I shall add to this as more information comes to hand. There is some good discussion at the Facebook page of Mimi German, some of which I have included
Hundreds of workers were told to take cover at the Hanford Nuclear Reservation after a tunnel full of highly contaminated materials collapsed Tuesday morning. But officials say no radiation was released and no workers were hurt.
Officials say a collapsed patch of ground above the tunnel was larger than first believed. The U.S. Department of Energy said the collapse covered about 400 square feet (37.1 square meters) instead of the 16 square feet (1.4 square meters) first reported.
Hundreds of workers were told to go into a "take cover" position after the tunnel in a plutonium uranium extraction (PUREX) plant collapsed.
The agency says the rail tunnels are hundreds of feet long, with about eight feet (2.4 meters) of soil covering them. The U.S. Department of Energy says the incident caused the soil above the tunnel to sink between 2 and 4 feet (half to 1.2 meters).
"I would underscore this is confined to a small area of the Hanford site," Destry Henderson, deputy news manager for the Hanford Joint Information Center, told NBC News. "The facility does have radiological contamination right now but there is no indication of a radiological release," Henderson said.
A manager sent a message to all personnel telling them to "secure ventilation in your building" and "refrain from eating or drinking."
A source said "take cover" status was expanded to the entire site at 10:35 a.m. The source also said that crews doing road work nearby may have created enough vibration to cause the collapse, and that Vit Plant employees were in cover mode as well.
Robots were being used to determine possible air contamination.
Responding agencies include the U.S. Department of Energy; Richland, West Richland, and Kennewick city fire and police; Benton, Franklin, and Grant County fire and police officials; Washington state patrol; and Oregon and Washington state officials.
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.
Washington Gov. Jay Inslee said the Department of Energy and The White House reached out to his office after the incident.
“This is a serious situation, and ensuring the safety of the workers and the community is the top priority. Our understanding is that the site went into immediate lockdown, in which workers were told to seek shelter, and all access to the area has been closed," Inslee said in a statement.
Hanford, which is roughly half the size of Rhode Island, spent decades making plutonium for the nation's nuclear weapons arsenal.
Photo from source: Here is another view of the PUREX tunnel at Hanford. Hole from collapse seen under orange flag.
Hanford Nuclear Storage Facilty tunnel collapses after earthquake swarm
Hanford infoan explanation of Hanford's threat to Portland with Mimi German from No Nukes Northwest#fightchurchmedia