ML20106B502

Final Deficiency Rept,Item 142 Re Failure of Two Target Rock Solenoid Valves.Initially Reported on 841213.Engineering Design Package & Field Mod Request Issued to Change Field Wiring

ML20106B502
Person / Time
Site:	Fermi
Issue date:	02/01/1985
From:	Jens W DETROIT EDISON CO.
To:	James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
References
142, EF2-70239, NUDOCS 8502110636
Download: ML20106B502 (3)

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Nuclear Operatons 6400 Edison m=NormOmeHghway """"

February 1, 1985 EF2-70239 Mr.' James G. Keppler Regional Administrator Region-III' . _

U.rS. Nuclear Regulatory Commission

. 799 Roosevelt Road'

Glen Ellyn, Illinois 60137

Reference:

(1) Fermi 2 NRC Docket No. 50-341 (2) Letter, W. H. Jens to J. G. Keppler January 11, 1985, EF2-70234

Subject:

Final Report of.10CFR50.55(e) Item 142

" Failure of Two Target Rock Solenoid Valves" This is. Detroit Edison's final report of Item 142, _ " Failure of Two Target Rock Solencid Valves." Item.142,was originally reported as. potential deficiency on December 13, 1984and was subsequently documented in Reference 2. The valves were manufactured by the Target Rock Corporation of E. Farmingdale, New York.

Description of Deficiency During the Primary Containment-Integrated Leak Rate Test, 2 Target Rock solenoid valves (E41-F402 and Ell-F415) _w ere found to operate improperly. Valve Ell-F415 isolates.one of l the drywell pressure' instrument lines; valve E41-F402 3

isolates one of-the torus pressure / level instrument lines.

{ Each of these valves had remote position' indication _which i showed-the opposite ofLthe true' position of the valve.

j- Additionally, operation of the valve actuators for these l valves caused the valve to travel.to.the opposite position

from that intended.

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, . Valve Actuation: Two types of Target Rock solenoid valves j are used at Fermi 2: dual solenoid and single solenoid.

The single solenoid valve will operate properly regardless of the actuator coil; polarity although there is a preferred

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coil polarity. ' Detroit Edison has been. informed.by'the vendor,-Target: Rock ^ Corporation, that~ dual solenoid valves may not operate: properly when the coil polarity is reversed. g L

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Mr. James G. Keppler February 1,1985 EF2-70239 Page 2 Improper operation of the dual solenoid valves was caused by incomplete vendor information which did not identify the convention for marking positive and negative terminals or that reversing the coil polarity could cause improper operation of the valve. The drawings did not identify that the positive leads on each coil were differentiated from the negative leads with a marking ring. Additionally, the vendor procedure for aligning position indication included reversing coil polarity during the alignment procedure.

Valve Position: Position indication for Target Rock sole-noid valves is provided by 2 reed switches. The reed switches detect valve position by their proximity to the plunger and not direct contact; and, either switch can be adjusted to close with the valve either open or closed.

Since the design of the valve doce not permit visual verifi-cation of the plunger position, the valve position reed switches were adjusted to agree with the expected plunger position based on control room demand signal. As a result, position indication was adjusted to correlate to the improper valve position.

Other problems had previously been identified with position

• . indication for these valves. The reed switch mounting bracket is difficult to install, can be tipped easily and is susceptible to loosening from vibration. Also, the~ reed switch adjustment procedures lack sufficient detail to ensure proper adjustment. Although not directly related to improper operation of the valves these previous difficulties contributed to the delay in the identification of the problem.

Scope: Improper valve actuator operation is peculiar to the Target Rock dual solenoid valve because of sensitivity of the valve to the polarity of the actuator coil. Addition-ally, the coil polarity was identified on the drawings for the single solenoid valves while coil polarity was not identified on the drawings for the dual solenoid valves. Of the 41 QA Level I Target Rock solenoid valves installed, 10 are the dual solenoid type. Four of the ten dual solenoid valves were found to operate incorrectly.

Analysis of Safety Implications Target Rock dual solenoid valves are remote manually operated from the control room and are used to isolate containment instrumentation lines related to the Reactor Protection System and Emergency Core Cooling Systems.

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i Mr. James G. Keppler j February 1, 1985 EF2-70239 I Page 3 Improper operation and position indication'of these valves could result in the isolation of instrumentation sensing containment pressure.

Corrective Action Updated vendor drawings have been received. An Engineering Design Package and Field Modification Request has been.

Issued to change field wiring. The incorporation of:these documents will revise the engineering drawing to show the required polarity.

Improved procedures have been developed for position indication alignment and general maintenance of Target Rock solenoid valves.

All 10 Target Rock dual solenoid valves have been inspected for polarity, wiring convention, operating direction, reed switch adjustment and position indication.

An improved reed = switch mounting bracket is now available from the manufacturer. These brackets are being procured and will be installed on a schedule based on the availability of the valves for maintenance.

This is Detroit Edison's final. report of this item. If you have questions concerning this matter, please contact Mr. Lewis P. Bregni, (313) 586-5083.

Sincerely,

(/

60 cc: Mr. P. M. Byron Mr. R. C. DeYoung Mr. R. C. Knop USNRC Document Control Desk Washington, D.C. 20555 l

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