ML20009B045
| ML20009B045 | |
| Person / Time | |
|---|---|
| Site: | Duane Arnold  |
| Issue date: | 06/30/1981 |
| From: | Mineck D IES UTILITIES INC., (FORMERLY IOWA ELECTRIC LIGHT |
| To: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| References | |
| DAEC-81-363, NUDOCS 8107140701 | |
| Download: ML20009B045 (2) | |
Text
.
c Iowa Electric I.ighi and Ibwer Company June 30, 1981 DAEC-81-363 GfT g/1
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,v-o Mr. James G. Keppler, Director Z
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Office of Inspection and Enforcement b_ %, D,*gg/$7
- Region 111 c
U. S. Nuclear Regulatory Commission
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799 Roosevelt Road VX Glen Ellyn, Illinois 60137
/Q7gNJ Re:
Duane Arnold Energy Center
Subject:
Unique Report 81-3 File:
A-118, NRC-1
Dear Mr. Keppler:
This report is submitted in accordance with the requirements of Appendix A to Operating License DPR-49, Specification 6.11.3.
Problem:
During inspection of the HPCI turbine, performed during the 1981 refueling and maintenance outage, the turbine was found to have a cracked reversing chamber and a broken reversing chamber retaining cap screw. The head to the cap screw on chamber No. 5 could not be located within the turbine. The NSSS vendor was contacted to determine the effect the bolt head could potentially have on plant safety systems. There have been two previous similar occurrences reported. See Unique Report 78-1 and Unique Report 80-1.
Cause
Description:
The cause of the broken bolt head and the reversing chamber crack could not be determined.
Corrective Action:
The reversing chamber and bolt were replaced with like-for-like spares.
'l/
The GE analysis determined that "the part could not cause any potential for fuel bundle flow blockage since it cannot enter the reactor vessel". An engineering design review will be initiated to determine the cause and possible corrective actions for the repeated reversing chamber and reversing chamber retaining bolt failures.
G107140701 810630 PDR ADOCK 05000331 S
PDR I)n.une Amoki Encryy Center
- l'O Iks.t 351
- Centar ILuphis, Icmin 52406
- 319/351-5611
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8 Mr. James G. Keppler i
June 30,1981 Page 2 This report has been reviewed and approved by the DAEC Operations Committee.
Very truly yours, hffllYCkblfm Daniel L. Mineck Chief Engineer Duane Arnold Energy Center DLM/MSR/pl Docket No. 50-0331 cc:
P. Ward L. Root R. McGaughy J. Vinquist D. Wilson NRC Resident Inspector R. Anderson B. York