ML20151H008

IE Info Notice 81-30, Velan Swing Check Valves

ML20151H008
Person / Time
Issue date:	09/28/1981
From:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE)
To:
References
IEIN-81-30, NUDOCS 8107230027
Download: ML20151H008 (2)

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'NS No. 6835 V' ession No.:

8107230027 IN 81-30 t

UNITED STATED NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT WASHINGTON, D.C. 20555 September 28, 1981 IE INFORMATION NOTICE N0. 81-30: VELAN SWING CHECK VALVES Description of Circumstances:

Recent occurrences with Velan swing check valves are described below.

1. On June 30, 1981, Public Service Electric & Gas Company reported (LER 81-035/01T) that on June 6, 1981, while a leak in the bonnet of a swing check valve in the steam supply to the turbine driven auxiliary feedwater pump at Salem Generating Station, Unit 2, was being repaired, the valve was found to be internally damaged. The valve is a Velan 6-in. swing check valve (Type B14-2114 B-2TS).

The valve disk stud had broken and the valve disk was in the bottom of the valve body. The valve also had cracks in the disk, cracked bushings, a warped hinge pin, and all hinge pin holes were elongated.

The licensee inspected the corresponding swing check valve in the other

(. steam supply line and discovered similar damage. An inspection of the corresponding swing check valves on Unit 1 also revealed similar damage (LER 81-059/01T).

The licensee plans to radiologically examine the valves monthly until a reason for the damage can be determined.

2. On July 31, 1981, Wisconsin Electric Power Company reported (LER 81-010/01T-0) that on July 14, 1981, while a check valve leakage test at the Point Beach Nuclear Plant, Unit 1, was being performed, the check valves closest to the reactor coolant system in the low head safety injection lines were found to be leaking more than allowed by the leakage acceptance criteria. The valves are Velan 6-in. 1500 psig ASA swing check valves (Velan Orawing No. 78704).

The valves were disassembled and the disks were found to be stuck in the full-open position due to interference between the disk nut lockwire (disk wire) and the valve body. The disk nut and its shaft can rotate freely, and, in certain random rotational positions, this interference is likely to occur.

The licensee has replaced the disk wire with a cotter pin that will not cause interference with the valve body for any rotational position. Subsequent inspection of the other check valves in the low head safety injection lines s

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81-30 L N Jptember 28, 1981 Page ? of 2 was perfo'rmed. These valves were found to be closed. The lock wires were nevertheless replaced wit.h cotter pins.

The drawing for the same valve used at the Prairie Island plant was also checked. The drawing (Velan Drawing No. 78704) is annotated to require that the lock wire be tack welded down (so it cannot interfere with the valve body). Becausethisdetailisnotuniformonthesubjectdrawingandcan vary from plant to plant, a verification and/or changeout on this locking device may be necessary.

Additional occurrences with Velan swing check valves are described in IE Bulletin 79-04, "Incorrect Weights for Swing Check Valves Manufactured by Velan Engineering Corporation," and in IE Information Notice 80-41, "Failure of Swing Check Valve in the Decay Heat Removal System at Davis-Besse Unit No. 1."

This information is provided as notification of a potentially significant matter. It is expected that recipients will review the information for possible applicability to their facilities. No specific action or response is requested at this time. If you have questions regarding this matter, please contact the Director of the appropriate NRC Regional Office.

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