ML20099D824
| ML20099D824 | |
| Person / Time | |
|---|---|
| Site: | Braidwood  |
| Issue date: | 11/02/1984 |
| From: | Danni Smith AFFILIATION NOT ASSIGNED, COMMONWEALTH EDISON CO. |
| To: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| References | |
| 84-10, 9412N, NUDOCS 8411200568 | |
| Download: ML20099D824 (2) | |
Text
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f N Commonwealth Edison.
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. one First Nationil Pt;n, Chicago, libnois J
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} Address Reply to. Post Office Box 767 N
/ Chicago, liknois 60690 November 2, 1984
.Mr. James G. Keppler
' Regional Administrator U. S.. Nuclear Regulatory Commission Region III 799 Roosevelt Road Glen Ellyn, IL 60137 Sub ject:
Braidwood Station Units 1 and 2 10CFR50.55(e) Interim Report Piping Wall Thickness Deficiencies NRC Docket Nos.- 50-456/50-457
References:
(a):
E. D. Swartz Letter to J. G. Keppler dated July 20, 1984 l
(b):
D. H. Smith Letter to J. G. Keppler dated September 18, 1984
Dear Mr. Keppler:
References (a) and (b) provided information concerning a deficiency reportable pursuant to 10CFR50.55(e) regarding wall thickness inadequacies for small bore ASME Class II Piping at our Braidwood Station.
This deficiency was ass'igned Number 84-10 for tracking purposes.
This letter is to revise the deficiency description and provide an updated status of the corrective actions taken to resolve this issue, and 1.= considered to be an Interim Report.
Description of Deficiency Initial inspections of two inch schedule 80 carbon steel pipe, Heat Number KD6751 purchased as ASME Class II, determined that approximately 25% of the pipe in storage had wall thicknesses less than that required by the ASTM material specification.
The reduced wall thickness, which is primarily present as pits and grooves, apparently is the result of excessive corrosion.
This pipe was stored outdoors for an extended period of time after reccipt in 1977.
In 1981, corroded conditions were observed in the field and the pipe was subsequently chemically cleaned and stored indoors.
The chemical cleaning process was purchased as a non-safety related standard commercial service.
Specific chemical cleaning procedures were documented, however, and incorporated into the purchase order.
Other lots of small bore safety-related carbon steel pipe were received in bulk quantities during the same time period (1977) and subjected to prolonged outdoor exposure.
Large quantities of this 8411200568 841102 5 TRS DR ADOCK 05000456 8 01 g
PDR 0
mm
g d
t l Description of Deficiency pipe were also chemically cleaned due to excessive corrosion concurrently with Heat Number KD7651.- Continuing investigations by Commonwealth Edison Company have indicated that.the wall thickness problem is not confined to Heat Number KD6751.
Consequently, all small bore safety-related carbon steel pipe which'was stored outdoors for extended periods has been categorized as suspect pending futher evaluations.
Nine heats of material (ten size / schedule combinations) are affected.
Quantities of the suspect pipe have been installed in various plant systems including Class B, C and H safety-related systams.
Corrective Action Taken Commonwealth Edison Company NCR-633, which was written to track issue resolution, has been revised to include the additional heats of pipe that may be subject to reduced wall thickness problems.
Commonwealth Edison Company and Sargent and Lundy are developing a program to disposition installed pipe that may have reduced wall thicknesses and evaluate the effects of chemical cleaning.
All suspect pipe still in storage has been identified and placed on hold pending the dispositioning of installed pipe.
Once the program to disposition installed pipe has been fully developed, a followup report will be submitted.
This followup report is expected to be subnitted by 12/15/84.
Please address any questions that you or your staff may have concerning this matter to this office Ve y truly,yhhrs, H
David H. Smith Nuclear Licensing Administrator cc:
NRC Resident Inspector Braidwood Director of Inspection and Enforcement U. S. Nuclear Regulatory Commission Washington, D.C.
20555 9412N
..