Instantaneous Formation of Synroc-B Phases at Ambient Pressure

1995 ◽  
Vol 412 ◽  
Author(s):  
J. M. Mchale ◽  
N. V. Coppa
Keyword(s):  
Nuclear Waste ◽  
Ambient Pressure ◽  
Nuclear Materials ◽  
Phase Assemblage ◽  
Preparation Conditions ◽  
Nitrate Precursor ◽  
Freeze Dried ◽  
High Level Nuclear Waste ◽  
Nuclear Waste Immobilization ◽  
High Level

AbstractThe titanate based nuclear waste immobilization medium, Synroc-B, has been synthesized at atmospheric pressure from freeze dried nitrate precursors. Complete formation of the phase assemblage (CaTiO3, CaZrTi2O7, and BaAl2Ti5O14) occurred upon calcination of the nitrate precursor after only 10 minutes at 1100°C. This improvement in the preparation conditions may lead to practical application of the material in the safe disposal of high level nuclear waste and the immobilization of other strategic nuclear materials.

In Situ Radiation Damage Studies of Ca3Zr2FeAlSiO12 and Ca3Hf2FeAlSiO12

2008 ◽  
Vol 1124 ◽  
Author(s):  
Karl R Whittle ◽  
Mark Blackford ◽  
Gregory R Lumpkin ◽  
Katherine L Smith ◽  
Nestor J Zaluzec
Keyword(s):  
Nuclear Waste ◽  
National Laboratory ◽  
Argonne National Laboratory ◽  
Voltage Electron ◽  
Significant Difference ◽  
User Facility ◽  
High Level Nuclear Waste ◽  
Nuclear Waste Immobilization ◽  
High Level

AbstractGarnets, A3B2C3O12, are considered to be potential host phases for the immobilization of high-level nuclear waste as they can accommodate a number of elements of interest, including Zr, Ti and Fe. The naturally occurring garnet, kimzeyite, Ca3(Zr,Ti)2(Si,Al,Fe)3O12, can contain ˜30wt% Zr. An understanding of the radiation tolerance of these materials is crucial to their potential use in nuclear waste immobilization. In this study two synthetic analogues of kimzeyite of composition Ca3Zr2FeAlSiO12 and Ca3Hf2FeAlSiO12 were monitored in situ during irradiation with 1.0 MeV Kr ions using the intermediate voltage electron microscope-Tandem User Facility (IVEM) at Argonne National Laboratory. The structure of these materials was previously determined by neutron diffraction and 57Fe Mössbauer spectroscopy. Ca3Zr2FeAlSiO12 and Ca3Hf2FeAlSiO12 have very similar structural properties with cubic Ia3d symmetry, the only significant difference being the presence of Zr and Hf, respectively, on the 6 coordinated B sites.

Radiation Effects in Silicate Glasses - A Review

1988 ◽  
Vol 125 ◽  
Author(s):  
Ned E. Bibler ◽  
David G. Howitt
Keyword(s):  
Fiber Optics ◽  
Nuclear Waste ◽  
Radiation Effects ◽  
Alpha Particles ◽  
Phase Changes ◽  
Silicate Glasses ◽  
Atomic Displacements ◽  
High Level Nuclear Waste ◽  
Nuclear Waste Immobilization ◽  
High Level

ABSTRACTThe study of radiation effects in complex silicate glasses has received renewed attention because of their use in special applications such as high level nuclear waste immobilization and fiber optics. Radiation changes the properties of these glasses by altering their electronic and atomic configurations. These alterations or defects may cause dilatations or microscopic phase changes along with absorption centers that limit the optical application of the glasses. Atomic displacements induced in the already disordered structure of the glasses may affect their use where heavy irradiating particles such as alpha particles, alpha recoils, fission fragments, or accelerated ions are present. Large changes (up to 1%) in density may result. In some cases the radiation damage may be severe enough to affect the durability of the glass in aqueous solutions.In this paper, we review the literature concerning radiation effects on density, durability, stored energy, microstructure and optical properties of silicate glasses. Both simple glasses and complex glasses used for immobilization of nuclear waste are considered.

scholarly journals Vitreous Materials for Nuclear Waste Immobilisation and IAEA Support Activities

MRS Advances ◽  
2016 ◽  
Vol 1 (63-64) ◽  
pp. 4201-4206 ◽  
Author(s):  
Rebecca A. Robbins ◽  
Michael I. Ojovan
Keyword(s):  
Radioactive Waste ◽  
Nuclear Waste ◽  
Chemical Elements ◽  
Phosphate Glasses ◽  
Waste Vitrification ◽  
Waste Immobilization ◽  
High Level Nuclear Waste ◽  
Nuclear Waste Immobilization ◽  
High Level ◽  
High Degree

ABSTRACTVitreous materials are the overwhelming world-wide choice for the immobilisation of HLW resulting from nuclear fuel reprocessing due to glass tolerance for the chemical elements found in the waste as well as its inherent stability and durability. Vitrification is a mature technology and has been used for high-level nuclear waste immobilization for more than 50 years. Borosilicate glass is the formulation of choice in most applications although other formulations are also used e.g. phosphate glasses are used to immobilize high level wastes in Russia. The excellent durability of vitrified radioactive waste ensures a high degree of environment protection. Waste vitrification gives high waste volume reduction along with simple and cheap disposal facilities. Although vitrification requires a high initial investment and then operational costs, the overall cost of vitrified radioactive waste is usually lower than alternative options when account is taken of transportation and disposal expenses. Glass has proven to be also a suitable matrix for intermediate and low-level radioactive wastes and is currently used to treat legacy waste in USA, and NPP operational waste in Russia and South Korea. This report is also outlining IAEA activities aiming to support utilisation of vitreous materials for nuclear waste immobilisation.

Nuclear waste immobilization into structure of zirconolite by Complex Sol Gel Process

2014 ◽  
Vol 1683 ◽  
Author(s):  
Tomasz Smoliński ◽  
Andrzej Deptuła ◽  
W. Lada ◽  
Tadeusz Olczak ◽  
Andrzej G. Chmielewski ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Nuclear Waste ◽  
Thermal Analyses ◽  
Sol Gel ◽  
Complexing Agent ◽  
X Ray Diffraction ◽  
Sol Gel Process ◽  
High Level Nuclear Waste ◽  
Nuclear Waste Immobilization ◽  
High Level

ABSTRACTZirconolite (CaZrTi2O7) is one of the components of Synroc materials, which are regarded throughout the world nuclear as the second generation of high-level nuclear waste forms. The zirconolite phase was synthesized by a sol-gel method, with one variant of the method making use of ascorbic acid as a strong complexing agent. Into the structure of the zirconolite was incorporated 10 mol% Sr. Undoped and doped samples were examined by thermal analyses and X-ray diffraction. Addition of ascorbic acid to the sols lowered the firing temperature and promoted formation of the zirconolite phase.

Transmutation of high-level nuclear waste by means of accelerator driven system

2013 ◽  
Vol 3 (1) ◽  
pp. 60-69 ◽  
Author(s):  
Hamid Aït Abderrahim ◽  
Didier De Bruyn ◽  
Gert Van den Eynde ◽  
Sidney Michiels
Keyword(s):  
Nuclear Waste ◽  
Driven System ◽  
High Level Nuclear Waste ◽  
Accelerator Driven System ◽  
High Level
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