ML20083F929

Interim Deficiency Rept 107 Re RHR Pump B & D Impellers W/Linear Indications,Set Screws for Wear Rings in Pump Bowl Missing & Excessive Wear on Wear Rings & Hydrostatic Bearing Wear Ring.Initially Reported on 831121.GE Analysis Underway

ML20083F929
Person / Time
Site:	Fermi
Issue date:	12/22/1983
From:	Wells D DETROIT EDISON CO.
To:	James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
References
107, 10CFR-050.55E, 10CFR-50.55E, EF2-66490, NUDOCS 8401050625
Download: ML20083F929 (2)

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Donald A. Wells Manapouay Aswarce 013) 237 % S7 2000 secono Av ISOn amm"enue December 22, 1983 EF2-66490 Mr. James G. Keppler, Regional Administrator Region III U.S, Nuclear Regulatory Ccumission 799 Roosevelt Road Glen Ellyn, Illinois 60137 '

Subject:

Report on 10CFR50.55(e) Itan on Additional Problems with RHR Pumpc (#107)

Dear Mr. Keppler:

On Novenber 21, 1983, Detroit Edison's Mr. T.A. Alessi, Director -

Project Quality Assurance telephoned Mr. P. Pelke of NRC Region III to report on additional problems with RHR pumps at the Fenni II site.

Detroit Edison had been infonned by Byron-Jackson, manufacturer of the RHR pumps, that the anount of wear found on the pump bearings is excessive considering the length of time they have operated in tests. This is significant since it represents a potential for a premature failure.

Project Quality is separating those items that specifically relate .

to the RHR pumps frca 10CFR50.55(e) No.101, and including them as part of 10CFR50.55 (e) No.107. These items include the lost set screws, linear indications on two of the impe11ers, and excessive wear of the wear rings. 10CFR50.55(e) No.101 will cover the problems of foreign materials in the RHR piping.

Both RHR pumps "B" and "D" had impellers with linear indications, set screws for the wear rings in the pump bowls missing (2 of 3 in each case) and excessive wear on the wear rings and hydrostatic bearing wear rings. .

If the set screws, whose physical dimensions are larger than the clearance dimensions of the impeller, pass through the impeller, they may cause a temporary imbalance in the rotation of the impeller with subsequent galling or binding which could lead to a variety of inmediate or delayed failure mechanisms. The set screw l

could also lodge in an isolation valve seat or hinge (in the case of a check valve) resulting in the failure of the valve to fully close. General Electric has done a loose parts analysis and deter-mined that there are no safety implications should these parts enter into the vessel.

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Mr. James G. Keppler, Regional Administrator Decenber 22, 1983 EF2-66490 Page 2 The corrective action has been to reweld any significant linear indications, to replate the impeller wear rings and pump bowl wear rings with a harder material, and to remove the labyrinth seal frcm the impeller and pump bowl wear rings. These activities are expected to give the pumps improved longevity.

Another report on this item, either interim or final, will be sent when further information is available. If you have questions con-cerning this matter, please contact Mr. G.M. Trahey, Assistant Director - Project Quality Assurance.

Very truly yours, b i

/

DAW /EHN/pn cc: Mr. Richard DeYoung, Director Office of Inspection and Enforcement U.S. Nuclear Regulatory Ccumission Washington, D.C. 20555 Mr. Paul Byron, Senior Resident Inspector U.S. Nuclear Regulatory Canmission 6450 North Dixie Highway Newport, Michigan 48166 l