ML20062G765
| ML20062G765 | |
| Person / Time | |
|---|---|
| Site: | Oyster Creek |
| Issue date: | 11/15/1990 |
| From: | Stramback G GENERAL ELECTRIC CO. |
| To: | Naidu K Office of Nuclear Reactor Regulation |
| References | |
| GBS90043, IEIN-90-043, IEIN-90-43, MFN-143-90, NUDOCS 9011300214 | |
| Download: ML20062G765 (1) | |
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ll5 curtse Avat San Jost CA 95125 November 15,1990 GBS90043 y
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Director of Nuclear Reactor Regulation U.S. Nuclear Regulatory Comm ssion t-Mail Station 9.D4 Washington, D. C. 20555 ATTENTION:
K. R. Naidu Vendor Inspection Branch
SUBJECT:
TELEPHONE UPDATE ON IN 90-43 This is to document my conversation with Kamal Naidu of the NRC Vendor Inspection Branch et 12:25 p.m. on November 15,1990.
L 1 called Kamal to update him on the Molded Case Circuit Breaker (MCCB) problem with undervoltage trips devices that had been delivered to Oyster Creek. The NRC had issued Information Notice 90 43 " Mechanical Interference with Thermal Trip Function in GE Molded Case Circuit Breakers" on J:me 29,1990 which described the problem and further indicated actions
. by the GE product de 3artmeni (ED&C). In addition, INPO had issued SEN 71 Supplement 1 and GE Nuclear Energy ind notifica cil BWRs of the issue as well as GE's conclusion that the deficiency did not cause a substantial safety hazard.
The new information is that the same problem has been identified in the replacement MCCBs supplied to Oyster Creek.: Therefore, successful testing of a MCCB after installation of the undervoltage trip may not eliminate the potential for subsec uent failure of the thermal overcurrent trip functions on the "C" pole of the breaker. In addition, tie manufacture time frame of MCCBs which may be susceptible to failure is much wider than previously identified.
Evaluation of corrective actions is in progress at ED&C and these results will be provided when available. However, it :a still true that this concern only affects MCCB models TED and THED,
.and only if they also have undervoltage trip devices installed on them. The previous conclusion on
- safety significance still applies.
Very truly yours G. B. Stramback Safety Evaluation Programs Manager
- (408) 925-1913 M/C 187
, CC:
E. W. Brock (NRC) -
q C. H. Berlinger (NRC)
S. D. Alexander (NRC) ts..ad n
J. Rogers (Oyster Creek).
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2 L S. Gifford (GE Rockville)
P. W. Marriott (GE San Jose)
I 0
J. L Miller (GE King of Prussia)
PSC File 9011300214 901115 PDR ADOCK 05000219 G
..