ML18100A494

Special Rept:On 930707,process Monitor - Noble Gas effluent- Condenser Exhaust Sys Was Removed from Svc Due to Observed Water in Its Sample Line.Sample Line 2R15 Drained & Dried. W/930721 Ltr

ML18100A494
Person / Time
Site:	Salem
Issue date:	07/21/1993
From:	Vondra C Public Service Enterprise Group
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
NUDOCS 9307280111
Download: ML18100A494 (4)

Text

e PS~G Public Service Electric and Gas Company P.O. Box 236 Hancocks Bridge, New Jersey 08038 Salem Generating Station July 21, 1993 U. s. Nuclear Regulatory Commission Document Control Desk Washington, DC 20555

Dear Sir:

SALEM GENERATING STATION LICENSE NO. DPR-75 DOCKET NO. 50-311 UNIT NO. 2 SPECIAL REPORT 93-3 This Special Report addresses the circumstances surrounding the inoperability of the 2R15 Radiation Monitoring System {RMS) channel for greater than seven (7) days. This report is submitted in accordance with the requirements of Technical Specification 3.3.3.1 Table 3.3-6 Action 26 pursuant to Technical Specification 6.9.2.

It is required within fourteen (14) days from when the RMS channel was found inoperable.

Sincerely yours,

c. A. Vondra General Manager -

Salem Operations MJP:pc Distribution 93072801 f {' $1307!:> 1

~DR ADOCK 05000311 PDR The power is in your hands.

95-2189 REV 7-92

QPECIAL REPORT NUMBER ' - 3

'J' PLANT IDENTIFICATION:

Salem Generating Station - Unit 2 Public Service Electric & Gas Company Hancock's Bridge, New*Jersey 08038 IDENTIFICATION OF OCCURRENCE:

Technical Specification 3.3.3.1 - Radiation Monitoring Instrumentation Channel 2R15 Inoperable > 7 Days Event Date: 7/7/93 Report Date: 7/21/93 This Special Report is required due to Radiation Monitoring System (RMS) channel 2Rl5 being inoperable for greater than seven (7) days.

This report was initiated by Incident Report No.93-310.

CONDITIONS PRIOR TO OCCURRENCE:

Mode 1 Rx. Power 100% 1140 MWe DESCRIPTION OF OCCURRENCE:

On July 7, 1993, the 2R15 (Process Monitor - Noble Gas Effluent -

Condenser Exhaust System) was removed from service due to observed water in its sample line (discharge line from the Condensers).

Technical Specification Action 3.3.3.1.b, Action 26 was entered and a preplanned method of sampling was initiated.

Investigation identified that the condenser waterbox priming tank drainline had become plugged with silt and rust scale. Further investigation revealed that several condenser shell ball check float valves (Model M481 Multiplex Manufacturing Co.) had stuck open allowing water carry over to the priming tank. Silt and scale, which carried over with the water from the condenser water boxes, caused priming tank drainline blockage (see Attachment).

The ball check valves are designed to allow removal of entrained air and prevent water carry over from the condenser waterboxes.

Technical Specification 3.3.3.1.b states:

"With one or more radiation channels inoperable, take the ACTION shown in Table 3.3-6. 11 Table 3.3-6 states:

"With the number of OPERABLE Channels less than required by the Minimum Channels OPERABLE requirements, initiate the preplanned alternate method of monitoring the appropriate parameter(s),

within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />, and:

1. either restore the inoperable Channel(s) to OPERABLE status within 7 days of the event, or

CNIT 2 SPECIAL REPORT,-3 I DESCRIPTION OF OCCURRENCE: (cont'd)

2. prepare and submit a Special Report to the Commission pursuant to Specification 6.9.2 within 14 days following the event outlining the action taken, the cause of the inoperability and the plans and schedule to restoring the system to OPERABLE status."

APPARENT CAUSE OF OCCURRENCE:

The cause of the ball check float valve failure is inadequate design. River debris was found to cause the as found stuck open position. These valves are being replaced with new loop seals. This should prevent water "carry over" in the future.

ANALYSIS OF OCCURRENCE:

The 2R15 channel is used in conjunction with the 2R19 (Steam Generator Blowdown Process Monitor), 2R40 (Condensate Process Filter Monitor), and 2R46 (Main Steam Line Process Monitor) channels to provide an early indication of a primary to secondary leak in a steam generator. Had a leak developed in any steam generator with the 2R15 channel inoperable, the detection capabilities of the remaining systems would have functioned to allow mitigating actions.

As stated, this report is required due ~o the 2Rl5 RMS channel being inoperable for greater than seven days. It was not returned to service within seven days due to the time required to conduct investigations and complete priming tank cleaning, ball check valve repair and 2R15 RMS channel draining and channel functionals.

CORRECTIVE ACTION:

The 2R15 sample lines were drained and dried. Also the filter was replaced. The channel was returned to service on July 17 upon successful completion of a channel functional and channel calibration.

The ball check float valves are being opened and cleaned. The priming tank drain line and the priming tank were cleaned.

The ball check float valves are being replaced with new loop seals.

This should prevent water carry over i~ fut~re.

tfki/J-G~eral Manager -

Salem Operations MP:pc SORC Mtg.93-068

UNIT 2 SPECIAL REPORT ' - 3 ,

ATTACHMENT 1

>*-----, > TO STACK r-..--->_J PRIMING TANK 2R15 BALL VALVE x DRAIN 23 VACUUM PUMP CONDENSER WATER BOX