A rainbow appears over the Paducah Site's East End Smelter, a 21,000-square-foot complex used until the 1980s to smelt metal. Recovery Act workers used heavy equipment to demolish the smelter in September 2010, a year ahead of schedule and $10 million under budget.
Second-shift Recovery Act workers at the Paducah Site use scissor lifts and metal saws to remove the outer cover of old uranium hexafluoride process tie lines linking C-410 with other parts of the Paducah Gaseous Diffusion Plant.
Recovery Act workers have reduced contaminant levels by 96 percent in soil 30 feet below ground in what has been coined the Portsmouth Gaseous Diffusion Plant's "Big Dig." In the $34 million Recovery Act project, workers are excavating a 70,000-square-foot area of soil with a high concentration of trichloroethene (TCE) under a now-defunct holding pond. The chemical compound was used as an industrial solvent at the plant, which enriched uranium for defense and commercial nuclear purposes until production ended in 2001.
The last seven 120-foot tall towers are dropped all at once at the X-533 Electrical Switchyard in late September 2010.
The U.S. Department of Energy (DOE) established the Portsmouth/Paducah Project Office (PPPO) on October 1, 2003, to provide focused leadership to the Environmental Management missions at the Portsmouth, Ohio and Paducah, Kentucky Gaseous Diffusion Plants as well as the Depleted Uranium Hexafluoride (DUF6) conversion project.
The Lexington, Kentucky office opened in January 2004, and is located mid-way between the Kentucky and Ohio facilities. This centralized location facilitates the PPPO Manager’s frequent and routine site interactions at both the Portsmouth and Paducah Sites operations. Additionally, DOE maintains a strong presence at the sites on a daily basis through the Portsmouth and Paducah Operations Oversight Groups. The PPPO goal is to accelerate the site cleanup at the Portsmouth and Paducah Gaseous Diffusion Plants, eliminating potential environmental threats, reducing the DOE footprint at each of the sites, and reducing life-cycle cost.
The Portsmouth Gaseous Diffusion Plant (PORTS) is located in Pike County in southern central Ohio, approximately 20 miles north of the city of Portsmouth. PORTS was one of three large gaseous diffusion plants initially constructed to produce enriched uranium to support the nation's nuclear weapons program and later enriched uranium used by commercial nuclear reactors. The plant occupies about 1,200 acres of a 3,777-acre site.
Decades of uranium enrichment and support activities required the use of a number of typical and special industrial chemicals and materials. Plant operations generated hazardous, radioactive, mixed (both hazardous and radioactive), and nonchemical (sanitary) wastes. Past operations also resulted in soil, groundwater, and surface water contamination at several sites located within plant boundaries.
The extensive environmental cleanup program began in 1989 as a result of a Consent Decree signed between DOE and the state of Ohio and an Administrative Consent Order with DOE and the U.S. Environmental Protection Agency. Multiple missions are carried out at the site including decontamination and decommissioning (D&D) of inactive and unneeded facilities, environmental remediation and depleted uranium hexafluoride conversion (DUF6), as well as uranium enrichment activities through the American Centrifuge Technology Demonstration and Operations project, operated by Centrus Energy Corp. for UT-Battelle LLC, operator of DOE’s Oak Ridge National Laboratory (ORNL).
More than five decades of uranium enrichment operations at the former Portsmouth Gaseous Diffusion Plant generated millions of cubic yards of waste and resulted in soil, groundwater, and surface water contamination within the plant's boundary.
DOE and its D&D contractor, Fluor-B&W Portsmouth LLC, are performing environmental cleanup of the plant to remove contamination so the land can be used for new purposes by DOE or the community. Nearly 2,000 workers are part of this massive undertaking that will take decades to complete.
Three major projects encompass the majority of the site's cleanup mission:
- Environmental Remediation
DOE is performing cleanup of groundwater plumes contaminated primarily with the degreasing solvent trichloroethene (TCE), which was used during production years to clean process equipment used to enrich uranium. More than 680 million gallons of groundwater from four on-site plumes have been treated and are managed by pump and treat and slurry wall technology. A fifth plume is being treated by phytoremediation using planted hybrid poplar trees.
- Decontamination & Decommissioning
DOE is responsible for the decontamination and decommissioning (D&D) of 415 facilities and structures that supported uranium enrichment operations at the Portsmouth Gaseous Diffusion Plant for more than 50 years. More than 700,000 square feet of buildings, including 36 inactive facilities, have been demolished, eliminating contamination sources, improving worker safety, and reducing surveillance and maintenance costs.
The gaseous diffusion plant at Portsmouth includes three massive process buildings that house the gaseous diffusion process equipment and span an area the size of 158 football fields. The plant also includes various support structures that provide feed and transfer operations and site services such as maintenance, steam generation, cleaning, process heat removal, electrical power distribution, and water supply, storage and distribution.
- Waste Management
DOE manages the safe disposition of waste generated during the plant's uranium enrichment operations as well as building debris, contaminated soil, and other materials generated during the D&D and environmental cleanup. Approximately 581 million pounds of total waste have been shipped/disposed offsite to date.
The plant's waste streams include solid and liquid radioactive materials; hazardous wastes such as toxic, corrosive, reactive or ignitable materials; mixed waste, which contains both hazardous and radioactive components; and sanitary waste.
More than 37 million cubic feet of waste is expected to be generated from future D&D at the Portsmouth Site. Some of this waste may be disposed of in a proposed engineered, lined and monitored onsite disposal facility. As part of the D&D effort to date, about three-fourths of process gas equipment has been removed from one of the large process buildings that together cover nearly 100 acres. This waste is being shipped offsite to approved facilities.
The U.S. Department of Energy's Paducah Site consists of 3,556 acres in McCracken County in far western Kentucky. The reservation is part of a 16,126-acre tract assembled during World War II to build Kentucky Ordnance Works, a trinitrotoluene (TNT) facility. The Paducah Gaseous Diffusion Plant (PGDP), within about a 650-acre fenced security area, opened on the site in 1952. PGDP played a vital role in the production of enriched uranium during and after the Cold War until ceasing production for commercial reactor fuel purposes in 2013.
The Paducah Site has been on the National Priorities (“Superfund”) List since 1994. Strategic cleanup initiatives are broken into the areas of plant deactivation and groundwater, surface water, soils, burial grounds, and excess inactive facilities remediation. Cleanup of the site began in 1988, including remediation of groundwater, surface water, soil, burial grounds, and removal of inactive facilities. The initiatives include a series of prioritized response actions, ongoing site characterizations to support future response action decisions, and future decontamination and decommissioning of the gaseous diffusion plant. Every day, the EM organization works aggressively to improve the Paducah Site environment, understanding the safety and future of the site hinges on its accomplishments.
Paducah Deactivation Project
DOE resumed operation and regulatory control of the Paducah Gaseous Diffusion Plant (PGDP) and its more than 300 facilities from a commercial lease in 2014, and the PGDP Deactivation Project began under DOE's newest prime contractor, Fluor Federal Services, Inc. The scope of the current three-year deactivation contract includes optimizing the site’s utilities and infrastructure to support reduced operations and energy needs, facility surveillance and maintenance, deactivation, and waste management. Deactivation involves removing radioactive and hazardous materials from process equipment, shutting down facility systems, and de-energizing equipment in preparation for future decontamination and decommissioning (D&D). The electrical distribution system at the plant was designed and built to reliably supply large amounts of power for enrichment operations. Because that capacity is no longer needed, one project is focused on minimizing power costs by ensuring the electrical system is appropriately sized.
As part of the ongoing cleanup of the Paducah site’s leading source of groundwater contamination, DOE’s current Paducah remediation contractor, LATA Environmental Services of Kentucky LLC, used an electrical resistance heating system (ERH) to remove trichloroethene (TCE) from the top 60 feet of soil near an equipment cleaning building. Its regulatory objectives having been met, the treatment system is being taken out of commission after operating from July 2013 to October 2014. To date, DOE at Paducah has used ERH to remove nearly 3,600 gallons of TCE and related chemicals from the ground near the cleaning building. In 2015, EM is testing the effectiveness of using steam to remove TCE from 60 to 100 feet below ground in the same area.
Currently, a major source of onsite TCE groundwater contamination is being addressed through deep-soil mixing. LATA Kentucky is using an eight-foot-diameter auger to mix soil to a depth of about 60 feet in the cleanup zone located in the southwestern part of the site’s fenced area. Steam will be injected through the auger to remove TCE which will be recovered at the surface and captured in a treatment system. Following steam treatment, iron will be injected into the treatment area to degrade any residual TCE in the soil.
Pump and Treat
Pump and treat systems northwest and northeast of the fenced area of the site have treated about 3.3 billion gallons of contaminated groundwater since they began operating in 1995. Optimizing the existing pump and treat systems, which control the migration of off-site groundwater contamination, is expected to result in the continued dissipation of the contamination through 2020 and beyond.
Excess Facilities Removal
Thirty-two contaminated facilities were previously designated for removal and 31 of those have been removed. Demolition of the last inactive facility in the pre-shutdown cleanup scope will be completed in 2015. A total of more than 315,000 square feet will have been demolished by the end of 2015.
- C-340 Demolition
Removal of the C-340 Metals Plant, the first major uranium processing facility to undergo full-scale demolition at the site, was completed in February 2013. The 65,000-square-foot facility made uranium metal and operated from 1956 until the mid-1980s. Accelerated cleanup of radioactive contamination and hazardous materials under the American Recovery and Reinvestment Act (ARRA) allowed for removal of more than 100,000 cubic feet of systems waste. The Metals Plant was declared demolition-ready in early August 2011, avoiding $2.5 million in inflationary costs by being cleaned up five years ahead of schedule. The demolition phase involved removal of more than 2,000 heavy panels of cement-asbestos siding, disposition of PCB waste, and tearing down three major sections, one 120 feet high.
- C-410 Demolition
The C-410 Feed Plant, which operated from 1957 to 1977 to produce uranium hexafluoride (UF6) and fluorine, is slated to be finally cleaned up and razed to slab in 2015. In spring and summer 2014, heavy equipment was used to demolish nearly two-thirds of the Feed Plant. The section demolished in 2014 had a footprint roughly equivalent to a football field.
The Feed Plant originally spanned nearly 200,000 square feet and encompassed nine facilities. Cleanup was accelerated under ARRA and involved extensive recycling of copper bus bars and fluorine-generation cells. Final demolition was accelerated with the help of additional Congressional appropriations in 2014.
Physical construction of DOE’s depleted uranium hexafluoride conversion plants at Portsmouth and Paducah was completed in 2008. Approval to begin plant operations was granted to both sites in 2010. In December 2010, DOE awarded Babcock & Wilcox Conversion Services LLC a contract to operate the DUF6 conversion plants for five years.
More than 52,000 metric tons of DOE’s almost 800,000-metric-ton inventory of DUF6 has been converted to uranium oxide by the two plants to date. Aqueous hydrofluoric acid is a valuable co-product of the conversion process that is shipped offsite for commercial applications.
Other links that may help: