When Harrison Unit 1 comes back online following its current maintenance outage, the control room BTG (Boiler – Turbine – Generator) board will have a new look … which, in some ways, will appear a lot like its old look.

“We’re replacing the original, analog annunciator panels with new digital screens,” said project coordinator Mark Demko, Harrison engineer, “but we’ve designed them to, as much as possible, simulate the look of the old panels.”

Instrumentation & Controls (I&C) set up the new panels and alarms to mimic the old annunciators, which alert plant operators to potential issues with plant equipment and systems. During the replacement, care was taken to maintain the basic arrangement of the panels to reduce the possibility of human performance errors when the new annunciator banks become operational.

“Operators here have years of experience and training in this control room,” Mark said, “and we took the effort to change the overall annunciator design scheme as little as possible.”

The upgrade also includes replacement of amp meters and analog instrumentation.

Much of the equipment on the board is obsolete and replacement parts are hard to find. Other instruments no longer are needed because their function is now included in the DCS (Distributed Control System). Meters and dials that no longer are used were removed. The overall effect is a cleaner, more streamlined board.

“We did incorporate lessons-learned,” Mark said. “The Unit 3 control room was upgraded in 2014, and I&C took input from the operators, taking their feedback into consideration when designing the upgrade.”

Despite efforts to maintain the overall scheme, the upgrade is no small task. The work included pulling more than 200 new cables from monitoring points in the field and involved about 1,000 individual terminations to field devices, the BTG board and a new DCS cabinet.

The upgraded control room also will have a new state-of-the-art Sequence of Event system, which will allow any events that occur to be traced back to their source.