4. PROPERTY, PLANT AND EQUIPMENT

A summary of changes in property, plant and equipment follows (in millions):


	December 31, 2009			Capital Expenditures (Depreciation)			Transfers and Retirements			December 31, 2010			Capital Expenditures (Depreciation)			Transfers and Retirements			December 31, 2011			Capital Expenditures (Depreciation)			Transfers and Retirements			December 31, 2012
Construction work in progress	$	991.4		$	149.4		$	(14.5	)	$	1,126.3		$	135.9		$	(151.0	)	$	1,111.2		$	13.6		$	(1,122.1	)	$	2.7
Leasehold improvements		182.6			-			4.7			187.3			-			(4.4	)		182.9			-			0.8			183.7
Machinery and equipment		260.1			3.0			6.0			269.1			-			(17.9	)		251.2			0.3			(69.8	)		181.7
		1,434.1			152.4			(3.8	)		1,582.7			135.9			(173.3	)		1,545.3			13.9			(1,191.1	)		368.1
Accumulated depreciation and amortization		(319.0	)		(36.1	)		3.8			(351.3	)		(42.7	)		35.8			(358.2	)		(27.0	)		68.1			(317.1	)
	$	1,115.1		$	116.3		$	-		$	1,231.4		$	93.2		$	(137.5	)	$	1,187.1		$	(13.1	)	$	(1,123.0	)	$	51.0

Capital expenditures include items in accounts payable and accrued liabilities at December 31, 2012 for which cash is paid in subsequent periods.

American Centrifuge

USEC is working to deploy the American Centrifuge technology at the ACP in Piketon, Ohio. In the fall of 2011, instead of moving forward with a conditional commitment for a loan guarantee for the American Centrifuge project through the DOE Loan Guarantee Program, DOE proposed a two-year cost share RD&D program for the American Centrifuge project. USEC, its subsidiary American Centrifuge Demonstration, LLC ("ACD") and DOE entered into a cooperative agreement for the RD&D program on June 12, 2012. Additional details are provided in Note 18 under "American Centrifuge Plant – Project Funding." Beginning in the fourth quarter of 2011, as a result of the shift in focus of the American Centrifuge project, USEC began spending on the American Centrifuge technology at reduced levels with activities concentrating on development and demonstration. As a result, all project costs incurred since the fourth quarter of 2011 have been expensed, including interest expense that previously would have been capitalized.

Based on USEC's internal analysis concluded as part of its annual assessment, as of December 31, 2012, USEC expensed $1.1 billion of previously capitalized costs related to the American Centrifuge project. This included previously capitalized costs related to property, plant and equipment (including construction work in progress) of $1,075.6 million, prepayments made to suppliers of $9.9 million and deferred financing costs related to the DOE loan guarantee program of $6.7 million that were previously capitalized during the period 2007 through 2011.

Although USEC continues to make progress in the deployment of the ACP, including the effective execution of the RD&D program during 2012, and is planning to update its DOE loan guarantee application during 2013, the expense of previously capitalized costs is based on USEC's assessment of its ability to recover the full amount of this prior capital investment. In light of the significant remaining capital needed to deploy the ACP and USEC's view of its anticipated cash flow from operations available to finance the ACP given its other anticipated cash needs during that period, USEC anticipates that its ultimate share of the ownership of the ACP will likely be reduced, which affects USEC's likelihood of recovering this past investment. USEC is also currently developing a revised cost estimate and schedule for the project and several factors are putting pressure on the economics of the ACP, including delays in deployment and related carrying costs and other cost pressures as well as uncertainty regarding financing. This expense of previously capitalized costs does not affect any future capital investment in the ACP. USEC would anticipate that capitalization of amounts related to the ACP would resume if and when commercial plant deployment resumes.

On June 12, 2012, USEC, through its subsidiary ACD, entered into a contract with DOE to transfer to DOE title to the centrifuge machines and equipment produced or acquired under the RD&D program. The transferred property included specified existing machines and equipment having a cost of $44.6 million that were transferred in the second quarter of 2012, and the machines and equipment that are produced or acquired under the cooperative agreement.

Paducah GDP

USEC records leasehold improvements, machinery and equipment at acquisition cost and depreciates these assets on a straight line basis over the shorter of the useful life of the assets or the expected productive life of the plant, which has been June 2016 for the Paducah GDP commensurate with the term of the lease agreement. Maintenance and repair costs are charged to production costs as incurred.

USEC is preparing for the transition of the Paducah GDP after the end of the one-year term of the depleted uranium enrichment arrangement in May 2013. USEC is in discussions regarding the potential for continuing enrichment at Paducah for several months following the completion of the current arrangement at the end of May 2013. However, USEC may not be able to reach an agreement for a short term extension or other arrangement. USEC believes it will be difficult to continue commercial enrichment beyond the end of the current arrangement in May 2013 and any short-term follow-on arrangement. Under the terms of the lease, USEC can terminate the lease prior to June 2016 upon two years' notice. Also, as USEC's needs change, USEC can de-lease portions of the property under lease upon 60 days' notice with DOE's consent, which cannot be unreasonably withheld. Once USEC ceases enrichment at the Paducah GDP, for a period of time it will still need to lease certain areas used for ongoing operations such as shipping and handling, inventory management and site services. USEC is currently in discussions with DOE regarding the timing of its de-lease and is seeking to achieve an orderly transition of Paducah and to minimize its transition costs, which could be substantial.

In September 2012, USEC provided DOE with a non-binding notice of potential return of certain leased premises and property at the Paducah GDP. As a result of discussions with DOE and USEC's belief that it would be difficult to continue enrichment at the Paducah GDP through the expiration of the existing lease term, USEC began depreciating leasehold improvements, machinery and equipment at the Paducah GDP on an accelerated straight line basis prospectively starting in the fourth quarter of 2012. Based on internal analysis that provided management's view of the most likely scenarios, USEC did not foresee that the lease term would continue beyond 2014 and determined to depreciate its existing assets over this timeframe unless facts and circumstances affecting the expected term of the lease change.

The shorter expected service life of the Paducah GDP resulted in accelerated charges to expense of $5.6 million in 2012, including $3.5 million of costs that would have previously been capitalized as part of construction work in progress and $2.1 million of accelerated depreciation. Costs that would have been previously treated as construction work in progress are treated similar to maintenance and repair costs because of the short expected productive life of the Paducah GDP.