RICHLAND, Wash. — The collapse of a tunnel containing radioactive waste at the Hanford nuclear weapons complex underscored what critics have long been saying: that the toxic remnants of the Cold War are being stored in haphazard and unsafe conditions, and time is running out to deal with the problem.

“Unfortunately, the crisis at Hanford is far from an isolated incident,” said Kevin Kamps of the anti-nuclear group Beyond Nuclear.

For instance, at the Savannah River Site in South Carolina, which opened in the 1950s and produced plutonium and tritium, the government is laboring to clean up groundwater contamination along with 40 million gallons of radioactive liquid waste stored in tanks that are decades past their projected lifespan. The job is likely to take decades.

At Hanford, in addition to the tunnel collapse discovered on Tuesday, dozens of underground storage tanks, some dating to World War II, are leaking highly radioactive materials.

The problem is that the U.S. government rushed to build nuclear weapons during the Cold War with little thought given to how to permanently dispose of the resulting waste.

Safely removing it now is proving enormously expensive, slow-going, extraordinarily dangerous and so complex that much of the technology required simply does not exist. The cleanup has also been plagued with setbacks both political and technical.

For example, the nation’s only underground nuclear waste repository, in New Mexico, closed to new shipments in 2014 after an improperly packed drum of waste ruptured. The site just recently reopened.

The U.S. Department of Energy spends about $6 billion a year on managing waste left from the production of nuclear weapons.