ML20054A997

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Part 21 Rept Re Potential Deficiency in Pressurized Subcritical Experiment Exams of Pressure Vessel Inlet Nozzle to Pipe Welds from Inner Diameter Surface.Inspectors Advised of Potential Generic Implications on 820402
ML20054A997
Person / Time
Site: Palo Verde, San Onofre, 05000000
Issue date: 04/02/1982
From: Perkins G
AFFILIATION NOT ASSIGNED, NDE ENGINEERING CONSULTANTS, INC.
To:
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE)
References
REF-PT21-82-585-000 10CFR-50.55E, PT21-82-585, PT21-82-585-000, NUDOCS 8204160264
Download: ML20054A997 (1)


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Dear Sir:

This letter is written pursuant to the requirements of 10CFR Part 21, to inform you of a potential deficiency in the PSE examinations of the RPV Inlet Nozzle to Pipe Welds from the ID surface at the following power plants.

San Onofre Nuclear Generating Station Units 2 and 3 Arizona Palo Verde Plants Units 1, 2, and 3 The reason for my concern is that the wrong UT calibration standard may have been utilized as was the case at St. Lucie Unit 2, fortunately the error was noted and corrective action (re-examination) is underway at St. Lucie.

The problem is that calibration was performed on a 3 " roll bond clad calibration standard and half of the examination was performed from a surface that was of a 3 wire clad process.

The attenuation differences between these two clad types, as determined at St. Lucie Unit 2 is in the range of 12 to 16 db dependent on transducer angle used.

The result of this is that the examinations conducted from the 3 wire clad side could be as much as 12 to 16 db under sensitive, dependent on the attenuative characteristics of the standards used at each plant, thereby not showing relevant indications that should have been recorded.

I&E Inspectors B. Crowley and J. Coley of the Atlanta office are aware of the details of the situation as it pertains to FP&L and were informed by me on April 2, 1982 of the potential at the other sites I have listed.

If you wish further information please call me at 1-203-429-8769.

Sincerely,

&PA Glenn R. Perkins President NDE Eng. Cons. Inc.

8204160264 820402

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