ML20093K133
| ML20093K133 | |
| Person / Time | |
|---|---|
| Site: | Braidwood  |
| Issue date: | 07/20/1984 |
| From: | Swartz E COMMONWEALTH EDISON CO. |
| To: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| References | |
| 84-10, 9007N, NUDOCS 8407300456 | |
| Download: ML20093K133 (2) | |
Text
.
f~N : Commonwe:lth Edison 3
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) One First National Plaza. Chicago. tilenois
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"'t Address Riply to. Post Office Box 767
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/ Chicago, lltinois 60690 i
July 20, ! ?8 '
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Mr.-James G. Keppler Regional Administrator U. S.-Nuclear Regulatory Commission Region III 799 Roosevelt Road Glen Ellyn, IL 60137'
Subject:
Braidwood Station Units 1 and 2 10 CFR 50.55(e) 30 Day Report Piping Wall Thickness Deficiencies NRC Docket Nos. 50-456/457
Dear Mr. Keppler:
On June 21, 1984, the Commonwealth Edison Company notified Mr.
W. L. Forney of your office of a deficiency reportable pursuant to 10 CFR 50.55(e) regarding wall thickness inadequacies for small bore ASME Class II piping at our Braidwood Station.
For your tracking purposes, this deficiency was assigned Number 84-10.
This letter fulfills the thirty day reporting requirements of 10 CFR 50.55(e) regarding this matter,-and is considered to be an interim report because suf ficient information is not available at this time to provide a definitive report.
DESCRIPTION OF DEFICIENCY Inspections of two inch schedule 80 carbon steel pipe, heat number K06751, purchased as ASME Class II have determined that approximately 25% of the pipe in storage has wall thicknesses less than that required by the material specification.
The reduced wall thickness, which is primarily caused by pits and grooves, apparently is the result of excessive corrosion.
' Quantities of this pipe have been installed in various Class B, C and H systems.
ANALYSIS OF SAFETY IMPLICATION The reduced wall thicknesses could result in certain piping systems not meeting the code stress allowables.
If left undetected, this condition could potentially result in pipe failure and negatively impact on its associated system safety
. functions.
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.o J. G. Keppler July 20, 1984 CORRECTIVE ACTION TAKEN Commonwealth Edison Company NCR No. 633 has been initiated to address this problem.
Investigations conducted to date have indicated that this problem is limited to heat number KD6751 pipe.
That portion of this heat number which remains in storage has been placed on hold.
No release of this material will be authorized until measurements confirm that the pipe meets the minimum wall thickness requirements.
In order to determine the adequacy of pipe from this heat number which has already been installed, a program is being developed to measure, in detail, wall thicknesses of the most severely pitted or grooved pipe currently in storage.
Measurement results will be sent to Sargent and Lundy for evaluation and subsequent piping system assessments.
The extent of field inspections and rework will be determined based on the results of the Sargent and Lundy investigation.
When this lot of pipe was initially received, it was stored outdoors for an extended period of time which resulted in excessive corrosion.
This condition was observed in the field and the pipe was subsequently chemically cleaned and stored indoors.
A review has been conducted of the bulk storage of safety-related two inch and under carbon steel pipe by the Commonwealth Edison Company.
The results of this review indicate that present storage practices prevent excessive corrosion of pipe due to outdoor exposure.
A follow-up report will be submitted following the initial investigation by Sargent and Lundy which is expected by October 1,
1984.
Please address any questions that you or your staff may have concerning this matter to this office.
Very truly yoursf
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E. Douglas Swart 2 Nuclear Licensing Administrator 1m cc:
RIII Inspector - Braidwood Director of Inspection _and Enforcement U. S. Nuclear Regulatory Commission Washington, DC 20555 9007N