ML030970347
| ML030970347 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 03/26/2003 |
| From: | Salas P Tennessee Valley Authority |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| TAC MB4579 | |
| Download: ML030970347 (4) | |
Text
Tennessee Valley Authority, Post Office Box 2000, Soddy-Daisy, Tennessee 37384-2000 March 26, 2003 U.S. Nuclear Regulatory Commission ATTN:
Document Control Desk Washington, D. C. 20555 Gentlemen:
In the Matter of
)
Docket No.
50-328 Tennessee Valley Authority' SEQUOYAH NUCLEAR PLANT'- UNIT 2 -- SUPPLEMENT TO NRC REQUEST FOR ADDITIONAL INFORMATION REGARDING LICENSEE IDENTIFIED MATERIAL WASTAGE (TAC NO.
MB4579)
Reference:
- 1) NRC letter to TVA dated January 3, 2003, "Sequoyah Nuclear Plant Unit 2 -
Request for Additional Information Concerning Licensee Identified Material Wastage (TAC No. MB4579)"
- 2) TVA letter to NRC dated February 3, 2003, "SequoyahNuclearPlant_- Unit 2 - Response to NRC Request For Additional Information Regarding Licensee Identified Material Wastage (TAC No. MB4579)"
The purpose of this submittal is to provide supplemental information to the TVA letter (Reference No. 2) that was in response to the NRC staff's letter (Reference No.' 1).
This supplemental response provides requested root cause informirttijon.
At-'thl time-that -TVA re's~pohdedz to the "reque'st fcir' 'ddi5tional information, TVA was in the process of conducting the root cause aalysi-s.' The roo'tt'cause 'analysis is now complete and is provided in the enclosure.
Pnled on recycled paper
U.S. Nuclear Regulatory Commission Page 2 March 26, 2003 This letter is being sent in accordance with NRC RIS 2001-05, "Guidance on Submitting Documents to the NRC by Electronic Information Exchange, CD-ROM, or Hard Copy."
If you have any questions about this change, please telephone me at (423) 843-7170 or J. D. Smith at (423) 843-6672.
S ii?'g~rj las Li sing and Industry Affairs Manager Enclosure cc (Enclosure):
Mr. Michael J. Marshall, Jr, Senior Project Manager U.S. Nuclear Regulatory Commission MS 0-8G9A One White Flint North 11555 Rockville Pike Rockville, Maryland 20852-2739
U.S. Nuclear Regulatory Commission Page 3 March 26, 2003 JDS:JB:PDW Enclosure cc (Enclosure):
R. J. Adney, LP 6A-C J. L. Beasley, OPS 4A-SQN M. J. Burzynski, BR-4X-C D. L. Koehl, POB 2B-SQN J. E. Maddox, LP 6A-C NSRB Support, LP 5M-C R. T. Purcell, OPS 4A-SQN J. A. Scalice, LP 6A-C K. W. Singer, LP 6A-C E. J. Vigluicci, ET 1OA-K WBN Site Licensing Files, ADM lL-WBN EDMS, WTC A-K I:Llcense/Bulletin/RAI Material Wastage Response Supplement.doc
ENCLOSURE TENNESSEE VALLEY AUTHORITY SEQUOYAH NUCLEAR PLANT (SQN)
UNIT 2 DOCKET NO.
328 SUPPLEMENT TO REQUEST FOR ADDITIONAL INFORMATION RESPONSE REGARDING LICENSEE IDENTIFIED MATERIAL WASTAGE NRC Question No. 7 What was the root cause for leakage occurriin~g iin-the RVLIS mechanical fitting and how will you confirm that there will not be any additional leaks of this nature?
TVA Response The root cause of the reactor vessel level indication system (RVLIS) mechanical fitting leakage was an inadequate procedure.
Analysis determined that the removal and reinstallation instructions did not provide direction as to which side of the reducing fitting should be loosened to remove the RVLIS tubing.
Additionally, there were no reinstallation instructions to check the three-quarter inch side for tightness.
As a result the three-quarter inch tube fitting was not tight enough to prevent leakage.
This latent organizational weakness was masked because past practices relied on the fact that the same person was assigned both the removal and reinstallation of the line and would therefore have knowledge of what would be necessary to remake the fitting(s).
Actions to prevent this condition are the following:
- 1)
The procedure for removal and reinstallation of the RVLIS connection was revised to provide guidance for verifying proper assembly of the 3/4 inch and the 3/8 inch fittings.
- 2)
Visual inspection will be performed on the RVLIS tubing connections at normal operating pressure and temperature for leakage using remote video or other means.
Otherwise, an alternative method for ensuring no wastage to the reactor pressure vessel will be installed.
These actions, to prevent recurrence, are contained within the Corrective Action Program.