Tunnel Collapses at Hanford Nuclear Facility in Washington State

FILE - In this July 9, 2014 file photo, a sign informs visitors of prohibited items on the Hanford Nuclear Reservation near Richland, Wash. No radiation leak has been detected and no release of contamination has been determined according to a Hanford Site press release release. The reason behind the incident is still unknown, though Department of Energy spokesman Mark Heeter noted that there has never been a tunnel collapse at Hanford.

Over the course of its operating lifetime, the facility produced almost 56 million gallons of radioactive and chemical waste that is now stored in 177 underground tanks. As of Tuesday afternoon about 3,000 Hanford workers remain in a "take-cover" situation.

A representative at the Hanford Emergency Operations Center who would not give her name said there were no injuries reported.

The directive was sent out because crews discovered that a 20-foot section of one of the underground tunnels in the site had caved in.

According to CBS News, the Hanford Nuclear Reservation was created during World War II to secretly build the atomic bomb.

The Department of Energy said the affected tunnel was located next to the Plutonium Uranium Extraction Facility known as PUREX.

"Officials continue to monitor the air and are working on how they will fix the hole in the tunnel roof", the Hanford Emergency Information site announced.

The two tunnels were used at the beginning of the 1950s to store contaminated equipment and the cave-in apparently took place in an area where the two join together.

"In 2015, a preliminary report identified the tunnels and the PUREX facility as a major risk area on the Hanford site".

The Statesman Journal reports the Oregon Department of Energy has activated its emergency operation center in response to the Hanford emergency, which is 35 miles away from Oregon.

The U.S. Department of Energy, Richland, West Richland, and other local fire and police officials as well as Washington state patrol and OR and Washington state officials all responded to the scene, according to KING5.

A massive cleanup that started in the 1980s is still ongoing at Hanford, with the project expected to be completed by 2060.

Workers in one building were evacuated, and others in the immediate vicinity were ordered to take cover and turn off ventilation systems as a precaution after minor damage was discovered in the wall of a transport tunnel, a spokeswoman for the Department of Energy told Reuters.

There was speculation that the cave-in may have been caused by vibrations from nearby road works. The tunnels are hundreds of feet long, with about 8 feet (2.4 meters) of soil covering them, the agency said.

For decades, Hanford made plutonium for nuclear weapons, and now is engaged in cleaning up the nation's largest volume of radioactive defense wastes.