During Tuesday nights Democratic Debate, a question about the viability of the Yucca Mountain nuclear facility lead to a discussion of energy priorities among the three candidates.

Here's a quick summary of their positions and criticism from their fellow candidates:

Senator John Edwards: was criticized by Senator Clinton about his voting twice for funding for the Yucca mountain nuclear waste site. His defense was that the "technology has changed" since his previous votes, and that there was some fraud committed in obtaining permits. Now he says he is against the building of any new nuclear power plants because they are terrorist targets, and that even if the amount of nuclear plants were doubled, it would still only address one-seventh of the greenhouse gas emissions. He is also against the building of new coal power plants unless sequestration technologies are developed. He also mentioned the importance of cellulosic ethanol.

Senator Hillary Clinton: was criticized by Senator Edwards for taking lobbyist money from the energy industries. She said she voted against the 2005 energy bill because it was designed by Dick Cheney and included millions in giveaways to the oil and gas industries. Senator Edwards referred to her previous statement of being "agnostic towards nuclear" as a future energy source.

Senator Barack Obama: was criticized by Senator Clinton because he voted for the 2005 energy bill that was generous towards the oil and gas industries. He said that he voted for it because it also provided funding for wind and solar energy. That bill also provided support for nuclear power, of which Illinois has more than any other state. He said that he voted against Yucca mountain despite his state's pro-nuclear stance. He said he supports nuclear energy as part of the "menu of options" for reducing greenhouse gases. He was the only candidate who spoke about the need for conservation and support for the cap and trade system.