Commissioning McNary Fishway Hydro Project · History & Lessons Learned McNary Northshore Fishway Hydro Project ... Disassembly of Plant Components ... headcover line bored for wicket

McNary Northshore

Fishway Hydro Project

May 6, 2017

History & Lessons Learned

4/8/2017

21th Annual TECHNICAL SEMINAR

Machines, Maintenance, and Management:

Keeping Hydro Facilities Up and Running

History & Lessons Learned McNary Northshore Fishway

Hydro Project

• McNary project history

• McNary re-powering project aka Runner install (part 1)

• Powerhouse crane failure & repair

• Rewind Project

• Runner install (part 2)

• Commissioning

• Lessons learned

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McNary Lock and Dam

5

• On September 30, 1991, the Federal Energy Regulatory Commission (FERC)

issued a 50-year license to North Wasco County Peoples Utility District

(NWCPUD) to construct, operate and maintain a hydroelectric project at the

McNary Dam.

• Originally, BPA entered into a power purchase agreement with NWCPUD in 1993.

• BPA withdrew from the agreement in 1994.

• Klickitat PUD then joined with NWCPUD to develop the McNary Project.

• The PUD’s entered into an Ownership Agreement in August of 1995

• The McNary North shore hydroelectric project was completed and started

production on October 17th 1997.

• The total cost of the project was $29 million.

Brief Project History

Project Design7

• The project uses attraction water from the north shore fish ladder on the McNary Dam for power generation.

– Attraction water flow is diverted through penstocks, runs through the turbine and is then routed back to the entrance of the fish ladder to attract migrating fish and lamprey.

• The intake structure at McNary is located at the bottom of the dam and draws water from about 80 ft below the surface of the dam forebay.

• The generator at McNary produces approximately 10 MW of power, which is split equally between NWPCUD and KPUD.

– Over a year, this amounts to approximately 80,000 MWh of energy – enough power to provide electricity to about 8,000 homes

Construction Photos

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4/8/2017Kurt Conger, NWCPUD9

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McNary Fishway Hydro Project

Unit Cross Section

McNary Re-powering Project Runner Install - Part 1

4/8/2017

• Review repair history of turbine blade cracks

• Review welding procedures from past blade repairs.

• Evaluate failure risk and cost associated with a blade failure

• Recommend remedial protection measures, e.g. vibration

monitoring, startup/shutdown timing, other, that may mitigate

damage if a blade failure occurs.

• Make recommendations for repair or replacement of turbine

runner or other in-water equipment.

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• 10 MW vertical unit commissioned in 1997

• Orenco supplied Hangzhou turbine & generator,

manufactured in China

• History of propeller runner blade cracking

• Runner casting quality poor with dimensional problems

• Initial McMillen Jacobs site visit on June 17, 2014

• Annual outages with weld repairs

Project Information

4/8/2017

Early cracks near anti-cavitation fin

Cracks needing repair every 6 months

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Cracks getting worse after each weld repair

Crack NDE

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Recommendations

4/8/2017

• Contract for additional engineering, including developing

contract documents

• Perform generator detailed inspection early 2015

• Bid and award new runner contract

• Bid and award runner install site work contract

Action: Owners direct McMillen to develop runner procurement

bid documents and runner installation bid documents.

Runner Procurement

4/8/2017

• Bid documents prepared and issued to bidders

• Bids evaluated and recommendation for award February 2015

• Weir – American Hydro awarded contract effective March 31,

2015

• Runner to be delivered within 311 days

New Runner

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Old Runner

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Runner Installation Contract

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• Bid documents prepared and issued to bidders

• Bids evaluated and recommendation for award August

2015

• HCMS awarded contract effective September 9, 2015

• Runner to be installed by February 5, 2016

• Outage begins October 2015

November 18, 2015 - Crane Failure

4/8/2017

• During the last lift of major equipment from the turbine pit, a

defective weld in the powerhouse crane failed.

• The old runner, shaft, bearings, brackets and head-covers

dropped 18”.

• Parts of the crane fell into the powerhouse damaging the

stator and concrete.

• Nobody was injured!

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Powerhouse

Crane

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Crane Failure Damage

4/8/2017

• The crane failure damaged several major components of

the project:

• Generator stator windings and core

• Turbine bearing bracket that supports the runner and

shaft

• Lower guide bearing support bracket

• And the crane itself was no longer serviceable for the

runner installation work

Other Component Defects4/8/2017

• Stator winding defects

• Loose wedges and missing side/depth packing

• Caused excessive wear, winding damage and reduced life expectancy

• Lack of strand transpositions or internal transpositions resulting in higher losses

• Tin/lead solder results in higher losses and increased outage risk

• Other (PD evidence, inadequate end winding clearances)

• Wicket gates, bearing surface degradation, runout measurements too high

• Multiple inner and outer head cover defective welds

• Upper and lower bearing bracket defective welds

• Possible defective rotor welds investigated – need rewelding

Project Timeline

4/8/2017

• Late 2015: HCMS Stabilized the Project

• Early 2016: Disassembly of Plant Components

• Feb-Aug 2016: Off-site Component Repairs

• May-June 2016: Crane Repair and Installation

• April 2016: Boards Authorized Stator Rewind

• May-July 2016: Stator Rewind

• June-October 2016: Reassembly of Plant

• Nov 2016 – Feb 2017: Commissioning

Generator Rewind

4/8/2017

• Based on inspections during repair of damage to stator core

laminations a rewind was recommended

• Developed rewind bid documents and issued bid documents

• Evaluated bids and awarded a contract for stripping coils and

installing new to National Electric Coil (NEC)

• After coils were manufactured HCMS took short break while

installed new windings

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Runner Install – Part 24/8/2017

• While rewind was underway 300 ton mobile crane used to service work

• Meanwhile powerhouse crane components are repaired/replaced

• HCMS weld repairs rotor spider following EME fracture mechanics analysis

• HCMS begins reassembly of unit in July 2016 following rewind

• Other work included: headcover line bored for wicket gate bushings, discharge

ring machined, wicket gate stems repaired, bracket weld repairs, etc.

• Unit alignment complete in November 2016

• Unit water up attempted mid-November 2016, but leakage from wicket gate

cartridges causes delay

• Corp of Engineers ladder outage (December 2016 through January 2017) delays

commissioning to February 2017.

• Commissioning begins February 7 and is complete February 12, 2017

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Commissioning4/8/2017

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Turbine Power vs. Servo %

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Commissioning Conclusions

• Runner met guaranteed output

• Load rejection unit speed rise and pressure rise acceptable

• Generator temperature rise acceptable

• Bearing temperatures acceptable

• Vibration levels below maximum allowable

Lessons learned

4/8/2017

• Purchasing Chinese equipment is risky – extreme vetting is

needed

• Weld repair of CA6NM castings very difficult

• Crane load testing isn’t the final word

• Need a good team to recover from an extreme situation

• Be prepared to respond to changed conditions based on

disassembly inspections

• Watch out for bad paint system specifications

Acknowledgements

4/8/2017

• NWCPUD and KPUD staff

• HCMS

• American Hydro

• National Electric Coil

Congratulations to Bob Guidinger on his retirement!

Questions?

4/8/2017