Cleanup workers at the Idaho National Laboratory have successfully removed the last wooden box of radioactive waste from the above-ground Transuranic Storage Area. Technicians signed their names to the final retrieval container on the night of February 21, 2017. This is an important step in INL’s overall cleanup plan for transuranic (TRU) waste, both above-ground and buried.

The next step will be to treat the retrieved waste at the Advanced Mixed Waste Treatment Plant. The waste will still eventually have to be shipped out of Idaho for permanent disposal, but in the meantime, it will be stored much more safely than it has been.

Until 1970, transuranic waste, which is contaminated with plutonium, was buried in unlined pits and trenches at INL. But plutonium remains hazardous for 240,000 years, and the government realized that, until a deep geologic repository was available, it was safer to store it above ground. At INL, the waste was stacked on concrete pads next to the burial grounds and then covered with dirt, so it was essentially above-ground buried waste. Over the years, the Transuranic Storage Area grew to cover 7 acres and was eventually enclosed in a giant metal building.

Efforts to process all the above-ground TRU waste began in 2003. As workers moved to older waste stored in increasingly damaged barrels and boxes, the work became more dangerous. In 2010, one worker was exposed when a waste container released plutonium-238 as it was being opened. Work was suspended for more than a year to install movable enclosures to contain contamination as workers handled the old packages.

Despite the difficulties, the INL workforce removed approximately 65,000 cubic meters of plutonium-contaminated waste from unsafe storage in TSA. Well done.

Efforts to exhume waste from the burial grounds next door, which began in earnest in 2005, will continue.