A5061673858- Molten salt chemistry and electrochemical processes
- Nuclear Materials and Properties
- Nuclear materials and radiation effects
- Metallurgical Processes and Thermodynamics
- Extraction and Separation Processes
- Thermodynamic and Structural Properties of Metals and Alloys
- Nuclear reactor physics and engineering
- Graphite, nuclear technology, radiation studies
- Radioactive element chemistry and processing
- Nuclear and radioactivity studies
- Bauxite Residue and Utilization
- Metal Extraction and Bioleaching
- Recycling and utilization of industrial and municipal waste in materials production
- Advancements in Battery Materials
- Iron and Steelmaking Processes
- Healthcare Systems and Public Health
- Semiconductor materials and devices
- Medical and Biological Sciences
- Coal and Its By-products
- Recycling and Waste Management Techniques
- Chemical Synthesis and Characterization
- Advancements in Semiconductor Devices and Circuit Design
- GaN-based semiconductor devices and materials
- Advanced Power Generation Technologies
- Polymer Science and Applications
Central Research Institute of Electric Power Industry
2013-2024
Japan Atomic Energy Agency
1998
University of Missouri
1996
Kawasaki Heavy Industries (Japan)
1996
Rockwell Automation (United States)
1996
Kyoto University
1990
To develop an electrochemical reduction technique for the reprocessing of nuclear fuels, behavior at cathode and anode reactions were investigated in both LiCl salt baths. In about , was reduced into metal over potential range vs . The uranium cohered due to high temperature a dense skin covered surface disk sample. It prevented transportation oxygen from inside bulk often stopped with remaining inside. A significant underpotential deposition calcium observed. sample satisfactorily because...
Thermodynamic property measurements for actinides in the LiCl‐KCl/Cd system have been obtained as part of development an electrochemical pyropartitioning process to remove from PUREX waste residues. Electrochemical potential and distribution ratios were employed obtain standard Gibbs free energies formation actinide chlorides LiCl‐KCl, activity coefficients reduced Cd, relative neodymium. The temperature‐dependent U, Np, Pu , when T is K. energy was −548.7 kJ/mol at 450°C. U LiCl‐KCl ranged...
The design of a molten metal‐molten salt based chemical and electrochemical process for separation actinides from plutonium‐uranium extraction waste requires consistent set thermodynamic properties the rare earths present in nuclear waste. Standard potential data Y, La, Ce, Pr, Gd LiCl‐KCl were obtained. Americium obtained standard potentials activity coefficients Cd Bi. Data between 400 500°C. Results earth chlorides using an improved experimental technique with theory, free energy...
Two series of pyrochemical reprocessing tests for oxide fuels, consisting pretreatment, electrolytic reduction, and electrorefining processes, were conducted using ~100 g UO2. In the pretreatment process, UO2 pellets starting material oxidized into U3O8 powder, which simulated fuel decladding by voloxidation. Then, sinter with a porosity 30 to 38% was fabricated from powder. cathode baskets charged prepared, two reduction carried out in LiCl-Li2O electrolyte at 650°C. The results suggested...
Pyro-processing fuel cycle technology is a promising technological candidate to realize advanced with reduced burdens of proliferation risk and long life radioactive waste. CRIEPI have been studying pyro-processing metal since 1986 for obtaining basic properties, process chemistry engineering technologies. In this century, JRC-ITU jointly demonstrated the recovery MAs from both irradiated fuels spent MOX fuels. Since 2009, accumulation design basics through tests engineering-scale equipment...
Some oxidation states (0, +1, +2, and +4) of zirconium exist in a LiCl-KCl eutectic system over the temperature range 450-550°C, behavior is complicated. In cyclic voltammograms at 500°C, cathodic peak was observed about −1.2 V vs. Ag/AgCl reference electrode, which might be due to reduction Zr(IV) ZrCl metal. Two anodic peaks correspond metal, respectively. The electrolysis cathode potential −1.1 yielded nodular deposit identified as ZrCl, appeared metastable compound this system. When...
The electrochemical reduction process has been recently developed for converting oxide nuclear fuels to metals. In order characterize the mechanism and investigate appropriate conditions improving rate, several tests were conducted in a LiCl-Li2O electrolyte at 650°C using various types of cathode baskets containing 10 100 g UO2. progressed from outside center basket, rate might be determined by transportation oxygen ion bulk salt. It was verified that feeding small UO2 particles reducing...
The solubility of oxide ions in LiCl-rich (, K, Cs, Ca, Sr, or Ba) melts was measured the temperature range 723–923 K as part development an electrolytic reduction process for spent nuclear fuel because strongly affects rate reduction. With exception system, precipitate under oversaturated condition. molten LiCl at 923 determined to be . significantly decreased when alkali metal chlorides (NaCl, KCl, and CsCl) were added slightly added. In contrast, addition increased solubility. Empirical...
AbstractA pyrometallurgical partitioning technology to recover actinides from high level radioactive wastes is being developed. In the process, are separated fission products by electrorefining in molten chloride systems. It expected that REs (rare earth elements), main components of hardly actinides. order estimate separation factors, experiments LiCl-KC1 eutectic salt containing actinide (U, Np, Pu and Am) RE (Y, La, Ce, Nd Gd) chlorides were carried out at 450°C. Actinides removed a...
A series of pyrochemical reprocessing tests involving pretreatment, electrolytic reduction, and electrorefining processes were conducted using [approximately]100 g simulated spent oxide fuel. In the pretreatment process, a fuel consisting dense UO2 pellets containing typical fission product elements (strontium, cerium, neodymium, samarium, zirconium, palladium, molybdenum) was powderized by voloxidation, which corresponds to decladding. Porous then fabricated from obtained powder. reduction...
Liquid Cd is used as a reaction medium in the pyrometallurgical reprocessing for spent nuclear fuels. The diffusion coefficient of series key elements, such actinides and rare earths, liquid one important physical properties kinetic analysis reprocessing. Recently, authors applied an electrochemical method to measurement metal. This presentation summarizes coefficients (U Pu) earths (La, Pr, Nd, Gd, Y Sc) measured by method.
A pyrometallurgical partitioning technology to recover actinides from high level radioactive wastes is being developed. In the process, are separated fission products by electrorefining in molten chloride systems. It expected that REs (rare earth elements), main components of hardly actinides. order estimate separation factors, experiments LiCl-KC1 eutectic salt containing actinide (U, Np, Pu and Am) RE (Y, La, Ce, Nd Gd) chlorides were carried out at 450°C. Actinides removed a liquid...
AbstractA concept of pyroprocessing light water reactor (LWR) spent fuels based on an electrochemical reduction technology is proposed, and the material balance processing mixed oxide (MOX) or high-burnup uranium (UO2) fuel evaluated. Furthermore, a burnup analysis for metal fast breeder reactors (FBRs) conducted low-decontamination materials recovered by pyroprocessing. In case MOX (40 GWd/t), UO2 separately collected ~60 wt% in advance step, product through rare earth (RE) removal which...