----

----

| ý | QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15 (d) OF THE SECURITIES EXCHANGE ACT OF 1934 |
|--------|------------------------------------------------------------------------------------------|

| o | TRANSITION REPORT PURSUANT TO SECTION 13 OR 15 (d) OF THE SECURITIES EXCHANGE ACT OF 1934 |
|---|-------------------------------------------------------------------------------------------|

| Delaware                 | 52-2107911                           |
|--------------------------|--------------------------------------|
| (State of incorporation) | (I.R.S. Employer Identification No.) |

| Large accelerated filer | ý |   | Accelerated filer         | o |
|-------------------------|--------|--------|---------------------------|---|
| Non-accelerated filer   | o      |   | Smaller reporting company | o |

----

----

----

|          |                                                                                                           | Page   |
|---------------|----------------------------------------------------------------------------------------------------------------|--------|
|          | PART I – FINANCIAL INFORMATION                                                                           |   |
|          |                                                                                                           |
| Item 1.       | Financial Statements:                                                                                          |   |
|          | Consolidated Condensed Balance Sheets at March 31, 2010 and December 31, 2009 (Unaudited)                      | 3      |
|          | Consolidated Condensed Statements of Operations for the Three Months Ended March 31, 2010 and 2009 (Unaudited) | 4      |
|          | Consolidated Condensed Statements of Cash Flows for the Three Months Ended March 31, 2010 and 2009 (Unaudited) | 5      |
|          | Notes to Consolidated Condensed Financial Statements (Unaudited)                                               | 6      |
| Item 2.       | Management's Discussion and Analysis of Financial Condition and Results of Operations                          | 14     |
| Item 3.       | Quantitative and Qualitative Disclosures about Market Risk                                                     | 33     |
| Item 4.       | Controls and Procedures                                                                                        | 33     |
|          | PART II – OTHER INFORMATION                                                                              |   |
|          |                                                                                                           |
| Item 1.       | Legal Proceedings                                                                                              | 34     |
| Item 1A.      | Risk Factors                                                                                                   | 34     |
| Item 2.       | Unregistered Sales of Equity Securities and Use of Proceeds                                                    | 34     |
| Item 6.       | Exhibits                                                                                                       | 35     |
| Signature     | 36                                                                                                             |
| Exhibit Index | 37                                                                                                             |

----

USEC

|                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |   | March 31,2010 |    |   | December 31,2009 |   |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--------|---------------|---------|--------|------------------|--------|
| ASSETS                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |   |          |    |   |             |   |
| Current Assets                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |   |          |    |   |             |   |
| Cash and cash equivalents                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |   | $             | 32.5    |   |             | $      | 131.3 |   |
| Accounts receivable, net                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |   |          | 189.0   |   |             |   | 191.4 |   |
| Inventories                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |   |          | 1,282.7 |   |             |   | 1,301.2 |   |
| Deferred income taxes                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |   |          | 43.4    |   |             |   | 48.6 |   |
| Other current assets                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |   |          | 343.4   |   |             |   | 297.1 |   |
| Total Current Assets                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |   |          | 1,891.0 |   |             |   | 1,969.6 |   |
| Property, Plant and Equipment, net                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |   |          | 1,143.7 |   |             |   | 1,115.1 |   |
| Other Long-Term Assets                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |   |          |    |   |             |   |   |   |
| Deferred income taxes                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |   |          | 265.5   |   |             |   | 270.3 |   |
| Deposits for surety bonds                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |   |          | 155.3   |   |             |   | 158.3 |   |
| Deferred financing costs, net                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |   |          | 11.6    |   |             |   | 12.0 |   |
| Goodwill                                                                                                                                                                                                                                                                                                                                                                                                                                     |   |          | 6.8     |   |             |   | 6.8 |   |
| Total Other Long-Term Assets                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |   |          | 439.2   |   |             |   | 447.4 |   |
| Total Assets                                                                                                      |   | $             | 3,473.9 |   |             | $      | 3,532.1 |   |
|                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |   |          |    |   |             |   |   |   |
| LIABILITIES AND STOCKHOLDERS’ EQUITY                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |   |          |    |   |             |   |   |   |
| Current Liabilities                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |   |          |    |   |             |   |   |   |
| Accounts payable and accrued liabilities                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |   | $             | 131.6   |   |             | $      | 153.4 |   |
| Payables under Russian Contract                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |   |          | -       |   |             |   | 134.8 |   |
| Inventories owed to customers and suppliers                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |   |          | 525.1   |   |             |   | 469.4 |   |
| Deferred revenue and advances from customers                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |   |          | 416.9   |   |             |   | 325.0 |   |
| Total Current Liabilities                                                                                                                                                                                                                                                                                                                                                                                                                                   |   |          | 1,073.6 |   |             |   | 1,082.6 |   |
| Long-Term Debt                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |   |          | 575.0   |   |             |   | 575.0 |   |
| Other Long-Term Liabilities                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |   |          |    |   |             |   |   |   |
| Depleted uranium disposition                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |   |          | 108.8   |   |             |   | 155.6 |   |
| Postretirement health and life benefit obligations                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |   |          | 170.5   |   |             |   | 168.9 |   |
| Pension benefit liabilities                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |   |          | 178.5   |   |             |   | 176.6 |   |
| Other liabilities                                                                                                                                                                                                                                                                                                                                                                                                                                                               |   |          | 98.3    |   |             |   | 97.8 |   |
| Total Other Long-Term Liabilities                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |   |          | 556.1   |   |             |   | 598.9 |   |
| Commitments and Contingencies (Note 10)                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |   |          |    |   |             |   |   |   |
| Stockholders’ Equity                                                                                                                                                                                                                                                                                                                                                            |   |          | 1,269.2 |   |             |   | 1,275.6 |   |
| Total Liabilities and Stockholders’ Equity                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |   | $             | 3,473.9 |   |             | $      | 3,532.1 |   |

----

USEC

|                                           |   | Three Months EndedMarch 31, |   |
|------------------------------------------------|--------|-----------------------------|--------|
|                                           |   | 2010                        |   |   | 2009 |   |
| Revenue:                                       |   |                        |   |   |   |   |
| Separative work units                          |   | $                           | 266.6  |   |   | $ | 427.9 |   |
| Uranium                                        |   |                        | 15.6   |   |   |   | 28.6 |   |
| U.S. government contracts and other            |   |                        | 62.5   |   |   |   | 49.1 |   |
| Total revenue                                  |   |                        | 344.7  |   |   |   | 505.6 |   |
| Cost of sales:                                 |   |                        |   |   |   |   |   |   |
| Separative work units and uranium              |   |                        | 267.2  |   |   |   | 414.9 |   |
| U.S. government contracts and other            |   |                        | 50.8   |   |   |   | 48.5 |   |
| Total cost of sales                            |   |                        | 318.0  |   |   |   | 463.4 |   |
| Gross profit                                   |   |                        | 26.7   |   |   |   | 42.2 |   |
| Advanced technology costs                      |   |                        | 25.7   |   |   |   | 31.4 |   |
| Selling, general and administrative            |   |                        | 15.1   |   |   |   | 14.5 |   |
| Other (income)                                 |   |                        | (9.7   | ) |   |   | - |   |
| Operating (loss)                               |   |                        | (4.4   | ) |   |   | (3.7 | ) |
| Interest expense                               |   |                        | -      |   |   |   | 0.5 |   |
| Interest (income)                              |   |                        | (0.1   | ) |   |   | (0.6 | ) |
| (Loss) before income taxes                     |   |                        | (4.3   | ) |   |   | (3.6 | ) |
| Provision (benefit) for income taxes           |   |                        | 5.4    |   |   |   | (1.5 | ) |
| Net (loss)                                     |   | $                           | (9.7   | ) |   | $ | (2.1 | ) |
| Net (loss) per share – basic             |   | $                           | (.09   | ) |   | $ | (.02 | ) |
| Net (loss) per share – diluted           |   | $                           | (.09   | ) |   | $ | (.02 | ) |
| Weighted-average number of shares outstanding: |   |                        |   |   |   |   |   |   |
| Basic                                          |   |                        | 111.7  |   |   |   | 110.7 |   |
| Diluted                                        |   |                        | 111.7  |   |   |   | 110.7 |   |

----

USEC

|                                                                                                                                     |   | Three Months EndedMarch 31, |   |
|------------------------------------------------------------------------------------------------------------------------------------------|--------|-----------------------------|--------|
|                                                                                                                                     |   | 2010                        |   |   | 2009 |   |
| Cash Flows from Operating Activities                                                                                                     |   |                        |   |   |   |   |
| Net (loss)                      |   | $                           | (9.7   | ) |   | $ | (2.1 | ) |
| Adjustments to reconcile net (loss) to net cash provided by (used in)operating activities:                                               |   |                        |   |   |   |   |   |   |
| Depreciation and amortization                                                     |   |                        | 9.7    |   |   |   | 7.1 |   |
| Deferred income taxes                                                                                 |   |                        | 9.0    |   |   |   | (3.2 | ) |
| Other non-cash income on release of disposal obligation                                                                   |   |                        | (9.7   | ) |   |   | - |   |
| Changes in operating assets and liabilities:                                                                                             |   |                        |   |   |   |   |   |   |
| Accounts receivable – (increase) decrease                                                                                |   |                        | 2.4    |   |   |   | (105.3 | ) |
| Inventories – (increase) decrease                                                                                        |   |                        | 74.2   |   |   |   | 237.9 |   |
| Payables under Russian Contract – (decrease)                                                                        |   |                        | (134.8 | ) |   |   | (121.5 | ) |
| Deferred revenue, net of deferred costs – increase                                                                       |   |                        | 62.6   |   |   |   | 15.4 |   |
| Accrued depleted uranium disposition                                                   |   |                        | (46.8  | ) |   |   | 6.6 |   |
| Accounts payable and other liabilities – (decrease)                                                                      |   |                        | (11.7  | ) |   |   | (21.8 | ) |
| Other, net                                                                                                      |   |                        | 11.9   |   |   |   | 10.7 |   |
| Net Cash Provided by (Used in) Operating Activities                                                                            |   |                        | (42.9  | ) |   |   | 23.8 |   |
|                                                                                                                                     |   |                        |   |   |   |   |   |   |
| Cash Flows Used in Investing Activities                                                                                                  |   |                        |   |   |   |   |   |   |
| Capital expenditures                                                                                                           |   |                        | (49.0  | ) |   |   | (117.1 | ) |
| Deposits for surety bonds – decrease (increase)                                                                     |   |                        | 3.0    |   |   |   | (20.6 | ) |
| Net Cash (Used in) Investing Activities                                                                                             |   |                        | (46.0  | ) |   |   | (137.7 | ) |
|                                                                                                                                     |   |                        |   |   |   |   |   |   |
| Cash Flows Used in Financing Activities                                                                                                  |   |                        |   |   |   |   |   |   |
| Repayment and repurchases of senior notes                                                                                      |   |                        | -      |   |   |   | (95.7 | ) |
| Payments for deferred financing costs                                                                                               |   |                        | (7.5   | ) |   |   | - |   |
| Tax benefit related to stock-based compensation                                                                 |   |                        | 0.3    |   |   |   | - |   |
| Common stock issued (purchased), net                                                                                      |   |                        | (2.7   | ) |   |   | (1.0 | ) |
| Net Cash (Used in) Financing Activities                                                                                             |   |                        | (9.9   | ) |   |   | (96.7 | ) |
| Net (Decrease)                                                                                                                 |   |                        | (98.8  | ) |   |   | (210.6 | ) |
| Cash and Cash Equivalents at Beginning of Period                                                                               |   |                        | 131.3  |   |   |   | 248.5 |   |
| Cash and Cash Equivalents at End of Period                                                                                     |   | $                           | 32.5   |   |   | $ | 37.9 |   |
| Supplemental Cash Flow Information:                                                                                                      |   |                        |   |   |   |   |   |   |
| Interest paid, net of amount capitalized                                                                        |   | $                           | -      |   |   | $ | 1.8 |   |
| Income taxes paid                                                                                          |   |                        | 14.7   |   |   |   | 2.2 |   |

----

USEC

| 1.   | BASIS OF PRESENTATION |
|----------------|-----------------------|

|                                                                                                                                                                                                                                                                                                                                                                                                                                                             |   | March 31,2010 |    |   | December 31,2009 |   |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--------|---------------|---------|--------|------------------|--------|
|                                                                                                                                                                                                                                                                                                                                                                                                                                                             |   | (millions)    |    |
| Current assets:                                                                                                                                                                                                                                                                                                                                                                                                                                                  |   |          |    |   |             |   |
| Separative work units                                                                                                                                                                                                                                                                                                                                                                           |   | $             | 770.0   |   |             | $      | 805.1 |   |
| Uranium                                                                                                                                                                                                                                                                                                                                  |   |          | 499.3   |   |             |   | 482.1 |   |
| Materials and supplies                                                                                                                                                                                                                                                                                                                                                      |   |          | 13.4    |   |             |   | 14.0 |   |
|                                                                                                                                                                                                                                                                                                                                                                                                                                                             |   |          | 1,282.7 |   |             |   | 1,301.2 |   |
| Current liabilities:                                                                                                                                                                                                                                                                                                                                                                                                                                             |   |          |    |   |             |   |   |   |
| Inventories owed to customers and suppliers                                                                                                                                                                                                                                                                                                                                                                                                                      |   |          | (525.1  | )      |             |   | (469.4 | ) |
| Inventories, net                                                                         |   | $             | 757.6   |   |             | $      | 831.8 |   |

----

|                                                                                                                                                                                                                                                                               |   | December 31,2009 |    |   | Capital Expenditures(Depreciation) |   |      | TransfersandRetirements |   |   | March 31,2010 |   |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--------|------------------|---------|--------|------------------------------------|--------|-----------|-------------------------|--------|--------|---------------|--------|
| Construction work in progress                                                                                                                                                                                                                                                      |   | $                | 991.4   |   |                               | $      | 35.5      |                    |   | $      | (3.9          | )      |   | $ | 1,023.0 |   |
| Leasehold improvements                                           |   |             | 182.6   |   |                               |   | -         |                    |   |   | 2.3           |   |   |   | 184.9 |   |
| Machinery and equipment                                                                                                                                                                                                                                                            |   |             | 260.1   |   |                               |   |  1.2 |                    |   |   | 1.5           |   |   |   | 262.8 |   |
|                                                                                                                                                                                                                                                                               |   |             | 1,434.1 |   |                               |   | 36.7      |                    |   |   | (0.1          | )      |   |   | 1,470.7 |   |
| Accumulated depreciation and amortization                                                                                                                                                                                                                                          |   |             | (319.0  | )      |                               |   | (8.1      | )                       |   |   | 0.1           |   |   |   | (327.0 | ) |
|                                                                                                                                                                                                                                                                               |   | $                | 1,115.1 |   |                               | $      | 28.6      |                    |   | $      | -             |   |   | $ | 1,143.7 |   |

----

|                    |   | March 31,2010 |       |   | December 31,2009 |   |
|-------------------------|--------|---------------|------------|--------|------------------|--------|
|                    |   | (millions)    |       |
| Deferred revenue        |   | $             | 341.0      |   |             | $      | 301.9 |   |
| Advances from customers |   |          |  75.9 |   |             |   | 23.1 |   |
|                    |   | $             | 416.9      |   |             | $      | 325.0 |   |

----

|                                                                                                                                                                                                                                                                                                                                                                                                                                          |   | March 31,  |   |   | December 31, |   |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--------|------------|--------|--------|--------------|--------|
|                                                                                                                                                                                                                                                                                                                                                                                                                                          |   | 2010       |   |   | 2009         |   |
|                                                                                                                                                                                                                                                                                                                                                                                                                                          |   | (millions) |   |
| Short-term borrowings                                                                     |   | $          | -      |   |         | $      | - |   |
| Letters of credit                                                                         |   |       | 47.2   |   |         |   | 45.4 |   |
| Available credit                                                                          |   |       | 159.5  |   |         |   | 295.5 |   |

|                                                                                                  |   | CommonStock,Par Value$.10 perShare |   |   | Excess ofCapital overPar Value |   |    |   RetainedEarnings |   |   |   TreasuryStock |   |   | AccumulatedOther Compre-hensive Income (Loss) |    |   |  TotalStockholders’ Equity |   |   |  Comprehensive Income (Loss) |   |
|-------------------------------------------------------------------------------------------------------|--------|------------------------------------|--------|--------|--------------------------------|--------|---------|------------------------------|--------|--------|---------------------------|--------|--------|-----------------------------------------------|---------|--------|---------------------------------------|--------|--------|-----------------------------------|--------|
| Balance at December 31, 2009                                                                          |   | $                                  | 12.3   |   |                           | $      | 1,179.6 |                         |   | $      | 322.4                     |   |   | $                                             | (71.3   | )      |                                  | $      | (167.4 | )                                 |   | $ | 1,275.6 |   |   |   |   |
| Restricted and other stock issued, net                                                                |   |                               | -      |   |                           |   | (9.3    | )                            |   |   | -                         |   |   |                                          | 10.6    |   |                                  |   | -      |                              |   |   | 1.3 |   |   |   | - |   |
| Amortization of actuarial losses and prior service costs (credits), net of income tax of $1.0 million |   |                               | -      |   |                           |   | -       |                         |   |   | -                         |   |   |                                          | -       |   |                                  |   | 2.0    |                              |   |   | 2.0 |   |   |   | 2.0 |   |
| Net (loss)                                                                                            |   |                               | -      |   |                           |   | -       |                         |   |   | (9.7                      | )      |   |                                          |  - |   |                                  |   | -      |                              |   |   | (9.7 | ) |   |   | (9.7 | ) |
| Balance at March 31, 2010                                                                             |   | $                                  | 12.3   |   |                           | $      | 1,170.3 |                         |   | $      | 312.7                     |   |   | $                                             | (60.7   | )      |                                  | $      | (165.4 | )                                 |   | $ | 1,269.2 |   |   | $ | (7.7 | ) |

|                                                                                                           |   | Defined Benefit  Pension Plans |   |   | Postretirement Health and Life Benefit Plans |   |
|----------------------------------------------------------------------------------------------------------------|--------|-------------------------------------|--------|--------|----------------------------------------------|--------|
|                                                                                                           |   | Three Months Ended March 31,        |   |   | Three Months Ended March 31,                 |   |
|                                                                                                           |   | 2010                                |   |   | 2009                                         |   |   | 2010 |   |   | 2009 |   |
| Service costs                                                          |   | $                                   | 4.8    |   |                                         | $      | 4.7 |   |   | $ | 1.2 |   |   | $ | 1.2 |   |
| Interest costs                                                                        |   |                                | 12.2   |   |                                         |   | 11.9 |   |   |   | 3.0 |   |   |   | 3.2 |   |
| Expected returns on plan assets (gains)                           |   |                                | (12.1  | )      |                                         |   | (10.7 | ) |   |   | (0.9 | ) |   |   | (0.8 | ) |
| Amortization of prior service costs (credit)                                               |   |                                | 0.4    |   |                                         |   | 0.4 |   |   |   | (2.1 | ) |   |   | (3.6 | ) |
| Amortization of actuarial losses              |   |                                | 4.0    |   |                                         |   | 6.0 |   |   |   | 0.7 |   |   |   | 1.0 |   |
| Net benefit costs                                       |   | $                                   | 9.3    |   |                                         | $      | 12.3 |   |   | $ | 1.9 |   |   | $ | 1.0 |   |

----

|                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |   | Three Months Ended March 31, |   |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--------|------------------------------|--------|
|                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |   | 2010                         |   |   | 2009 |   |
|                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |   | (millions)                   |   |
| Total stock-based compensation costs:                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |   |                         |   |   |   |   |
| Restricted stock and restricted stock units                                                                                 |   | $                            | 2.9    |   |   | $ | 2.0 |   |
| Stock options, performance awards and other                                                                                 |   |                         | 0.7    |   |   |   | 0.7 |   |
| Less: costs capitalized as part of inventory                                                                                |   |                         | (0.1   | ) |   |   | (0.1 | ) |
| Expense included in selling, general and administrative                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |   | $                            | 3.5    |   |   | $ | 2.6 |   |
| Total after-tax expense                                                                                                                         |   | $                            | 2.3    |   |   | $ | 1.7 |   |

|                                   | Three Months Ended March 31, |
|----------------------------------------|------------------------------|
|                                   | 2010                         |   | 2009 |
| Risk-free interest rate                | 1.4%                         |   | 1.4% |
| Expected dividend yield                | -                            |   | - |
| Expected volatility                    | 72%                          |   | 65% |
| Expected option life                   | 4 years                      |   | 3.8 years |
| Weighted-average grant date fair value | $2.81                        |   | $1.81 |
| Options granted                        | 766,050                      |   | 1,091,300 |

----

----

----

|                                                                                                                                                                                                                                                                                                                                                                                                                                          |   | Three Months EndedMarch 31, |   |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--------|-----------------------------|--------|
|                                                                                                                                                                                                                                                                                                                                                                                                                                          |   | 2010                        |   |   | 2009 |   |
|                                                                                                                                                                                                                                                                                                                                                                                                                                          |   | (millions)                  |   |
| Revenue                                                                                                                                                                                                                                                                                                                                                                                                                                       |   |                        |   |   |   |   |
| LEU segment:                                                                                                                                                                                                                                                                                                                                                                                                                                  |   |                        |   |   |   |   |
| Separative work units                                                                     |   | $                           | 266.6  |   |   | $ | 427.9 |   |
| Uranium                                                                                                                                                                                                                                                                                                                                                                                                                                       |   |                        | 15.6   |   |   |   | 28.6 |   |
|                                                                                                                                                                                                                                                                                                                                                                                                                                          |   |                        | 282.2  |   |   |   | 456.5 |   |
| U.S. government contracts segment                                                                                                                                                                                                                                                                                                                                                                                                             |   |                        | 62.5   |   |   |   | 49.1 |   |
|                                                                                                                                                                                                                                                                                                                                                                                                                                          |   | $                           | 344.7  |   |   | $ | 505.6 |   |
|                                                                                                                                                                                                                                                                                                                                                                                                                                          |   |                        |   |   |   |   |   |   |
| Segment Gross Profit                                                                                                                                                                                                                                                                                                                                                                                                                          |   |                        |   |   |   |   |   |   |
| LEU segment                                                                                                                                                                                                                                                                                                                                                                                                                                   |   | $                           | 15.0   |   |   | $ | 41.6 |   |
| U.S. government contracts segment                                                                                                                                                                                                                                                                                                                                                                                                             |   |                        | 11.7   |   |   |   | 0.6 |   |
| Gross profit                                                                                                                                                                                                                                                                                                                                                                                                                                  |   |                        | 26.7   |   |   |   | 42.2 |   |
| Advanced technology costs                                                                                                                                                                                                                                                                                                                                                                                                                     |   |                        | 25.7   |   |   |   | 31.4 |   |
| Selling, general and administrative                                                                                                                                                                                                                                                                                                                                                                                                           |   |                        | 15.1   |   |   |   | 14.5 |   |
| Other (income)                                                                                                                                                                                                                                                                                                                                                                                                                                |   |                        | (9.7   | ) |   |   | - |   |
| Operating (loss)                                                                                                                                                                                                                                                                                                                                                                                                                              |   |                        | (4.4   | ) |   |   | (3.7 | ) |
| Interest expense (income), net                                                                                                                                                                                                                                                                                                                                                                                                                |   |                        | (0.1   | ) |   |   | (0.1 | ) |
| (Loss) before income taxes                                                                                                                                                                                                                                                                                                                                                                                                                    |   | $                           | (4.3   | ) |   | $ | (3.6 | ) |

----

Item

| ·   | supply LEU to both domestic and international utilities for use in about 150 nuclear reactors worldwide,  |
|--------------------|----------------------------------------------------------------------------------------------------------------|

| ·   | are deploying what we anticipate will be the world’s most advanced uranium enrichment technology, known as the American Centrifuge,  |
|--------------------|-------------------------------------------------------------------------------------------------------------------------------------------------|

| ·   | are the exclusive executive agent for the U.S. government under a nuclear nonproliferation program with Russia, known as Megatons to Megawatts,  |
|--------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------|

| ·   | perform contract work for the U.S. Department of Energy (“DOE”) and its contractors at the Paducah and Portsmouth gaseous diffusion plants (“GDPs”), and  |
|--------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|

| ·   | provide transportation and storage systems for spent nuclear fuel and provide nuclear and energy consulting services. |
|--------------------|-----------------------------------------------------------------------------------------------------------------------|

----

----

----

| ·   | sales of the SWU component of LEU, |
|--------------------|------------------------------------|

| ·   | sales of both the SWU and uranium components of LEU, and |
|--------------------|----------------------------------------------------------|

| ·   | sales of uranium. |
|--------------------|-------------------|

----

|                                                                                                                                                                                                                                                                                                                                                             |   | March 31, |   |   | December 31, |   |   | March 31, |   |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--------|-----------|--------|--------|--------------|--------|--------|-----------|--------|
|                                                                                                                                                                                                                                                                                                                                                             |   | 2010      |   |   | 2009         |   |   | 2009      |   |
| Long-term SWU price indicator ($/SWU)                                                                                                                                                                                                                                                                                                                            |   | $         | 163.00 |   |         | $      | 165.00 |      |   | $ | 161.00 |   |
| UF6:                                                                                                                                                                                                                                                                                                                                                             |   |      |   |   |         |   |   |      |   |   |   |   |
| Long-term price composite ($/KgU)                                                                                                                                                                                                                                                                                                                                |   |      | 167.77 |   |         |   | 167.77 |      |   |   | 192.54 |   |
| Spot price indicator ($/KgU)                                                       |   |      | 115.00 |   |         |   | 120.00 |      |   |   | 121.00 |   |

----

----

----

|                                                                                                                                                                                                                                                                                                                             |   | Three MonthsEnded March 31, |   |   | Cumulativeas ofMarch 31, |   |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--------|-----------------------------|--------|--------|--------------------------|--------|
|                                                                                                                                                                                                                                                                                                                             |   | 2010                        |   |   | 2009                     |   |   | 2010 |   |
| Amount expensed (A)                                                                                                                                                                                                                                                                                                         |   | $                           | 25.2   |   |                     | $      | 31.4 |   |   | $ | 684.8 |   |
| Amount capitalized (B)                                                                                                                                                                                                                                                                                                      |   |                        | 37.4   |   |                     |   | 130.3 |   |   |   | 1,085.7 |   |
| Total ACP expenditures, including accruals (C)                                                                                                                                                                                                                                                                              |   | $                           | 62.6   |   |                     | $      | 161.7 |   |   | $ | 1,770.5 |   |
|                                                                                                                                                                                                                                                                                                                             |   |                        |   |   |                     |   |   |   |   |   |   |   |
| (A) Expense included as part of Advanced Technology Costs.                                                                                                                                                                                                                                                                  |   |
| (B) Amounts capitalized as part of property, plant and equipment total $1,052.4 million as of March 31, 2010, including capitalized interest of $54.2 million. Prepayments to suppliers for services not yet performed totaled $33.3 million as of March 31, 2010.                                                          |   |
| (C) Total ACP expenditures are all American Centrifuge costs including, but not limited to, demonstration facility, licensing activities, commercial plant facility, program management, interest related costs and accrued asset retirement obligations capitalized. This includes $13.4 million of accruals at March 31, 2010. |   |

----

----

|                              |   | Three Months Ended March 31, |   |   |   |   |   |   |   |
|-----------------------------------|--------|------------------------------|--------|--------|--------|--------|--------|--------|--------|
|                              |   | 2010                         |   |   | 2009   |   |   | Change |   |   | % |   |
| LEU segment                       |   |                         |   |   |   |   |   |   |   |   |   |   |
| Revenue:                          |   |                         |   |   |   |   |   |   |   |   |   |   |
|    SWU revenue     |   | $                            | 266.6  |   |   | $      | 427.9  |   |   | $ | (161.3 | ) |   |   | (38 | )% |
| Uranium revenue                   |   |                         | 15.6   |   |   |   | 28.6   |   |   |   | (13.0 | ) |   |   | (45 | )% |
| Total                             |   |                         | 282.2  |   |   |   | 456.5  |   |   |   | (174.3 | ) |   |   | (38 | )% |
| Cost of sales                     |   |                         | 267.2  |   |   |   | 414.9  |   |   |   | 147.7 |   |   |   | 36 | % |
| Gross profit                      |   | $                            | 15.0   |   |   | $      | 41.6   |   |   | $ | (26.6 | ) |   |   | (64 | )% |
|                              |   |                         |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| U.S. government contracts segment |   |                         |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| Revenue                           |   | $                            | 62.5   |   |   | $      | 49.1   |   |   | $ | 13.4 |   |   |   | 27 | % |
| Cost of sales                     |   |                         | 50.8   |   |   |   | 48.5   |   |   |   | (2.3 | ) |   |   | (5 | )% |
| Gross profit                      |   | $                            | 11.7   |   |   | $      | 0.6    |   |   | $ | 11.1 |   |   |   | 1850 | % |
|                              |   |                         |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| Total                             |   |                         |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| Revenue                           |   | $                            | 344.7  |   |   | $      | 505.6  |   |   | $ | (160.9 | ) |   |   | (32 | )% |
| Cost of sales                     |   |                         | 318.0  |   |   |   | 463.4  |   |   |   | 145.4 |   |   |   | 31 | % |
| Gross profit                      |   | $                            | 26.7   |   |   | $      | 42.2   |   |   | $ | (15.5 | ) |   |   | (37 | )% |

----

----

|                                 |   | Three Months Ended March 31, |   |   |   |   |       |   |   |
|--------------------------------------|--------|------------------------------|--------|--------|--------|--------|------------|--------|--------|
|                                 |   | 2010                         |   |   | 2009   |   |       | Change |   |   | % |   |
| Gross profit                         |   | $                            | 26.7   |   |   | $      | 42.2       |   |   | $ | (15.5 | ) |   |   | (37 | )% |
| Advanced technology costs            |   |                         | 25.7   |   |   |   | 31.4       |   |   |   | 5.7 |   |   |   | 18 | % |
| Selling, general and administrative  |   |                         | 15.1   |   |   |   | 14.5       |   |   |   | (0.6 | ) |   |   | (4 | )% |
| Other (income)                       |   |                         | (9.7   | )      |   |   | -          |   |   |   | 9.7 |   |   |   | - |   |
| Operating (loss)                     |   |                         | (4.4   | )      |   |   | (3.7       | )      |   |   | (0.7 | ) |   |   | (19 | )% |
| Interest expense                     |   |                         | -      |   |   |   | 0.5        |   |   |   | 0.5 |   |   |   | 100 | % |
| Interest (income)                    |   |                         | (0.1   | )      |   |   |  (0.6 | )      |   |   | (0.5 | ) |   |   | (83 | )% |
| (Loss) before income taxes           |   |                         | (4.3   | )      |   |   | (3.6       | )      |   |   | (0.7 | ) |   |   | (19 | )% |
| Provision (benefit) for income taxes |   |                         | 5.4    |   |   |   | (1.5       | )      |   |   | (6.9 | ) |   |   | (460 | )% |
| Net (loss)                           |   | $                            | (9.7   | )      |   | $      | (2.1       | )      |   | $ | (7.6 | ) |   |   | (362 | )% |

----

----

| ·   | Changes to the electric power fuel cost adjustment from our current projection; |
|--------------------|---------------------------------------------------------------------------------|

| ·   | The timing of recognition of previously deferred revenue, particularly related to the sale of uranium; |
|--------------------|--------------------------------------------------------------------------------------------------------|

| ·   | Ability to expand the existing credit facility or otherwise raise capital for investment in the ACP; |
|--------------------|------------------------------------------------------------------------------------------------------|

| ·   | Movement and timing of customer orders; |
|--------------------|-----------------------------------------|

| ·   | Changes to SWU and uranium price indicators, and changes in inflation that can affect the price of SWU billed to customers; and |
|--------------------|---------------------------------------------------------------------------------------------------------------------------------|

| ·   | Ability to underfeed the production process at the Paducah GDP and make additional uranium sales possible. |
|--------------------|------------------------------------------------------------------------------------------------------------|

----

----

|                                                |   | Three Months EndedMarch 31, |   |
|-----------------------------------------------------|--------|-----------------------------|--------|
|                                                |   | 2010                        |   |   | 2009 |   |
| Net Cash Provided by (Used in) Operating Activities |   | $                           | (42.9  | ) |   | $ | 23.8 |   |
| Net Cash (Used in) Investing Activities             |   |                        | (46.0  | ) |   |   | (137.7 | ) |
| Net Cash (Used in) Financing Activities             |   |                        | (9.9   | ) |   |   | (96.7 | ) |
| Net (Decrease) in Cash and Cash Equivalents         |   | $                           | (98.8  | ) |   | $ | (210.6 | ) |

----

|                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |   | March 31,  |   |   | December 31, |   |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--------|------------|--------|--------|--------------|--------|
|                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |   | 2010       |   |   | 2009         |   |
|                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |   | (millions) |   |
| Cash and cash equivalents                                                                                        |   | $          | 32.5   |   |         | $      | 131.3 |   |
| Accounts receivable, net                                                                                         |   |       | 189.0  |   |         |   | 191.4 |   |
| Inventories, net                                                                                                 |   |       | 757.6  |   |         |   | 831.8 |   |
| Other current assets and liabilities, net                                                                        |   |       | (161.7 | )      |         |   | (267.5 | ) |
| Working capital                                                                                                                 |   | $          | 817.4  |   |         | $      | 887.0 |   |

|                                                                                                                                                                                                                                                                                                                                                                                                                                          |   | March 31,  |   |   | December 31, |   |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--------|------------|--------|--------|--------------|--------|
|                                                                                                                                                                                                                                                                                                                                                                                                                                          |   | 2010       |   |   | 2009         |   |
|                                                                                                                                                                                                                                                                                                                                                                                                                                          |   | (millions) |   |
| Short-term borrowings                                                                     |   | $          | -      |   |         | $      | - |   |
| Letters of credit                                                                         |   |       | 47.2   |   |         |   | 45.4 |   |
| Available credit                                                                          |   |       | 159.5  |   |         |   | 295.5 |   |

----

|   | · | the sum of (1) the greater of a) the JPMorgan Chase Bank prime rate, b) the federal funds rate plus 1⁄2 of 1%, or c) 1-month LIBOR plus 1%  plus (2) a margin ranging from 2.25% to 2.75% based upon availability, or  |
|--------|--------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|

|   | · | the sum of LIBOR plus a margin ranging from 4.0% to 4.5% based upon availability. |
|--------|--------|-----------------------------------------------------------------------------------|

----

|                           | Standard & Poor’s | Moody’s |
|--------------------------------|-----------------------------|---------------|
| Corporate credit/family rating | CCC+                        | Caa1          |
| 3.0% convertible senior notes  | CCC-                        | Caa2          |
| Outlook                        | Developing                  | Developing    |

----

Item

|   | • | commodity price risk for electric power requirements for the Paducah GDP (refer to “Overview – Cost of Sales” and “Results of Operations – Cost of Sales”), and |
|--------|---------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|

|   | • | interest rate risk relating to any outstanding borrowings at variable interest rates under our revolving credit agreement (refer to “Liquidity and Capital Resources – Capital Structure and Financial Resources”). |
|--------|---------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|

Item

----

Item

Item

Item

|                           |   |         |   |       |   | (c) Total Number     |   | (d) Maximum Number     |
|--------------------------------|--------|--------------|--------|------------|--------|----------------------|--------|------------------------|
|                           |   | (a) Total    |   | (b)        |   | of Shares (or Units) |   | (or Approximate Dollar |
|                           |   | Number of    |   | Average    |   | Purchased as Part    |   | Value) of Shares (or   |
|                           |   | Shares (or   |   | Price Paid |   | of Publicly          |   | Units) that May Yet Be |
|                           |   | Units)       |   | Per Share  |   | Announced Plans      |   | Purchased Under the    |
|  Period                   |   | Purchased(1) |   | (or Unit)  |   | or Programs          |   | Plans or Programs      |
|                           |   |         |   |       |   |                 |   |                   |
| January 1 – January 31   |   | 3,414        |   | $4.30      |   | -                    |   | -                      |
| February 1 – February 28 |   | -            |   | -          |   | -                    |   | -                      |
| March 1 – March 31       |   | 506,950      |   | 5.22       |   | -                    |   | -                      |
|    Total        |   | 510,364      |   | $5.21      |   | -                    |   | -                      |

| (1) | These purchases were not made pursuant to a publicly announced repurchase plan or program. Represents 510,364 shares of common stock surrendered to USEC to pay withholding taxes on shares of restricted stock under the Company’s equity incentive plan.   |
|-----|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|

----

Item

|   | 10.1 | Modification No. 3 dated January 28, 2010, to Agreement dated June 17, 2002 between U.S. Department of Energy and USEC Inc., incorporated by reference to Exhibit 10.1 of the Current Report on Form 8-K filed on February 2, 2010 (Commission file number 1-14287). |
|--------|------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|

|   | 10.2 | Second Amended and Restated Revolving Credit Agreement, dated as of February 26, 2010, among USEC Inc., United States Enrichment Corporation, the lenders party thereto, JPMorgan Chase Bank, N.A., as administrative and collateral agent, JPMorgan Securities, Inc., Wachovia Capital Finance Corporation (New England), and UBS Securities LLC, as joint book managers and joint lead arrangers, Wachovia Capital Finance Corporation (New England), as syndication agent, and UBS Securities LLC, as documentation agent, incorporated by reference to Exhibit 10.1 of the Current Report on Form 8-K filed on February 26, 2010 (Commission file number 1-14287). |
|--------|------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|

|   | 10.3 | Second Amended and Restated Omnibus Pledge and Security agreement dated as of February 26, 2010 by USEC Inc., United States Enrichment Corporation and NAC International Inc., in favor of JPMorgan Chase Bank, N.A., as administrative and collateral agent for the lenders, incorporated by reference to Exhibit 10.2 of the Current Report on Form 8-K filed on February 26, 2010 (Commission file number 1-14287). |
|--------|------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|

|   | 10.4 | Cooperative Agreement dated March 23, 2010 between the U.S. Department of Energy and USEC Inc., incorporated by reference to Exhibit 10.1 of the Current Report on Form 8-K filed on March 23, 2010 (Commission file number 1-14287). |
|--------|------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|

|   | 31.1 | Certification of the Chief Executive Officer pursuant to Rule 13a-14(a)/15d-14(a). |
|--------|------|------------------------------------------------------------------------------------|

|   | 31.2 | Certification of the Chief Financial Officer pursuant to Rule 13a-14(a)/15d-14(a). |
|--------|------|------------------------------------------------------------------------------------|

|   | 32 | Certification of CEO and CFO pursuant to 18 U.S.C. Section 1350. |
|--------|----|------------------------------------------------------------------|

----

SIGNATURE

|        | USEC Inc.                                         |
|-------------|---------------------------------------------------|
|        |                                              |   |   |
|        |                                              |   |   |
|        |                                              |   |   |
| May 5, 2010 | By:                                               | /s/ John C. Barpoulis |   |
|        |                                              | John C. Barpoulis |   |
|        | Senior Vice President and Chief Financial Officer |
|        | (Principal Financial Officer)                     |

----

EXHIBIT

| 10.1 | Modification No. 3 dated January 28, 2010, to Agreement dated June 17, 2002 between U.S. Department of Energy and USEC Inc., incorporated by reference to Exhibit 10.1 of the Current Report on Form 8-K filed on February 2, 2010 (Commission file number 1-14287). |
|------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|

| 10.2 | Second Amended and Restated Revolving Credit Agreement, dated as of February 26, 2010, among USEC Inc., United States Enrichment Corporation, the lenders party thereto, JPMorgan Chase Bank, N.A., as administrative and collateral agent, JPMorgan Securities, Inc., Wachovia Capital Finance Corporation (New England), and UBS Securities LLC, as joint book managers and joint lead arrangers, Wachovia Capital Finance Corporation (New England), as syndication agent, and UBS Securities LLC, as documentation agent, incorporated by reference to Exhibit 10.1 of the Current Report on Form 8-K filed on February 26, 2010 (Commission file number 1-14287). |
|------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|

| 10.3 | Second Amended and Restated Omnibus Pledge and Security agreement dated as of February 26, 2010 by USEC Inc., United States Enrichment Corporation and NAC International Inc., in favor of JPMorgan Chase Bank, N.A., as administrative and collateral agent for the lenders, incorporated by reference to Exhibit 10.2 of the Current Report on Form 8-K filed on February 26, 2010 (Commission file number 1-14287). |
|------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|

| 10.4 | Cooperative Agreement dated March 23, 2010 between the U.S. Department of Energy and USEC Inc., incorporated by reference to Exhibit 10.1 of the Current Report on Form 8-K filed on March 23, 2010 (Commission file number 1-14287). |
|------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|

| 31.1 | Certification of the Chief Executive Officer pursuant to Rule 13a-14(a)/15d-14(a). |
|------|------------------------------------------------------------------------------------|

| 31.2 | Certification of the Chief Financial Officer pursuant to Rule 13a-14(a)/15d-14(a). |
|------|------------------------------------------------------------------------------------|

| 32 | Certification of CEO and CFO pursuant to 18 U.S.C. Section 1350. |
|----|------------------------------------------------------------------|

----