Public Utility District No. 2 of Grant County in Washington operates the 912-MW Priest Rapids facility on the Columbia River. The powerhouse contains 10 Kaplan-type turbines that are more than 50 years old. Plans are under way to install new runners. The Columbia River is a migratory pathway for several species of threatened and endangered juvenile and adult salmonids, thus safe fish passage is a major consideration when upgrading the turbines.
To ensure biological impact is considered during design of the replacement turbines, the PUD has included specific criteria in the contract with prospective manufacturers for addressing fish passage risk. Pacific Northwest National Laboratory (PNNL) has developed a method for estimating this risk, called the biological performance assessment (BioPA). BioPA computes a suite of biological performance indicators based on data from a computational fluid dynamics (CFD) model of a proposed turbine design.
This article presents the strategy Grant County PUD used to incorporate fish passage criteria into the design phase of the Priest Rapids turbine upgrade project.