ML20235D282
| ML20235D282 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 07/06/1987 |
| From: | Domer J TENNESSEE VALLEY AUTHORITY |
| To: | NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM) |
| References | |
| NUDOCS 8707100113 | |
| Download: ML20235D282 (4) | |
Text
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TENNESSEE VALLEY AUTHORITY CHATTANOOGA. TENNESSEE 37401 SN 157B Lookout Place JUL 0 6 887 U.S. Nuclear Regulatory Commission ATTN:
Document Control Desk Washington, D.C.
20555 Gentlemen:
In the Matter of
)
Docket Nos. 50-327 Tennessee Valley Authority
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50-328 SEQUOYAH NUCLEAR PLANT (SQN) UNITS 1 AND 2 - NRC INSPECTION REPORT NOS.
50-327/87-28 and 50-328/87 RESPONSE TO VIOLATION NO. 50-328/87-28-01 Enclosed is our response to Gary C. Zech's June 4, 1987 letter to S. A. White that transmitted the subject Notice of Violation. There are no commitments contained in our response.
If you have any questions, please telephone M. R. Harding at (615) 870-6422.
To the best of my knowledge, I declare the statements contained herein are complete and true.
Very truly yours, TENNESSEE VALLEY AUTHORITY J. A. Domer, Assistant Director Nuclear Safety and Licensing Enclosure cc: See page 2 I
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An Equal Opportunity Employer
. U.S. Nuclear Regulatory Commission JUL 0 6 G87 Enclosure cc (Enclosure):
Mr. G. G. Zech, Assistant Director for Inspection Programs Office of Special Projects
(
U.S. Nuclear Regulatory Commission Region II 101 Marietta Street, NW, Suite 2900 Atlanta, Georgia 30323 Mr. J. A. Zwolinski, Assistant Director for Projects Division of TVA Projects Office of Special Projects U.S. Nuclear Regulatory Commission 4350 East West Highway EWW 322 Bethesda, Maryland 20814 Sequoyah Resident Inspector Sequoyah Nuclear Plant 2600 Igou Ferry Road Soddy Daisy. Tennessee 37379 L-
ENCLOSURE RESPONSE TO NOTICE OF VIOLATION
-NRC INSPECTION REPORT NOS. 50-327/87-28 and 50-328/87-28 GARY G. ZECH'S LETTER TO S. A. WHITE DATED JUNE 4, 1987
- Violation 50-328/87-28-01 Criterion V of 10 CFR 50, Appendix B, as implemented by TVA Nuclear Quality Assurance Manual Part 1, Section 2.5, requires that activities affecting quality be prescribed by documented instructions, procedures, or drawings, of a type appropriate to the circumstances.
Contrary to the above, Basic Engineers pipe hanger drawings for pipe support numbers 2RCH-184, 2AFDH-229, 2CVCH-154, and 2CSH-457 were not appropriate.
l This resulted in installation of undersized snubbers in these pipe supports.
That is, the hanger design loads exceeded the rated load capacity of the installed snubbers.
This is a Severity Level IV violation (Supplement I).
1.
Admission or Denial of the Alleged Violation TVA admits the violation occurred as stated.
2.
Reasons for the Violation Design personnel selected snubbers and specified the model numbers on the drawings.
Installation was accomplished using these drawings. None of the personnel selecting, reviewing, and installing the snubbers were aware that two generations of mechanical snubbers have been manufactured by the company and that both generations have the same model numbers but different part numbers and load ratings. They are commonly referred to as pre "NF" and "NF."
The NF snubbers are all designed and manufactured in accordance with Section 3 of the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code.
The pre-NF shock arrestors were designed to good commercial practice.
The NF snubbers have a higher load rating.
3.
Corrective Steps Which Have Been Taken and the Results Achieved When it was disclosed that the pre-NF and NF situation existed, TVA performed a walkdown inspection and identified the location, size, and rating of all unit 2 pipe supports with pre-NF. snubbers. An engineering evaluation by design personnel of the walkdown data resulted in the identification of four supports where the design loads exceeded the capacity of the installed pre-NF snubbers. The undersized snubbers were installed on pipe support Nos. 2-RCH-184, 2-AFDH-229, 2-CVCH-154, and 2-CSH-457.
The drawings were revised to include the appropriate information, and the inadequate snubbers were replaced with NF snubbers that meet the current design loads. As noted in Inspection Report 50-328/87-28, the inspector examined the revised drawings and the installation of the NF snubbers; and he verified that the new snubbers had been installed as required by the drawings.
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Corrective Steps Taken To Avoid Further Violations Maintenance Instruction (MI)-6.13A, revision 4. " Removal and Reinsta11ation of Hydraulic and Mechanical Snubbers," has been revised to require a quality control inspector verify the snubber is as specified by the drawing and the nameplate capacity is adequate for the design load shown on the drawing. Modifications and' Additions Instruction (M&AI)-11, revision 16, specifies that snubber installation shall be covered under MI-6.13A.
5.
Date When Full Compliance Will Be Achieved Full compliance was achieved April 28, 1997, when all fieldwork for the subject snubbers was verified complete.
MI-6.13A, revision 4, was approved May 14, 1987, to satisfy the long-term corrective actions.
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