ML19322A668
| ML19322A668 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 03/02/1972 |
| From: | Murphy C NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | |
| Shared Package | |
| ML19322A662 | List: |
| References | |
| 50-269-72-01, 50-269-72-1, 50-270-72-01, 50-270-72-1, 50-287-72-01, 50-287-72-1, NUDOCS 7911210725 | |
| Download: ML19322A668 (2) | |
See also: IR 05000269/1972001
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U. S. ATOMIC ENERGY COMMISSION
REGION II
DIVISION OF COMPLIANCE
S
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CO Inquiry Report Nos. 50-269/72-1
50-270/72-1
50-287/72-1
Subject: Duke Power Ccmpany
Seneca, South Carolina
License Nos.: CPPR-33, 3h and 35
Facility: Oconee Nuclear Station Units 1, 2 and 3
Descriptive Title: ValveSemFailyes
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Prepared By: [I M k
f 2. '7 /
C. E. Mur$hy,pffeac p Inspector
tate
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A.
Date and Manner AEC Was Infor=ed:
Mr. J. E. Smith, Superintendent, Oconee Nuclear Station, advised the
inspector of the problem during the inspection conducted February 22-25,
1972. Additional preliminary infor=atien was provided by Mr. E. D.
Brown, Maintenance Supervisor.
B.
Description of Particular Event or Circumstances:
Mr. Smith advised the inspector that trouble had been experienced with
leakage pass the valve stems on a few instrumentation and drain valves.
The valves leaked after repacking and even though opened to the back
seat position.
Disassembly and examination of a defective valve revealed a straight
hairline crack the full length of the valve stem. Seven valves ranging
in size from 1/2 inch to 1-1/2 inches have been found to have defective
stems. The valves were manufactured by Velan. The stems were fabri-
cated from a h00 series stainless steel. Records indicated that the
stem material was heat treated and quenched at 620*F.
Five heat
numbers have been found to be involved. These are 11716, 7157, 3255,
h988, and 2761.
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CO Rpt. Nos. 50-269/72-1
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Although a defective stem was returned to Velan for examination, Brown
advised the inspector that the report was ' inconclusive.
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Brown advised the inspector that rust spots had been noted on some of
the stems so he had soaked them in a hot borated water solution. The
stems corroded severely in this environment.
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C.
Action by Licensee:
The valve stems will be replaced with stems fabricated.from either
17 k PH steel or from a 300 series steel. Approximately 600 valves
for Unit 1 and 2000 valves total are involved.
The licensee plans to generate an in-house report en the problem.
Additional information vill be supplied to Region II as it becomes
available.
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