PROPERTY, PLANT, EQUIPMENT AND MINE DEVELOPMENT COSTS, NET

The components of net property, plant, equipment and mine development costs follow:



	December 31,
	2017			2016
Proven and probable mineral reserves	$	3,974		$	3,863
VBPP	447			559
Mine development and other	6,212			5,755
Buildings and infrastructure	7,520			7,479
Machinery and equipment	12,201			11,744
Mobile equipment	3,764			3,725
Construction in progress	2,964			2,831
Property, plant, equipment and mine development costs	37,082			35,956
Accumulated depreciation, depletion and amortization	(14,246		)	(12,737		)
Property, plant, equipment and mine development costs, net	$	22,836		$	23,219

FCX recorded $1.6 billion for VBPP in connection with the FMC acquisition in 2007 (excluding $634 million associated with mining operations that were sold or included in assets held for sale) and transferred $112 million to proven and probable mineral reserves during 2017 and $640 million prior to 2017 (none in 2016). Cumulative impairments of VBPP total $485 million, which were primarily recorded in 2008.

Capitalized interest, which primarily related to FCX’s mining operations’ capital projects, totaled $121 million in 2017, $92 million in 2016 and $157 million in 2015.

In connection with the decline in copper and molybdenum prices and revised operating plans at FCX’s mining operations, FCX evaluated its long-lived assets (other than indefinite-lived intangible assets) for impairment during 2015 and as of December 31, 2015, as described in Note 1. FCX’s evaluations of its copper mines at December 31, 2015, were based on near-term price assumptions reflecting prevailing copper future prices, which ranged from $2.15 per pound to $2.17 per pound for COMEX and from $2.13 per pound to $2.16 per pound for LME, and a long-term average price of $3.00 per pound. FCX’s evaluations of its molybdenum mines at December 31, 2015, were based on near-term price assumptions that were consistent with then-current market prices for molybdenum and a long-term average price of $10.00 per pound.

FCX’s evaluations of long-lived assets (other than indefinite-lived intangible assets) resulted in the recognition of a charge to production costs for the impairment of the Tyrone mine totaling $37 million in 2015, net of a revision to Tyrone’s ARO.

During 2016 and 2017, FCX concluded there were no events or changes in circumstances that would indicate that the carrying amount of its long-lived mining assets might not be recoverable. Additionally, copper and molybdenum prices have improved. The LME copper spot prices were $3.25 per pound and $2.50 per pound at December 31, 2017 and 2016, respectively, which were higher than the LME spot price of $2.13 per pound at December 31, 2015; the weekly average prices for molybdenum were $10.15 per pound and $6.74 per pound at December 31, 2017 and 2016, respectively, which were higher than the weekly average price of $5.23 per pound at December 31, 2015.