ML19270G382

LER 79-009/03L-0 on 790429:while Measuring MSIV Limit Switch Trip positions,10 of 12 Switches Were Set Greater than 10% of MSIV Closure.Caused by Lack of Precise Field Calibr of Exact Limit Switch Trip Point.Special Procedure Developed

ML19270G382
Person / Time
Site:	Quad Cities
Issue date:	05/11/1979
From:	Vahrenwald J COMMONWEALTH EDISON CO.
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
Shared Package
ML19270G379	List: ML19270G378 ML19270G382
References
LER-79-009-03L-04, LER-79-9-3L-4, NUDOCS 7906060245
Download: ML19270G382 (2)

Text

NiiC FORM 366 U. S. NUCLE AR REGULATORY CCMMISSION (7 7J) .

., LICENSEE EVENT REPORT

' CONTROL BLOCK: l l 1

l l l l 6

lh (PLEAsE PRINT On TYPE ALL REQUIRED'INFORMATION) j o l 1 l l l l L l Q l A l D l 2 l@l 0 l 0 l 0 l -

7 8 9 LICENSEE CODE 14 15 0

0 l0 l- l0 l0 l0 l@l4 LICENSE LICENSE NUYBER 25 26 1l1l1l1l@l T YPE J0 l

57 CAT 58 l@

con'T 7

O i 8

TRJ l 60L l@l610 s l DOCKET 010 l 01216 l s l@l0 14 12 19 17 lg l@l 015 l 1 l 1 l 7 ! 9 l@

NUYBER 63 63 EVENT DATE 74 75 HEPORT DATE 80 EVENT DESCRIPTION ANo PROBABLE CONSEQUENCES h o 2 l While measuring the MSlV limit switch trip positions during a weekend outaqe. 10 of thel go;3; [ 12 switches measured on 6 MSIV's were found to be set greater than 10% of MSIV closure.1 0 4 l These measurements were performed at the request of NRC Inspector G. Wright. The I o s l 10% closure settings were originally set at the factory prior to installation and l o e unit startup. Monthly MSIV closure scram functional testing has been perfarmed to l 0 7 l verify scram function operability. The remaining 2 MSIV's will be checked at a j o a i future outage of sufficient length. I 7 8 9 80 SYSTEM CAUSE CAUSE COMP. VALVE CODE CODE SUBCODE COMPONENT CODE SUBCODE SUSCOOE 9

7 o

8 l 1 l A l@ l Bl@ W@ l 1 l N l S lT l R lU l@ l Sl@ l Zl@

9 to 11 12 13 16 19 20 SE QUE N T ..,t OCCURRENCE Fs E P OR T REVISION LER EVENT YE AR REPORT NO. COOE TYPE N O.

@ yugAO aE l 7l 9]

21 l-l l 0l 0l 9l l/l lo 13 l Ll l-l l 0l 22 23 24 26 27 28 23 33 31 32 TAK ACT ON ON PL T TH HOURS S 8 IT D FO t LB. 5 P LI E VAN F CT PER l33El@l34Z l@ W@

35 36 Z l@ l0l0l0l0l 37 40 41 Yl@ l42N l@ lN 43 l@ lN 44 l0 11 1547l @

CAUSE DESCRIPTION AND CORRECTIVE ACTIONS i o l The need for prior precise field calibration of the exact limit switch trio ,n'nt had I

, , not been deemed necessary to be performed. A special procedure was developed to enable]

, , exact measuring of the switch trip position in the field. As-found and corrected g 3 3 l switch positions are attached. The switches were adjusted tog 10% closure and l gij,j [ functionally tested. [

7 8 9 . 83 ST S *.POWER OTHER STATUS iSCO HY DISCOVERY DESCmPTIGN i s W@ l0 l0 l0 l@l NA l lCl@l Test l A CTIVI TY CO TENT RELE ASED OF RELEASE AMOUNT OF ACTIVITY LOCATION OF RELEASE 7

i 6 8 3

@lZj@l to 11 NA 44 l l 45 NA 60 PERSONNEL EXPOSURES NUV8ER TYPE DESCRf PTION

• i 7 l 0101 Oj@l Z @l NA l

' _ 8eR,ERSONa'lJES li i s l I o f 01 O l@ ESC-N@ NA O

2274 289 l 7 8 9 11 12 dG LCSS OF CR DAMAGE TO FACILITY .

TVPE C E SCRIP TIO N li lold I3 Zi@l 7 10 NA _J il NRC UsE CN'M 12101

.SSuE N

''lSCmPTiON C

l NA 79060609 M llll l!IIIIIII,$

l 7 8 9 10 68 63 SC %

J. Vahrenwald 309-654-2261 Ee loc N A'.'E OF PREPAHE R  ? SONE: $