(c)(1) _. 50.73(a)(2)(v) ,_, 73.71(c)

LEVEL __ 20.405(a)(1)(ii) __ 50.36(c)(2) __ 50.73(a)(2)(vii) _ Other ($pecify (IRL _0 J !O _ 20.405(a)(1)(iii) 50.73(a)(2)(i) 50.73(a)(2)(viii)(A) in Abstract

////////////////////////,/,/ __ 20.405(a)(1)(lv) __ 50.73(a)(2)(ii) __ 50.73(a)(2)(viii)(B) below and in

///////////////////////}/}// ._ 20.405(a)(1)(v) ._ 50.73(a)(2)(ill) __._ 50.73(a)(2)(x) text)

LICENSC[l0HIAC1_IQLIHl$_LRllli Name .1[LLEttDSLEV$1R Jerald D. Wagner Regulatory Assurance AREA CODE Est a 4J7 .e l_1 I s 4L513L-llLe1.91J COMELLILDELLIELI0fLIACILI0BE0NENLIAILVRLDESMIBED I!LIH1$31PDRf (13)

CAU$E $Y$1EM COMPONENT MANUFAC- REPORTABtt CAU$[ $YSTEM COMPONENT MANUFAC- REPORTABLE

_._I1!RER 103ERDL .,__IURIR _.ID_hERDL I- __1_ L_J_ _j i 1._. I  ! I I I I I I _1_j _ l 1 1 I I l - l_L_ l !l SUP.tLLMENTAL ret 0RLIXEL(IID (14) Expected MonittjJanJ_Ittr submission lYti_11Lyesdorflete_LEICIID $VBMI5110tLD&IL) X130

(' ) I l LJ_t_

ABSTRACT (Limit to 1400 spaces, i.e, approximately fif teen single-space typewritten lines) (16)

The Reactor Trip Dreaker and Gripper Coll Response Time Measurement surveillance was in progress. The Rod l Orive system was not capable of rod withdrawal as the disconnect switches for the rod lif t circuits were open for

( all Rod Drive power cabinets as specified in the Limitations and Actions". The procedure required switch $501 of the $olid State Protection System ($$PS), be returned to the OFF position. At 0334 on May 17, 1990 as switch

(

$501 was being rotated from position 7 to 0FF in a clockwise direction, the Unit At Power permissive circuit l (P-10) actuated on Train A of the $$P$. Reactor trips that are normally automatically blocked when power is less than ten percent were enabled for less than one second. As a result, a reactor trip signal was generated. No i components repositioned since the Reactor Trip Breakers were already open. Annunciator reset was accomplished by the time $501 was in the OFF position. In an ef fort to duplicate the malfunction, switch $501 was slowly rotated through each position from 7 to 0FF in a clockwise direction. At 0420 when the switch was placed in position 21, the symptoms were repeated. Cause of this event was a procedural deficiency in that the direction of switch rotation was not specified, the procedure will be revised. There have been no previous similar occurrences.

1 i

3025m(061490)/1 I

l

m 5'

• t LCLN$[LLYLHI.ALIMLlLLKLILALCOM11NaI10N F prinJtt!JL F ACILITY NAME (1) DOCKET NU@[R (2) _LLLIMfi M ftL __ rege (3)

Year /// $equential /j/j/7 Revision

/j/jj1 .J!geher . /H Number 3reinmit 2 DJ 5 Lo ! o 1 DJ.3L1LtJJ._0 -

o Lo 1 e -

LLo_ _01L JL _olt itXi Energy Industry Identification System (EII$) codes are identified in the tent as (XX)

A. PLANT CONDITIONS PRIOR TO EVENT:

Unit: Braldwood 2 Event Date: May 17, 1990 twent Time: 0334; Mode: 5 - Cold Shutdown; Rn Power: 0%

RC$ [AB) Temperature / pressure: Ambient / Atmospheric

8. OLSCRIPTION OF EVENT; There were no systems or temponents inoperable at the beginning of the event which contributed to the severity of the event.

Th] Reactor Trip Breaker and Gripper Coil Response Time Measurement surveillance was in progress. The  ;

surveillance was being conducted in accordance with Braidwood Technical $taff Surveillance procedure BwVS 3.1.2-2. The Rod Drive system was not capable of rod withdrawal since the disconnect switches for the rod lif t circuits were open for all rod drive power cabinets. As a result, the Rod Control system was properly removed f rom service as specified in the " Limitations and Actions" section of Dwva 3.1.2 2.

BwV$ 3.1.2 2, Step 2.9 states, "At 2PA09J, prTURN switch $501 (Logic A) to 0FF." as part of the restoration of the system.

At 0334 on May 17, 1990 as switch $501 was being rotated f rom position 7 to 0FF in a clockwise direction, the Unit At Power perinissive circuit (P-10) actuated on Train A of the solid State Protection System ($$P$) [Jf).

R; actor trips that were normally automatically blocked when power was less than ten percent, were enabled for less than one second. As a result, a reactor trip signal was generated from Train A of $$Ps since actual reactor pr;ssure was below the trip setpoint of 1885 psig and the RCS flow in all four Loops was less than the trip s;tpoint of 90 percent.

No components repositioned since the Reactor Trip Breakers were open prior to Step 2.9. The annunciators reset by the time that $501 was in the OFT position.

At approximately 0405 in an effort to duplicate the malfunction. it was decided to perform the surveillance on Train 8 of $$ps to determine if the actuation on Train A was the result of a problem O the logic Test Panel or a d;ficient procedure.

Bwv$ 3.1.2-2. Step 3.9 states, 'At 2PA10J. RETURN switch $501 (togle A) to 0FF " as part of the restoration of the system.

The switrh was rotated slowly and deliberately through each position from 7 to 0FF in a clockwise direction, at 0420 when the switch was placed in position 21, the Unit At Power permissive circuit actuated on Train B of the Solid State Protection $ystem and the same reactor trip signals were generated. I As a conservative measure. the NRC was notified via the ENS phone system at 0700 pursuant to 10CTR50.73(b)(2)(li).

Based upon further review of the event, it appeared that the EN$ notification could be retracted. Discussions w;re held with the NRC Region Ill Resident Inspector, NRC Region !!! Reactor Projects Branch I Chief and AEOD. It cas reconinended that this event shoulo be reported pursuant to 10CFR50.73(a)(2)(lv) - any event or condition that resulted in manual or automatic actuation of any Engineered safety Feature, including the Reactor Protection system, pending further evaluation.

3025m(061490)/2

i

.y. .

LICLM5LLEYLRLRLEORL11L!LLILX1 CONTINWL110N form Rer_2 1 FACILITY NAME (1) DOCKET NUSER (2) ... L ER_tMfi!Lifti Page (3)

Year /// Sequential ff//j/ Revision

///j ff

__.RWEktr /// _ NabtL a u m no L 2 0J3JJJJJ3JJ13LL AJo -

ALo_Le - DJ o el 3 at DJL TEXT Energy Industry Identification System (Ell 5) codes are identified in the text as (XX)

C. CAV$E Or EVENT:

The root cause of this event was a procedural deficiency. The author of the procedure assumed that the operator would rotate $501 in a counter-clockwlse direction going from position 7 to 0FF. However, the operator rotated $501 in the clockwise direction to restore it to the OFF position. The procedure did not specify which direction to rotate the switch.

The failure of the procedure to identify the direction of switch rotation allowed the event to occur.

D. $AFETY ANALY$l$:

This event had no effect on the safety of the plant or public. The Reactor Trip Breakers were open and the l Rod Drive system had been properly removed from service in accordance with the Limitation and Actions section j of BwV$ 3.1.2-2. The Rod Control system was not in a condition where credit could be given for its operation '

and it was not physically capable of performing its design function or capable of being placed in a condition where it could be able to perfom its design function. 1 Discussion of redundant equipment operability is not appropriate since Rod Control was removed f rom service.

All systems operated as designed and only annunciation occurred, no component actuations.

The reactor trip signal was not required in response to actual plant conditions.

There are tio credible alternative conditions that would have been more severe.

E. ,0RRECTIVE ACTION $:

3 Immediate Corrective Actions: i

1. $501 on the Logic fest panel was taken to the OFT position.

2. The annunciators were reset.

Long Term Corrective Actions:

DwV$ 3.1.2-2 will be revised. The procedure revision will be tracked to completion by action item 457-200-90-02701.

F. Previous Occurances:

There have been no previous similar occurrences. I i

i G. Component failure Data: '

This event was not the result of component failure, nor did any components f ail as a result of this event.  !

3025m(061490)/3

_ _ _ _ ,