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The American Centrifuge Demonstration Facility at the Piketon, Ohio, site is located in a portion of an existing process building that is ultimately expected to house the American Centrifuge Plant.
In August 2007, USEC began the Lead Cascade test program at the facility, an integrated testing phase of the American Centrifuge technology involving multiple machines in a cascade configuration.
The license issued by the U.S. Nuclear Regulatory Commission for the demonstration facility specifies that the machines be operated in a closed-loop configuration where the uranium gas is enriched, depleted and recombined in a repetitive cycle. The demonstration facility license permits test samples of enriched uranium to be withdrawn through a mass spectrometer. The ability to separate uranium isotopes is tested by analyzing these samples.
In a centrifuge enrichment facility, a cascade is a group of centrifuge machines connected in a series and parallel arrangement to achieve an intended isotope separation capability. A commercial uranium enrichment facility that uses gas centrifuge technology is made up of multiple cascades.
The number and arrangement of centrifuge machines in a cascade can vary. The cascades tested during the Lead Cascade test program consist of fewer machines than would ultimately be in a commercial cascade. Initiating the Lead Cascade test program marked another important step in the deployment of the American Centrifuge Plant.
USEC has achieved a number of key objectives through the Lead Cascade test program, including:
USEC continues its Lead Cascade test program in Piketon. USEC has operated centrifuges as part of its Lead Cascade test program for more than 480,000 machine hours. Data from this testing program has provided valuable assembly, operating and maintenance information, as well as operations experience for the American Centrifuge staff. The remaining machines in a cascade of prototype centrifuge machines that had operated since August 2007 were taken out of service in April 2010 at the completion of the initial Lead Cascade testing program.
The initial design for the AC100 machine reflects improvements learned during individual machine testing and integrated cascade testing of the prototype machine.
During 2008, USEC released the initial AC100 machine design to its strategic suppliers in preparation for installing a test cascade of AC100 series machines in Piketon. During 2009, the strategic suppliers manufactured parts for a test cascade of the initial AC100 series machines, replicating on a commercial basis manufacturing that USEC previously self-performed in building the prototype machines.
In March 2010, USEC began operation of its AC100 Lead Cascade in Piketon. Approximately two dozen AC100 machines have been operating in a cascade in a commercial plant configuration. This is an important accomplishment in the Company’s efforts to respond to DOE’s technical concerns. These are production machines primarily built by USEC’s suppliers, and the cascade’s operation highlights the continued progress USEC is making. The cascade has been operating successfully, and USEC’s objective is to accumulate significant cascade run-time while it continues to manufacture and install additional centrifuge machines.
USEC’s centrifuge manufacturing suppliers assembled approximately 20 additional machines earlier this year that the Company has operated individually. During the third quarter USEC has reconfigured the AC100 cascade to introduce these additional machines, thus creating a cascade with more than 40 AC100 machines. USEC’s suppliers are continuing to build and assemble additional AC100 machines, which will increase the total number of machine hours of AC100 centrifuge operation.
During the second quarter, USEC took the initial cascade of prototype machines that had been operating since August 2007 off-line. USEC staff disassembled and examined components from some of those prototype machines as an element of the Company’s deterministic approach to assuring reliability of the AC100 centrifuges. The machine positions in the demonstration area used for the initial cascade have been refurbished with upgraded control systems and instrumentation in preparation for installation of 25 AC100 machines during 2010. These additional machines will run individually to provide additional data and to accumulate additional operating hours. By the end of 2010, USEC expects to have roughly 65 AC100 machines in operation. This activity maintains USEC’s supplier base and demonstrates the capability to manufacture production-ready centrifuge machines within its design specifications.
Although this cascade is operating in a closed-loop configuration, where the enriched and depleted streams are recombined after going through the cascade, the flow of uranium feed and tails between individual machines in the cascade is similar to those expected in commercial plant operations. This cascade is intended to provide additional data on equipment operation and reliability that could identify opportunities to further optimize the centrifuge and cascade design.