ML20079J232
| ML20079J232 | |
| Person / Time | |
|---|---|
| Site: | Bellefonte  |
| Issue date: | 01/13/1984 |
| From: | Mills L TENNESSEE VALLEY AUTHORITY |
| To: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| References | |
| REF-PT21-84-273-000 NCR-2162, PT21-84-273, PT21-84-273-000, NUDOCS 8401240264 | |
| Download: ML20079J232 (3) | |
Text
,s TENNESSEE VALLEY AO't riORITY CH ATTANOOGA TENNESSEE 374o1 400 Chestnut Street Tower II January 13, 1984 BLRD-50-438/83-12 U.S. Nuclear Regulatory Commission Region II Attn:
Mr. James ?. O'Reilly, Regional Administrator 101 Marietta Street, NW, Suite 2900 Atlanta, Georgia 30303
Dear Mr. O'Reilly:
BELLEFONTE NUCLEAR PLANT UNIT 1 - DEFECTIVE SEQUENCER CONTROL CARDS FROM CONSOLIDATED CONTROL CORPORATION - BLRD-50-438/83 FINAL REPORT The' subject deficiency was initially reported to NRC-0IE Inspector
- P. E. Fredrickson on January 12, 1983 in accordance with 10 CFR 50.55(e) as NCR 2162. This was followed by our interim report dated February 8,1983 Enclosed is our final report,. We consider 10 CFR Part 21 applicable to -
this deficiency.
If you have any questions, please get in touch with R. H. Shell at FTS 858-2688.
Very truly yours, TENNESSEE VALLEY AUTHORITY
.b.
L. M. Mills, Manager Nuclear Licensing Enclosure cc:
Mr. Richard C. DeYoung, Director (Enclosure)
Office of Inspection and Enforcement
-U.S.-Nuclear Regulatory Commission Washington, D.C.
20555 Records Center (Enclosure) l Institute of Nuclear Power Operations
[
1100 Circle 75 Parkway, Suite 1500 Atlanta, Georgia 30339 l
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l 8401240264 840113 1[Z7 PDR ADOCK 05000438
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g PM l g 1983-TVA SOTH ANNIVERSARY I
j An Equal Opportunity Employer t
ENCLOSURE BELLEFONTE NUCLEAR PLANT UNIT 1 g
f.EFECTIVE SEQUENCER CONTROL CARDS FROM CONSOLIDATED CONTROLS CORPORATION BLRD-50-438/83-12 NCR 2162 10~CFR 50.55(e)
FINAL REPORT l
l t
Description of Deficiency Sequencer Control Card 6N194-1, SN009, in the Solid State Control System Logic Cabinet 1IX-IR-006-A, slot 38, failed during an undervoltage test. Replacement card SN012 was installed and e.rienced a similar failure. Replacement card SNO33 was then installed and a slightly dif ferent failure was noted. Finally, another replacement card was installed and system operation returned to normal.
The Solid State Centrol System has been supplied to TVA by Consolidated Controls Corporation (CCC) of Bethel, Connecticut.
TVA has verified the adaquacy of the supplier quality controls program in the resolution of NCR 1950 (BLRD-50-438/82-68, BLRD-50-439/82-61). Analysis of the failures of boards SN009, SN012, SNO33 does not in.dicate any common mode The failure of board SN009 during operation is due to a random failure failure.
of one or more board components. A more definitive cause of failure was 'not
. possible due to physical damage by mishandling or improper shipping after discovery of the failures. The failure 9 of boards SN012 and SNO33 may be due to mishandling and improper installation by plant personnel. In addition, TVA and CCC concluded that some damage to compenents could be caused by static electricity discharges during handlinx.
Safety Implications The type of failure which was identified in the cards would have resulted in automatic switching of safety-related systems to the " loss of power" mode. This Had results in the automatic starting or stopping of certain plant features.
this defect remained uncorrected, the operator wou'.d be unable to mgain control of some featums erroneously placed in the " loss of power" mode. The features would,. in turn, become necessary to maintain safe operation of the plant.
Corrective Action The failed cards were returned to the supplier (CCC) for inspection and repair.
CCC found that some components on boards SN009 and SNO33 had teen physically damaged by mishandling or improper shipping. Replacement of these components was accomplished; the boards then passed all functional and burn-in testing.
= CCC identified several shorted components on board SN012, which were replaced; the board then passed all functional and burn-in testing. All boards have been returned to Bellefonte Nuc1 car Plant for use as spares.
!s ordtr to prevent tha phycical damagcs from recurring, sita managtment issued o memor ndun to cpplicibla pzrsonnsl which provided instructions on board removal, handling, and packaging. Vendor information was also distributed to provide guidance to prevent damage due to static electricity discharge. TVA is monitoring all component failures in all CCC-supplied board and module types to ensure detection of common mode failures.
(There have been no additional failures of 6N194 boards since these three boards failed on or about January 7, 1983.)
TVA hac concluded that these failures are random events that have been fbily corrected; therefore, no fbrther actions are required.
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