ML19345G012
| ML19345G012 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 02/09/1981 |
| From: | Mills L TENNESSEE VALLEY AUTHORITY |
| To: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| References | |
| 10CFR-050.55E, 10CFR-50.55E, NCR-SWP-79-S-5, NUDOCS 8102190724 | |
| Download: ML19345G012 (1) | |
Text
~-
I.2:cI 400 Chestnut Stroet Tower II February 9, 1981 Mr. James O'Reilly, Director Office of InsMction and Enforcemt U.S. Nuclear Re'aulstory Comission Region II - Suite 100 101 Marietta Street Atlanta, Georgia 303
Dear Mr. O'Reilly:
SEQUOYAH NUCLEAR PLANT UNITS 1 AND 2 - EXCESSIVE OUTPUT FLUCTUATIONS FOXBCR0 INSTRUMENTATION - NCR SiiP-79-3 FIFTH INTERIM REPORT The subject deficiency was initially reported to NRC-0IE Inspector M. J. Gouge en August 28, 1979, in accordance with 10 CFR 50.55(e).
Intets reports were submitted cc September 26 and October 30, 1979, and February 5 and August 11, 1980. We expect to submit our next repcrt by March 24, 1981.
Westinghouse has developed and tested a field modification kit for the Foxbero instruments that function as current / current repeaters.
The pre-li:sinary test results indicate a significant improvement in performance.
The :nodificatico involves regulating the output of the module's de power supply which a s determined to be the primary source of magnetic amplifier instability.
It appears likely that with this modification the instruments will ibnction acceptably for the life of the plant. TVA, however, will perform fbrther testing before accepting this change as a permanent solution.
A similar modificatice kit is being developed for the square root converter instruments.
If you have any questions, please get in touch with D. L. Lambert at FTS 857-2581.
l Very truly yours, TENNESSEE VALLEY AUTHORITY L. M. Mills, Manager Nuclear Regulation and Safety Mr. Victor Stello, Director j SO/9 cc:
l Office of Inspection and Enforcement 3,
U.S. Nuclear Regulatory Commission Washington, DC 20555 gQ l
81021go7)f 3
_