X-333 demolition begins

Cleanup crews recently removed the first transite panel from the X-333 facility to prepare for the demolition of the second of three former uranium enrichment process buildings at the US Department of Energy (DOE) Portsmouth Site. Crews finished demolishing X-326 in 2022, and X-330 will be the third process building to be knocked down.

The outer panels covering the building are made of transite, a known asbestos-containing material that must be cautiously removed to meet environmental regulatory requirements. “Transite removal is the first step toward the demolition process,” Federal Project Director Christy Brown said. “The workers will work in teams using personnel lifts. They will remove, lower, and stack each panel, one at a time, so it is a big job.”

Crews will have to remove more than 16,000 transite panels from the X-333 Process Building over the next 17 months. Each panel measures 8 feet by 4 feet and weighs 90-140 pounds. “This is the first phase of bringing down the largest of the two remaining process buildings onsite,” Federal Project Director Jud Lilly said. “A lot of work has been done prior to this to ensure this process is completed efficiently and safely.”

Crews worked inside the building to complete deactivation of the two-storey, 33-acre X-333 prior to beginning removal of the transite panels. Deactivation included: characterising the building and equipment from a radiological standpoint; disconnecting process equipment; segmenting, crushing and preparing waste for onsite or offsite disposal; removing asbestos and other hazardous waste; and isolating and disconnecting utilities. Workers also installed fencing and removed above- and below-grade obstructions around the building.

Workers completed several activities to ensure safety of the workforce, community and environment. For example, they installed a water detention system that includes a lined perimeter berm to capture water runoff from the X-333 demolition project area. The water will be sent to a treatment system designed to treat all contaminants of concern.

Prior to demolition, crews will apply a fixative to the transite panels, inside and out, to reduce dust. They also will spray water on portions of the facility as they are demolished to suppress dust. Air monitors installed around the building will measure air quality to ensure the safety measures are effective.

Teardown of X-333 is set to take several years due to the facility’s size. It is scheduled to be completed in 2030. The team will look for opportunities to accelerate the schedule without compromising safety.

DOE’s Portsmouth Paducah Project Office conducts cleanup activities at the Portsmouth Site in accordance with a consent decree with the state of Ohio and director’s final findings and orders with the Ohio Environmental Protection Agency.

Crews finished deactivating and demolishing the first of the three process buildings – X-326 – in June 2022. As part of deactivation work, crews took over 1m measurements of the quantities of uranium deposits that remained from enrichment operations in dozens of miles of process pipes, and removed over 7,000 process components.

The X-333 deactivation involved taking more than 130,000 characterisation measurements over 208 miles of piping, disconnecting and segmenting 626 massive enrichment converters, and disposing of 13,000 cubic yards of deactivation debris.

“The personnel at the Portsmouth Site are commended for their successful deactivation while making improvements to the processes with lessons learned and maintaining diligence in safety,” Portsmouth Site Lead Jeremy Davis said. “We have made sure that lessons learned in the X-326 Process Building deactivation were applied to X-333 Process Building and will be shared … for deactivation of remaining process buildings.”

One of the main challenges at X-333 was the size of the equipment. The conversion equipment in X-326 fitted in shipping containers for disposal offsite. However, X-333 was the entry point for feed material and had the largest equipment for uranium enrichment, with some converters more than 20 times larger than those in X-326.

“Due to the larger size of the components in the X-333 Process Building, deactivation was very different. In the X-333 Process Building, we had the challenge of removing, segmenting and then compacting massive converter components,” explained Lilly. “The team had to figure out and perfect each step as we proceeded but were able to continuously improve their work practices to maintain safety and get the job done.”

Another X-333 challenge was incorporating a system that measures equipment up to 12 feet high, 12 feet wide and 20 feet long. “The strategic placement of the Large Component Assay System (LCAS) adjacent to the X-333 Process Building was instrumental in efficiently completing more than 1,750 measurements,” said Greg Wilkett, site project director for Fluor-BWXT Portsmouth, the Portsmouth Site deactivation and demolition contractor. “The focus tends to be on the larger deactivation tasks, such as the converters, but every auxiliary process gas system must be deactivated and addressed before declaring deactivation complete.”

Crews disconnected and disassembled more than 600 converters in the Material Sizing Area. Following disassembly, they measured internal components, such as tube bundles, from the converters in LCAS to verify compliance with disposition requirements. Workers crushed and placed a total of 623 tube bundles in containers in the nearby X-343 Feed Facility for potential nickel recovery efforts.

Deactivation crews collected and staged containers of excess materials for segregation and inspection by Waste Operations personnel who determined the proper disposal path.