The Senate has approved President Barack Obama's nominee to chair the Nuclear Regulatory Commission, an agency marked by discord in recent years.

Geologist Allison Macfarlane will replace Gregory Jaczko (YAHTS'-koh), who announced his resignation last month after a tumultuous three-year tenure. Jaczko came under fire for an unyielding management style that fellow commissioners and agency employees described as bullying.

Macfarlane, a Democrat, told a Senate panel this month that she will work to restore collegiality at the NRC. She also pledged to ensure "a respectful working environment" at the agency, which oversees safety at the nation's 104 commercial nuclear reactors. Her term runs through June 2013.

The Senate also approved Republican Kristine Svinicki to a new five-year term on the commission. Svinicki has served on the panel since 2008.