ML20008E756

LER 81-010/03L-0:on 810202,MSIV Bypass Valve Ms 100 a Failed to Close.Probably Caused by Component Failure.Actuator Spring Adjusted to Increase Tension Until Valve Would Close

ML20008E756
Person / Time
Site:	Davis Besse
Issue date:	03/04/1981
From:	Trautman D TOLEDO EDISON CO.
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
Shared Package
ML20008E751	List: ML20008E750 ML20008E756
References
LER-81-010-03L, LER-81-10-3L, NUDOCS 8103090568
Download: ML20008E756 (2)

Text

. P RC FORM 3GG G. U. ml%L(llG t1 in ec - l LICENSEE EVENT REPORT (PLEASE PRINT OR TYPE ALL REQUIRED INFORMATION)

CONTROL BLOCK: l 1

l l l l l o

lh jolt l l 0l Hl Dl Bl Sj 1l@l 0 l 0 l 0] 0 l 0 l 0 l 0 l 0 ] 0 l 0 l 0J'Jl@l 4 l 1LICENSE 2ts l 1 lT 1l 1l@lbl CAl I Sdl@

YPE JO

? 8 9 LICENSEE CODE 14 1$ LICENSE NUYdEH COYT .-

10111 i 8

[n"c'E l Ll@l 0l 5l 60 61 0l -] 0l 3l 4 l 6 63@l 0EVENT DOCK ET NUVSER 6d l 2DATE l 0 l 2 l 8 l l l@l 14 75 REPORT ODATEl 31 O 80 l 4 l 8 l 1 EVENT DESCRIPTIO J AND PROBA8LE CONSEQUENCES h foTil I (NP-33-81-09) On 2/2/81 at 0345 hours0.00399 days <br />0.0958 hours <br />5.704365e-4 weeks <br />1.312725e-4 months <br /> during the performance of the Main Steam Isola-i l

l o [ 3 ] I tion Valve Closure Test ST 5073.01, operations personnel noted that the Main Steam

[

l o l4 l l Isolation Valve Bypass Valve MS 100 A failed to close. This placed the unit in the The valve was closed to satisfy l o 5 l action statement of Technical Specification 3.6.3.1.

I o is l l the action statement. There was no danger to the health and safety of the public or l lo l 7 l l station personnel. The valve is located outside of containment and can be closed l I

l o i s l I during plant operation. 80 SYSTE41 CAUSE CAUSE COMP. VALVE CODE CODE SUSCODE COYPONENT CODE SUBCODE SUBCODE

[o~{T) lS lD l@ y@ l Xl@ l V l A l L l V l E l X l@ lE l@ y @ 13 18 ts 20 7 8 9 10 11 12 OCCU A RENCE REPORT REVISION S E QU E N T I A'.

REPORT NO. CODE TYPE N O.

LER RO EVENT YEAR

@ uEP RT l8l1l l-l l0l1l0l l0 l3 l l Ll [.--J l0 l 32 23 24 26 27 28 29 30 31

_ 21 22 O PLA*T HOURS S S IT FOH f B. SUPPLIE MAN FACT REH KE ACT C' 1ET I33E lg]J4X lQ lJ5Z l@ l Z l@

Jte l 0l 0l 0l 0l40 37 W@ lN l@ W@ lRl3l4l0l@

41 42 43 44 4; CAUSE DESCRIPTION AND CORRECTIVE ACTIONS h

g l The cause is not exactly known. However, the tension of the closing spring was in-gi l3 j l creased and the valve would then fully close. The conditions that caused the need g y,,,,l for additional closing tension have not been determined. The above adjustment was  ;

The valve was successfully stroked and returned to serviceg g l made under MWO IC-234-81.

, 4  ; at 0455 hours0.00527 days <br />0.126 hours <br />7.523148e-4 weeks <br />1.731275e-4 months <br /> on 2/2/81. l 83 7 8 9

.POAER OTHE R ST ATUS DISCO RY RIPTIO ST S DISCOVERY ST DES 50 73. d1 i s lC j@ l 0l 0l 0lg] NA l [ B g l Surveillance Test [

ACil /i f y CONTENT RELE ASED OF RE LE ASE AMOUNT OF ACTIVITY LOCATION OF RELE ASE 7

i G 8 9 h to l NA 11 44 l l 45 80 l

PERSONNEL E =POSURES NUUfd A TYPE DESCRIPTION -

I i 7 101010 l@l l@l NA PE RSONNE L INJV ES NUYBE R D E SC rip T ION I

7 i 4 8 9 l0l0l0l@l NA 11 12 80 LO55 OF CR C AV AGE To F ACILITY TYPE D ESCf uP TION lj_l]lZl@l 2 NA 60 l

7 11 9 to PU4 sciTY NRC USE ONLY l> l ol Ld81 NA I 11111ll111111

? s 9 to 08 69 80 5 DVR 81-016 g fg Dan Trautman p (419) 259-5000, Ext. 2350

\

J TOLEDO EDlSON COMPANY DAVIS-BESSE NUCLEAR POWER STATION UNIT ONE SUPPLEMENTAL INFORMATION FOR LER NP-33-81-09 DATE OF EVENT: February 2, 1981 FACILITY: Davis-Besse Unit 1 IDENTIFICATION OF OCCURRENCE: Failure of MS 100 A to close during performance of Surveillance Test ST 5073.01, Main Steam Isolation Valve Closure Test Conditions Prior to Occurrence: The unit was in Mode 3 with Power (MWT) = 0 and Load (Gross MWE) = 0.

Description of Occurrence: On February 2, 1981 at 0345 hours0.00399 days <br />0.0958 hours <br />5.704365e-4 weeks <br />1.312725e-4 months <br /> during the performance of ST 5073.01, Main Steam Isolation Valve Closure Test, operetions personnel noted that MS 100 A, Main Steam Isolation Valve Bypass Valve, failed to close. This event placed the unit in the actic a statement of Technical Specification 3.6.3.1 which requires this valve, MS 100 A, to be operable in Modes 1, 2, 3, and 4. The unit was in Mode 3 at the time of the occurrence. MS 100 A was closed to satisfy the action statement requirement.

Designation of Apparent Cause of Occurrence: Initial belief was that limit switches were out of adjustment, however, further investigation proved this not to be the problem. Adjustment was made to the actuator spring to increase tension slightly which allowed the valve to achieve stroke distance as was previously specified in instrument records. Inreation relating to this occurrence is still being evaluated.

This cause is being attributed to component failure.

Analysis of Occurrence: There was no danger to the health and safety of the public or to station personnel. At the time of the occurrence there was no primary to secon-dary leakage and therefore would have posed no threat to the health and safety of the public or station personnel.

Corrective Action: Maintenance Work Order IC-234-81 was written and the above men-tioned adjustments were performed under this maintenance work order.

Failure Data: Similar occurrences were reported in Licensee Event Report h7-33-80-104 (80-082) which included two events.

LER #81-010

~" .