ML20151H015

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IE Info Notice 81-36, Replacement Diaphragms for Robertshaw Valve(Model No. VC-210)
ML20151H015
Person / Time
Issue date: 12/03/1981
From:
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE)
To:
References
IEIN-81-36, NUDOCS 8107230039
Download: ML20151H015 (2)


Text

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8107230039 IN 81-36 UNITED STATES NVCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT WASHINGTON, D.C. 20555 December 3, 1981 IE INFORMATION NOTICE N0. 81-36: REPLACEMENT OIAPHRAGMS FOR ROBERTSHAW VALVE (MODEL N0. VC-210)

Description of Circumstances:

The Georgia Power Company's Hatch 1 facility experienced problems in early July 1981 with the Robertshaw Diaphragm Control Valve (Model No. VC-210) installed in the Terry Turbina Mechanical Hydraulic Overspeed Complex which contributed toward unreliability of the High Pressure Coolant Injection (HPCI) system.

During a routine inspection of'the valve, it was discovered that the diaphragm supplied by Robertshaw was enlarged and leaking oil. The diaphragm was replaced on July 12, 1981 and failed again on July 21 and August 11, 1981. The cause of the failures was determined to be incompatibility of a neoprene replacement diaphragm, supplied by Robertshaw, with oil in the hydraulic overspeed complex.

Folloking the August 11, 1981 failure, a fabric reinforced Buna-N diaphragm was installed. The diaphrag.a satisfied the following service conditions:

Compatible with the turbine oi_1._ recommended by the turbine vendor

. 40 psig maximum service pressure

. 250 F maximum service temperature

. 1000 minimum cycles Replacement Buna-N diaphragms are available from Terry Corporation or through the General Electric Company. An order placed directly with Robertshaw will result in the supply of a thin, non-reinforced neoprene diaphragm with reduced duty cycle life because the valves are supplied for other applications. We understand that the reinforced Buna-N diaphragm should be identified as Terry piece No. 890151A01 on the purchase order. Also, if a replacement Robertshaw Valve (Model No. VC-210) is ordered (Terry piece No. 107282A01), it is necessary to separately order the reinforced diaphragm (Terry piece No. 890151A01). The diapnragm is shown in the Terry HPCI Instruction Manual, Section 15-M-14, In-struction for Robertshaw Diaphragm Control Valve No. VC-210, Figure 14, Part 4.

This information notice or, replacing diaphragms is being proviaed as an early notification of a potentially significant matter. This experience with diaphragm failures serves as a reminder that a single material change may adverselj affect safety system reliability. Such a change may reduce service life or negate environmental qualification. Each component or material change in a system important to safety should be carefully reviewed in order to assure system ope nbility. Recipients should review the information for possible applicabi;ity to their facilities.

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December.3,-1981

, Page 2 of.2 Nd written response ~-to this.information notice is required. For additional information regarding'this matter, contact the Regional Administrator of the appropriate NRC Reg?onal~0ffice.

Attachment:

Recently; issued IE Information Notices 4

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