September 2008

Welders lead the cost-cutting charge

As cost pressures drive up electricity prices, individuals and organizations across TVA are working to hold the line on costs. Skilled crafts and technical staffs at Browns Ferry Nuclear Plant put their knowledge and experience to work for big savings there. As you see employees working smarter and reducing costs, let us know. E-mail to ljones@tva.gov or mail to Inside TVA, SP 2B-C.

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When 70 welders and an engineer at Browns Ferry Nuclear Plant were asked how to clean grit out of pipes, their answer saved TVA close to a quarter million dollars and helped the performance of the Unit 3 reactor.

After making modifications to the systems and equipment needed to “uprate” and be ready to increase the generating capacity of units 1 and 2 based on Nuclear Regulatory Commission approval, the units’ reactor cooling water needed additional clean-up. Impurities in the cooling water made it necessary to operate the cooling water filters every two days for six weeks, at a cost of about $250,000 per unit, until the water finally returned to proper purity.

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From left, Browns Ferry Nuclear Plant Task Engineer Martin Reischman and Chemist Jamie Johnson, at the Unit 1 condensate demineralizer system, were part of a team effort that led to saving TVA more than $200,000. The chemistry guys started the investigation, the task engineer figured out it was soot, and they, with the welders, devised the plan for cleaning up the separators before they were put back into service.

Plant chemists traced the problem to the units’ moisture separators. The chemists figured the impurities were grit and other debris caused by welding, so they asked the task engineer for the moisture separator work and the welders who did the work what to do differently when the uprate modifications were made on Unit 3 during a regular refueling outage.

The engineer and welders had a different theory. They said they’d seen soot and other smoke remnants from the welding — not grit or debris — collect inside the moisture separators of units 1 & 2. After some discussion, a plan was developed to wipe down and hose out the Unit 3 separators before the unit returned to operation.

As a result, the Unit 3 reactor water returned to proper purity in two days, rather than six weeks. The clean-up system had to operate only every 30 days, as designed, rather than every two days. Total cost was $10,000, rather than $250,000.