ML20081H440

Interim Deficiency Rept,Item 101 Re Check Valve in RHR Sys Stuck in Open Position.Initially Reported on 830920.Impeller Cracks Evaluated by Manufacturer to Determine Impact on Operation

ML20081H440
Person / Time
Site:	Fermi
Issue date:	10/20/1983
From:	Wells D DETROIT EDISON CO.
To:	James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
References
101, 10CFR-050.55E, 10CFR-50.55E, EF2-65288, NUDOCS 8311070438
Download: ML20081H440 (2)

Text

> T bO!h Donald A. Wells v3,acero s , es m e Detroit "OM $$o$.*ElcYo^aNe*22e October 20, 1983 lQVI I (313) 237-ecco EF2-65288 Mr. James G. Keppler, Regional Administrator Region III U.S. Nuclear Regulatory Commission 799 Roosevelt Road Glen Ellyn, Illinois 60137

Subject:

Report of 10CFR50.55(e) Item on RHR Pump "B" Problems (#101)

Dear Mr. Keppler:

On September 20, 1983, Detroit Edison's Mr. W. R. Wingfield, Quality Engineer - Construction Quality Assurance telephoned Mr. H. M. Wescott of NRC Region III to identify problems related to RHR pump "B".

Region III was informed that during preoperational testing, a check valve (V8-2104) in the RHR system stuck in the open position.

The valve was subsequently disassembled and a small set screw (approximately 1/4" x 1/2") was found to be jamming the valve. RHR pump "B", immediately upstream of the valve, was disassembled to determine if the set screw had come from the pump and if any damage had been caused by it. There was no apparent damage to the pump from the set screw, however, the following deficiencies were identified:

a. Two (2) of three (3) set screws were missing from the lower wear ring of the pump. One (1) is believed to be that which prevented the check valve from closing. The other is still missing. A lost parts analysis is being performed.

b. A piece of 1/2" x 12" x 12" plywood was discovered inside the RHR pump "B" suction pipe.

c. Cracks were identified on the RHR pump impeller via visual examination, and confirmed by liquid penetrant examination.

d. During disassembly of the RHR pump impeller from the shaf t, the shaft was galled.

Safety implications of the identified pump problems include reduced overall pump reliability and/or shorter pump life.

The valve has been blue checked and inspected and returned to service.

No further problems are expected with this valve.

8311070430 PDR ADOC

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DCT 2 61983 ZApy \\D j

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Mr. Jents G. Keppler, Regional Administrator October 20, 1983 EF2-65288 Page 2 Actions necessary to correct the remaining deficiencies are:

a. As previously noted, one (1) of the missing set screws was located in Valve V8-2104 An investigation into the location and impact of the other missing set screw is continuing.

b. The plywood was removed from the piping and was thought to be an isolated incident; however, when RHR pump "B" was disassembled to remove the impeller and shaft for return to the manufacturer, another piece of plywood was discovered in the same location. A program is being implemented to discover the source of the plywood and determine if additional debris is in the system.

c. The cracks in the impeller are being evaluated by the manufac-turer to determine the impact such cracks could have during operation. The results of the evaluation will also determine the method of repairing the impeller.

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

Very truly yours ,

f 7 4 /

cc: Mr. Richard DeYoung, Director Office of Inspection and Enforcement U.S. Nuclear Regulatory Commission Washington, D.C. 20555 Mr. Paul Byron, Senior Resident Inspector U.S. Nuclear Regulatory Commission 6450 North Dixie Highway Newport , FEchigan 48166