WANAPUM DAM — Just like remodeling a house, upgrading components of a hydroelectric project brings with it some good surprises, some bad surprises and some adjustments to the budget and time schedule. Project managers Molly Hill and Jeff Niehenke updated Grant County PUD commissioners on upgrades to the turbine-generator units at Priest Rapids Dam at the commission meeting Tuesday.
Upgrades to the first generator-turbine unit started in August 2016. The plan is to upgrade one unit each year for 10 years.
Both the turbine and generator units have been disassembled, and the various parts are undoing inspection. Some unexpected problems have turned up, and PUD employees are still trying to figure out how to solve some of them.
One piece of the generator is stuck together, despite the best efforts to pry it apart, Niehenke said. That made it impossible – at least so far – to do the planned refurbishment and inspections. “At this time we’ve decided to put the unit back into service as it is, with a plan to take it out sometime in the future.”
But “this is just a continuing, evolving story over this last month. And I can’t tell you exactly where we’re at because we’re doing more inspection, more investigation,” Niehenke said. There are some options – there’s an alternative method of getting the piece apart, but that would end up costing almost as much as buying new pieces.
Replacing the piece is under discussion; that would cost about $2.5 million over the 10 units. “We’re pushing forward to start the design process (for the piece) and that will buy us about three, four months to make a decision” on buying new parts, Niehenke said.
The good news, Niehenke said, is that a different piece might not need replacement, which would save an estimated $3 million over original estimates.
Hill said rehabilitation of the first turbine cost about $400,000 more than budgeted. There were some delays, but other parts of the project were delayed so they didn't affect the overall timeline. For the next unit, PUD engineers know that more time needs to be added to the schedule for removing the existing lead paint and repainting, and taking time to do a test fitting for certain pieces.
Cheryl Schweizer can be reached at firstname.lastname@example.org.