FEATURES OF SYNTHESIS, COMPOSITION AND PROPERTIES OF MAGNESIUM POTASSIUM PHOSPHATE COMPOUND FOR RADIOACTIVE WASTE IMMOBILIZATION

The paper presents a comprehensive study exploring the immobilization of radioactive waste (RW) simulants containing
14C and spent sorbent from the chromatographic separation of americium-curium using a low-temperature
mineral-like magnesium potassium phosphate (MPP) compound. It shows that the order in which the binding components
are introduced has great impact on the intensity of undesirable processes during the solidifi ation of these
RW types, including gas evolution, foaming, heat generation, high setting rate. Optimal basic solidifi ation modes
were selected for the considered RW. The properties of a MPP compound containing 10 wt. % of calcium carbonate
as a waste form with 14C, and 20 wt. % of spent ion-exchange resin simulants were studied. The study shows that
the physicomechanical properties of compound samples comply with the regulatory requirements for solidified RW.
The proposed solidifi ation modes will be tested on a prototype of a pilot unit that is now being developed for RW
solidifi ation in a MPP compound.

Keywords: radioactive waste, magnesium potassium phosphate matrix, MPP compound, 14C immobilization, spent sorbent, americium, curium, compressive strength, frost resistance, water resistance, microstructure.

Krapivina M. K., Chernikov M. A., Suntsov D. Yu., Kascheev V. A., Artobolevskii S. V., Fimina S. A.,
Chalysheva N. D., Vinokurov S. E. Features of Synthesis, Composition and Properties of Magnesium
Potassium Phosphate Compound for Radioactive Waste Immobilization Radioactive Waste, 2026, no. 2 (35),
pp 31—42 DOI: 10.25283/258 -9707-2026-2-31-42 (In Russian).