Three technologies are sufficiently developed for consideration to treat some of the low-activity radioactive waste stored at the Energy Department’s Hanford Site in Washington state, according to a new report from a National Academies panel.
The panel plans to issue four reports on supplemental treatment of Hanford low-activity waste. Congress ordered the study, which is being led by the Savannah River National Laboratory and independently reviewed by the National Academies of Sciences, Engineering, and Medicine.
The Waste Treatment Plant under construction at Hanford was never planned to convert the site’s 56 million gallons of tank waste into glass in a reasonable amount of time. About 90 percent of the waste in the tanks is expected to be low activity, and the plant might be able to only vitrify a third to a half of that material in 40 to 50 years of operation. The other material is being called supplemental waste.
The initial report said vitrification, grouting, or steam reforming technologies appear to be sufficiently developed or have sufficient likelihood of success to warrant detailed analysis. The team performing the analysis should prepare an assessment of the potential problems and technical challenges as well as the potential barriers to acceptance of any of the technologies, the National Academies’ report said.
Vitrification, while a known technology, is still technologically challenging and thus technologically risky, particularly for the chemically complex mixtures in Hanford waste and for processing on the large scale planned at the former plutonium production facility, the report said.
Grouting would require high-quality materials that could become more expensive or less available when supplemental treatment might be expected to start several years in the future and for the decades that the treatment would continue, the report said.
It also pointed out troubles at the Integrated Waste Treatment Unit at the Idaho National Laboratory, a steam reforming project. The Idaho project may not be a useful model for the team to consider as it has yet to work to scale and has experienced technical and management problems since 2012, the report said.
