The following information is a synopsis of information received via E-mail:
During refurbishment of General Electric AK-25 type circuit breakers (P/N's: AK-2A-25-1, AK-3A-25-1, and AK-7A-25-1) by United Controls International (UCI), non-current carrying/non-copper based components of the upper stud assembly were silver plated. Bubbling of the silver plating was later noted which is an indication that the plating material was not adhering to the base metal. Flaking of the silver plating material may occur and may introduce conductive foreign material into the host circuit breaker. Introduction of this conductive material could create the possibility of a short circuit of the current sensor terminal board for circuit breakers configured with RMS-9 trip units and subsequent failure of the circuit breaker.
Fort Calhoun Nuclear Station is the only known recipient of affected breakers. Fort Calhoun received 18 breakers that contained improperly
silver plated components. 14 of these 18 circuit breakers have been returned to UCI. Four of the 18 circuit breakers have been installed at Fort Calhoun and UCI is currently awaiting the return of these four circuit breakers.