If the Senate confirms President Obama's choice to be the next chair of the Nuclear Regulatory Commission—George Mason University professor Allison M. Macfarlane—she would join the panel as it faces a host of challenges.

The NRC has 10 license applications pending for 16 new nuclear reactors and is determining what new requirements it may set for U.S. nuclear powerplants in the wake of last year's Fukushima Daiichi nuclear disaster in Japan.