Environmental Science Division (EVS) a Division of Argonne National Laboratory

High-activity fission products mineralized and immobilized in vitrified borated Ceramicrete

July 7, 2014

A newly filed patent for an enhancement of Argonne’s proven Ceramicrete™ technology provides a solution to a key issue for the nuclear industry — protecting the environment from the materials (fission products) released when radioactive atoms split. With this new Argonne technology, borated Ceramicrete, DOE will be able to immobilize very high-activity waste streams stored in tanks at its Hanford site and elsewhere, the nuclear industry can store spent fuel in glass (vitrified) form without risk of fission products escaping during processing, and the DOE National Nuclear Security Administration (NNSA) and the National Research Council (NRC) will be able to propose safer commercial sources of radioactive cesium for use by American industry.

The original Ceramicrete technology was developed to immobilize nuclear waste stored in the DOE complex. EVS has now advanced this technology to the next level by addressing the problem of fission products in spent fuel. These products exhibit very high activity and become airborne when spent fuel or high-level waste is vitrified to produce glass for permanent storage. They dissolve easily in groundwater and hence are highly dispersible. Cesium-137, strontium-90, and technetium-99 are examples.

To develop a means for preventing dispersion of fission products in the environment, the NNSA built on an idea conceived by Argonne’s Ceramicrete inventor and funded a research team including Argonne and nuclear scientists from the Kharkov Institute of Physics and Technology in Ukraine. The Boron Department of Ceradyne Corporation (a 3M Company) participated as an industrial collaborative research and development (CRADA) partner. Funded under the NNSA’s Global Initiatives for Proliferation Prevention program, the intensive two-year collaboration resulted in the borated Ceramicrete process, which can immobilize fission product waste streams so that they can be mineralized and kept out of both water and air streams. The treated waste can be placed in dry casks for interim storage and vitrified for safe permanent storage in repositories.

Collaborators from Argonne, Ceradyne Corporation, and Ukraine worked on the Ceramicrete vitrification project funded by the Global Initiatives for Proliferation Prevention program of the DOE National Nuclear Security Administration.
Collaborators from Argonne, Ceradyne Corporation, and Ukraine worked on the Ceramicrete vitrification project funded by the Global Initiatives for Proliferation Prevention program of the DOE National Nuclear Security Administration. [Source: Argonne National Laboratory]

The invention of borated Ceramicrete is very timely, because most commercial nuclear power plants are switching to high-burnup fuels to extract more power from a given amount of fuel. More power means more fission reactions and more fission products in the spent fuel. Borated Ceramicrete will make such spent fuel safer.

The borated Ceramicrete treatment also makes it possible to produce safe commercial radioactive isotope sources for use by the oil, pharmaceutical, and medical industries in exploration, calibration of instruments, medical treatment, and many other applications. The International Atomic Energy Agency, the NRC, and DOE had identified many of these isotope sources, especially cesium sources, as unsafe. The technology disclosed in the patent application can be used to design safer sources.

The comparatively simple pretreatment in the new borated Ceramicrete process involves mixing fission product streams, oxides, and phosphate powders with water to produce room-temperature-forming ceramic. The fission products react and form insoluble phosphate minerals that do not dissolve in water or evaporate when heated. The fission products are bound in the ceramic and hence are not easily separated.

The development of the borated Ceramicrete technology promises a solution to a difficult problem with disposal of spent fuel for the nuclear industry, as well as improved safety for the commercial isotope sources used in a wide range of applications.

For more information, contact Arun Wagh at asw@anl.gov.

Vitrified borated Ceramicrete with high-activity simulated waste.
Vitrified borated Ceramicrete with high-activity simulated waste. [Source: Argonne National Laboratory]