Humboldt Bay Power Plant Decommissioning
Owner: Pacific Gas and Electric Co.
Lead Design Firm: McMillen Jacobs
General Contractor: Aptim
Civil Engineer: Whitchurch Engineering
Structural Engineer: Drill Tech Drilling & Shoring
Nuclear Demolition Contractor: Northwest Demolition & Dismantling; Northwest Demolition Canada ULC
Geotechnical-Dewatering Consultant: Geosyntec Consultants
Decommissioning the nation’s seventh commercially licensed nuclear plant, a 1960s structure known as Unit 3, required demolition and removal of all nuclear facilities, including above-grade structures, below-grade utilities and components associated with a pair of fossil plants, Units 1 and 2.
Initial plans called for removing a reactor pressure vessel (RPV) as a single unit and shipping it off site. But after assessing radiation levels and confined-space access, the project team developed an alternative approach. Rather than removing the vessel as a whole, workers sectioned the RPV in place using specially fabricated, remote-controlled cutting tools. That eliminated a critical crane lift and the need to construct surface facilities. The team also completed intake and discharge canal remediation and created numerous wetland areas.