ML20009B576

LER 81-036/01T-0:on 810602,CRD P-10 Inserted Slowly, Exceeding Limits for One Four Control Rod Array.Caused by Sticking Scram Solenoid Valve S02-0305-118.CRD Rebuilt & Returned to Svc

ML20009B576
Person / Time
Site:	Dresden
Issue date:	06/12/1981
From:	Holland P COMMONWEALTH EDISON CO.
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
Shared Package
ML20009B571	List: ML20009B570 ML20009B576
References
LER-81-036-01T, LER-81-36-1T, NUDOCS 8107160312
Download: ML20009B576 (3)

Text

NRC FORM 366 - - - - - - - - - - - - - - - - - - -- --

U.S. NUCLEAR REGULATORY COMMISSION (7 77) *

. , . LICENSEE EVENT REPORT CONTROL SLOCK: l 1

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lh (PLEASE PRINT OR TYPE ALL REQUIRED INFORMATION) l o l8t9l l I lUCENSEE 7 L l DCODE l R l S l 2 l@15 0l UCENSE 14 0l -l NUMSER0 l 0 l 0 l 0 l 0 l- l0 l 0 25 26 l@lTYPE UCENSE 4l JQ1l 1l57 1l l

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7 8 80 61 DOCKET NUMBER 68 69 EVENT DATE 74 75 REPORT QATE 80 EVENT DESCRIPTION AND PROSA8LE CONSEi UENCES h I o I a I l Durine scram testine usine DTS 300-2, CRD P-10 inserted slow 1v, causing T.S. 3.3.C.1 1 A l limits to be exceeded for one four control rod array. The rod was inserted to 00 and l

.loI4l l taken out-cr-service. The safety significance was minimal since the 100 percent in- l l o I s l I sertion time was within 7 seconds. There was no effect on public health or safety. l lo ts l l Previous occurrence; Docket 050-237, R.O. 12-2-81-32/01T. l l0l7ll l 10181 l l 7 8 9 80 C ODE SU C E COMPONENT CODE SUB CDE SU l0l9l ~

7 8 lR[B[g { g lBlg lVlAlLlV lE lX [ g lE g lI [Eg 9 10 11 12 13 18 19 20 SEQUENTIAL OCCURAENCE REPORT REVISION Lgpfpo EVENT YEAR REPORT NO. CODE TYPE NO.

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_ 22 26 27 28 N CT C Ch P T M T5 HOURS 22 US I PoR B. PL MANUPA RER _

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CAUSE DESCRIPTION AND CORRECTIVE ACTICNS @

lijollThe cause of this event was a sticking SO2-0305-11t.' scram solenoid valve. The valve l l,tij lwas rebuilt and satisfactorily tested. Tne CRD was returned to service and tested, all l 1 i I 2 I I times were well within Tech. Spec limits. Scram testing per DTS 300-2 will continue l

,,;3g l to be performed every 16 weeks d'uring operation. l l li tal l 80 I

7 8 9 RY A  % POWER OTHER STATUS 01 DISCOVERY DESCRIPTION h 11151 l El@ l0 l4 l512l@li3 N/A l lBl@l Operator observation l

• a 46 46 80 A$nviTY e$0 TENT cELEASEo Os RELEASE LOCATION CP RELEASE @

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l l AMOUNTOP N/A ACTIVITY l N/A @ l ,

l PERSONNEL ExPOSEEES NUMSER TYPE DESCRIPTION @ N/A j l l 1 l 7 l l 0l 0 l 0 l@l Z l@l

• l' ,ERSON~EL%u%ES l Nuv8ER CESCRIPTION N/A lil3ll0l0l0lgl l i 7 8 9 11 12 80

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o ATTACHMENT TO LICENSEE EVENT REPORT Rl-036/0lT-0 COMMONWEALTH EDISON COMPANY w JE)

DRESDEN UNIT 2 (ILDRS2)

DOCKET # 050-237

, During normal operations, with DTS 300-2 Control Rod Drive Scram

. Testing in progress, CRD P-10 inserted slowly, causing Tech. Spec. 3.3.C.1 limits to be exceeded for one four control rod array. The safety significance ,

of this . vent was minimal since the control rod did meet the Tech. Spec.

limit of 7 seconds for full insertion. There was no effect on public health or safety. Previous occurrence: Docket 050-237, R.O. 12-2 032/0lT.

The cause of the event was.a sticking scram pilot solenoid valve s S02-0305-118. This delayed full opering of the scram valves and in-creased.the time required to start rod movement. The valve was rebuilt and satisfactorily tested. The CRD P-10 was placed back in service and scram tested, all times were well within the Tech. Spec. limits. DTS 300-2 will continue to be performed every 16 weeks during operation.

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[2> DEVIATION REPORT

.n Commonwealth Ed.ison DVR NO.

STA UNIT YEAR N O.

D 2 57 PART 1l TI TLE OF DEVI ATION OCCU RRED 6-2-81 17:30 CRD P-10 (54-39) Pilot Serm Valve Solenoid Malfunction DATE TIME SYSTEM AFFECTED 300 PLANT CONDITIONS TESilNG CRD Run 1166 313 O

MODE p w n ,9w73 , LOAD (MWE) YES NO

)

OtSCRIPTION OF EVENT During full core scram testing, CRD P-10 had a slow scram time of about 6.9 seconds. The 5 to 90 percent times exceeded T.S. 3.3.C.1 limits. Investigation revealed 118 pilot scram valve solenoid was closing slowly. Drive inserted to "00" and removed from service.

DESCRIPTION OF CAUSE Unknown at this time T6THER APPLICABLE INFOPNATION Scram solenoid was repaired.

EQUIPMENT A YES DR NO. WR NO.

Bob Herbert 6/2/81 FAILU RE R NO N/A D-13990 '

RESPONSib E SUPERVISOR DATE PART 2 l OPERATING ENGINEERS COMMENTS Following the repairs on scram solenoid, the drive was satisfactorily scram tested.

I SAFETY-TYPE OF CEVI ATION EVENT OF POTENTIAL TECH SPEC NON-REPORTABLE ANNUAL RELATED RE' PORTABLE OCCURRENCE PUBLIC INTEREST VIOLATION OCCURRENCE REPORTING 'dR ISSUED 10CFR21 YES

_K., 14 DAY _ _ YES ]

l l 30 C AY NOTI 71 CATION _ _,,,

j,,_ NO NO 6.6.B.l.b REPORTABLE CCCURRENCE ACTION ITEM NO. PROMPT ON-SITE NOTIFICATION NUMBER R. M. Ragan 6/2/81 1800 l

g 81/36/0lT-0 C "[

i TITLE CATE TIME l

l 24-HOUR NRC NOTIFICATION PROMPT OFF-SITE NOTIFICATION TPH Tom Tongue 6/3/81 0730 F. A. Palmer 6/3/81 REGION 111 DATE TIME TITLE DATE TIME

{TGM J. G. Keppler 6/3/81 1403 REGION lil a COL CATE TIME T I TL E CATE TIME RESPONSI BLE CCVP ANY OFFI CER INFORYED OF 10CFR21 CONO!T!ONS AND THETR CEDO PT TO NPC + TITLE DATE iiME REV!EW AND COMPLETED .T. I.ang 6/3/81 OPERATING ENGtNEEH DATE ACCEPTANCE BY STATION REVIEW AS RECUIRED gW s

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l RESOLU(ION APPROVEC AND M P 66Y [l.  !

AUTHORIZED FOR CISTRIBUTION STATip SLp itlNTENDENT C A'TE 68 *S f 7' 10-77 (FORu f5*S?*t)

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