At the Tennessee Valley Authority’s (TVA) 160-MW Chickamauga hydro plant on the Tennessee River, as at many hydro facilities, open floor space in the powerhouse is at a premium. When TVA started a rehab, there was not enough space to store parts removed from the turbine-generating units that were going to be needed again when the unit was reassembled. These parts included oil piping, water piping, valves, components for the permanent magnet generator (PMG), small fittings, nuts, and bolts. In addition, space at Chickamauga was limited for temporary storage of new components, such as the programmable logic controller (PLC), seals, and O-rings.
Before beginning the rehabilitation work, the outage manager developed a laydown plan, using a drawing of the generator floor. This plan would allow personnel to correctly lay out big components as they were removed. But adequate storage of smaller components – such as nuts, bolts, and valves – was still a concern.
Problems encountered during the outage of the first unit at Chickamauga highlighted the need for a better storage solution. All the materials needed to reassemble the unit were laying on the generator floor. There was no space left for personnel to walk, the materials posed a tripping hazard, and there was no organization to the various materials laying on the floor. Personnel working on the outage decided they needed to purchase several large shelving units and install them on the back wall of the powerhouse, where the materials would be accessible but out of the way during the refurbishment work.
Plant personnel purchased several standard commercial grade steel shelving units, such as those that would be used in a warehouse, and installed them on the headwater side of the powerhouse. This solution alleviated crowding on the generator floor. It allowed the space to be better used for actual work and promoted safe work habits in several ways. First, it encouraged personnel to keep the aisles clean. Second, personnel decided to put down yellow tape to help mark off walkways and encourage people to keep the designated area clean. Third, keeping the walkways clear promoted increased awareness of plant cleanliness.
To properly organize materials on the shelves, plant personnel numbered all shelves. They then tagged all pieces before storing them in bags or boxes on the shelves.
To keep an adequate inventory of incoming equipment, plant personnel developed a log sheet that included the item description and location on the shelves.
Once the Chickamauga rehab was complete, plant personnel built a new warehouse and moved the shelving units to that location.
– By William B. (Ben) O’Brien, Tennessee Valley Authority, 714 Swan Pond Road, KIF1 A-KST, Harriman, TN 37748; (1) 865-717-4053; E-mail: firstname.lastname@example.org.
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