Allison M. Macfarlane, chairman of the Nuclear Regulatory Commission (NRC), announced on Oct. 21 that she will leave the NRC effective Jan. 1, 2015, to take a position at George Washington University.

Macfarlane took over the chair in July 2012—completing the last year of Dr. Gregory Jaczko’s term—and was confirmed for a second term in June 2013. The five-year term was slated to run through June 30, 2018.

“I came to the Commission with the mission of righting the ship after a tumultuous period for the Commission, and ensuring that the agency implemented lessons learned from the tragic accident at Fukushima Daiichi, so that the American people can be confident that such an accident will never take place here,” Macfarlane said in a statement. “With these key objectives accomplished, I am now returning to academia as Director of the Center for International Science and Technology Policy at George Washington University.”

During Macfarlane’s tenure, the NRC implemented safety improvements, such as the addition of protective equipment at reactor sites and at regional centers around the country, seismic and flood protection enhancements at power plants, and progress on hardening venting systems at plants of similar design to those at Fukushima.

Her term has also seen heightened attention to the back-end of the nuclear fuel cycle. In August, the NRC issued the “Continued Storage of Spent Nuclear Fuel Rule” revising the Waste Confidence Decision, which was vacated by the D.C. Circuit in June 2012. Just last week, it issued Volume 3 of an expected five-part safety evaluation report (SER) for the Yucca Mountain permanent nuclear waste repository.

But Macfarlane’s term has not been all roses. In January, all five NRC commissioners were called before the U.S. Senate Committee on Environment and Public Works to review progress made by the NRC to incorporate lessons learned from the disaster in Japan. While Macfarlane tried to highlight accomplishments, senators focused the questioning on NRC struggles. Sen. Barbara Boxer (D-Calif.) continued to press Macfarlane about the senator’s right to obtain documents from the NRC pertaining to the flawed steam generators at San Onofre Nuclear Generating Station—a long-standing issue between the two. Several other senators raised their own issues with the NRC, including on a perceived lack of progress on the Yucca Mountain SER.

Prior to joining the NRC, Macfarlane was an associate professor of environmental science and policy at George Mason University. She also served on the Blue Ribbon Commission on America’s Nuclear Future, created by the Obama administration to make recommendations about a national strategy for dealing with the nation’s high-level nuclear waste. She is well versed in technical issues at the proposed waste disposal facility at Yucca Mountain, having co-edited a book on the subject in 2006.

“It has been a great privilege to serve with the men and women who work for the NRC and public safety with such dedication. I came to the agency as an outsider, but leave with warm feelings for the many friends I have made here. The NRC staff display on a daily basis how seriously they take their responsibility as regulators and I have valued the time I spent with them,” said Macfarlane.

Aaron Larson, associate editor (@AaronL_Power, @POWERmagazine)