The 200-foot-tall ventilation stack at the Hanford Site’s Plutonium Finishing Plant crashed to the ground Saturday in an explosive demolition. It was another step toward bringing the plant down to slab on grade by the end of September as required by a Tri-Party Agreement (TPA) milestone.
Demolition work at the plant had shifted in recent weeks to the ventilation building, which housed powerful exhaust fans, to allow for the scheduled explosive demolition of the stack on Saturday.
The ventilation building, also called the fan house, was torn down to ground level after removal of equipment with radioactive contamination and any hazardous materials, such as asbestos. It then was backfilled with soil to provide space for the demolition of the stack.
The stack, which was about 18 feet in diameter at its base, had fixative blown up its length to help contain any radioactive contamination before the ventilation system for the plant was turned off. A wedge was cut near its concrete base to control where it fell. A gravel pad was laid on the ground to provide a somewhat cushioned and flat landing area for the stack. It was expected to fall in one piece and pancake into rubble to be loaded out to the Environmental Restoration Disposal Facility in central Hanford.
The next demolition is planned for the main part of the site, before work resumes on the Plutonium Reclamation Facility, believed to be the most contaminated area of the Plutonium Finishing Plant. Demolition will be done on the main plant near the Plutonium Reclamation Facility to provide more space for the facility’s demolition and at an area that housed worker lockers. “Even though we have resequenced the facility demolition order, we are still working to meet the TPA milestone basically by the end of September,” said Tom Teynor, Department of Energy project manager for the Plutonium Finishing Plant.
