Many years ago, the United States government started a project aimed at proving that nuclear waste can be safely left underground.

The government approved plans to set up a processing center, known as the Waste Isolation Pilot Plant, or WIPP, in the New Mexico desert. The plant received its first shipment of radioactive waste in March of 1999.

Twenty years later, workers have stored more than 12,380 shipments of waste in the plant's underground salt caverns.

In this March 6, 2014, file photo, empty nuclear waste shipping containers sit in front of the Waste Isolation Pilot Plant near Carlsbad, N.M. (AP Photo/Susan Montoya Bryan, File)

What is WIPP?

WIPP is the U.S. government's only permanent underground storage area registered to take what is called transuranic waste. The term transuranic means waste made by the nation's nuclear weapons program that has only radioactive elements heavier than uranium.

The nuclear waste repository was cut out of an ancient salt formation about eight-tenths of a kilometer below the desert. The idea was that the salt would eventually completely contain the waste.

Peter Swift is a scientist at Sandia National Laboratories. He worked on the development of WIPP. He noted that it was "exciting" to work on "what was then going to be the world's first deep-geologic repository for that class of waste." Swift added that "nothing that radioactive had been put that deep underground before. And that's still true 20 years later."

J.R. Stroble is the head of business operations at the Department of Energy's Carlsbad Field Office in New Mexico. He told the Associated Press that the goal of WIPP is to prevent radioactive waste from reaching "people and the things people need in order to live life on Earth."

Stroble and others in the communities surrounding WIPP strongly believe that the plant is a success. They point to 22 areas around the nation that have been cleaned up because of WIPP's storage capabilities.

One example is Rocky Flats, a former nuclear weapons plant outside Denver, Colorado. It had a history of leaks, spills and other violations.

Problems and Criticism of WIPP

For critics, the success of WIPP is not clear.

Don Hancock works with the Southwest Research and Information Center, a watchdog group. He notes that WIPP is "80 percent through its lifetime, and it has disposed of less than 40 percent of the waste and has cost more than twice as much as it was supposed to."

"How great of a success is that?" he asked.

A 2014 radiation leak at WIPP forced a costly, nearly three-year closure.

More recently, the Department of Energy said it would investigate reports that workers may have been exposed to dangerous chemicals last year.

Hancock says a large problem is that the federal government and nuclear power plants keep producing more waste.

"How much nuclear power waste are we going to create, how much nuclear weapons waste are we going to create?" Hancock asked. He noted the importance of knowing answers to those questions, "so that we can then put our arms around the problem."

Susan Montoya Bryan reported on this story for AP. John Russell adapted it for VOA Learning English. George Grow was the editor.

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