Hydrolytic and thermal stability of magnesium potassium phosphate compound for immobilization of high level waste
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The samples of the magnesium potassium phosphate (MPP) compound have been synthesized during solidification of high level waste (HLW) surrogate. The compound consists of a main phosphate phases Mg1.1Na0.35K0.45PO4 × (4–6)H2O and MgCs0.5Na0.2K0.3PO4 × (5–6)H2O. Differential leaching rates of 239Pu, 152Eu and 90Sr from the MPP compound after heat treatment (450 °C) are 7.8 × 10−9; 1.7 × 10−7 and 8.8 × 10−6 g cm−2 day−1, respectively. The coefficient of thermal expansion of MPP compound—(11.6 ± 0.3) × 10−6 °C−1; coefficient of thermal conductivity averages 0.5 W m−1 K−1. The properties of MPP compound meet the regulatory requirements for solidified HLW.
KeywordsMagnesium potassium phosphate compound High level waste Immobilization Thermal stability Leaching rate Leaching mechanism
The study was carried out through the Russian Science Foundation Grant (Project No 16-13-10539).
- 2.Vinokurov SE, Kulikova SA, Krupskaya VV, Myasoedov BF (2018) Magnesium potassium phosphate compound for radioactive waste immobilization: phase composition, structure, and physicochemical and hydrolytic durability. Radiochemistry 60:70–78. https://doi.org/10.1134/S1066362218010125 CrossRefGoogle Scholar
- 3.Wagh AS (2016) Chemically bonded phosphate ceramics: twenty-first century materials with diverse applications, 2nd edn. Elsevier, AmsterdamGoogle Scholar
- 5.IAEA-TECDOC-1701 (2013) Behaviour of cementitious materials in long-term storage and disposal of radioactive waste. International Atomic Energy Agency (IAEA), Vienna, Austria, p 61. https://www-pub.iaea.org/MTCD/publications/PDF/TE-1701_web.pdf
- 6.GOST R 52126-2003 (2003) Radioactive waste. Determination of chemical stability of cure high level waste by method of long-term leaching. Gosstandart of Russia, Moscow (in Russian) Google Scholar
- 7.de Groot GJ, van der Sloot HA (1992) Determination of leaching characteristics of waste materials leading to environmental product certification. In: Gilliam TM, Wiles G (eds) Stabilization and solidification of hazardous, radioactive and mixed wastes, vol 2. ASTMSTP 1123, ASTM, Philadelphia, pp 149–170CrossRefGoogle Scholar
- 9.Federal norms and regulations in the field of nuclear energy use, NP-019-15 (2015) Collection, processing, storage and conditioning of liquid radioactive waste. Safety requirements(in Russian) Google Scholar
- 11.Rabinovich VA, Khavin ZYa (1978) A brief chemical handbook. Chemistry, Leningrad (in Russian) Google Scholar