American Centrifuge Achieves Two RD&D Program Milestones

USEC Inc.’s (NYSE:USU) American Centrifuge uranium enrichment technology recently achieved two important technical milestones under its research, development and demonstration (RD&D) program with the Department of Energy (DOE). The DOE certified completion of two key tests. To date, four milestones have been achieved and five remain. In addition, with the final installation of 120 AC100 centrifuges in a commercial cascade in January 2013, the program has met three of five non-binding performance indicators.

“Our team continues to work closely with the Department of Energy to demonstrate the technical readiness of the American Centrifuge technology to meet national security needs and its readiness for commercial deployment,” said Paul Sullivan, vice president of American Centrifuge and chief engineer. “We have made significant progress and remain on course to complete the program on schedule and within budget.”

The RD&D program comprises nine technical milestones, including four that were added in March related to specific requirements associated with a supplemental test program developed by DOE. In addition, the cooperative agreement contains five non-binding performance indicators that are designed to be achieved throughout the RD&D program and ensure that the program is on track to achieve the milestones and other program objectives.

USEC recently achieved milestones relating to the completion of testing on extended feed rate range and testing machine performance parameters. Both tests demonstrated advanced design features and robustness of the centrifuges to adverse operating conditions. In addition, by manufacturing the 120 AC100 centrifuges required for the demonstration cascade, the program has met the third performance indicator. To date, the program has completed four milestones and is on track to achieve the final remaining milestones by the end of the year.

Background

USEC and DOE are executing a $350 million cooperative cost-shared RD&D program to confirm the technical readiness of the American Centrifuge technology, the next-generation U.S. uranium enrichment technology. The program is within budget and on schedule to be completed in December 2013.

The RD&D program supports building, installing, operating, and testing commercial plant support systems and a 120-machine cascade that would be incorporated in the full commercial plant of 96 identical cascades in Piketon, Ohio.

The cooperative agreement between USEC and DOE defines the scope, funding and technical goals for the program. The total investment in the program will be up to $350 million, with DOE providing 80 percent, and USEC providing 20 percent of the total. The RD&D program is currently funded through June 15, 2013. The recently enacted FY2013 continuing appropriations resolution included additional funding for continued work on the RD&D program at an annual rate of $110 million, which is expected to fund the RD&D program through September 30, 2013. The Company will continue to work with Congress and the administration to fund the balance of the RD&D program through December 2013 to achieve the remaining program milestones.

An informational video on the RD&D program can be accessed at http://www.usec.com/video/american-centrifuge-investing-americas-energy-future. You can also view photographs of the full 120-machine demonstration cascade at http://www.usec.com/media/photo-gallery.

USEC Inc., a global energy company, is a leading supplier of enriched uranium fuel for commercial nuclear power plants.

Forward Looking Statements

This news release contains “forward-looking statements” within the meaning of Section 21E of the Securities Exchange Act of 1934 – that is, statements related to future events. In this context, forward-looking statements may address our expected future business and financial performance, and often contain words such as “expects”, “anticipates”, “intends”, “plans”, “believes”, “will” and other words of similar meaning. Forward-looking statements by their nature address matters that are, to different degrees, uncertain. For USEC, particular risks and uncertainties that could cause our actual future results to differ materially from those expressed in our forward-looking statements include, but are not limited to: uncertainty regarding the timing, amount and availability of additional funding for the RD&D program and the dependency of government funding on Congressional appropriations; restrictions in our credit facility on our spending on the American Centrifuge project and the potential for us to demobilize the project; limitations on our ability to provide any required cost sharing under the RD&D program; uncertainty concerning our ability through the RD&D program to demonstrate the technical and financial readiness of the centrifuge technology for commercialization; uncertainty concerning the ultimate success of our efforts to obtain a DOE loan guarantee and other financing for the American Centrifuge project and the timing and terms thereof; potential changes in our anticipated ownership of or role in the American Centrifuge project, including as a result of the need to raise additional capital to finance the project; the impact of actions we have taken or may take to reduce spending on the American Centrifuge project, including the potential loss of key suppliers and employees, and impacts to cost and schedule; the impact of delays in the American Centrifuge project and uncertainty regarding our ability to remobilize the project; changes in U.S. government priorities and the availability of government funding, including loan guarantees; and other risks and uncertainties discussed in our filings with the Securities and Exchange Commission, including our annual report on Form 10-K and quarterly reports on form 10-Q, which are available on our website at www.usec.com. We do not undertake to update our forward-looking statements except as required by law.