FOR IMMEDIATE RELEASE
December 21, 2011

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USEC's Supply Agreement with TENEX Takes Effect
- U.S. and Russia complete final administrative arrangements -

          BETHESDA, Md. - The supply agreement signed in March between JSC "Techsnabexport" (TENEX) and United States Enrichment Corporation, a wholly owned subsidiary of USEC Inc. (NYSE:USU), took effect today. The supply agreement is a multi-year contract for the supply of low enriched uranium (LEU) beginning in 2013 that will build on USEC's long-term relationship with TENEX.

          "We are excited to continue our fruitful relationship with TENEX, which has been built on the foundation of the successful Megatons to MegawattsT program," said Phil Sewell, USEC senior vice president of American Centrifuge and Russian HEU. "This supply agreement will be a key component to helping us continue to meet our customers' needs. We appreciate the work and support of the U.S. government to complete the administrative arrangements under the U.S. - Russia nuclear cooperation agreement that now allows this commercial contract to move ahead."

          Under the terms of its agreement with TENEX, the supply of LEU to USEC will begin in 2013 and ramp up until it reaches a level in 2015 that is approximately one-half the level currently supplied by TENEX to USEC under the Megatons to Megawatts program with the mutual option to increase the quantities up to the same level as that program. The Megatons to Megawatts program is scheduled to expire at the end of 2013.. Unlike the Megatons to Megawatts program, the quantities supplied under the new contract will come from Russia's commercial enrichment activities rather than from downblending of excess Russian weapons material.

           Deliveries under the agreement are expected to continue through 2022. USEC will purchase the separative work units (SWU) contained in the LEU and deliver natural uranium to TENEX for the LEU's uranium component. The pricing terms for SWU under the agreement are proprietary but are based on a mix of market-related price points and other factors.

          Effectiveness of the agreement occurred following an exchange of notices between TENEX and USEC that the administrative arrangements under the U..S.-Russia nuclear cooperation agreement have been completed. These administrative arrangements, among other things, provide the framework for the return to Russia of natural uranium delivered by USEC to TENEX under the supply agreements.

          The supply agreement assures USEC continued access to an important part of its existing supply mix. USEC continues to work towards the deployment of the American Centrifuge Plant in Piketon, Ohio. As it does, the Company is also continuing to review structuring options and strategic alternatives in evaluating the best path forward to realize long-term shareholder value. In that context, USEC and TENEX have agreed to conduct a feasibility study to explore the possible deployment of an enrichment plant in the United States employing Russian centrifuge technology. Any decision to proceed with such a project would depend on the results of the feasibility study and would be subject to further agreement between the parties and their respective governments.

          The Megatons to Megawatts program is a unique, commercially financed government-industry partnership in which bomb-grade uranium from dismantled Russian nuclear warheads is being recycled into LEU used to produce fuel for American nuclear power plants. USEC, as executive agent for the U.S. government, and TENEX, acting for the Russian government, implement this 20-year, $8 billion program at no cost to taxpayers. This program is on track to complete the downblending of the equivalent of 20,000 nuclear warheads into commercial nuclear fuel by the program's conclusion at the end of 2013.

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

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Forward-Looking Statements
          This news release contains "forward-looking statements" - 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: limitations on our ability to import the Russian LEU we buy under the new supply contract into the United States and other countries; uncertainty regarding the results of the feasibility study to be conducted regarding the possible deployment of an enrichment plant in the United States employing Russian centrifuge technology; risks related to the deployment of the American Centrifuge technology, including risks related to performance, cost, schedule and financing; the outcome of ongoing discussions with the U.S. Department of Energy ("DOE") regarding a potential research, development and demonstration ("RD&D") program for the American Centrifuge project, including uncertainty regarding the timing, amount and availability of funding for such RD&D program and the dependency of government funding on Congressional appropriations and the potential for us to make a decision at any time to further reduce spending and demobilize the project based on the timing and likelihood of an agreement with DOE and any government funding; the economics of extended Paducah plant operations beyond May 2012, including our ability to negotiate an acceptable power arrangement, our ability to obtain a contract to enrich DOE's depleted uranium and sufficient market demand for the remaining output; the competitive environment for our products and services; 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.

Contact:
Media: Paul Jacobson (301) 564-3399
Investors: Steve Wingfield (301) 564-3354