Underpinning 324 Building: Supporting Hanford Nuclear Site Remediation Efforts-PPT Presentation

PPT Presentation

Pdf Summary

The 324 Building at the Hanford Site is a three-story, Category II nuclear facility built in 1962 for radiological research and operations. Hanford’s nuclear production began during World War II and continued through the Cold War. In 1989, the U.S. Department of Energy, EPA, and Washington State established the Tri-Party Agreement to guide cleanup of the site.<br /><br />During cleanup work in 2009, workers discovered a breach in the building’s B-Cell sump. Subsequent investigations identified a radiological plume containing contaminants including strontium, cadmium, and silica. The facility’s mission shifted to safe stabilization and deactivation, with ongoing maintenance to support its eventual decommissioning and demolition.<br /><br />To support the building and remediation efforts, the project designed an underpinning system using micropiles and permeation grouting. Design began in 2017, with verification testing to confirm micropile bond strength and demonstrate constructability. Testing met performance requirements, and 13 micropiles had been installed at the time of the presentation.<br /><br />Work inside the Category II nuclear environment required extensive controls. Drilling used a contained system with air handling, casing diversion, and filtration to limit airborne contamination. The team also addressed tight access and low overhead clearance, control of drill spoils, ventilation, and the risk of transferring contamination between clean and contaminated areas. Grouting preparations included contingency planning, specialized equipment, backup personnel, and procedures for handling contaminated tools and casing.<br /><br />Radiological protections included controlled work areas, shielding, long-reach tools, sealed connections, negative-air containment, sticky floor coverings, continuous air monitoring, surveys, permits, detailed work packages, training, and protective clothing and dosimetry. These engineering and administrative measures enabled underpinning work to proceed while protecting workers and limiting the spread of contamination.

Keywords

Hanford Site

324 Building

nuclear facility

radiological contamination

Tri-Party Agreement

micropiles

permeation grouting

radiological protection

decommissioning

contaminated plume