ML20127L087

Ro:On 730917,sodium Pentaborate Solution Found in Number 12 Standby Liquid Control Pump Lubricating Oil.Caused by Stuffing Box Drain Valve Closed on 730917 for Painting.Drain Valves Will Be Seal Wired to Prevent Future Closure

ML20127L087
Person / Time
Site:	Monticello
Issue date:	09/25/1973
From:	Mayer L NORTHERN STATES POWER CO.
To:	Oleary J US ATOMIC ENERGY COMMISSION (AEC)
References
NUDOCS 9211230419
Download: ML20127L087 (1)

Text

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Rigulatory Docket se

/%d NSED NOHTHERH STATES POWER COMPANY MIN N E A PO U S MIN N E S OTA 95400 I

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- N I E SEP 281973

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~? l Mr. J. F. O' leary, Director  ; $ 0 g Directorate of Licensing Office of Regulation  ?'Qg ,Oh1EIM 8 fM '

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United States Atomic Energy Connistion y cp '

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Washington, DC 20545  ;

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Dear Mr. O' Leary:

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MONTICELLO NUCLEAR GENERATING PIANT Docket No. 50-263 License No. DPR-22 Sodium Pentaborate Solution in No. 12 SBLC Pump Lubricating 011 A condition occurred at the Monticello Nuclear Generating Plant which we are reporting to your office in accordance with Section 6.7.B.1. Abnormal Occurrence Reports, of the Appendix A Technical Specifications, of Provisional Operating License DPR-22.

On September 17, 1973, sodium pentaborate solution was found in the No. 12 Stand-by Liquid Control pump lubricating oil. An investigation of-the problem revealed that the stuffing box drain valve was closed, which caused the normal pump packing leakage to collect in the stuffing box until it leaked into the crankcase through the plunger stub ports. The drain valve was immediately opened. It was deter-mined that the stuffing box drain valve had been closed on or about September 17th for painting of the pump mounting base.

Th No. 12 pump crankcase was drained, flushed, and refilled with new oil. The No. 11 SBLC pump was inspected and also found to have the stufring box drain valve closed; however, the amount of solution which accumulated in the stuffing box was not sufficient to result in leakage into the crankcase. The drain valves will be seal wired in the open position to prevent future inadvertent closure.

This occurrence did not affect safe operation of the plant since the redundant Standby Liquid Control pump was fully operable. Standby Liquid Control pump operability has not been compromised on any previous occasions due to inadvertent closure of the stuffing box drain valves.

Very truly yours, Y.

L 0 Mayer, PE Director of Nuc1 car Support Services J G Keppler 9211230419 730925 mot

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cc: PDR ADOCK 05000263 G Charnoff S PDR Minnesota Pollution Control Agency--Attn. K Dzugan

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