Transuranic waste (TRU) is stated by U.S. regulations, and independent of state or origin, to be waste which has been contaminated with alpha emitting transuranic radionuclides possessing half-lives greater than 20 years and in concentrations greater than 100 nCi/g (3.7 MBq/kg).
Under U.S. law, TRU is further categorized into "contact-handled" (CH) and "remote-handled" (RH) on the basis of the radiation field measured on the waste container's surface.
In contrast, RH TRU can be highly radioactive, with surface dose rates up to 10 Sv/h (1000 rem/h)[citation needed].
The United States currently permanently disposes of TRU generated from defense nuclear activities at the Waste Isolation Pilot Plant, a deep geologic repository.
Other countries do not include this category, favoring variations of High, Medium/Intermediate, and Low Level waste.