Question: The Portsmouth Gaseous Diffusion Plant is located in a town that was originally called what?

Context paragraphs:
596 (nuclear test): 596, originally named by the US intelligence agencies Chic-1, is the codename of the People's Republic of China's first nuclear weapons test, detonated on October 16, 1964, at the Lop Nur test site.  It was a uranium-235 implosion fission device made from weapons-grade uranium (U-235) enriched in a gaseous diffusion plant in Lanzhou.  The bomb had a yield of 22 kilotons, comparable to the Soviet Union's first nuclear bomb RDS-1 in 1949 and the American Fat Man bomb dropped on Nagasaki, Japan in 1945.  With the test, China became the fifth nuclear power.  This was the first of 45 total nuclear tests China has conducted to date, all of which occurred at the Lop Nur test site.

Piketon, Ohio: Piketon is a village in Pike County, Ohio, United States, along the Scioto River.  The village is best known for the uranium enrichment plant located there (one of only three such plants in the United States).  The population was 2,181 at the 2010 census.  Originally called Jefferson, it was the county seat of Pike County 1815–1845, when James Emmitt, a wealthy local entrepreneur, influenced removal of the county seat to Waverly, due to its closer proximity to the then new Ohio & Erie Canal.  Piketon is the location of the Pike County Fairgrounds and is served by the Scioto Valley School District.

Paducah Gaseous Diffusion Plant: The Paducah Gaseous Diffusion Plant (PGDP) is a facility located in McCracken County, Kentucky, near Paducah, Kentucky that produced enriched uranium 1952–2013.  It is owned by the U.S. Department of Energy (DOE).  The PGDP was the only operating uranium enrichment facility in the United States in the period 2001–2010.  The Paducah plant produced low-enriched uranium, originally as feedstock for military reactors, weapons and later for nuclear power fuel.

Eurodif: Eurodif, which means "European Gaseous Diffusion Uranium Enrichment Consortium", is a subsidiary of the French company AREVA, which operates a uranium enrichment plant established at the Tricastin Nuclear Power Center in Pierrelatte in Drôme.  The nuclear site of Pierrelatte includes many nuclear installations, of which the largest are the Eurodif fuel factory and the Tricastin nuclear power station.

Eugene T. Booth: Eugene Theodore Booth, Jr. (28 September 1912 – 6 March 2004) was an American nuclear physicist.  He was a member of the historic Columbia University team which made the first demonstration of nuclear fission in the United States.  During the Manhattan Project, he worked on gaseous diffusion for isotope separation.  He was the director of the design, construction, and operation project for the 385-Mev synchrocyclotron at the Nevis Laboratories, the scientific director of the SCALANT Research Center, and dean of graduate studies at Stevens Institute of Technology.Booth was the scientific director of the SCALANT Research Center, in Italy.

Happy Valley, Oak Ridge, Tennessee: Happy Valley was a construction camp of trailer homes and hutments at the Clinton Engineer Works of the Manhattan Project in the 1940s.  It was located near the K-25 gaseous diffusion plant in Oak Ridge, Tennessee, to lessen travelling time for the seventeen thousand construction men working there.

Kellex Corporation: The Kellex Corporation was a wholly owned subsidiary of M. W. Kellogg Company.  Kellex was formed in 1942 so that Kellogg's operations relating to the Manhattan Project could be kept separate and secret.  "Kell" stood for "Kellogg" and "X" for secret.  The new company's goal was to design a facility for the production of enriched uranium through gaseous diffusion.  In gaseous diffusion, isotopes of Uranium-235 could be separated from Uranium-238 by turning uranium metal into uranium hexafluoride gas and straining it through a barrier material.

K-25: K-25 was the codename given by the Manhattan Project during World War II for the project to produce enriched uranium for atomic bombs using the gaseous diffusion method.  Originally the codename for the product, over time it came to refer to the project, the production facility located at the Clinton Engineer Works in Oak Ridge, Tennessee, the main gaseous diffusion building, and ultimately the site.  When it was built in 1944, the four-story K-25 gaseous diffusion plant was the world's largest building, with over 1640000 sqft of floor space and a volume of 97500000 cuft .

Gaseous diffusion: Gaseous diffusion is a technology used to produce enriched uranium by forcing gaseous uranium hexafluoride (UF) through semipermeable membranes.  This produces a slight separation between the molecules containing uranium-235 (U) and uranium-238 (U).  By use of a large cascade of many stages, high separations can be achieved.  It was the first process to be developed that was capable of producing enriched uranium in industrially useful quantities.

Portsmouth Gaseous Diffusion Plant: The Portsmouth Gaseous Diffusion Plant is a facility located in Scioto Township, Pike County, Ohio, just south of Piketon, Ohio that previously produced enriched uranium, including weapons-grade uranium, for the United States Atomic Energy program and U.S. nuclear weapons program.  The plant is in shutdown status and is in preparation for decontamination and decommissioning (D&D), with some facilities overseen by the United States Enrichment Corporation, a subsidiary of USEC Incorporated, a publicly traded corporation (NYSE: USU).  The D&D work on the older facilities to prepare the site for future use is expected to continue through 2024 and is being conducted by Fluor-B&W Portsmouth LLC.

Supporting paragraphs: Piketon, Ohio Portsmouth Gaseous Diffusion Plant
Answer: Jefferson