The same day, Senate Energy and Natural Resources Committee Chair Lisa Murkowski (R-Alaska) and the committee's top Democrat, Maria Cantwell (Wash.), introduced a bill to establish a policy for addressing the long-term storage of nuclear and defense radioactive waste.

The political back-and-forth over whether an underground site at Nevada's Yucca Mountain would ever serve as a long-term waste repository has been a sticking point for decision-makers for a long time. Some nuclear-energy advocates say the lack of a solution could deter construction of new nuclear powerplants.

For years, powerful lawmakers such as Sen. Harry Reid (D-Nev.) have strongly opposed using Yucca Mountain, and the White House halted construction there in 2010.

In remarks on March 25 at the Bipartisan Policy Center, a Washington, D.C.-based organization, Energy Secretary Ernest Moniz said, “We don’t view Yucca Mountain as workable,” adding that the lack of support from the community near Yucca “is a fatal flaw.” 

Moniz said the administration now would take “affirmative steps” to identify one or more potential alternative sites for pilot and full-scale facilities for consolidated interim storage of commercial, used nuclear fuel. 

He said the search for interim storage “in no way minimizes the need for a permanent disposal capability, and we are committed to advancing the development of both.”

Potential sites would be identified with the cooperation and consent of communities interested in hosting storage facilities, Moniz said. “What we want to do now is move the process forward where there is consent-based interaction with communities and states to get our storage program going,” he noted.

At the same time, as Obama's directive indicates, administration officials have decided to search for a separate repository for  high-level radioactive waste from atomic-energy defense activities.

Carving out defense-related waste from spent fuel from nuclear plants could create greater flexibility in site selection and bring costs down for a variety of reasons, Moniz said.

First, the U.S. is no longer generating the high-level waste associated with weapons production, so the inventory of high-level defense waste is “finite,” Moniz said.

Second, he said, some defense waste is less radioactive, cooler and easier to handle than commercial waste, which could mean that, potentially, a separate defense repository would require a simpler design and pose fewer licensing and transportation challenges.

Although the DOE does not currently have the authority to begin constructing any repository, it can begin laying the groundwork to identify potential sites, Moniz said.

The Murkowski-Cantwell bill is a sign that at least some in Congress also want to tackle the waste-disposal issue.

Sen. Lamar Alexander (R-Tenn.), one of the bill’s cosponsors, said in a statement: “If we want to have low-cost, clean power from nuclear reactors, which, today, produce about 80% of our country’s emission-free electricity, then we have to have a place to put the used nuclear fuel. That means we need to end the stalemate over what to do with our country’s nuclear waste by finding a way to create both temporary and permanent storage sites that would complement other solutions.”