Crystalline phosphates for HLW immobilization - composition, structure, properties and production of ceramics. Spark Plasma Sintering as a promising sintering technology

Применение метода GIXRD для исследования нарушенных слоев в керамиках NaNd(WO_4)-=SUB=-2-=/SUB=- и NaNd(MoO_4)-=SUB=-2-=/SUB=-, подвергнутых облучению высокоэнергетическими ионами

“…В качестве перспективных материалов для иммобилизации компонентов радиоактивных отходов исследуются керамики на основе минералоподобных соединений [9,10], в том числе со структурой минерала шеелита [11,12]. Изоструктурные шеелитоподобные соединения могут содержать в своем составе многие элементы, изотопы которых присутствуют в отходах радиохимических технологий [13,14].…”

(Na, Zr) and (Ca, Zr) Phosphate-Molybdates and Phosphate-Tungstates: I–Synthesis, Sintering and Characterization

“…In this paper, the inorganic compounds with the NaZr 2 (PO 4 ) 3 (NZP-type) structure are studied extensively in connection with the prospects of application for solving the problems of immobilization of the highly active components of radioactive waste (HLW) [ 1 , 2 , 3 , 4 ]. In particular, the Mo-containing fractions of the radioactive waste solidify as inclusions in glass, together with other nuclides, for example, the wedge-shaped glass ceramics in the borosilicate glasses [ 5 , 6 , 7 ].…”

“…The sintering of the crystalline compounds into ceramics increases their relative density, while preserving the phase composition. At the same time, the resulting ceramics have high strength characteristics [ 1 , 4 , 17 , 18 , 19 , 20 ].…”

“…Therefore, the cations in the M sites and the total occupancy of the sites affect the changes in the thermal expansion coefficients. Some of these compounds have small or ultra-low [down to (1–2)·10 −6 deg −1 ] controlled thermal expansion coefficients [ 1 , 4 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 ]. Also, these compounds are stable under hydrothermal conditions at temperatures up to 400 °C and at durations of contact with water up to two years [ 1 , 4 , 18 , 44 , 45 , 46 ].…”

“…Some of these compounds have small or ultra-low [down to (1–2)·10 −6 deg −1 ] controlled thermal expansion coefficients [ 1 , 4 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 ]. Also, these compounds are stable under hydrothermal conditions at temperatures up to 400 °C and at durations of contact with water up to two years [ 1 , 4 , 18 , 44 , 45 , 46 ]. Such a unique hydrolytic resistance of the ceramics with the NZP-type structure increases interest in them as materials for solving the radiochemical problems of immobilization of radioactive waste [ 1 , 4 , 21 ].…”