President Obama may have undercut his ability to meet his climate change goals by scrapping the Yucca Mountain nuclear waste dump in Nevada, which would slow the growth of zero-emission nuclear power plants.

Energy Secretary Ernest Moniz told a Senate subcommittee Wednesday that the U.S. needs to find a solution to the debate on nuclear waste, and that the country is running out of time to send positive signals about nuclear power’s role in the future before a “wave” of plants close.

The U.S. nuclear fleet is aging so that Moniz expects a “wave of retirement” in about 2030, he said. Nuclear power plants take a lot of money and time to launch, so the country doesn’t have much time to send “clear signals of support for nuclear power” before the energy source’s potential will be significantly limited, he said. Moniz said that within the next five years, he hopes to see the country “weave nuclear energy into that planning.”

Officials “must find a path on waste,” Moniz said. The department is moving ahead with a “consent-based” siting process for opening nuclear waste storage sites, Moniz said. That contrasts with how the facility at Yucca Mountain in Nevada was proposed with no support from Nevada’s congressional delegation.

Although the administration opposes a central storage site being built at Yucca Mountain, Moniz is heading an effort to find an interim storage facility to move the waste being stored at power plants until a permanent site is opened.