About $2 billion of work done by the Department of Energy for other agencies had little oversight, according to the U.S. Government Accountability Office.

The projects, known as "Work for Others," allow non-Energy Department agencies to use 17 of the agency's "unique and highly specialized facilities."

The Energy Department performed about $2.1 billion of work under the WFO program in 2012, with $1.5 billion of the projects sponsored by the Department of Defense.

Despite the high price of this program, GAO found that the Energy Department has failed to make sure the program requirements are consistently met.

"DoE has not ensured compliance with requirements for the approval of WFO projects, cost recovery, program reviews, and annual reporting," GAO found.

House Energy and Commerce Committee Chairman Fred Upton, R-Mich., said the report shows more work is needed to ensure programs like WFO are properly supervised.

“With Secretary [Ernest] Moniz implementing a number of agency management reforms, this report underscores the kind of detailed work necessary for the agency to perform more effective oversight of how it spends taxpayer dollars and what it gets for that spending," Upton said.

The Energy Department also has no set plans to deal with changing budgets or costs as they occur simultaneously with ongoing projects, GAO said.

Without a detailed plan, GAO said agency officials can't be sure that its "cost recovery requirements" are consistently met.

Management reviews of the WFO program were few and far between — despite being required by the Energy Department.

Even when reviews were done, however, DoE failed to require what the reviews considered. Though GAO said DoE has taken steps to improve how it evaluates WFO performance, it was missing "key attributes" while doing so.

The GAO questioned if the Energy Department's response plans will solve the problems identified by the congressional watchdog agency.

View the full GAO report below.