TY - JOUR
T1 - Synthesis of nuclear waste simulants by reaction precipitation
T2 - Formation of caesium phosphomolybdate, zirconium molybdate and morphology modification with citratomolybdate complex
AU - Paul, Neepa
AU - Hammond, Robert B.
AU - Hunter, Timothy N.
AU - Edmondson, Michael
AU - Maxwell, Lisa
AU - Biggs, Simon
PY - 2015/3/29
Y1 - 2015/3/29
N2 - Caesium phosphomolybdate (Cs3PMo12O40·xH2O) and zirconium molybdate ([ZrMo2O7(OH)2]·2H2O) solids are known to precipitate out from highly active liquors (HAL) during reprocessing of spent nuclear fuel. Here, a new synthesis for these simulants is reported; with the initial step producing spherical ceasium phosphomolybdate particles, which can then be converted into cubic Zirconium molybdate. Additionally, the addition of citric acid prior to the formation of the zirconium salt is investigated. In this case, a citratomolybdate complex is generated, leading to the synthesis of elongated cuboidal zirconium citratomolybdate ([ZrMo2O7(OH)2]·2H2O·[(MoO2)2O(cit)2]). A key focus of this study is to explore the optimisation of reaction conditions to create a controlled environment for the particles to form with high conversion rates and with desired shape properties. Elemental and structural characterisation of the particles at various points during the synthesis, as well as post-synthesis, was undertaken to provide further insights. Ultimately, it is of importance to determine the mechanism of how these simulants are formed within the components in HAL. Establishing the influence of particle properties on HAL behaviour is key for current processing, post operational clean out (POCO) and life-time assessment of the nuclear waste facilities.
AB - Caesium phosphomolybdate (Cs3PMo12O40·xH2O) and zirconium molybdate ([ZrMo2O7(OH)2]·2H2O) solids are known to precipitate out from highly active liquors (HAL) during reprocessing of spent nuclear fuel. Here, a new synthesis for these simulants is reported; with the initial step producing spherical ceasium phosphomolybdate particles, which can then be converted into cubic Zirconium molybdate. Additionally, the addition of citric acid prior to the formation of the zirconium salt is investigated. In this case, a citratomolybdate complex is generated, leading to the synthesis of elongated cuboidal zirconium citratomolybdate ([ZrMo2O7(OH)2]·2H2O·[(MoO2)2O(cit)2]). A key focus of this study is to explore the optimisation of reaction conditions to create a controlled environment for the particles to form with high conversion rates and with desired shape properties. Elemental and structural characterisation of the particles at various points during the synthesis, as well as post-synthesis, was undertaken to provide further insights. Ultimately, it is of importance to determine the mechanism of how these simulants are formed within the components in HAL. Establishing the influence of particle properties on HAL behaviour is key for current processing, post operational clean out (POCO) and life-time assessment of the nuclear waste facilities.
KW - Caesium phosphomolybdate
KW - Inorganic compounds
KW - Nuclear waste
KW - Zirconium citratomolybdate
KW - Zirconium molybdate
UR - http://www.scopus.com/inward/record.url?scp=84961380451&partnerID=8YFLogxK
U2 - 10.1016/j.poly.2014.12.030
DO - 10.1016/j.poly.2014.12.030
M3 - Article
AN - SCOPUS:84961380451
SN - 0277-5387
VL - 89
SP - 129
EP - 141
JO - Polyhedron
JF - Polyhedron
ER -