Fort Calhoun Nuclear Power Plant is an island, but authorities are hoping it stays dry. Associated Press A fire in Nebraska's Fort Calhoun nuclear power plant briefly knocked out the cooling process for spent nuclear fuel rods, ProPublica reports.

The fire occurred on June 7th, and knocked out cooling for approximately 90 minutes. After 88 hours, the cooling pool would boil dry and highly radioactive materials would be exposed.

On June 6th, the Federal Administration Aviation (FAA) issued a directive banning aircraft from entering the airspace within a two-mile radius of the plant.

"No pilots may operate an aircraft in the areas covered by this NOTAM," referring to the "notice to airmen," effective immediately.

Since last week, the plant has been under a "notification of unusual event" classification, becausing of the rising Missouri River. That is the lowest level of emergency alert.

The OPPD claims the FAA closed airspace over the plant because of the Missouri River flooding. But the FAA ban specifically lists the Fort Calhoun Nuclear Power Plant as the location for the flight ban.

The plant is adjacent to the now-flooding river, about 20 minutes outside downtown Omaha, and has been closed since April for refueling.

WOWT, the local NBC affiliate, reports on its website:

"The Ft. Calhoun Nuclear Facility is an island right now but it is one that authorities say is going to stay dry. They say they have a number of redundant features to protect the facility from flood waters that include the aqua dam, earthen berms and sandbags."

OPPD spokesman Jeff Hanson told Business Insider that the nuclear plant is in a "stable situation." He said the Missouri River is currently at 1005.6" above sea level, and that no radioactive fuel had yet been released or was expected to be released in the future.

Asked about the FAA flight ban, Hanson it was due to high power lines and "security reasons that we can't reveal." He said the flight ban remains in effect.

Here's a video from last week. The first forty seconds are video that Omaha's Action 3 News shot of the besieged plant, despite OPPD's requests that it not do so. The rest of the video is from a radio show in New York reporting on the unfolding events in Nebraska.

We'll keep you apprised of the situation as more details come to light.