The Portsmouth Gaseous Diffusion Plant is located in south central Ohio, approximately 32 kilometers (20 miles) north of Portsmouth, Ohio, and 112 kilometers (70 miles) south of Columbus, Ohio. The site is situated on a 1,483-hectare (3,708-acre) federal reservation approximately 6.5 kilometers (4 miles) south of the Village of Piketon.

The plant, which employs about 2,000 people, has a fenced area of about 640 acres, 93 of which contain process buildings under roof that include about 2,100 enrichment stages. The plant has a design capacity of 7.4 million SWU per year. The Portsmouth plant enriches product shipped from the Paducah plant to meet customer requirements and manages the delivery of low enriched uranium to customers worldwide.

In August 1952, the AEC selected a tract of land in the Ohio Valley along the Scioto River in Pike County for the site of the Portsmouth Gaseous Diffusion Plant. Site selection was based on the availability of a vast expanse of relatively flat terrain -- the original tract was 4,000 acres -- as well as availability of large amounts of electrical power, a dependable source of water, local labor and suitable transportation routes.

In March 1956, the more than $1.2 billion plant was completed six months ahead of schedule by Peter Kiewett Sons of Nebraska, the construction contractor, at a cost of $750 million, or more than $460 million less than the estimated construction cost. Construction required 69 million man-hours, more than 68,000 drawings and as many as 22,500 construction workers at its peak in the summer of 1954. More than 1,200 acres were cleared and more than 4.5 million cubic yards of earth were moved.

In the 1960s, the Portsmouth plant's mission changed from enriching uranium for nuclear weapons to a more commercial focus. Today, the USEC facilities in Paducah, Kentucky, and Portsmouth, Ohio, work in tandem to enrich uranium for fuel in commercial nuclear power plants. The Paducah Gaseous Diffusion Plant enriches uranium up to 2.75 percent and then ships it to Portsmouth for further enrichment to five percent.

Construction of the Portsmouth Gaseous Diffusion Plant began in late 1952 to expand the Federal Government's gaseous diffusion program already in place at Oak Ridge, Tennessee and Paducah, Kentucky. The facility was built to increase the production of enriched uranium at rates substantially above the other two facilities because highly-enriched uranium was required for use in nuclear submarine reactors, and low-enriched uranium was needed for commercial nuclear power plants. The first process cell went online in September 1954. A gas centrifuge uranium enrichment program was initiated in the early 1980s at Portsmouth. However, full operation was never implemented for the centrifuge process.

The cleaning and change out of process equipment at the site generated spent solvents and other contaminants that were disposed of in on site landfills and surface impoundments. Contamination has also been found in process buildings, cooling towers, burial grounds and waste water ponds. Although the plant is now leased and operated by U. S. Enrichment Corporation, environmental restoration and related waste management activities associated with past practices will be conducted by the Department of Energy. However, under the provisions of the lease, future plant shut down and cleanup activities will be the responsibility of U.S. Enrichment Corporation.

PORTSMOUTH GASEOUS DIFFUSION PLANT TIMELINE

	Delivery of slightly enriched uranium The Paducah Tiger rail cars deliver slightly enriched uranium hexafluoride from the Paducah Gaseous Diffusion Plant in Kentucky to the Portsmouth Plant's Feed Vaporization and Sampling Facility.
	Production feed cylinder A Paducah product feed cylinder is shown being loaded into Autoclave No. 2 of the Feed Vaporization & Sampling Facility. Cylinders are weighed and selectively sampled for purity and adherence to specifications.
	Cascade Feed enters the Portsmouth Cascade in a Process Building.
	Process cell This is one of the process cells used to enrich uranium at the Portsmouth Plant. The large tanks are called converters. Each cell has eight stages; consisting of one converter, one motor and one compressor. Uranium gas passes through the converter and is separated into U-235 and U-238. The enriched gas stream moves up the cascade to the next stage from the pressure generated by a large compressor driven by a 3,300 horsepower motor. The depleted stream moves down to a lower stage through a similar compressor and motor.
	Process building Enriched product flows through piping between process buildings. The process equipment shown on the previous tour stops is located in these buildings.
	Transformers In the Switchyard, 16 transformers rated between 90 and 176 Megavolt Amperes, transform 345Kilovolts to 13.8 Kilovolts. A three-phase 345Kilovolt gas circuit breaker is pictured in the foreground.
	Withdrawing the product Product is withdrawn from the cascade in 10-ton USEC-owned cylinders, heated to a liquid state, sampled to ensure product meets all customer specifications, and then transferred into 2.5 ton customer-owned cylinders.
	Withdrawal of depleted stream Depleted uranium is withdrawn from the bottom of the cascade into 48-inch diameter cylinders shown here on scales. Each cylinder contains 14 tons of UF-6.
	Product preparation shipping facility In the Product Preparation Shipping Facility, approximately 1,800 customer cylinders are filled each year with the desired product assay. All cylinders are weighed on the accurate scale located inside to account for all material processed through this facility.
	Steam Plant The Steam Plant provides steam for the enrichment process, heating auxillary buildings, and other purposes. Steam is generated by combinations of three coal-fired boilers.
	Cylinder Stacker This cylinder stacker is used to stack 14-ton cylinders of depleted UF6 in the storage yards.
	Plant control facility All cascade operations and other enrichment activities are monitored from the Plant Control Facility, which has emergency shutdown capability for the process equipment.
	Control room instrumentation Upper-level instrumentation of the Control Room provides monitoring and control instrumentation for portions of the process buildings. Bottom-level instrumentation provides power operations monitoring and control of the switchyards.
	Indoor firing range The Portsmouth site's security program consists of a variety of responsibilities. The indoor firing range is used by protective force personnel to can train and test their skills.
	Fire Station The fire station was built in 1979. The building was occupied in 1984 to cover all plant operations 24 hours a day, 7 days a week. The staff includes firefighters, shift fire captains, shift training officers, operations officer, fire protection engineers, a chief, and a secretary. Part of their assignment is to maintain all fire suppression systems on plantsite, which include approximately 280 fire hydrants, 460 sprinkler systems, and 4,800 portable fire extinguishers of different types. They also provide medical treatment when the plant medical treatment facility is not staffed on weekends and holidays. The fire department has mutual aid agreements with local fire departments and emergency response groups in Pike County and with Valley Township in Scioto County.