Lawyers for Uncle Sam shelled out more than $3 billion in taxpayer funds last year to resolve lawsuits against the federal government — more than twice as much as in 2010, and the most in at least five years, an analysis of government records shows.

The lion’s share of expenses can be attributed to the Department of Energy, which single-handedly accounted for $1.3 billion in payments. [see chart] The agency in 2011 quietly settled a series of breach-of-contract suits with utilities over the storage of spent nuclear fuel, resulting in a $1 billion spike in legal bills compared with 2010.