ML20211G532

Provides Clarification of 861227 four-hour Nonemergency Event Rept Re Unplanned Closure of Excess Flow Check Valve. Caused by Loose Reed Switch Assembly Atop Excess Flow Check Valve,Giving Erroneous Indication.No LER Necessary

ML20211G532
Person / Time
Site:	Hope Creek
Issue date:	02/04/1987
From:	Salvesen R Public Service Enterprise Group
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
NUDOCS 8702250422
Download: ML20211G532 (2)

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n O PSEG Public Service Electric and Gas Company P.O. Box L Hancocks Bridge, New Jersey 08038 Hope Creek Operations February 4, 1987 U.S. Nuclear Regulatory Commission Document Control Desk Washington, DC 20555

Dear Sir:

HOPE CREEK GENERATING STATION DOCKET NO. 50-354 UNIT NO. 1 CLARIFICATION OF FOUR-HOUR NON EMERGENCY EVENT REPORT OF 12/27/86 On December 27, 1986, the Hope Creek Generating Station Senior Nuclear Shift Supervisor (SNSS) made a four hour non emergency report to the NRC Operations Center regarding the unplanned actuation (closure) of an excess flow check valve. The check valve is installed in one of the reactor recirculation flow sensing lines and provides an isolation function in the event of a line break outside of the primary containment. The event which precipitated the notification was the receipt of alarms in the control room at 1729 which indicated the excess flow check valve had closed. An inspection of downstream instrument piping revealed no leakage and the valve was reset. The alarms were received again at 1902 at which time the valve was declared inoperable and the appropriate notifications made.

An investigation into the event revealed that the reed switch assembly atop the excess flow check valve was not securely fastened. This assembly detects the position of a plunger internal to the excess flow check valve thus providing indication of the valve position. With this assembly loose, erroneous indication of valve position is likely. After reviewing the check valve assembly, indications present at the time the valve was reported to have closed, and considering the actual conditions required to close the valve, plant management has concluded that the excess flow check valve did not actuate as reported but rather erroneous indication was received in the control room. This conclusion is based on the following:

o In plant surveillance testing of excess flow check valves has shown that the valves do not close unless there is actual leakage downstream of the valve. The spring which must be compressed to close the valve provides sufficient force to preclude spurious closures.

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e O To USNRC 2/4/87 o The reed switch assembly was found to be loose and in this condition, is likely to provide erroneous indication.

o The apparent'" reopening" of the valve which took-place after the -

first reported closure is attributed to the vibrating of the reed switch assembly when the DC coil (used to actuate a bypass plunger) was energized.

Since the excess flow check valve did not actually close, no Engineered Safety Feature occurred. In addition, the isolated component malfunction is not considered a generic problem nor one which would satisfy other reporting criteria of 10CFR59.72. Thus, i the report made by the SNSS is considered a conservative measure taken based upon the information available at the time but not one required by regulations. Similarly, the event does not moet the reporting requirements of 10CFR50.73 and as such, a Licensee Event Report will not be submitted for this event.

Sincerely, R.h S h l9 w R. S. Salvesen General Manager -

Hope Creek Operations WJM:tib

. NRC-001 IR 86-275 C Distribution l

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