Fabrication of UO2Porous Pellets on a Scale of 30 kg-U/Batch at the PRIDE Facility

In the pyroprocess integrated inactive demonstration (PRIDE) facility at the Korea Atomic Energy Research Institute (KAERI), UO2porous pellets were fabricated as a feed material for electrolytic reduction on an engineering scale of 30 kg-U/batch. To increase the batch size, we designed and modified the corresponding equipment for unit processes based on ceramic processing. In the course of pellet fabrication, the correlation between the green density and sintered density was investigated within a compaction pressure range of 106–206 MPa, in terms of the optimization of processing parameters. Analysis of the microstructures of the produced UO2porous pellets suggested that the pellets were suitable for feed material in the subsequent electrolytic reduction process in pyroprocessing. This research puts forth modifications to the process and equipment to allow the safe mass production of UO2porous pellets; we believe these results will have immense practical interest.

Download Full-text

Effect of Sintering Time on the Density, Porosity Content and Microstructure of Copper – 1 wt. % Silicon Carbide Composites

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1064.32 ◽

2014 ◽

Vol 1064 ◽

pp. 32-37 ◽

Cited By ~ 3

Author(s):

Mohammed A. Almomani ◽

Ahmad M. Shatnawi ◽

Mohammed K. Alrashdan

Keyword(s):

Silicon Carbide ◽

Grain Size ◽

High Pressure ◽

Powder Metallurgy ◽

Surface Energy ◽

Sintered Density ◽

Compaction Pressure ◽

Boundary Surface ◽

Sintering Time ◽

Diffusion Enhancement

In this paper, several copper matrixes reinforced with 1 wt. % silicon carbide (SiC) were fabricated using powder metallurgy (PM). The effect of sintering time (30 min, 60 min, 90 min, and 180 min) on composite density and porosity, and grain size were investigated. The results showed that longer sintering time gives higher sintered density, and smaller porosity content. This is due to the diffusion enhancement, which leads to reduce pore size, and close porosities. Also, for a given compaction pressure, the grains tend to be coarser for longer sintering time, due to the materials tendency to reduce grain boundary surface energy. In addition, samples compacted at high pressure have finer grain than corresponding grains compacted at low pressure but sintered for the same time.

Download Full-text

An experimental study for Li recycling in an electrolytic reduction process for UO2 with a Li2O–LiCl molten salt

Journal of Nuclear Materials ◽

10.1016/j.jnucmat.2013.06.009 ◽

2013 ◽

Vol 441 (1-3) ◽

pp. 232-239 ◽

Cited By ~ 11

Author(s):

Wooshin Park ◽

Jin-Mok Hur ◽

Sun-Seok Hong ◽

Eun-Young Choi ◽

Hun Suk Im ◽

...

Keyword(s):

Experimental Study ◽

Molten Salt ◽

Reduction Process ◽

Electrolytic Reduction

Download Full-text

Density Measurement of Thin Sputtered Carbon Films

Advances in X-ray Analysis ◽

10.1154/s0376030800020632 ◽

1988 ◽

Vol 32 ◽

pp. 323-330 ◽

Cited By ~ 1

Author(s):

G. L. Gorman ◽

M.-M. Chen ◽

G. Castillo ◽

R. C. C. Perera

Keyword(s):

Carbon Film ◽

Processing Condition ◽

Density Measurement ◽

Practical Interest ◽

Processing Parameters ◽

Carbon Films ◽

Nondestructive Method ◽

Gas Pressure ◽

X Ray ◽

Thin Carbon

AbstractThe densities of sputtered thin carbon films have been determined using a novel X-ray technique. This nondestructive method involves the measurement of the transmitivity of a characteristic soft (low energy) X-ray line through the carbon film, and using the established equation I1 = I0eμpt where I1/I0 is the transmitivity, fi the photo absorption cross section, t the independently measured thickness, the density p can be easily solved for. This paper demonstrates the feasibility of using this simple technique to measure densities of carbon films as thin as 300 Å, which is of tremendous practical interest as carbon films on this order of thickness are used extensively as abrasive and corrosive barriers (overcoats) for metallic recording media disks. The dependence of the density upon film thickness for a fixed processing condition is presented, as also its dependence (for a fixed thickness) upon different processing parameters (e.g., sputtering gas pressure and target power). The trends noted in this study indicate that the sputtering gas pressure plays the most important role, changing the film density from 2.4gm/cm3 at 1 mTorr to 1.5gm/cm3 at 30 mTorr for 1000 Å thick films.

Download Full-text

Influence of Various Process Parameters on the Density of Sintered Aluminium Alloys

Acta Polytechnica ◽

10.14311/1604 ◽

2012 ◽

Vol 52 (4) ◽

Author(s):

Mateusz Laska ◽

Jan Kazior

Keyword(s):

Sintered Density ◽

Sintering Temperature ◽

Compaction Pressure ◽

Nitrogen Atmosphere ◽

Chemical Compositions ◽

Green Density ◽

Heating And Cooling ◽

Wide Range ◽

Different Temperatures ◽

Metallurgy Industry

This paper presents the results of density measurements carried out on Alumix sintered parts. ECKA Alumix aluminium powders were used because of their wide application in the powder metallurgy industry. The compacts were produced using a wide range of compaction pressures for three different chemical compositions. The compacts were then sintered under a pure dry nitrogen atmosphere at three different temperatures. The heating and cooling rates were the same throughout the entire test. The results showed that the green density increases with compaction pressure, but that sintered density is independent of green density (compaction pressure) for each sintering temperature.

Download Full-text

Effect of Processing Parameters on the Properties of Glass–Ceramics from Arc-Melting Slag of Incineration Fly Ash

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.399-401.864 ◽

2011 ◽

Vol 399-401 ◽

pp. 864-868

Author(s):

Han Qiao Liu ◽

Guo Xia Wei ◽

Yin Liang ◽

Jun Lan Yang

Keyword(s):

Mechanical Properties ◽

Fly Ash ◽

Milling Time ◽

Bending Strength ◽

Compaction Pressure ◽

Glass Ceramics ◽

Physical And Mechanical Properties ◽

Processing Parameters ◽

Arc Melting ◽

Melting Slag

The glass-ceramics were made of arc-melting slag from incinerator fly ash mixed with glass cullet additive by sintering method. The effects of ball milling time and powder compaction pressure on the microstructure, physical and mechanical properties of the glass–ceramics were respectively investigated. Results showed that with milling time delaying, granularity of the parent glass evidently reduces, the major phases of glass–ceramics have no change but the diffraction peaks present intensive trend, the crystal sizes of glass–ceramics decrease, the properties such as volumetric densities, compressive strength, bending strength and toughness are improved, the appropriate milling time is 6h with fifty percent of the volume (d50 value) of 10.62μm. The physical and mechanical properties first increase and then decrease with compaction pressure increasing, and the optimal compaction pressure is 60MPa.

Download Full-text

Distillation characteristics of LiCl–Li2O electrolyte for UO2 electrolytic reduction process

Journal of Radioanalytical and Nuclear Chemistry ◽

10.1007/s10967-016-4936-9 ◽

2016 ◽

Vol 310 (3) ◽

pp. 1165-1171 ◽

Cited By ~ 6

Author(s):

Hyun Woo Kang ◽

Eun-Young Choi ◽

Sung-Wook Kim ◽

Sun-Seok Hong ◽

Min Ku Jeon ◽

...

Keyword(s):

Reduction Process ◽

Electrolytic Reduction

Download Full-text

Impact of layup rate on the quality of fiber steering/cut-restart in automated fiber placement processes

Science and Engineering of Composite Materials ◽

10.1515/secm-2013-0257 ◽

2015 ◽

Vol 22 (2) ◽

pp. 165-173 ◽

Cited By ~ 8

Author(s):

Jihua Chen ◽

Teresa Chen-Keat ◽

Mehdi Hojjati ◽

AJ Vallee ◽

Marc-Andre Octeau ◽

...

Keyword(s):

Compaction Pressure ◽

Experimental Studies ◽

Process Condition ◽

Processing Parameters ◽

Experimental Results ◽

High Quality ◽

Fiber Placement ◽

Automated Fiber Placement

AbstractDeveloping reliable processes is one of the key elements in producing high-quality composite components using an automated fiber placement (AFP) process. In this study, both simulation and experimental studies were carried out to investigate fiber steering and cut/restart under different processing parameters, such as layup rate and compaction pressure, during the AFP process. First, fiber paths were designed using curved fiber axes with different radii. Fiber placement trials were then conducted to investigate the quality of the steered fiber paths. Furthermore, a series of sinusoidal fiber paths were fiber placed and investigated. Moreover, a six-ply laminate with cut-outs in it was manufactured in the cut/restart trials. The accuracy of the fiber cut/restart was compared at different layup rates for both one- and bi-directional layups. Experimental results show that it was possible to layup steered fiber paths with small radii of curvature (minimum 114 mm) designed for this study when the proper process condition was used. It was observed from the cut/restart trials that the quality of tow cut was independent of layup speed; however, the accuracy of tow restart was related to the layup speed. The faster the layup speed, the less accurate was the tow restart.

Download Full-text

Characterization and Sintering Behaviors of Fe Based Nanopowders Prepared by Arc Discharge Process

Materials Science Forum ◽

10.4028/www.scientific.net/msf.638-642.1755 ◽

2010 ◽

Vol 638-642 ◽

pp. 1755-1759 ◽

Cited By ~ 1

Author(s):

C.J. Choi ◽

J.H. Yu ◽

Jung Goo Lee

Keyword(s):

Sintered Density ◽

Arc Discharge ◽

Spherical Shape ◽

Processing Parameters ◽

Sintering Behavior ◽

Surface Oxide Layer ◽

Discharge Process ◽

Plasma Arc Discharge ◽

Average Size ◽

Micron Powder

The formation of Fe nanopowders by Plasma Arc discharge process and sintering behavior of Fe nanopowder has been investigated. The effect of processing parameters on the size and microstructure and their pressureless sintering behaviors have been analyzed. Also the addition effect of micron powder to nanopowder on the compaction and sintering was studied. The prepared Fe nanpowder showed nearly spherical shape with the average size of 100 nm. The surface oxide layer of nanopowder played an important role on the initial densification of the green compact. The hardness and sintered density of nano/micron bimodal powder was similar to those of pure nanopowder.

Download Full-text