Corrosion resistance and mechanical properties of Armakap cement for nuclear applications

Highlights: • Material improvements are needed for safe long-term storage of spent nuclear fuel. • Corrosion resistance of magnesium phosphate concretes is better than Portland. • Magnesium phosphate concretes improve upon the strength of Portland as well. Nuclear waste containers are prone to environmental degradation – over time, corrosion/erosion can cause the leakage of radioactive material which is a significant safety hazard. In the current work, environmental degradation of magnesium phosphate cement formulated by Armakap (2020, 3030) is investigated by using corrosion/erosion circulators that provide both acidic and saline environments. Test results indicate that Armakap formulations have reduced mass loss due to acidolysis by more than a factor of two in highly acidic conditions relative to a standard Portland cement sample. Additionally, the mechanical strength of Armakap 2020 formulation surpass that of Portland cement while Amrakap 3030 depicts a minor reduction. Although the Armakap 3030 provides good corrosion resistance, we conclude that Armakap 2020 shows optimal performance and is better suited than conventional Portland cement for a variety of nuclear waste storage applications at temperatures not exceeding 55 °C.