TRANSURANIC (TRU) WASTE
The Waste Isolation Pilot Plant (WIPP) permanently disposes of transuranic (TRU) waste that is the byproduct of the nation’s nuclear defense program.
TRU waste consists of tools, rags, protective clothing, sludges, soil and other materials contaminated with radioactive elements, mostly plutonium. These man-made elements have atomic numbers greater than uranium on the periodic table of elements (thus “trans-uranic” or beyond uranium).
WIPP was designed to dispose of two kinds of TRU waste. Contact-handled (CH) TRU waste has a radiation dose rate not greater than 200 millirem (mrem) per hour, as measured at the surface of the waste container. Remote-handled (RH) TRU waste can have a dose rate up to 1,000 rem per hour. About 96 percent of the waste to be disposed of at WIPP is CH TRU waste. When transported, both RH and CH TRU waste have the same dose rate limit on the outside of the shipping casks due to lead shielding.
CH TRU waste barrels and boxes are stacked in rows on the floor of WIPP’s underground disposal rooms, while RH TRU waste canisters are placed in boreholes drilled into the walls of the same rooms.