ML19326B330
| ML19326B330 | |
| Person / Time | |
|---|---|
| Site: | Arkansas Nuclear  |
| Issue date: | 07/16/1974 |
| From: | Reuter D ARKANSAS POWER & LIGHT CO. |
| To: | |
| Shared Package | |
| ML19326B328 | List: |
| References | |
| NUDOCS 8004150712 | |
| Download: ML19326B330 (3) | |
Text
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Abnormal Occurrence Report No.
S0-313/74-4 I
2.
Report Date:
July 16, 1974 3.
Occurrence Date: July 6, 1974 4.
Facility:
Arkansas Nuclear One-Unit 1 Russellville, Arkansas S.
Identification of Occurrence:
Radial Bearing failure, Primary Makeup Pump P-36A 6.
Conditions Prior to Occurrence:
Steady-State Power Reactor Power 0
Mith llot Standby Net Output 0
Mic Cold Lutdown X
. Percent of Full Power 0 %
Refueling Shutdown Routine Startup Operation Routine Shutcown b
Operation Load Changes During Routine Power Operation Other (Specify)
Prior to Initial Criticality 7.
Description of Occurrence:
1 On July.6,-1974, at 2137 hours0.0247 days <br />0.594 hours <br />0.00353 weeks <br />8.131285e-4 months <br />, the primary makeup pump, P-36A', was stopped due to excessive vibration. Makeup pump P-36B was started, the Operations Supervisor notified, and investigation of the cause of the vibration was initiated.
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8004150 f/q
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gs Abnormal Occurrence Report No.
50-313/74-4 Sheet 2 I
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Designation of Apparent Cause of Occurrence:
Design Procedure bhnufacture Unusual Service Condition Including Installation /
Environmental Construction Component Failure X
Operator 1
Other (Specify)
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Upon investigation it was determined that the mating pins on the radial (coupling end) bearing of P-36A had become dislodged. This allowed the lower section of the split sleeve type bearing to slide. slightly longitudinally toward the coupling end of the pump. As a result, lubrication was impaired and the bearing was severely l1maged.
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Analysis of Occurrence:
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Two of the three makeup pumps were operable at the time of the occurrence, s_,)
though their operability was not required at the stated plant condition
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of cold shutdown. No safety implications were involved and the health and safety of the public was not effected.
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Corrective Action:
In order to eliminate the possibility of a similar occurrence, the mating pins were lengthened from h" to approximately 1".
During further inspection, the anti-rotation pin in the sleeve bearing appeared to be too start for adequate assurance against bearing rotation..This pin was lengthened from 3/8" to 3/4".
This modifi-cation has been performed on all three makeup pumps.
The bearing failure allowed extensive damage to the impeller, impeller wear rings, and pump shaft to occur. Repair of the damaged parts will be made upon-availability of parts.
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Abnormal Occurrence Report No.
50-313/74-7 Sheet 3 l
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Failure Data:
'Ihere have been no previous failures of this type. All three makeup pumps were modified to prevent similar failures. The failed component identification is as follows: Byron-Jackson, horizonstal double bearing pump, Type DVMX, Serial Number 691N0064.
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12.
Reviews and Approvals:
Reviewed and Approved by: Plant Safety Committee Yes (X)
No ( )
Plant Super.ntendent Yes (X).
No ( )
Reference:
JWA-394 Date: 7/12/74 s.
Date: 7/
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Reviewed by:
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Licensing Supervisor Approved by: d'EM/,%
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ate: 2/[ 7v s
fety eview mmit ee
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7 [d !W Approved by:
Date:
Manager of.Nuc1E r Servic
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,5l ",iv' Approved by:
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-.s Date:
Director of o 'er duction
'7'/'f~7 Approved by:
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/d Date:
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/ Senior Vice Prelii' dent
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