(05-09) 14:03 PDT Red Wing, Minn. (AP) --

An accidental release of radioactive gas at a nuclear plant in southeastern Minnesota exposed about 100 workers to low levels of radiation last week, the Nuclear Regulatory Commission said.

The Prairie Island plant was shut down for maintenance and refueling at the time, and no radiation was released outdoors, said Jan Strasma, commission spokesman.

The workers were wearing protective gear May 2 when they were exposed to low levels of radioactive iodine, said Arline Datu, spokeswoman for Nuclear Management Co. Most received 10 to 20 millirems of radiation, about the same as a dental X-ray. They were decontaminated and allowed to go home, she said.

Nuclear Management Co., which operates Xcel Energy's nuclear plants, said residual radioactive gas in some equipment was inadvertently released without being routed through a filtering system.

URL: http://sfgate.com/cgi-bin/article.cgi?file=/news/archive/2006/05/09/national/a112934D44.DTL