Paraphrasing a Source

From the article "Nuclear Waste Solutions Seen in Desert Salt Beds"

Passage:

The process is deceptively simple: Plutonium waste from Los Alamos National Laboratory and a variety of defense projects is packed into holes bored into the walls of rooms carved from salt. At a rate of six inches a year, the salt closes in on the waste and encapsulates it for what engineers say will be millions of years.

Paraphrase:
 
Storing the nuclear waste relies on a basic idea. The radioactive material (consisting mostly of plutonium) comes from Los Alamos National Laboratory and from the creation of nuclear weapons. The waste is then filled into cavities drilled out of the salt walls of the repository. The basic idea is that the salt will "creep" in around the waste, sealing the hazardous materials for millions of years into the future.