High-level waste

The highly radioactive materials produced as byproducts of fuel reprocessing or of the reactions that occur inside nuclear reactors. HLW includes:

• Irradiated spent nuclear fuel discharged from commercial nuclear power reactors
• The highly radioactive liquid and solid materials resulting from the reprocessing of spent nuclear fuel, which contain fission products in concentration (this includes some reprocessed HLW from defense activities and a small quantity of reprocessed commercial HLW)
• Other highly radioactive materials that the Commission may determine require permanent isolation