Steve Jaczko, Chairman of the Nuclear Regulatory Commission (NRC), announced his resignation this week amidst unflattering reports of his leadership and congressional hearings. Jaczko spent three years as Chairman and more than 7 years on the Commission. He will step down after a successor is confirmed, or after June of 2013, when his term would have ended.

His tenure was marked by efforts to address longstanding safety concerns at nuclear reactors across the U.S., although these efforts were viewed with skepticism by those in the industry, according to the New York Times. Jaczko was criticized for ending the government’s consideration of the proposed Yucca mountain nuclear waste site, and for assuming emergency powers at the NRC in the wake of the nuclear reactor meltdown in Fukishima last year.

It’s unclear who will be nominated for the appointment, but POLITICO’s Morning Energy listed two possibilities: “Allison Macfarlane, a George Mason University environmental science professor who was considered in 2005 before the spot went to Jaczko, and Dave Lochbaum, the director of the Union of Concerned Scientists’ nuclear program”.

What changes do you expect a new NRC Chairperson to bring to the agency? How would you change the NRC?