ML20247D926

Special Rept:On 890327,main Steam Line Monitors Inoperable for Greater than 7 Days.Caused by Normal Equipment Deterioration.Proposed Change 228 to Tech Specs 3.3.3.1, Addresses Actions to Be Taken If Monitors Become Inoperable

ML20247D926
Person / Time
Site:	Yankee Rowe
Issue date:	07/21/1989
From:	St Laurent N YANKEE ATOMIC ELECTRIC CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
BYR-89-114, NUDOCS 8907250338
Download: ML20247D926 (3)

Text

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L YANKEE ATOMIC ELECTRIC COMPANY r.i.v on.ta,s><2<.s2e.

u Star Route, Rowe, Massachusetts 01367

, YANKEE July 21, 1989 BYR 89-114 U.S. Nuclear Regulatory Commissic'

-Document Control Desk

. Washington, DC 20555-

Subject:

Special Report:

Main' Steam Line Monitors Inoperable for Greater Than.7 Days (Proposed T.S. 3.3.3.1, Table 3.3-4 Item 2(c))

Dear Sir:

In accordance with our Proposed Change No. 228 to Technical Specification 3.3.3.1, Table 3.3-4, Item 2(c) and Technical Specification 6.9.6.k. the attached Special Report outlining the actions taken, the cause of the inoperability and the plans and schedule for restoring the instruments to operable status is hereby submitted.

Very truly yours, Normand N. St. Laurent Plant Superintendent ELM / elm Enclosure cci [3] NSARC Chairman (YAEC)

[1] Institute of huclear Power Operations (INPO)

[1] USNRC, Region I ill Resident Inspector 4

8907250338 890721 PDR ADOCK 05000029 S PDC )

~

YANKEE ATOMIC ELECTRIC COMPANY Page 1 BYR 89-114 BACKGROUND on 3/27/89, No. 1 Main Steam Line Area Radiation Monitor (MSLARM) was declared inoperable because of an apparent erroneous high reading. Maintenance Request (MR) No.89-831 was initiated. A second MR (89-1200) was generated on 6. /89 because of the high reading on No. 1 MSLARM. On 6/9/89, No.

3 MSLARM was declared inoperable and MR 89-1246 initiated after failing its source check. On 6/25/89, erratic indication was noted on No. 2 MSLARM. No. 2 MSLARM was declared inoperable and MR 89-1314 was issued. No. 4 MSLARM was declared inoperable on 6/26/89 following a failed source check and MR 89-1320 was issued to investigate.

ACTION TAKEN Proposed Change 228 to the Technical Specifications was formulated and submitted for review and approval by the NRC on 7/7/89. The change will add the MSLARMs and Primary Vent Stack noble gas monitor to Technical Specification 3.3.3.1 and will address the actions to be taken if the monitors are not operable. These actions include initiating a preplanned alternate monitoring method and restoring the channel (s) to operable status within seven days or generating a Special Report within fourteen days outlining the actions taken, cause of the inoperability and the plans and schedule to restore the system to operable status.

MR 89-831, for No. 1 MSLARM, was completed on 6/13/89 but the instrument remained inoperable awaiting completion of MR 89-1200. On 6/19/89, No. 3 MSLARM was declared operational after the Mainv.enance Request was closed out with no corrective maintenance action required. No. 2 MSLARM was declared operatlocal (7/11/89) following repair of the preamp's low range amplifier and the detectors cable replacement. No. 4 MULARM was returned to service (7/17/89) after completion of the repairs to the preamp's low range amplifier and detector, cable, and readout replacement.

During the time the channels were inoperable necessary manual measurements to compensate for the loss of remote ,

instrumentation were available as outlined in plant procedure  !

OP-8741, " Determination of Noble Gas Release Rates from the Main Steam Lines with the Victoreen Channels Inoperable".

1 CAUSE_OF TEE INOPERABI_LI.TX The root cause of the inoperability was attributed to normal equipment deterioration. A single component or failure mode was not be identified during the troubleshooting, inspections and evaluations conducted as part of the restoration process.

YANKEE ATOMIC ELECTRIC COMPANY Page 2 BYR 89-114 Continued instrumentation performance will be trended as part of the normal surveillance and maintenance program.

S C._H E D U L E _ F_O R R E S T O R A T I O N Nos. 2, 3, and 4 MSLARMs have been returned to service.

Troubleshooting on No. 1 MSLARM is still in progress at this time. The parts suspected to have caused the malfunctions have been ordered from Victoreen. The parts are to be shipped on 7/24/89. Upon arrival, the installation of the new parts, testing and further troubleshooting will be accomplished as a high priority. If no other problems are encountered the monitor is expected to be back in service no later than 8/2/89. The NRC resident inspector will be kept informed of any changes made to the restoration schedule and cause determination.

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