Deactivation & Demolition (D&D)
The D&D process includes the removal of hazardous and radioactive materials to ensure adequate protection of workers, public health and safety, and the environment; placing the facility in a stable condition, thereby limiting the long-term cost of surveillance and maintenance, after which, demolition/disposition occurs.
Deactivation is the process of placing a contaminated (nuclear, radiologically or radioactive), excess facility in a stable condition to minimize existing risks and protect workers, the public and the environment. Once deactivation is complete, the final facility activity is decommissioning, where the facility is taken to its ultimate end state through decontamination and/or dismantlement to demolition. Decommissioning is the final process of closing and securing the facility consistent with established end states, to provide adequate protection from radiation exposure and isolation from the human environment.
From 2011 through 2020, the X-326 Process Building was deactivated, with more than 1 million Nondestructive Assay (NDA) measurements for residual contamination completed and more than 7,000 components removed and safely shipped to off-site licensed facilities for disposal. In 2021, safe, controlled structural demolition of the X-326 Process Building began, and the first placement of waste in the Portsmouth On-Site Waste Disposal Facility was completed. The waste placement of the demolition debris from this half-mile-long building was completed on Aug. 24, 2023. For the latest environmental monitoring information about the Portsmouth X-326 Process Building Demolition, visit portsdemo.com.
The X-333 Process Building is one of two remaining large process buildings with 65 acres of floor space, formerly used for uranium enrichment at the Portsmouth Gaseous Diffusion Plant. It was the first process building used for enriching uranium and contained the largest process gas equipment onsite.
Deactivation of the X-333 Process Building is complete and the building is currently undergoing pre-demolition. Lessons learned from the X-326 Process Building are being implemented in this building. Portsmouth crews relied on detailed planning, collaboration and teamwork to successfully complete characterization activities in the X-333 Process Building. The characterization included approximately 134,000 measurements, analyses and documentation of all equipment components, piping and valves that could contain uranium deposits at the X-333 Process Building.
The X-330 Process Building was the first building of the gaseous diffusion plant to be operational with the first cell on line in September 1954. When in operation, the X-330 Process Building enriched uranium of an assay of 3% to 10%, with 1,100 stages, 1,700 horsepower motors and intermediate size equipment. The X-330 Process Building will be the final process building to be deactivated and demolished. The building is in initial deactivation stages with a target year of 2029 for complete deactivation.
For the latest environmental monitoring information about the Portsmouth Site, visit portsdemo.com.
Current D&D
After 10 years of preparation, the safe, controlled structural demolition of the large X-326 Process Building began in 2021. Prior to the start of demolition, the facility was deactivated. This effort comprised more than 1 million Nondestructive Assay (NDA) measurements to identify residual contamination in the building, removal and offsite shipment of more than 7,000 components, installation of a water-runoff detention and treatment system and installation of additional air monitors. The X-333 Process Building deactivation was completed in 2024 and is undergoing pre-demolition activities. Also, under the D&D project, the Portsmouth Site continues to change. More than 38 facilities have been demolished after deactivating utilities and removing stored waste, materials, process equipment, and piping.
Going forward, continuing and completing facility D&D activities will be the main focus at Portsmouth. Next will be the X-333 Process Building, where deactivation work is underway including size reduction of its large components. Demolition of the X-333 Process Building is expected to begin in 2025 and to be completed by FY 2030. The last former process building at Portsmouth, X-330 Process Building, is expected to begin demolition in 2030 and be completed by FY 2032. By FY 2034, PPPO expects to complete demolition of remaining “balance of plant” facilities at Portsmouth.
Cleanup Progress
Various remediation efforts have taken place at the Portsmouth Site since 1989, to address groundwater and soil contamination. These efforts include closing landfills and lagoons, removing waste and inactive facilities, and decontaminating and decommissioning facilities. Recently the site has accomplished treating more than 680 million gallons of groundwater and removed more than 35,000 pounds of Trichloroethylene (TCE). More than 125 solid waste management units have attained No Further Action (NFA) determinations under the Resource Conservation and Recovery Act corrective action program. All legacy waste from the site has been removed in addition to 40 facilities removed including 700,000 square feet of buildings. The Portsmouth Site has also recycled 25 million pounds of material, including more than 14 million pounds of steel, aluminum and copper from the demolition of a former electrical switchyard.
Groundwater Cleanup Continues
All five groundwater plumes have ongoing groundwater treatment to contain and reduce contamination either by pump and treatment through extraction wells and groundwater treatment facilities, bioremediation or phytoremediation. More than 955 million gallons of groundwater from four on-site plumes have been treated.
More than 1,000 groundwater monitoring wells have been installed around the 3,777-acre federal plant site to sample and identify five separate groundwater areas, called plumes, primarily contaminated with Trichloroethylene (TCE). About 600 monitoring wells are sampled regularly. More than 37,788 pounds of TCE have been removed from groundwater. A fifth plume is being treated by phytoremediation using planted hybrid poplar trees. More than 3,300 hybrid poplar trees were planted as part of an Ohio EPA-approved groundwater cleanup remedy (phytoremediation).
Landfills & Lagoons - Early Remediation
Five landfills on-site have been closed in accordance with regulatory requirements. These landfills cover 60 acres and long-term surveillance and maintenance monitoring of the landfills continues today. The landfills were used for the disposal of a variety of wastes such as construction debris, low-level contaminated scrap materials, hazardous materials, classified materials and sanitary wastes.
Besides the landfills, a number of sludge lagoons, impoundments and oil biodegradation plots have been remediated in accordance with Decision Documents issued under the Consent Decree with the State of Ohio and the Administrative Consent Order.