ML20039C079

Interim Deficiency Rept Re Swing Check Valves in HPCI & Reactor Core Isolation Cooling Turbine Exhaust Lines, Initially Reported 811117.Manufacturer to Supply Hardware for Field Mod of Unit 1 Valves & to Modify Unit 2 Valves

ML20039C079
Person / Time
Site:	Hope Creek, 05000355
Issue date:	12/15/1981
From:	Martin T Public Service Enterprise Group
To:	Haynes R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
References
10CFR-050.55E, 10CFR-50.55E, NUDOCS 8112280384
Download: ML20039C079 (2)

Text

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o Thomas J. Martin Public Service Electric and Gas Company 80 Park Plaza Newark, N.J. 07101 201/4304316 Via PreWent Mailing Address: P.O. Box 570, Newark, N.J. 07101 Eryneering and Construction December 15, 1981 Mr. Ronald C. Haynes U. S. Nuclear Regulatory Commission v Office of Inspection and Enforcement O D Region ! ,b Y

631 Park Avenue kib7 King of Prussia, Pennsylvania 19406 I;C..g

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Dear Mr. Haynes:

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HPCI/RCIC EXHAUST CHECK VALVES o POTENTIAL SIGNIFICANT DEFICIENCY \ _

NO. 1 AND 2 UNITS HOPE CREEK GENERATING STATION On November 17, 1981, a verbal report was made to Region I, Office of Inspection and Enforcement representative, Mr.

W. H. Bateman, advising of potential significant deficiency concerning failure of swing check valves (supplied by Anchor Darling) in HPCI and RCIC turbine exhaust lines.

The following information is submitted as an interim report in accordance with the requirements of 10CFR50.55(e).

Failure of swing check valves in HPCI and RCIC turbine ex-haust valves has been experienced at other nuclear facili-ties. Investigation of the problem revealed that steam flow conditions during low speed operation causes the valve disc to cycle violently open and closed. Since the check valve was sized for full flow, operation of the system, low flow --

causes the disc function to be erratic. As a_ result, the end of the disc stud gradually wears a hole in the valve bonnet which serves as the stop. The additional travel al-lows the disc edge to impact against the valve body. The loads and stresses, experienced by the disc, result in frac-ture of the disc stud. Installation of vacuum breakers in the HPCI and RCIC systems has been found to be inef fective in preventing the disc from slamming during low speed opera-tion and subsequent valve failure.

PSE&G's architect engineer, Bechtel Power Corporation, is performing an analysis of the safety implications of this type failure. The analysis will be based, in part, <xt a comparison of our HPCI and RCIC system design with those of facilities that experienced such a failure.

8112280384 011215 [#}

PDR ADOCK 05000354 / D S

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Mr. Ronald C. Haynes 12/15/81 By way of corrective action, Bechtel has issued instructions to the valve manufacturer to provide hardware to modify the Unit #1 valves in the field. The Unit #2 valves will be re-turned to the manufacturer for modification. The modifica-tion will consist of an extended hinge and a larger diameter stud.

The estimated completion date for the corrective action and the impact study is July 31, 1982, at which time a report will be made to the NRC.

Very truly yours,

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CC: Office of Inspection and Enforcement Division of Reactor Construction - Inspection Washington, D.C.

NRC Resident Inspector - Hope Creek P. O. Box 241 Hancocks Bridge, New Jersey 08039 l

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