Prof.
David Shoesmith
(Western University)
30/10/2017, 14:30
National and international collaborative waste management programs
Oral Presentation
The internationally accepted approach for the disposal of spent nuclear fuel is to seal it in corrosion-resistant metal containers and bury it in a stable deep geologic repository. If containers were to fail, and the fuel become exposed to groundwater, radiolytic corrosion of the fuel could release radionuclides to the groundwater, the critical first step in their transport into the...
Prof.
Kastriot Spahiu
(SKB, Stockholm, Sweden and Chalmers University of Technology, Gothenburg, Sweden)
30/10/2017, 15:00
National and international collaborative waste management programs
Oral Presentation
Our experimental data indicate that the hydrogen effect is a complex phenomenon and has several aspects. The decomposition of hydrogen peroxide on the surface of SIMFUEL is followed by the reaction of the produced hydroxyl radicals with hydrogen to give water, or their reaction with H2O2 to give O2. Only a very small part of the initial hydrogen peroxide (<0.02%) causes oxidative dissolution...
Prof.
Nicolas DACHEUX
(University of Montpellier)
30/10/2017, 15:15
National and international collaborative waste management programs
Oral Presentation
Due to the concomitant formation of oxygen vacancies in the fluorite structure, it was found that the incorporation of trivalent lanthanide elements in ThO2 or CeO2 strongly affect their chemical durability during dissolution or leaching tests [1-4]. On the contrary, the impact of such elements on the dissolution of UO2 remains largely unknown. For this purpose, several lanthanide – uranium...
Dr
Anders Puranen
(Studsvik Nuclear)
30/10/2017, 15:30
National and international collaborative waste management programs
Oral Presentation
Leaching results on fragments of high burnup (65 MWd/kgU) UO2 fuel from a commercial pressurized water reactor are presented. The experiments were performed in simplified granitic groundwater under a hydrogen pressure of up to 5 MPa, representing conditions in a water intrusion scenario for a Swedish KBS-3 design spent nuclear fuel repository. The freshly crushed fragments were...
Mr
Beng Thye Tan
(University of Cambridge, Singapore Nuclear Research and Safety Initiative)
30/10/2017, 15:45
National and international collaborative waste management programs
Oral Presentation
The migration of radionuclides from underground nuclear waste repositories will involve the formation of uranium secondary minerals when ground water reacts with the spent nuclear fuel.
During oxic or anoxic spent fuel dissolution, amorphous phases can precede the development of well-defined crystalline mineral phases. Nuclear magnetic resonance (NMR) can probe the structure of these...
Prof.
Nicolas DACHEUX
(University of Montpellier)
30/10/2017, 16:30
National and international collaborative waste management programs
Oral Presentation
Dissolution or leaching of the spent nuclear fuels (SNF) is a key step either in the field of their reprocessing or their long-term storage in underground repository. Moreover, SNF contain a wide variety of fission products including platinoid elements (PGM’s) either incorporated in the UO2 matrix, or present in various separated phases for which the specific impact on the overall dissolution...
David Shoesmith
(Western University)
30/10/2017, 17:00
National and international collaborative waste management programs
Oral Presentation
The corrosion of high level copper nuclear waste containers under permanent disposal conditions can occur via a number of processes which change in importance as the environment within a deep geologic repository evolves from warm and oxic to cool and anoxic. Under warm and oxic conditions the container could be exposed to gamma irradiated conditions which evolve from aerated vapour to fully...
Mr
Ernesto González-Robles Corrales
(Karlsruhe Institute of Technology)
30/10/2017, 17:15
National and international collaborative waste management programs
Oral Presentation
Zircaloy claddings of fuel rods for nuclear reactors are considered as first technical barrier for retention of radionuclides produced in the nuclear fuel. The integrity of the cladding is influenced by various processes during reactor operation and beyond, e.g. oxidation, hydrogen uptake, PCI, fission product precipitation, -decay, and radiation damage. Composition of agglomerates found on...
Dr
Michel Herm
(Karlsruhe Institute of Technology)
30/10/2017, 17:30
National and international collaborative waste management programs
Oral Presentation
Cladding tubes of water-cooled nuclear reactors are usually made of Zircaloy and are an important retaining element for radionuclides present in the fuel. However, cladding integrity is affected by various processes during reactor operation and beyond, e.g. oxidation, hydrogen uptake, PCI, fission product precipitation, alpha-decay, and radiation damage. Using experimental and modelling...
Dr
Tomofumi Sakuragi
(Radioactive Waste Management Funding and Research Center)
30/10/2017, 17:45
National and international collaborative waste management programs
Oral Presentation
On the issue related on a safe disposal of spent fuel claddings is the corrosion and the subsequent gas and radionuclides release. The Zircaloy corrosion under a prospected disposal condition has recently been investigated by sensitive hydrogen measurements at 30℃, and reported that the kinetics in the rate around nm/y follows the parabolic rate law.
In the present work, an improved equipment...
