By Nicholas K. Geranios / Associated Press

RICHLAND — Future accidental radiation releases at the largest U.S. site of waste from nuclear weapons production are likely following back-to-back emergency evacuations of workers in May and June because aging infrastructure is breaking down, the top Energy Department official at the site told The Associated Press.

Adding to the likelihood of more nuclear mishaps at the sprawling Hanford Nuclear Reservation is inadequate government funding to quickly clean up the millions of gallons of toxic nuclear waste at the site, said Doug Shoop, who runs the department’s operations office at Hanford.

Hanford has an annual budget of $2.3 billion for cleanup but Shoop said it will cost at least $100 billion to clean up the highly toxic radioactive and chemical wastes on the 580-square mile site which produced up to 70 percent of the plutonium for the U.S. nuclear arsenal since it was established in World War II.

“The infrastructure is not going to last long enough for the cleanup,” Shoop said in an interview this week. “It will be another 50 years before it is all demolished.”

Shoop made the comments after hundreds of Hanford workers were evacuated May 9 when the roof of a 1950s rail tunnel storing a lethal mix of waste from plutonium production collapsed. Tests show no radiation was released.

Then, on June 8, demolition work at a 1940s plutonium plant sent 350 workers seeking cover inside. Radiation was emitted but not deemed at a level harmful to people.

More money would lead to a faster cleanup, Shoop said. But President Donald Trump’s proposed budget for next year includes a $120 million cut for Hanford.

The official deadline for cleaning up Hanford is 2060, but Shoop said so much infrastructure at the site is deteriorating that “some facilities are not going to withstand that time.”

The site’s cleanup began in 1989 and critics have accused regulators of allowing the U.S. government to delay cleanup deadlines by decades, putting lives and the environment at risk.

“Every year that we don’t have an earthquake … has been just luck,” said Gerry Pollet, a Washington state legislator who represents a liberal Seattle district, about 200 miles from Hanford.

Shoop said about half of the site is free of pollution. And parts of Hanford make up the new Manhattan Project National Historical Park, where visitors can learn about the development of the atomic bomb.

But Hanford’s most dangerous contaminated waste has not been cleaned up, and the two recent evacuation incidents illustrated problems that could become more frequent in the future.

In the May rail tunnel collapse, a huge sinkhole suddenly emerged above the 360-foot long tunnel holding eight railroad cars that transported waste in the 1950s. The earth that fell into the tunnel helped prevent radiation from going into the air because it covered the railroad cars. Workers have since filled in the sinkhole and covered the tunnel with a fabric similar to what is used to cover farmers’ haystacks.

Officials were aware of the risk to the tunnel, Shoop said. He warned other aging facilities at Hanford also pose a risk.

“There are a whole bunch of things analogous to the tunnels,” he said.

In the June incident, radiation warnings sounded as workers removed outdoor equipment from a plant that once churned out disks of plutonium for use in nuclear weapons and is now one of Hanford’s most polluted areas.

The event illustrated how Hanford’s precautions to protect its workers have paid off and how they’ll likely face similar situations in the future, Shoop said.

“We are sending people into environments no one was expected to go to,” Shoop said. “Is there the potential for more alarms? Absolutely.”

Hanford’s has 177 underground tanks made of steel that contain more that 54 million gallons of radioactive and chemical wastes.

In late May, radioactive contamination was also found on robotic equipment surveying the space between the walls of a double-walled underground nuclear waste storage tank, indicating a possible leak. Some radioactivity was discovered on the clothing of the worker who removed the robot from the tank, although no skin contamination was found, Hanford officials said.

In addition, vapors for several years have escaped from underground storage tanks and made dozens of workers sick, most recently on Tuesday. In that event, eight reported smelling vapors and three underwent medical checks.

The tunnel collapse prompted a group of northwestern U.S. lawmakers to press the federal Government Accountability Office to review the Hanford cleanup work, saying they “are concerned that future events could put the safety of workers, the public and environment at risk.”

Shoop defended progress at Hanford, pointing to numerous successes from three decades of cleanup.

He is aware that some people may feel little has been done.

“Some things are not proceeding as fast as we’d all like,” Shoop said. “You can’t do it all at once.”