High-level radioactive waste is the waste that comes from producing nuclear materials for defense purposes. Ultimately, this waste is stored as sludge, liquid, or pellets, and must be solidified before manufacturers or labs can dispose of it. Currently, the United States does not reprocess spent nuclear fuel, nor does it have a disposal facility for high-level radioactive waste. Most high-level radioactive waste is stored at the facility in which it was produced.
For information on the ways the Nuclear Regulatory Commission (NRC) classifies and processes high-level radioactive waste, visit High-Level Waste and Waste Incidental to Reprocessing.
For more information on high-level radioactive waste, visit Radioactive Regulations and Laws at EPA.gov.