Fast/Instant Radionuclide Release: Effects inherent to the experiment

2014 ◽  
Vol 1665 ◽  
pp. 233-243
Author(s):  
B. Kienzler ◽  
A. Loida ◽  
E. González-Robles ◽  
N. Müller ◽  
V. Metz
Keyword(s):  
Nuclear Fuel ◽  
Spent Nuclear Fuel ◽  
Fission Products ◽  
Solution Chemistry ◽  
Release Rates ◽  
Radionuclide Sorption ◽  
Series Of Experiments ◽  
Radionuclide Release

ABSTRACTThe release of radionuclides measured during washing cycles of spent nuclear fuel samples in a series of experiments using different solutions are analyzed with respect to the fission products Cs, Sr, and Tc and the actinides U, Pu, and Am. Based on the concentrations of the dissolved radionuclides, their release rates are evaluated in terms of fraction of inventory in the aquatic phase per day. The application of this information on the fast/instant radionuclide release fraction (IRF) is discussed and following issues are addressed: Duration of the wash steps, solution chemistry, and radionuclide sorption onto surface of the experimental vessels. Data for the IRF are given and the correlation between the mobilization of the various elements is analyzed.

Predicting Radionuclide Release Rates from Spent Nuclear Fuel Inside a Failed Waste Disposal Container Using a Finite Element Model

CORROSION ◽  
10.5006/2866 ◽  
2018 ◽  
Vol 75 (3) ◽  
pp. 302-308 ◽  
Author(s):  
Nazhen Liu ◽  
Ziyan Zhu ◽  
Linda Wu ◽  
Zack Qin ◽  
James J. Noël ◽  
...  
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Nuclear Fuel ◽  
Waste Disposal ◽  
Spent Nuclear Fuel ◽  
Element Model ◽  
Release Rates ◽  
Radionuclide Release

Diffusion of Plutonium in Compacted, Brine-Saturated Bentonite

1984 ◽  
Vol 44 ◽  
Author(s):  
E. J. Nowak
Keyword(s):  
Radioactive Waste ◽  
Packing Density ◽  
Solution Chemistry ◽  
Lithostatic Pressure ◽  
Release Rates ◽  
Rock Types ◽  
Diffusion Studies ◽  
Engineered Barriers ◽  
Radionuclide Release ◽  
Wyoming Bentonite

AbstractDiffusivities were measured for plutonium in brine-saturated compacted Wyoming bentonite. Complexities of the solution chemistry and retardation of transuranics necessitate diffusion studies under conditions that are specific for repository host rock types in this case salt. Diffusivity values in the range of 10−15 to 10−14 m2/s were obtained for bentonite at a packing density of 1800 kg/m3. That density was obtained by compaction at 15 i0Pa, a typical lithostatic pressure in a repository in salt at 650 m depth. Even a 0.05 m (2 inch) thick bentonite-containing engineered barrier could decrease radionuclide release rates by approximately 4 orders-of-magnitude if the diffusivity for that radionuclide were in the observed range of 10−15 to 10−14 m2/s. These results confirm the effectiveness of uncompacted bentonite-containing materials as engineered barriers for radioactive waste isolation.

Conceptual Study of Neutron Physics of Nuclear Fuel Cycle for Ceramic Fast Reactor

2021 ◽  
Author(s):  
Xuesong Yan ◽  
Yaling Zhang ◽  
Yucui Gao ◽  
Lei Yang
Keyword(s):  
High Temperature ◽  
Nuclear Fuel ◽  
Fast Reactor ◽  
Spent Nuclear Fuel ◽  
Fuel Cycle ◽  
Fission Products ◽  
Nuclear Fuel Cycle ◽  
Purification Method ◽  
Neutron Physics ◽  
Conceptual Study

Abstract To make the nuclear fuel cycle more economical and convenient, as well as prevent nuclear proliferation, the conceptual study of a simple high-temperature dry reprocessing of spent nuclear fuel (SNF) for a ceramic fast reactor is proposed in this paper. This simple high-temperature dry (HT-dry) reprocessing includes the Atomics International Reduction Oxidation (AIROX) process and purification method for rare-earth elements. After removing the part of fission products from SNF by a HT-dry reprocessing without fine separation, the remaining nuclides and some uranium are fabricated into fresh fuel which can be used back to the ceramic fast reactor. Based on the ceramic coolant fast reactor, we studied neutron physics of nuclear fuel cycle which consists operation of ceramic reactor, removing part of fission products from SNF and preparation of fresh fuels for many time. The parameters of the study include effective multiplication factor (Keff), beam density, and nuclide mass for different ways to remove the fission products from SNF. With the increase in burnup time, the trend of increasing 239Pu gradually slows down, and the trend of 235U gradually decreases and become balanced. For multiple removal of part of fission products in the nuclear fuel cycle, the higher the removal, the larger the initial Keff.

Determination of concentrations of fission products by ICP–AES in solutions from spent nuclear fuel reprocessing

2017 ◽  
Vol 59 (6) ◽  
pp. 618-623 ◽  
Author(s):  
Yu. A. Naumova ◽  
N. V. Sapozhnikova ◽  
O. N. Egorova ◽  
A. A. Lumpov
Keyword(s):  
Nuclear Fuel ◽  
Spent Nuclear Fuel ◽  
Fission Products ◽  
Spent Nuclear Fuel Reprocessing ◽  
Nuclear Fuel Reprocessing ◽  
Fuel Reprocessing

Spent Fuel: Characterization Studies and Dissolution Behaviourunder Disposal Conditions

1987 ◽  
Vol 112 ◽  
Author(s):  
L. H. Johnson ◽  
D. W. Shoesmith ◽  
S. Stroes-Gascoyne
Keyword(s):  
Release Kinetics ◽  
Fission Products ◽  
Solution Chemistry ◽  
Future Research ◽  
Spent Fuel ◽  
Research Areas ◽  
Dissolution Model ◽  
Underground Disposal ◽  
Radionuclide Release

AbstractThe concept of disposal of unreprocessed spent fuel has now been under study internationally for over ten years. Considerable progress has been made in understanding the factors that will control radionuclide release from spent fuel in an underground disposal vault. This progress is reviewed and the research areas of significance in providing further data for source term models are discussed. Key areas for future research are identified; these include improved characterization of spent fuel to determine the inventories of fission products at grain boundaries, together with their release kinetics; and a better understanding of the effects of solution chemistry on spent fuel dissolution, in particular the effects of salinity, redox chemistry, and radiolysis of groundwater. Approaches to modelling the dissolution of spent fuel are discussed, and a possible approach for developing an oxidative dissolution model is outlined.

scholarly journals Depleted Uranium Oxides and Silicates as Spent Nuclear Fuel Waste Package Fill Materials

1996 ◽  
Vol 465 ◽  
Author(s):  
C. W. Forsberg
Keyword(s):  
Nuclear Fuel ◽  
Spent Nuclear Fuel ◽  
Chemical Species ◽  
Fission Products ◽  
Depleted Uranium ◽  
Improve Performance ◽  
Waste Package ◽  
Reducing Conditions ◽  
Nuclear Fuel Waste

ABSTRACTA new repository waste package (WP) concept for spent nuclear fuel (SNF) is being investigated. The WP uses depleted uranium (DU) to improve performance and reduce the uncertainties of geological disposal of SNF. The WP would be loaded with SNF. Void spaces would then be filled with DU (∼0.2 wt % 235U) dioxide (UO2) or DU silicate-glass beads.Fission products and actinides can not escape the SNF UO2 crystals until the UO2 dissolves or is transformed into other chemical species. After WP failure, the DU fill material slows dissolution by three mechanisms: (1) saturation of WP groundwater with DU and suppression of SNF dissolution, (2) maintenance of chemically reducing conditions in the WP that minimize SNF solubility by sacrificial oxidation of DU from the +4 valence state, and (3) evolution of DU to lower-density hydrated uranium silicates. The fill expansion minimizes water flow in the degraded WP. The DU also isotopically exchanges with SNF uranium as the SNF degrades to reduce long-term nuclear-criticality concerns.

X-ray fluorescence determination of palladium and other fission products in solutions used for reprocessing of spent nuclear fuel

1990 ◽  
Vol 69 (2) ◽  
pp. 692-693 ◽  
Author(s):  
P. A. Gal'tsev ◽  
B. S. Iokhin ◽  
S. L. Levunin ◽  
V. I. Khorev
Keyword(s):  
Nuclear Fuel ◽  
Spent Nuclear Fuel ◽  
Fission Products ◽  
X Ray ◽  
Fluorescence Determination

A Strategic Recovery of Rare-Metal Fission Products in Spent Nuclear Fuel

2004 ◽  
Vol 148 (3) ◽  
pp. 348-357 ◽  
Author(s):  
Yuichi Sano ◽  
Yoshihiko Shinoda ◽  
Masaki Ozawa
Keyword(s):  
Nuclear Fuel ◽  
Spent Nuclear Fuel ◽  
Fission Products ◽  
Rare Metal
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