FOR IMMEDIATE RELEASE

March 16, 2010

USEC Takes Major Step in American Centrifuge Program

- Cascade of Production-Ready AC100 Machines Begins Operation -

BETHESDA, Md. - USEC Inc. (NYSE:USU) announced today a major step in the American Centrifuge program with the operation of a cascade of AC100 centrifuge machines in a commercial-plant configuration in Piketon, Ohio.  USEC refers to its production centrifuge machine design as the AC100 series centrifuge machine.

"This is an important step forward beyond our earlier prototype machines.  These are production machines built by our suppliers for the commercial American Centrifuge Plant," said USEC President and CEO John K. Welch.  "Operating these AC100 machines in commercial-plant configuration shows the progress we continue to make in deploying the American Centrifuge technology.

"We have invested more than $1.7 billion in this project to update the technology, to reestablish critical manufacturing infrastructure and to begin construction of the commercial plant.  This phase is one of the last steps necessary to demonstrate that the world's most advanced centrifuge technology is ready for commercial deployment.  It validates our supply chain for manufacturing of centrifuge machines and confirms that the technology is ready to transition for commercial operation.

"Lead Cascade operations are integral to our efforts to address DOE's requirements for a loan guarantee.  Our mission now will be to accumulate significant run-time on the cascade while we continue to manufacture and install a limited number of additional AC100 centrifuge machines as we keep our manufacturing base active and positioned for remobilization of the project."

The cascade is operating in a commercial plant configuration and at commercial plant assays.  USEC expects to operate the machines at commercial plant conditions obtaining data on machine-to-machine interactions, system performance and plant design.  The cascade is anticipated to run until a brief, scheduled outage in June required by our operating license issued by the Nuclear Regulatory Commission. 

Beginning in August 2007, USEC has operated prototype machines as part of a Lead Cascade test program that has provided valuable data on operational characteristics of the machines, aided in developing improvements to the design of the commercial production machines and given staff operational experience. The Company has operated centrifuges for more than 338,000 machine hours during the Lead Cascade testing program that includes both prototype machines and the AC100 series machines.

            For more information, visit USEC's new dedicated website for the American Centrifuge Project: http://www.americancentrifuge.com.

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

###

Contact:
Media: Elizabeth Stuckle (301) 564-3399
Investors: Steven Wingfield (301) 564-3354

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: risks related to the deployment of the American Centrifuge technology, including risks related to performance, cost, schedule and financing; our success in obtaining a loan guarantee for the American Centrifuge Plant, including our ability to address the technical and financial concerns raised by the U.S. Department of Energy ("DOE") and the impact of a potential loan guarantee award to a competitor; the impact of the demobilization of the American Centrifuge project and uncertainty regarding our ability to remobilize the project and the potential for termination of the project; our ability to meet milestones under the June 2002 DOE-USEC Agreement related to the deployment of the American Centrifuge technology; 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 (the "SEC"). Investors are urged to carefully review and consider the various disclosures made in our filings with the SEC, including our annual report on Form 10-K, that attempt to advise interested parties of the risks and factors that may affect our business.  We do not undertake to update our forward-looking statements to reflect events or circumstances that may arise after the date of such statements except as required by law.