Development of an Iodine Immobilization Technique by Low Temperature Vitrification With BiPbO2I

2007 ◽  
Author(s):  
Atsushi Mukunoki ◽  
Tamotsu Chiba ◽  
Yasuhiro Suzuki ◽  
Seiichiro Uehara ◽  
Hidekazu Asano ◽  
...  
Keyword(s):  
Low Temperature ◽  
Glass Matrix ◽  
Leaching Tests ◽  
Geological Disposal ◽  
Lead And Zinc ◽  
Amorphous Glass ◽  
Altered Surface ◽  
Process Studies ◽  
Altered Surface Layer ◽  
Simulated Seawater

This paper describes low temperature vitrification process with BiPbO2I (BPI) as a promising immobilization technique in which Iodine-129 reacts with BiPbO2NO3 (BPN) to form BPI, which is then solidified into a lead-boron-zinc glass matrix (PbO-B2O3-ZnO) using a low temperature vitrification process. Studies with EPMA, STEM-EDS and XRD found that iodine, lead and zinc were homogeneously dispersed in the waste form, and that there were no residual crystalline minerals in the amorphous glass matrix. Leaching tests conducted under typical geological disposal conditions show that iodine dissolves congruently with the BPI glass matrix in simulated seawater, whereas it dissolves incongruently in alkaline Ca(OH)2 solutions. This is due to retention within an altered surface layer.

Long-Term Corrosion of Zircaloy Hull Waste under Geological Disposal Conditions: Corrosion Correlations, Factors Influencing Corrosion, Corrosion Test Data, and Preliminary Evaluation

2014 ◽  
Vol 1665 ◽  
pp. 203-214 ◽  
Author(s):  
Hiromi Tanabe ◽  
Tomofumi Sakuragi ◽  
Hideaki Miyakawa ◽  
Ryota Takahashi
Keyword(s):  
Low Temperature ◽  
Corrosion Rate ◽  
Preliminary Evaluation ◽  
Leaching Tests ◽  
Geological Disposal ◽  
Temperature Range ◽  
Corrosion Rates ◽  
Factors Influencing ◽  
Hull Waste

ABSTRACTThe carbon-14 generated in Zircaloy (Zry) hull waste is considered an important radionuclide in the TRU waste geological disposal concept in Japan. Given that the metal Zry is highly corrosion-resistant in the anaerobic and low-temperature conditions of the repository, and that the C-14 release rate is assumed to be controlled by the corrosion rate, a variety of corrosion and leaching tests have been performed. However, since the Zry corrosion rate is extremely slow, it is not possible to predict long-term corrosion behavior through low-temperature corrosion tests conducted in a reasonable time period. A vast amount of testing has been conducted in the higher-temperature range of 523 to 633 K, and corrosion correlations have been obtained from these tests. Corrosion correlations have been used to predict the corrosion rate of Zry in a tuff repository. Long-term Zry autoclave corrosion data have been analyzed to develop new corrosion correlations. Extrapolating these correlations to a lower temperature range requires verification that the mechanisms do not change over the range of testing and extrapolation. Factors that influence corrosion rates under geological disposal conditions, such as material and environmental factors, should also be examined. Corrosion correlations, factors influencing corrosion rates, the results of corrosion and leaching tests, and a preliminary evaluation are discussed.

Exemple de gisements plombo-zinciferes epigenetiques dans des niveaux calcaires de sillon subsident; les mineralizations du Diois et des Baronnies

1962 ◽  
Vol S7-IV (6) ◽  
pp. 816-825
Author(s):  
Henri Rouvier
Keyword(s):  
Low Temperature ◽  
Metallic Ions ◽  
Upper Eocene ◽  
Mineral Concentration ◽  
Zinc Blende ◽  
Lead And Zinc ◽  
Zinc Concentrations ◽  
Individual Specimen ◽  
The Individual ◽  
Hydrosulfuric Acid

Abstract The mineralization of Diois and Baronnies (France) is examined on the individual specimen, bed, and regional levels. The mineral composition consists essentially of zinc blende, galena and pyrite with some marcasite in a calcitic gangue. Study of galena and calcite samples indicates a low temperature of deposition. Three phases of mineral concentration are hypothesized; precipitation of water-dissolved metallic ions by hydrosulfuric acid; upper Eocene deposition of lead and zinc concentrations along faults by ground water; and upper Miocene to Recent superficial alteration of the beds.

Microstructure and thermoelectric transport properties of BiCuSeO thin films on amorphous glass substrates

2018 ◽  
Vol 47 (32) ◽  
pp. 11091-11096
Author(s):  
Dachao Yuan ◽  
Shuang Guo ◽  
Shuaihang Hou ◽  
Yuejin Ma ◽  
Jianjun Hao ◽  
...  
Keyword(s):  
Thin Films ◽  
Low Temperature ◽  
Transport Properties ◽  
Structural Defects ◽  
Thermoelectric Transport ◽  
Glass Substrates ◽  
Thermoelectric Transport Properties ◽  
Amorphous Glass

Effect of structural defects on the low temperature thermoelectric transport properties of c-axis-textured BiCuSeO thin films on amorphous glass substrates.

scholarly journals ANÁLISE PETROGRÁFICA DOS IGNIMBRITOS BEM PRESERVADOS DA FORMAÇÃO CACHOEIRA DA ILHA, CENTRO-NORTE DO CRÁTON AMAZÔNICO, ESTADO DE RORAIMA

2020 ◽  
Vol 30 (1) ◽  
pp. 100-114
Author(s):  
Nazaré Barbosa ◽  
Hilberto Soares ◽  
Lorena Feitosa
Keyword(s):  
Low Temperature ◽  
Hydrothermal Alteration ◽  
Glass Matrix ◽  
Welding Process ◽  
Central Portion ◽  
North Central ◽  
Pyroclastic Rocks ◽  
The North ◽  
Amazonian Craton

The Cachoeira da Ilha Formation (FCI) is located in the north central portion of the Amazonian Craton, northeast of Roraima. It is found by ignimbritic rocks with about 1990 Ma. Acid pyroclastic rocks in the region of the municipality of Amajari were classified as ignimbrites: solid, moderately welded and rheomorphic from variations in the degree in the welding process, proportion and type of pyroclasts and textural aspects. The crystalloclasts are made of quartz, sanidine and plagioclase and are dispersed in a glass-matrix. They are usually found with corrosion, dentate and intensely sericitized and/or saussuritized gulfs, showing low temperature hydrothermal alteration. It is also possible to distinguish mafic, microporphyritic and cognate lithitic fragments.

A New Approach to the RN Source Term for Spent Nuclear Fuel under Geological Disposal Conditions

2000 ◽  
Vol 663 ◽  
Author(s):  
Christophe Poinssot ◽  
Christophe Jegou ◽  
Pierre Toulhoat ◽  
Jean-Paul Piron ◽  
Jean-Marie Gras
Keyword(s):  
Low Temperature ◽  
Closed System ◽  
Source Term ◽  
Spent Nuclear Fuel ◽  
Driving Forces ◽  
Spent Fuel ◽  
Microscopic Description ◽  
New Approach ◽  
Geological Disposal ◽  
Source Term Model

ABSTRACTUnder the geological disposal conditions, spent fuel (SF) is expected to evolve during the 10,000 years while being maintained isolated from the biosphere before coming in contact with water. Under these circumstances, several driving forces would lead to the progressive intrinsic transformations within the rod which would modify the subsequent release of radionuclides. The major mechanisms are the production of a significant volume of He within the UO2 lattice, the accumulation of irradiation defects due to the low temperature which avoids any annealing, the slow migration of radionuclides (RN) within the system by (i) the α self-irradiation-induced athermal diffusion and (ii) locally the building-up of internal mechanical stresses which could turn the pellets into powder. However, the current RN source terms for SF have never accounted for this evolution as they are based on existing knowledge of the fresh SF. Two major mechanisms were considered, the leaching of the readily available fraction (one which was supposed to be instantly accessible to water), and the release of RN through alteration of the UO2 grains. We are now proposing a new RN source term model based on a microscopic description of the system in order to also take account of the early evolution of the closed system, the amplitude of which increases with the burnup and is greater for MOX fuels.

Influence of the Altered Surface Layer on the Corrosion of AA5083

2015 ◽  
Vol 162 (6) ◽  
pp. C209-C218 ◽  
Author(s):  
Jinwook Seong ◽  
Fan Yang ◽  
Frank Scheltens ◽  
G. S. Frankel ◽  
N. Sridhar
Keyword(s):  
Surface Layer ◽  
Altered Surface ◽  
Altered Surface Layer
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