ML20237G934

Special Rept SR-87-003-00:on 870731 & 0809,condenser Vacuum Vacuum Pump Discharge Wide Range Gas Monitor (WRGM) Inoperable.Caused by Water Blockage of Sample Lines.Wrgm Restarted & Being Tested for Operation

ML20237G934
Person / Time
Site:	Waterford
Issue date:	08/21/1987
From:	Carns N LOUISIANA POWER & LIGHT CO.
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
References
SR-87-003-00, SR-87-3, W3A87-0103, W3A87-103, NUDOCS 8708240300
Download: ML20237G934 (4)

Text

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I Ref:

10CFR50.36(c)(2)

LQUISIANA /

POWE R & LIGHT WATERFORD 3 SES + P. O. BOX B e KILLONA, LA 70066 l

$hkS SYNEM August 21, 1987

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i W3A87-0103 A4.05

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QA U.S. Nuclear Regulatory Commission ATTENTION: Document Control Desk Washington, D.C.

20555

SUBJECT:

Waterford 3 SES Docket No. 50-382 License No. NPF-38 Reporting of Special Report Attached is Special Report Number SR-87-003-00 for Waterford Steam Electric Station Unit 3.

This Special Report is submitted per 10CFR50.36(c)(2) and Technical Specifications 3.3.3.1. and 6.9.2.

Very truly yours, j

N.S. Carns Plant Manager - Nuclear NSC/DEBirk Attachment cc:

R.M. Martin, NRC Resident Inspectors Office, INPO Records Center (J.T. Wheelock), E.L. Blake, W.M. Stevenson, J.H. Wilson i

8708240300 870021 l

PDR ADOCK 05000302 "L-l S

PDR l

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l "AN EQUAL OPPORTUNITY EMPLOYER" I

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SPECIAL REPORT l

l SR-87-003-000 l

Inoperability of Condenser Vacuum Pump Wide Range Gas Monitor due to water

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blockage of Sample Lines l

INTRODUCTION At approximately 1444 hours0.0167 days <br />0.401 hours <br />0.00239 weeks <br />5.49442e-4 months <br /> on July 31, 1987, and again at approximately 0720 i

hours on August 9, 1987, Waterford Steam Electric Station Unit 3 was operating at 100% reactor power when operations personnel declared Condenser Vacuum Pump Discharge Wide Range Gas Monitor - (WRCM), PRM-IR-0002, inoperable.

In accordance

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with Technical Specification 3.3.3.1 Action 27, Health Physics personnel established the preplanned alternate method for monitoring Condenser Vacuum Pump discharge exhaust as defined in procedure EP-2-050, "Off-Site Dose Assessment (Manual)." The monitor is expected to be returned to service within a few dir s.

l Since the monitor could not be returned to service within seven days in both cases, this report is being submitted pursuant to Technical Specification 3.3.3.1 and 6.9.2.

NARRATIVE On July 31, 1987, Waterford Steam Electric Station Unit 3 was operating at 100% reactor power when Instrument and Controls (I&C) personnel were performing a functional test per procedure MI-3-386, " Condenser Vacuum Pump Discharge High Range Noble Gas Radiation Monitor Channel Functional Test PRM-IR-0002," on the Condenser Vacuum Pump Wide Range Gas Monitor (WRGM). During this functional test, the WRGM failed section 8.1 of MI-3-386, " Preparation for Testing", due to erratic sample flow. Therefore, at 1444 hours0.0167 days <br />0.401 hours <br />0.00239 weeks <br />5.49442e-4 months <br /> on July 31, 1987, operations personnel declared the WRGM inoperable.

In accordance with Technical Specification 3.3.3.1 Action 27, Health Physics personnel established the preplanned alternate method for monitoring Condenser Vacuum Pump discharge l

exhaust as defined in procedure EP-2-050, "Off-Site Dose Assessment (Manual)."

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l During subsequent troubleshooting, it was found that the sample lines from the Condenser Vacuum Pump discharge to the WRGM were filled with water. The j

Condenser Vacuum Pump discharge and WRCM sample lines were drained, and the i

sample dryers for the normal and WR gas monitors were overhauled. A functional test per MI-3-386.was satisfactorily performed, and the WRCM was placed back in service on August 8, 1987.

At 0720 hours0.00833 days <br />0.2 hours <br />0.00119 weeks <br />2.7396e-4 months <br /> on August 9, 1987 the WRCM was declared out of service by j

operations personnel. WRGM sample lines were again found to be full of water

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l which was causing erroneous readings on the WRCM due to erratic sample flow.

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This was apparently caused by a combination of high condenser circulating water j

inlet temperature, condenser fouling, and the Condenser Vacuum Pump lineup.

All three Condenser Vacuum Pumps were operating to maximize condenser efficiency.

This resulted in an unusually high carryover of steam which condensed at the Condenser Vacuum Pump discharge, thus preventing air flow from entering the i

WRCM sample lines at the Condenser Vacuum Pump discharge.

Blockage of the i

i sample lines by this condensation apparently caused a loss of loop seal at the l

sample inlet condensing pot drain which resulted in a mixture of entrained water droplets and turbine building atmosphere to enter the sample pump and WRGM causing erroneous readings. The WRCM is not designed to function correctly in a moist environment.

The cause of inoperability of the Condenser Vacuum Pump Discharge WRCM was

'I determined to be condensed water from Condenser Vacuum Pump steam carryover which blocked WRCM sample lines, thus preventing the discharged condenser j

non-condensable gases from being sampled. This is not a fault in the WRCM but is a system fault due to the interaction of high condenser temperatures and Condenser Vacuum Pump operating characteristics. Plant power was reduced on August 18, 1987, and several condenser waterboxes were cleaned. This resulted in sufficient improvement in condenser performance to reduce the number of operating vacuum pumps to one.

The WRGM was subsequently restarted and is presently being tested and observed for proper operation.

It is expected to be declared operable within a few days.

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Since the monitor was not returned to service.within the seven day limit in both cases (July 31, 1987 to August 7, 1987, and August 8, 1987, to present) as defined in Technical Specification 3.3.3.1 this Special Report is submitted pursuant to Specification 6.9.2.

Since Health Physics personnel have an alternate method of monitoring Condenser Vacuum Pump discharge exhaust and no measurable primary to secondary leakage l

presently exists, the inoperability of the wide range gas monitor does not pose a safety concern, i

PLANT CONTACT I

T. Smith, Maintenance Superintendent, 504/464-3138 3