Grant County PUD
Plant Upgrades at Wanapum and
Priest Rapids Dams
Kevin Marshall, PE
GC PUD Hydro
Engineering Manager
NWHA Conference
February 18, 2014
Ongoing Upgrades for
Wanapum Dam
 Turbine Replacement (Note: GCPUD took advantage of
CREB bonds and a DOE design/development grant) Work
is complete.
 Generator replacements
 New exciters
 Digital Governors
 Transformers
Reasons for Turbine Upgrades
 Original turbine runners had
reached the end of their
useful life
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Blade crack repairs
Trunnion seal issues
Operating linkage failures
Cavitation repair costs $75,000/unit/year (1987-1993
average costs)
 Performance improvements
 Improved fish passage
survival
Wanapum Turbine Upgrades
 Design Features
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Semi to fully spherical
Larger diameter: 20 inch increase
Deeper setting : 3.315 feet deeper
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Increased capacity: 120khp to 150khp
Efficiency improvement: 3% average weighted
efficiency
Cavitation repair costs: $0
 Performance Improvements

Reasons for Generator Upgrades
 Replace components at
the end of their life.
 Capture increased
output of new turbines
Wanapum Generator Upgrades
 New Parts
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Complete Rotor
Complete Stator
Generator Shaft
Ventilation System
Excitation System
Air-Gap Monitoring
Rotor spider arrives in 3
sections, stator frame in 4
Wanapum Governor/Unit Control
Upgrades
 What
 Mechanical governors
replaced with digital
 Dynamic exciters
replaced with static
exciter and digital
controllers
 Why
 Spare parts no longer
available
 Serviceman knowledge not
transferred with
retirements
 Improved control/efficiency
 Improved protection
 More info/better trouble
shooting
 Lower costs to maintain
Existing Wanapum Mechanical
Governors
New Wanapum Digital Governors
Current Wanapum Status
 10th turbine, 4th generator, 4th exciter, and 3rd governor
complete and put into service October 2013
 5th generator, 5th exciter, and 4th governor under
construction
 10th generator and exciter to be completed in 2019
 New turbines have a averaged, weighted efficiency gain of
3%
 As tested new generators have an increased efficiency
from 98.0% to 98.5%
 2 of 5 transformers replaced, 3rd transformer in process
Priest Rapids Dam
Upgrades
Planned Upgrades for
Priest Rapids Dam
 Turbine Replacement
or life extension
 Generator rewinds
 New exciters
 Digital Governors
 Transformers already
replaced
Reason for Upgrades
 Efficiency improvement
 Life Extension
 Aging equipment
 First unit in service in 1959
 Generators
 Rotor pole problems including pole to
pole connection failures (as pictured)
 Stator Winding age (oldest unit =
currently 27 years old)
 Exciters are obsolete
 Turbines starting to exhibit problems
 Increased cycling of governor oil pumps
 Wicket gate operating ring wear
Turbine Upgrade Process
 Goals
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Utilize lessons learned from Wanapum project
Obtain as many qualified bids as possible
Competitive turbine hydraulic model testing
Integrate biological considerations into design effort
Turbine Upgrade Process
 Step 1: Hydraulic design contract
 Professional Services Agreement
 Prequalification process – three
contractors prequalified
 All design solutions finalized by
contractors ahead of bidding
 All design solutions verified by
independent hydraulic laboratory
 Step 2: Manufacture and supply
contract
 Bidders must participate in
hydraulic design contract to bid
 Performance guarantees verified
prior to bidding
Status of Priest Rapids Upgrades
 Turbines
 Model testing was completed last week in Lausanne,
Switzerland for the 3 qualified vendors
 Bids are due March 5th
 Contract award this summer (if economics are
favorable)
 Generators: Pre-qualification of Vendors in process
 Controls: Governor specifications are in process
 Field work for upgrades is scheduled for 8/1/2016
Priest Rapids and Wanapum
Upgrades
 QUESTIONS