Officials at the Prairie Island nuclear power plant are investigating what it calls an "unusual event" after a piece of security equipment failed Wednesday afternoon, according to a news release. Xcel Energy said no radioactive material was released during the incident and there is no danger to the public or its workers.

The Minneapolis-based utility is asking Minnesota regulators to confirm the $310 million upgrade will benefit customers. Xcel says the project will take more time to complete and produce less power than originally thought. The company also says generating electricity with natural gas is more financially attractive because prices are at 10 year lows.

The Prairie Island Indian community says the failure of two backup generators at the Prairie Island nuclear plant is "very troubling," the Rochester Post Bulletin reports. Xcel Energy shut down one of its two reactors at the plant near Red Wing on Tuesday. Xcel assured no radiation was released.

The Minneapolis-based utility needs to add more portable generators and pumps at both its Monticello and Prairie Island plants, in case of an emergency. The Pioneer Press reports the new requirements will cost between $25 million and $50 million.

Dennis Koehl, currently the senior vice president and chief nuclear officer of Xcel Energy has been named the CEO of the South Texas Project Nuclear Operating Co. Koehl will leave in mid-September after nearly five years with the Minneapolis-based utility. The Business Journal reports an interim chief nuclear officer, responsible for the company's Prairie Island and Monticello nuclear plants, will be named soon.

Regulators say a security violation at Xcel Energy's nuclear plant near Red Wing was spotted during an October inspection and was corrected then. They won't reveal the details of the violation but say follow-up inspections are planned.