Projects & Programs
Design and Performance of Radioactive Waste Forms
When it comes to radioactive waste form development, PNNL is one of the go-to labs in the DOE complex. Currently, integrated programs from the DOE Offices of Nuclear Energy (NE) and Environmental Management (EM) aim to develop durable forms for radioactive waste both from the legacy weapons programs and from future processing of used civilian nuclear power rods. The RMTD group has over 40 years of programmatic funding in this area.
The wide variety of potential waste streams presents a complex materials design challenge, requiring the development of many different types of materials specifically tailored to efficiently immobilize specific streams. The materials being designed include:
- Glasses
- Glass-ceramics
- Crystalline Ceramics; generating Pollucite, Strontiocelsian crystals
Vermiculite-based crystalline ceramic for creating pollucite
- Cementicious materials and geopolymers
- Metallic alloys
- Vapor deposited materials
- Sol-gel derived materials
EDS dot map of glass ceramic in a scanning electron micrscope
One critical aspect to designing applicable waste forms is the assessment of durability, often for geologic time scales. The expertise of PNNL in performance assessment is unmatched in the DOE complex, and is sought out whenever a new waste form design must be vetted. The RM&TD group has taken the lead in establishing and running an international effort into understanding the long-term corrosion of high-level waste glasses. In this collaborative program, six nations coordinate their activities to minimize duplication and increase confidence in the resultant studies, while focusing on each nation’s specific research priorities. This approach is expected to increase national and international confidence in the robustness of understanding of glass corrosion, leading to cost savings in disposal because of reduced uncertainty.