ML20080L556
| ML20080L556 | |
| Person / Time | |
|---|---|
| Site: | Catawba  |
| Issue date: | 09/21/1983 |
| From: | Tucker H DUKE POWER CO. |
| To: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| References | |
| 10CFR-050.55E, 10CFR-50.55E, NUDOCS 8309300364 | |
| Download: ML20080L556 (2) | |
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nAs, n. limni:n Turenose 4 g,, j noy amou September 21, 1983 Mr. James P. O'Reilly, Regional Administrator U. S. Nuclear Regulatory Commission Region 11 101 Marietta Street, NW, Suite 2900 Atlanta, Georgia 30303 Re: Catawba Nuclear Station Unit 1 Docket No. 50-413
Dear Mr. O'Reilly:
Pursuant to 10 CFR 50.55e, please find attached a supplemental response to Significant Deficiency Report SD 413/83-07.
Very truly yours, j
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C llal B. Tucker RWO/php Attachment cc: Director INPO Records Center Office of Inspection and Enforcement Suite 1500 U. S. Nuclear Regulatory Commission 1100 Circle 75 Parkway Washington, D. C. 20555 Atlanta, Georgia 30339 NRC Resident Inspector Mr. Robert Guild, Esq.
Catawba Nuclear Station Attorney-at-Law P. O. Box 12097 Palmetto Alliance Charleston, South Carolina 29412 2135 Devine Street Columbia, South Carolina 29205 g,y }( I Al, CUN
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9309300364 030921 I
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b gf Duke Pov-- Company Catawb-.aclear Station Supplemental Response:
As noted in cur previouc responses of May 13, 1983 and July 29, 1983, Design drawing CN-1680-47 establishes standard dimensions for vent / drain valve pipe assemblics.
In accordance with this drawing and for those assemblies without offsets, it has been inspection practice to verify the length of the inlet nipple noted on CN-1680-47 to be 6" maximum, and to verify the total length of the assembly which CN-1680-47 restricted to 18".
For assemblies containing offsets, it was inspectien practice to allow up to 6 inches between each fittings on the inlet side and restrict the total length along the assembly to 18 inches.
During the investigation of NCI #16510, two vent valve assemblies without offsets were found to exceed the 6 inch maximum inlet nipple length by.25 inch in one case and.625 inch in another. Communications between Quality Assurance and Design confirmed that the valves were acceptable and that the 18 inch total length could be the limiting factor for installing stra1 nt assemblies as well 3
as those with offsets.
Thus, the 6 inch maximum restriction on the vent assembly would not be necessary and CN-1680-47 could be changed accordingly. This under-standing w9s the basis of our previous responses.
Prior to making the changes to drawing CN-1680-47, Design reverified the stress calculations and determined that the previous understanding was in error.
The 6 inch maximum inlet nipple length for straight vent / drain valve assemblies is a factor for analysis.
In addition, it was discovered that for assemblies with offsets, the analysis was based or a 3 inch dimension between fittings on the inlet side versus the 6 inches being allowed by QA inspection.
For both straight and offset assemblies, the 18 inch total length is also a limiting factor.
All vents and drains constructed in accordance with CN-1680-47 are being reviewed for reinspection, reanalysis and rework as required.
This condition has been reported on NCI #17144. The result of the investigation and scope of action is expected to be complete by March 1, 1984. A final response will be submitted when action is complete.