05000324/LER-1981-070-03, /03L-0:on 810718,RHR Shutdown Cooling Supply Inboard Isolation Valve 2-E11-F009 Would Not Open from Rtgb. Caused by Loose Fastening Screw in Valve Motor Control Ctr. Screw Tightened & Valve Stroked

/03L-0:on 810718,RHR Shutdown Cooling Supply Inboard Isolation Valve 2-E11-F009 Would Not Open from Rtgb. Caused by Loose Fastening Screw in Valve Motor Control Ctr. Screw Tightened & Valve Stroked

ML20010C643
Person / Time
Site:	Brunswick
Issue date:	08/10/1981
From:	Pastva M CAROLINA POWER & LIGHT CO.
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
Shared Package
ML20010C642	List: 05000324/LER-1981-070, Forwards LER 81-070/03L-0 05000324/LER-1981-070-03, /03L-0:on 810718,RHR Shutdown Cooling Supply Inboard Isolation Valve 2-E11-F009 Would Not Open from Rtgb. Caused by Loose Fastening Screw in Valve Motor Control Ctr. Screw Tightened & Valve Stroked
References
LER-81-070-03L, LER-81-70-3L, NUDOCS 8108200264
Download: ML20010C643 (2)

LER-1981-070, /03L-0:on 810718,RHR Shutdown Cooling Supply Inboard Isolation Valve 2-E11-F009 Would Not Open from Rtgb. Caused by Loose Fastening Screw in Valve Motor Control Ctr. Screw Tightened & Valve Stroked

Event date:
Report date:
3241981070R03 - NRC Website

text

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FORM 366 U. S. NUCLE AR C EGULATERY COMMISSION LICEN4EE EVENT REPORT CONTROL BLOCK: l l

l l

l l

j (PLEASE PRINT OR TYPE ALL REQUIRED INFORMATION) 1 6

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7 8 9 LICENSEE CODE 14 15 LICENSE NUMBER 25 26 LIC E NSt TYPE JO

$ 7 CAT 58 CON'T 10 l 1*l S$RCE d l0l5l0l 1013l2l4 hl0l711 l8l ail h oIRl1 l 0 ! R l1 !b 7

6 60 61 DOCKET NUMBER 68 69 EVENT DATE 74 75 REPORT D ATE 80 EVENT DESCRIPTION AND PROBABLE CONSEOUENCES h Ioi2l l Followinn a planned reactor shutdown while attempting to place RHR shutdown coolinn

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[ol3] l into service, the RHR shutdown cooling supply inbo; 4 isolation valve, 2-Ell-F009, J 1014 l l would not open f rom the RTGB.

The valve was manually opened, RHR shutdown coolinn i

I was placed into service and the plant was placed in cold shutdown within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />. A l a s l o lc l l similar event involving this valve was reported ia LER 2-81-19 on 3-16-81.

This i

l o 17 l l event did not affect the health and safety of the public.

l l o 15i l l Technical Specifications 3.6.3, 6.9.1.9b l

80 7

8 9 SYSTEM

CAUSE

CAUSE C OY P.

VALVE CODE CODE SUBCODE COMPONENT CODE SU8 CODE SUBCODE loloj l Cl Fj@ y@ W@ lV l A lL l\\ l0 lP l@ {@ y @

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9 10 11 12 13 18 19 20 SEQUENTI AL OCLURRENCE REPORT REVISION LER RC EVENT YE AH REPORT NO.

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40 41 42 43 44 47 CAUSE DESCRIPTION AND CORRECTIVE ACTIONS h l i l o l [A loose fastening screw in the valve motor control center allowed one of the valve l

lil ] l motor's thermal overload protective devices to bacome loose, creating an overcurrent I i,i7i l condition on 2 phases of the motor which tripped the valve motor breaker. The screw l p l 3 l l was properly tightened and the valve was stroked and returned to operation. Thisjs l [ij4ll considered an isolated event and requires no further action.

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ACYlVITY CONTENT RELE ASED OF RELE ASE AVCUN1 OF ACTIVITY LOCATION OF RELEASE l1 l6 l l

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pac-ra, Jr.

PHONE:

919-457-9521

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h LER A'lTACHMENT - RO #2-81-70 Facility: BSEP Unit No. 2 Event Date: 7-18-81 Following this event the F009 valve motor was meggared and bridged from the valve motor control center with the meggar readings satisfactory, but the bridge readings showing intermittent open motor windings. The valve motor was removed to determine the cause of the intermittent bridge readings. A test run of the valve motor in the plant shop test facility and bridge readings showed normal operation of the valve motor.

Additional troubleshooting at the valve motor control center determined that one of three valve motor thermal overload protective devices was not making contact with its associated electrical cable due to a loose fastening screw in the valve mater breakers compartment.

From the findings of the alve motor control center troubleshooting, it has been determined that the F009 valve motor tripped due to a phase overcurrent con-dition on two of the valve motor's three electrical phases caused by the loose motor phase thermal overload device.

A check of plant documentation shows no history of similar events involving loose fastening screws in motor control centers; therefore, this event is considered to be isolated with no further corrective action required. Plant preventative maintenance procedure MI 10-2K currently requirs s an inspection of all similar motor control centers once every three years, and this procedure checks for screw tightness.