Deconstruction of the UF6 Building 27 at the Cameco Conversion Facility

March 18, 2025
By: Connie Clearwater

The deconstruction and dismantling of Cameco’s UF6 Plant, commonly known as Building 27 (B27), was an abandoned processing facility, heavily contaminated with radiological and chemical material. It consisted of two, two-story building sections and a central seven-story tower section with a total footprint of 72,800 square feet.

Originally, work was planned to commence in June 2019 (with a completion date of 2021), but when the COVID-19 pandemic hit, the number of people on-site had to be reduced, and the project was delayed until September 2021. Initially, Priestly Demolition Inc. (PDI) was contracted to demolish the B27 tower down to the fourth floor, but this plan was later revised so that the entire structure would be demolished.

This undertaking is known as the Vision in Motion (VIM) project, a unique and timely opportunity that was made possible because of the Port Hope Area Initiative (PHAI). The PHAI Port Hope project was undertaken by Canadian Nuclear Laboratories (CNL) and included the construction of a Long Term Waste Management Facility (LTWMF) in Port Hope. PHAI made 150,000 cubic meters of space available for the site to dispose of the eligible legacy waste (pre-1988). This is what drove the VIM schedule.

Project Scope

The first step was to establish a waste processing area on the ground floor of B27 where demolished materials from other areas of the building could be processed, including interior contents (equipment, steel, piping, ducting fixtures, etc.). All materials were assumed to be contaminated and were required to meet the Waste Acceptance Criteria (WAC). Contents were then packaged as required for shipment to the LTWMF. In general, materials had to be cut into small pieces to minimize void spaces. Large pipes had to be split down the middle and then efficiently packed into the Cameco-supplied hazardous waste PacTec bags (Super Sacs) before they could be loaded into the supplied IP2 shipping containers and shipped to the LTWMF.

Large equipment slated for demolition was also cut to fit into hazardous waste bags at the workface; no equipment was removed whole. The bag labeling procedure was highly detailed and extremely important to ensure materials were identified correctly.

Upon removal of the interior building contents, all building surfaces within the building were thoroughly HEPA vacuumed to remove any remaining loose contamination. At the completion of this stage, only the interior structural steel (including flooring) and the fully intact building envelope remained.

Thorough HEPA vacuuming of the interior surfaces was the main control used to guard against the potential of contamination release into the environment. In subsequent steps, localized containment techniques were required to prevent a Loss of Primary Containment (LOPC).

The use of water to clean surface contamination was avoided when possible because the additional effluent material would need to be captured and transported to the water treatment circuit. Also, any water treatment requirements had to first be identified for Cameco approval.

In addition, a fixative coating was applied to all interior surfaces prior to any siding removals to “lock down” any remaining contaminants and provide a secondary means of preventing contamination release into the environment.

A radiological survey of the building was completed after the completion of interior cleaning and HEPA vacuuming. This was to confirm contamination levels before proceeding with the tower demolition activities.

The Tower

The tower floors were removed one by one (including transite siding and structural steel), starting at the top and proceeding to the ground. Because debris and equipment were not permitted to leave the footprint of the building before being packaged, the team created an opening in the lower-level roof to crane the super sacs and structural steel down from the building for further processing.

The extensive scaffolding setup and tower section had to be enclosed while asbestos transite siding and structural steel were being removed; additionally, a mobile crane was used in tandem to lift the cut structural steel and transite siding from the tower floors to the ground.

To add another level of complexity, water could leave the footprint of the building even once it was open to the elements. All the water had to be collected in totes and sent for evaporation.

Keeping our Crew Safe

An extensive ventilation system was installed, including 48 negative air machines with HEPA filters and ducting throughout the building. Emissions were modeled and monitored throughout the project with daily filter changes and air flow checks. The team used full-face respirators as well as powered air-purifying respirators throughout the demolition process.

Conclusion

Upon completion of the tower demolition, the remainder of the building, excluding the cylinder prep, was demolished to slab on grade, including the generator room and tote bin room. Once the building was fully decommissioned, the ground floor slab was prepared for future renovation activities. Cameco’s Port Hope Conversion Facility plans to refurbish the B27 building and slab and use it as a warehouse facility.

This was a hugely successful project for both Cameco and PDI. These two companies were fully dedicated to the safety of the team and the environmental controls that were required to ensure the success of the project.

Unique solutions were required for this project as it developed, and both teams are extremely proud of the work that was performed on-site.

“Cameco was pleased to contract Priestly Demolition to remove the redundant UF6 building at the Port Hope Conversion Facility; however, it was clear this was to be no normal demolition,” says George Trotter, program manager at Cameco Corporation. “Due to the nature of its former operation and the legacy wastes stored over the decades since, new procedures had to be developed to ensure radiological, conventional and environmental safety.”

Partners in Progress

The Cameco Corporation is a world leader in uranium production and is a major supplier of uranium processing services required to produce fuel for the next generation of clean energy. The PHCF produces uranium hexafluoride and uranium dioxide. These operations are based in Blind River, Cobourg, and Port Hope, Ontario, and are collectively referred to as the Fuel Services Division.

The PDI team greatly appreciates the opportunity to be a partner in the progress of this challenging project. We have built a strong and trusting relationship with Cameco as a result and continue to perform decommissioning work on the Port Hope site and the Vision in Motion project.

“I commend PDI’s willingness to adapt to change, ability to develop solutions and their unwavering commitment to doing it all safely. The entire team should be proud of what was accomplished,” says Andrew Turk, P.Eng, senior project engineer at Cameco Corporation.