ML19326B325
| ML19326B325 | |
| Person / Time | |
|---|---|
| Site: | Arkansas Nuclear  |
| Issue date: | 07/19/1974 |
| From: | Cavanaugh W, Phillips J, Reuter D ARKANSAS POWER & LIGHT CO. |
| To: | |
| Shared Package | |
| ML19326B323 | List: |
| References | |
| NUDOCS 8004150708 | |
| Download: ML19326B325 (3) | |
Text
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4 1.
Abnormal Occurrence Report No.
50-313/74-5 2.
Report Date: July 19,1974 3.. Occurrence Date: July 8, 1974 4
Facility: Arkansas' Nuclear One-Unit 1
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Identification of Occurrence: Valve leaks in the clean liquid radioactive h
waste and makeup systems.
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6.
Conditions Prior to Occurrence:
i Steady-State Power Reactor Power 0
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!!ot Standby Net Output 0
hMe Cold Shutdown X
Percent of Full Power 0 %
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Refueling Shutdown l
Routine Startup Operation I
i Routine-Shutdown Operation
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t Load Changes During Routine Power Operation L
Other (Specify)
Prior to Initial Criticality s
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Description of Occurrence:
,4 A leak at MU-30A, located at the inlet to the seal return comer, was discovered by observing boron crystals forming on the valve.
Further investigation resulted in the location of leaks at the following clean waste system 3" valves:
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CZ-8, inlet to vacuum degasifier
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CZ-17A, inlet to clean waste receiver tank B CZ-29, upstream from radwaste deminerali:er (for sluicing water)
C'-36A, downstream from C7.-29, inlet to spent resin storage tank CZ-47A, inlet to treated waste monitor tank A
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An investigation was initiated to determine the extent of the valve leaks.
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Abnormal Occurrence Report No. 50-313/74-5 Sheet 2 j
8.
Designation of Apparent Cause of Occurrence:
Design Procedure i
Shnufacture X
Unusual Service Condition Including Installt. tion /
Environmental Construction Component Failure Operator l
Other (Specify)
Initial investigation showed that all of the cican waste valves werc
~I cast using heat number 7978. MU-30A has the heat number 7984 Since all of the leaks occurred at approximately the same section of the valve, the leak problem appears to be the result of casting flaws and could be generic in nature.
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9.
Analysis of Occurrence:
At the time of occurrence, the reactor building integrity was not O
required since initial criticality had not been reached. No safety implications were involved and the health and safety of the public
- l' was not effected.
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Corrective Action:
l The extent and cause of defect in the valves are being investigated.
The valves will be repaired or replaced as required.
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' July 5, 1974 NSP-10, Rev. O Page 2 of 3
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Abnormal Occurrence Report No.
50-313/74-5 Sheet 3 11.
Failure Data:
There have been no previous failures of this type. All valves can be identified by the Bechtel mark number, R\\RK 29M2-III. Nameplate data is as follows:
1 3" 1508 B. B. Cate Valves S/S Valve Class N3 D@Q D
bw D
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Reviews and Approvals:
Reviewed and Approved by: Plant Safety Committee Yes (X)
No ( )
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Plant Superintendent Yes (.9 No ( )
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Reference:
JWA-411 Date:
7/18/74 fY(. twt l ),'.
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7 / ' '/ y' Reviewed by: t Licensing Supervisor Approved by:(
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7 /9 77 Approvedby&f,_
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inager ori ucicar ices
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Approved by:[d//// //
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Date: _ 'A. *> - M
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Director of Power Production m
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Approved by:
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Date:
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Senior Vice President i
I July 5, 1974 NSP-10, :.ev. O Page 3 of 3 L.
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