ML20094E437

Special Rept:On 951010,sys Engineer & Technicians Reintiated Work on B Channel of Reactor Bldg Vent Radiation Monitor, After Providing Proper Notification to Main Control Room. Caused by Incorrect Channels Removed from Svc

ML20094E437
Person / Time
Site:	Monticello
Issue date:	10/31/1995
From:	Hill W NORTHERN STATES POWER CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
NUDOCS 9511070238
Download: ML20094E437 (2)

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Northem States Power Company Monticello Nuclear Generating Plant 2807 West Hwy 75 Monticello. Minnesota 55362-9637 October 31,1995 Special Report per Monticello Technical Specification 3.14 US Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555 MONTICELLO NUCLEAR GENERATING PLANT Docket No. 50-263 License No. DPR-22 Special Report Reauired by Monticello Technical Specification 3.14 Monticello Technical Specifications, Section 3.14, " Accident Monitoring Instrumentation" specifies limiting conditions for operation for instrumentation which does not perform a protective function, but which does provide information to monitor and assess important parameters during and following an accident. Technical Specification Section 3.14 requires that a minimum of one channel of Reactor Building Vent Wide Range Radiation be operable.

When the number of operable channels is less than the minimum required, Technical Specifications require initiation of attemate monitoring methods for the appropriate parameter and submittal of a special report within the next 30 days outlining the actions taken, the cause of the inoperability and the plans and schedule for restoring the system to operable status.

This letter provides the above specified report.

On October 9,1995, the 'B' channel of the Reactor Building Vent Radiation Monitor was removed form service for refurbishment and calibration of the process and sample flow instrumentation. The process flow instrumentation work was completed on October 9,1995.

The system was retumed to service on October 9,1995, however; it was not declared operable since work was to continue on the sample flow instrumentation on Octot er 10,1995.

On October 10,1995, the system engineer and two Instrument and Control Technicians re-initiated work on the 'B' channel of the Reactor Building Vent Radiation Monitor, after providing proper notification to the Main Control Room. Upon taking actions to remove the 'B' channel of the Reactor Building Vent Radiation Monitor from service, it was immediately identified by the Control Room Operator that improper indications were present for the 'A' channel of the Reactor Building Vent Radiation Monitor Personnelimmediately identified that the incorrect channel of the Reactor Building Vent Radiation Monitor had been removed from service and restored the 'A' channel to operable status within approximately five (5) minutes after identifying the inoperable condition.

The cause for the number of operable Reactor Building Vent Radiation Monitor channels being less than the minimum number of channels specified by Monticello Technical Specifications, was that the incorrect channel was removed from service during a period of time that the remaining redundant channel was inoperable. As discussed above, immediate corrective action was taken to restore one channel of Reactor Building Vent Radiation Monitor to service.

9511070238 951031 rile: H:\ DATA \NRCCORR\SRTS3-14. DOC '

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1 USNRC . NORTHERN STATES POWER COMPANY October 31,1995 Page 2 i j A Monticello Non-conformance Report (NCR) has been initiated to provide additional assessment of this issue. Additional corrective actions may be initiated if required.

This letter contains no new NRC commitments, nor does it modify any prior commitments.

Please contact Mant Engen, Sr Licensing Engineer, at (612) 295-1291 if you require further information.

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William J Hill Plant Manager

, Monticello Nuclear Generating Plant O

I c: Regional Administrator- 111, NRC NRR Project Manager, NRC Sr Resident inspector, NRC State of Minnesota i Attn: Kris Sanda J E Silberg i

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