Clean Currents 2022

Operations and Maintenance Problem Solving

Presentations are:
— Zebra Mussel Mitigation in Powerhouse Raw Water Systems, presented by Spencer Heinz, U.S. Army Corps of Engineers

— Debris Boom Case Studies and Design Considerations for our Changing Climate, presented by Randy Presleigh, Pacific Gas and Electric Company

— New Sensor Needs for Hydropower Equipment, presented by John Yale, Chelan County Public Utility District

Special Presentation! Transformer Bushing Failure at Hoover Dam: Lessons Learned, presented by David J. Arend, Deputy Regional Director, Interior Region 8, Lower Colorado Basin, Bureau of Reclamation

Details about each presentation and the speakers are below.

Zebra Mussel Mitigation in Powerhouse Raw Water Systems, presented by Spencer Heinz, U.S. Army Corps of Engineers
This presentation shares what zebra mussels are, why they are considered a nuisance species, and how operators can go about getting rid of them in the hydroelectric powertrain.

Debris Boom Case Studies and Design Considerations for our Changing Climate, presented by Randy Presleigh, Pacific Gas and Electric Company
Debris booms are floating barriers that serve as the first line of protection to prevent blockage of spillway gates and powerhouse intakes from floating trees and other woody debris. In recent years our changing climate has brought a renewed focus on this sometimes-overlooked dam safety element. Forest fires followed by heavy precipitation can transfer unprecedented debris flows into our reservoirs that result in novel loading scenarios and unexpected debris boom failures. Most dams include a potential failure mode that is initiated by debris boom failure and eventually results in dam overtopping.

This presentation will delve into the history of debris booms using several case studies, provide an overview of debris boom design guidance materials and defined typical design criteria considerations. Additionally, a detailed case study will be presented on the typical lifecycle for a debris boom project starting with analysis of alternatives, preliminary design considerations, final design detailing, selection of vendors, construction, and long-term maintenance.

New Sensor Needs for Hydropower Equipment, presented by John Yale, Chelan County Public Utility District
Asset management and data analytics applied to hydropower equipment has increased the need for sensors to feed the data needs of the models and the frequency that the data is collected. As more sophisticated models are developed, new sensor and sensor applications will be needed. These needs may be met by application of conventional sensors, application of sensors new to the industry, and development of new sensors and technologies.

This presentation will discuss Chelan’s work in developing new sensors and methods for acquiring data from the rotating parts of the turbine-generators.

Currently, the only means to observe that the seals are leaking is observing a loss of oil from the hub to the river, or shutting the unit down, dewatering the unit and checking for water in the hub by draining a sample. The first is unacceptable where the goal is no oil loss to the river, and the second usually incurs significant cost in outage time and labor to dewater the unit, install staging and safety equipment and draining the sample from the hub. It would be advantageous to operations to have a reliable online method of determining that significant water has entered the hub to allow a proactive response to leakage at the blade trunnion bushings.

This presentation outlines the technology used to address the significant economic costs associated with this problem.

Special Presentation! Transformer Bushing Failure at Hoover Dam: Lessons Learned, presented by David J. Arend, Deputy Regional Director, Interior Region 8, Lower Colorado Basin, Bureau of Reclamation
This presentation shares the recent transformer bushing failure and subsequent fire at Hoover Dam, actions taken, and lessons learned from an operations and maintenance standpoint. Attendees will learn what to do at their facilities to minimize the chance of repeating some of the lessons learned at the Hoover Dam.

Presenter Information

Juan Medina

Juan Medina
Sales Territory Manager
L&S Electric
Emcee


Spencer Heinz

Spencer Heinz
Mechanical Engineer, Hydroelectrical Design Center (HDC)
U.S. Army Corps of Engineers
Presenter


Randy Presleigh

Randy Presleigh
Major Projects Dam Safety Engineer
Pacific Gas & Electric Company (PG&E)
Presenter


John Yale

John Yale
Hydro Engineering Manager
Chelan County Public Utility District
Presenter


David Arend

David Arend
Deputy Regional Director, Interior Region 8, Lower Colorado Basin
Bureau of Reclamation, U.S. Department of the Interior
Presenter