A/Es cut downtime by squeezing retrofits into refueling outages

This paper describes an electrical retrofit that had minimal impact on a refueling outage: the addition of a second reserve auxiliary transformer for each unit at the Prairie Island station. The work was split into three stages: work that could be performed before, during, and after the outage. It was found that most of the work could be performed before the outage. By minimizing actual outage work, the project was kept almost problemfree. The only work that needs to be completed during the outage involves tie-ins and retest. Piping components can be similarly rerouted to reduce the amount of work needed during the outage. Post-outage work included removing unused bus ducts, sealing wall openings and installing permanent end caps on bus ducts