Major classes of utility plant and other property and their respective balances at December 31, 2019 and 2018 were as follows:

At December 31,	2019		2018
(millions)
Gross utility plant:
Generation	$	5,765	$	5,751
Transmission		1,905		1,758
Distribution		4,685		4,456
Storage		73		74
General and other		549		535
Intangible		231		229
Construction work in progress		339		350
Nuclear fuel		608		611
Total gross utility plant	$	14,155	$	13,764
Gross nonutility property	$	75	$	73

DESC jointly owns and is the operator of Summer. Each joint owner provides its own financing and shares the direct expenses and generation output in proportion to its ownership. DESC’s share of the direct expenses of Summer is included in the corresponding operating expenses on its income statement. The units associated with the NND Project have been reclassified from construction work in progress to a regulatory asset as a result of the decision to stop their construction. See additional discussion at Note 3. In May 2019, DESC and Santee Cooper entered into an agreement in which DESC agreed to purchase 11.7% of Santee Cooper’s ownership interest in the NND Project nuclear fuel, which will be used at Summer, for $8 million to true up the ownership percentage from the 55% ownership percentage that was applicable for the NND Project to the 66.7% ownership percentage applicable for Summer.

At December 31,	2019			2018
	Summer Unit 1			Summer Unit 1
Percent owned	66.7%			66.7%
Plant in service	$	1.4	billion	$	1.5	billion
Accumulated depreciation	$	684	million	$	644	million
Construction work in progress	$	79	million	$	128	million

Included within other receivables on the balance sheet were amounts due to DESC from Santee Cooper for its share of direct expenses. These amounts totaled $50 million at December 31, 2019 and $46 million at December 31, 2018.

In May 2019, DESC entered into an agreement to sell certain warranty service contract assets for total consideration of $7 million. The transaction closed in August 2019, resulting in a $7 million ($5 million after-tax) gain recorded in other income (expense), net in DESC’s Consolidated Statements of Comprehensive Loss. Pursuant to the agreement, upon closing DESC entered into a service agreement with the buyer under which the buyer will compensate DESC in connection with the right to use DESC’s brand in marketing materials and other services over a ten-year term.