As operational experience is gained in the disposal of transuranic waste from nuclearweapons facilities at the Waste Isolation Pilot Plant in New Mexico, the Departmentof Energy (DOE) has opportunities to change how it "characterizes" waste to confirmthat it is appropriate for shipment to and disposal at the underground repository.The waste shipped to the facility includes gloves, rags, tools, and other debris ordried sludge that has been contaminated by radioactive elements, including plutonium,during production or cleanup activities in the DOE weapons complex. However,before the DOE seeks regulatory approval for changes to its characterization program,the agency should conduct and publish a systematic and quantitative assessmentto show that the proposed changes would not affect the protection of workers,the public, or the environment, according to the committee. The assessmentshould take into account technical factors, societal and regulatory impacts, and thetime and effort required to make the changes.