Szenknect Stéphanie, Alby Delhia, López García Marta, Wang Chenxu, Podor Renaud, Miserque Frédéric, Mesbah Adel, Duro Lara, Zetterström Evins Lena, Dacheux Nicolas, Bruno Jordi, Ewing Rodney C
ICSM, Univ Montpellier, CEA, CNRS, ENSCM, 30207, Bagnols sur Cèze, France.
Amphos 21, Consulting, Carrer Veneçuela, 103, Planta 2, 08019, Barcelona, Spain.
Sci Rep. 2020 Jul 22;10(1):12168. doi: 10.1038/s41598-020-69161-1.
Most of the highly radioactive spent nuclear fuel (SNF) around the world is destined for final disposal in deep-mined geological repositories. At the end of the fuel's useful life in a reactor, about 96% of the SNF is still UO. Thus, the behaviour of UO in SNF must be understood and evaluated under the weathering conditions of geologic disposal, which extend to periods of hundreds of thousands of years. There is ample evidence from nature that many uranium deposits have experienced conditions for which the formation of coffinite, USiO, has been favoured over uraninite, UO, during subsequent alteration events. Thus, coffinite is an important alteration product of the UO in SNF. Here, we present the first evidence of the formation of coffinite on the surface of UO at the time scale of laboratory experiments in a solution saturated with respect to amorphous silica at pH = 9, room temperature and under anoxic conditions.
世界上大部分高放射性乏核燃料（SNF）最终都将被深埋于地质储存库中进行处置。在反应堆中燃料的使用寿命结束时，约96%的乏核燃料仍是UO。因此，必须了解并评估乏核燃料中UO在地质处置的风化条件下的行为，这种条件会持续数十万年。自然界有充分证据表明，许多铀矿床经历过这样的条件，即在随后的蚀变事件中，硅铀矿（USiO）的形成比沥青铀矿（UO）更有利。因此，硅铀矿是乏核燃料中UO的一种重要蚀变产物。在此，我们首次展示了在pH = 9、室温且缺氧条件下，在相对于无定形二氧化硅饱和的溶液中，于实验室实验的时间尺度上，UO表面形成硅铀矿的证据。
