Hanford

Hole in radioactive waste tunnel filled, difficult work ahead

Work begins to stabilize Hanford radioactive waste tunnel collapse

Destry Henderson, deputy news manager at the media center in the Federal Building in Richland, gives an update on the collapsed Hanford waste tunnel. A mixture of sand and soil is being slowly added to the breach.
Up Next
Destry Henderson, deputy news manager at the media center in the Federal Building in Richland, gives an update on the collapsed Hanford waste tunnel. A mixture of sand and soil is being slowly added to the breach.

Hanford crews finished filling a breach in a radioactive waste storage and disposal tunnel at the nuclear reservation late Wednesday night, ending the immediate threat of a release of radioactive contamination into the atmosphere.

More challenging work lies ahead at the site about 20 miles northwest of Richland.

Now the Department of Energy has to figure out how to prevent any further collapses at the two tunnels holding highly radioactive equipment at the defunct PUREX plant in central Hanford.

“Our next step is to identify and implement longer-term measures to further reduce risks,” new Energy Secretary Rick Perry said Thursday.

Washington state, a Hanford regulator, issued a legal order late Wednesday requiring a plan of correction after the hole measuring about 20-by-20 feet was discovered Tuesday in the top of the oldest tunnel.

No release of radioactive material into the air has been detected by state or federal monitoring and no one was hurt.

Near-term actions are expected to include placing a protective cover over the 360-foot-long tunnel with the breach, according to DOE.

“We’re planning additional protective measures slowly and methodically,” said Destry Henderson, spokesman for DOE contractor CH2M Hill Plateau Remediation Co. “They won’t take place until we’re sure we can do it safely.”

Among options being considered for the cover is a layer of thick plastic. The plastic would keep off rain that could add weight to the eight-foot layer of soil over the tunnel. It also would keep radioactive material from scattering into the atmosphere if there were another collapse.

The aging tunnel is built of creosoted timbers and some concrete that radiation could have deteriorated.

This week’s incident is a reminder that the men and women who work for the Department of Energy do incredible work, but that work does not come without risk.

Energy Secretary Rick Perry

Planning for the next stage of stabilization is underway, but installing a cover will be dependent on the weather, Henderson said.

Many Hanford workers returned to work Thursday, but a couple hundred employees who work near the PUREX plant in the 200 East Area were told to stay home for another day.

Most worked at nearby tank farms, where radioactive sludge is stored in underground tanks.

“Once additional protective measures are in place, we will evaluate lifting restricted areas,” Henderson said.

When an emergency was declared Tuesday morning at the nuclear reservation, including more than 3,000 workers, were ordered to take cover in buildings with ventilation systems turned off.

Between 1960 and 1965, eight rail cars holding contaminated equipment from the plant were pushed into the tunnel and left. A second, longer tunnel attached to the first was built in 1964 for additional waste.

Hanford workers north of the Wye Barricade, a secure entrance north of Richland, who were not essential to safety or security, were told to state home Wednesday.

“This week’s incident is a reminder that the men and women who work for the Department of Energy do incredible work, but that work does not come without risk,” Perry said. “Thankfully, the system worked as it should and all are safe.”

“As secretary, the safety of our workforce, the communities and tribal nations that surround our sites, and the environment is my highest priority,” he said in the statement.

During his Senate confirmation hearing, Perry pledged to visit Hanford.

Tuesday night, Hanford nuclear reservation employees began building a gravel road to get heavy equipment to the site of the collapse. Work to fill the breach in the tunnel with a mixture of sand and soil stretched from morning to night Wednesday.

Covering the breach with the mixture was planned to prevent any possible releases of radioactive contamination into the atmosphere.

Our focus remains on near-term protective actions.

Destry Henderson, CH2M spokesman

Crews placed 53 truckloads, or about 550 cubic yards of sand and soil, in the tunnel using an excavator with a scoop. An emergency declaration was lifted when the work was completed.

No cause for the collapse has been determined.

“Our focus remains on near-term protective actions,” Henderson said.

To meet the state order it must assess if there are risks of failures to either of the PUREX waste tunnels by July 1.

The PUREX plant was used starting in 1956 to chemically process irradiated uranium fuel to remove plutonium for the nation’s nuclear weapons program during the Cold War.

Between 1960 and 1965, eight rail cars holding contaminated equipment from the plant were pushed into the tunnel and left. A second, longer tunnel attached to the first was built in 1964 for additional waste.

The newer tunnel had more robust construction, with internal steel I-beams attached to reinforced concrete arches. Both were sealed.

Additional deadlines set by the state will require DOE to develop a plan to ensure the safe storage of waste in both tunnels and to submit a plan for permanently cleaning up the waste in the tunnels.

Annette Cary: 509-582-1533, @HanfordNews

  Comments