ML20088A176

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Suppls 830314 Response to Generic Ltr 82-28 Re Instrumentation for Inadequate Core Cooling Per Telcon Request.Containment Penetration Connector Issues Resolved & Procedures for Subcooling Monitor Will Be Revised
ML20088A176
Person / Time
Site: Prairie Island  Xcel Energy icon.png
Issue date: 04/02/1984
From: Musolf D
NORTHERN STATES POWER CO.
To:
Office of Nuclear Reactor Regulation
References
GL-82-28, NUDOCS 8404110133
Download: ML20088A176 (2)


Text

l Northem States Power Company 414 Nicollet Mall Minneapohs. M.nnesota 55401 ,

Telephone (612) 330-5500 l i

April 2,1984 Director Office of Nuclear Reactor Regulation U S Nuclear Regulatory Commission Washington, DC 20555 PRAIRIE ISLAND NUCLEAR GENERATING PLANT Docket Nos. 50-282 License Nos. DPR-42 50-306 DPR-60 Additional Information Related to Instrumentation for Inadequate Core Cooling (Generic Letter 82-28)

The purpose of this letter is to provide, for the information of the Staff, seme updated inforn tion related to our response to Generic Letter 82-28.

This information supplements our letter dated March 14, 1983.

During a recent telephone conference call with our Project Manager in the Division of Licensing and Staff reviewers assigned to this issue, we were requested to supplement and provide clarification of our March 14, 1983 letter. The following information is supplied in response to this request:

Final Design Description - Vessel Level Control Bocrd Display We will implement the Westinghouse approved reactor vessel level instrumentation with the exception of the control board display.

The final design report for this display will be submitted by July 1, 1984.

Schedule for Completing Vessel Level Instrumentation NRC requirements for this instrumentation were not defined until Generic Letter 82-28 was issued in December of 1982. Our schedule calls for completion of the installation in Unit 1 by May 30, 1985 and in Unit 2 by December 31, 1985. These schedules were' established taking into account the following factors:

a. Earliest possible delivery date for meeting NRC required specifications.
b. The 10-year inspection outage for each unit.

This outage will last approximately three months and is of sufficient duration to complete the required in-containment work.

0 8404110133 840402 i N PDR ADOCK 05000282 P l PDR

NORTHERN CTATED POWER COMPANY

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- Dir of NRR April 2,1984 Page 2 Oualified Displav for Core Exit Thermocouples (TC's) Thirty-six fully qualified (up to the display device) TC's are installed in each unit. Of these, 28 can be displayed on the plant process computer and the in-core instrument panel. These displays are not qualified. Eight TC's from each reactor (two per quadrant) are displayed on the sub-cooling margin monitors in the control room (two monitors per unit). The sub-cooling margin monitors are fully qualified display devices. Four TC's are displayed on each monitor.

The NRC requirement for a minimum of 16 (four per quadrant) qualified TC's per unit will be met in conjunction with the plant process computer upgrade and safety parameter display system modification project now in progress. The schedule for this work has been discussed with our Licensing Project Manager in the Division of Licensing and will be confirmed by NRC order. All applicable Regulatory Guide 1.97, Revision 2, requirements will be satisfied for this computerized system as noted in Table I, page 8, of our letter dated September 15, 1983.

Containment penetration connector problems described in our l'etter dated March 14, 1983 have been resolved.

Subcooling Monitors Subcooling monitors with fully qualified inputs are operable in Unit No. 2 and procedures have been modified to direct operators to use this monitor in lieu of the alternate plant process computer display. Subcooling monitors will be fully opera.ble in Unit No. 1 following the next scheduled hot shutdown of that unit when required testing of the new qualified TC inputs can be completed.

Unit No. 1 procedures will also be revised at that time to require use of the subcooling monitor in lieu of the plant process computer for determining subcooling margin.

Please contact us if you have any remaining questions concerning our implemen-l tation of the NRC's requirements for inadequate core cooling instrumentation.

l l

l David Musolf l

Manager - Nuclear Suppo Services DMM/ dab c: Resident Inspector, NRC Project Manager, NRR, NRC Regional Administrator-III, NRC G Charnoff