ML19211A658

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Notifies NRC That Util Cannot Meet 781025 Schedule for Resolving Issue of Asymmetric LOCA Loads,Due to Delays in Matl Procurement.Pipe Restraints Will Be Installed During Refueling Outage
ML19211A658
Person / Time
Site: Prairie Island  Xcel Energy icon.png
Issue date: 12/17/1979
From: Mayer L
NORTHERN STATES POWER CO.
To:
Office of Nuclear Reactor Regulation
References
TAC-8731, TAC-8732, TACS-8731, TACS-8732, NUDOCS 7912200385
Download: ML19211A658 (1)


Text

NSP N O R T et E R N STATES POWER COMPANY M I N N E A P80 LI S. M I N N E S OTA 55401 ,

December 17, 1979 Director 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 Installation of Pipe Restraints in Unit No. 2 Reactor Shield Wall Our letter dated October 25, 1978 outlined to the Commission our planned actions and schedule for resolving the issue of asymmetric loss of coolant accident loads. At that time our schedule called for installing pipe restraints in the Unit No. 2 reactor shield wall in the autumn of 1979 to limit the area of a break in the reactor annulus area to less than one square foot. We will be unable to meet this schedule.

Due to delays in material procurement, the restraints will not be completed in time for installation during the next Unit No. 2 refueling outage (now scheduled for January,1980) . It appears, however, that the installation can be completed as planned during the next refueling of Unit No. 1 (now scheduled for July, 1980).

The installation of pipe restraints in Unit No. 2 will be deferred to the 1981 refueling outage. We also tentatively plan to replace the reactor vessel nozzle inspection port sand plugs with redesigned low-mass plugs during the 1981 refueling outages. The redesigned plugs will assist in relieving pressure in the reactor annulus area due to the postulated break.

Please contact us if you have any questions related to this change in schedule.

L 0 Mayer, PE bb Manager of Nuclear Support Services LOM/DMM/ak cc: J G Keppler G Charnoff 7 912200 35'S