• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.12 no.1
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• pp.79-88
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• 2014

We have developed a smart decontamination device for small-size radioactive scrap metal (SSRSM) necessarily generated from nuclear facilities. This is a multi-modal device such as rotation of magnetic field focusing on the region containing the abrasion pins placed around target and ultrasonic cleaner. Additionally, in order to increase the decontamination efficiency we have modified some configuration of the device so that it could work on them evenly and totally. With the Optimal operating for operation of the new device, we tried to decontaminate some various metal selected as a sample during 15 minutes sequentially using each method, magnetic and ultrasonic device. As a result, the range of decontamination factor has been highly increased to 18~56. After decontamination, all samples were found its activity less than background level.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.38 no.9
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• pp.1013-1018
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• 2014

Magnetic Abrasive Polishing (MAP) process is a nontraditional method for polishing the surface of workpiece by using the flexibility of tool. At present, a mixture of polishing abrasives and ferrous particles is used as the tool in the MAP process. Previously, an experiment was conducted with different sizes of polishing abrasives with an aim to improve the polishing accuracy. However, the sizes of ferrous particles are also expected to have a dominant effect on the process, warranting a study on the effect of the size of ferrous iron particles. In this study, an experiment was conducted using three different sizes of ferrous particles. Iron powder of average diameters 8, 78 and $250{\mu}m$ was used as ferrous particles. The effect of each ferrous particle size was evaluated by comparing the improvements in surface roughness. The particle size of a ferrous iron was found to play a significant role in MAP and particles of $78{\mu}m$ facilitated the best improvement in surface roughness.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.947-952
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• 1997

The magnetic polishing is the useful method to finish using magnetic power of a magnet. The time hasn't been that long since the magnetic polishing method was introduced to korea as one of precision polishing techniques. However, the reasons for not being spreaded widely are the magnetic polishing method don't have mediocrity for machine, the efficiency of magnet-abrasive is confined as a bad polishing, and there are not many researchers in this field. The mechanism of this R&D is dealing with the dynamic state of magnet-abrasive. This paper deals with mediocritizing magnetic polishing device into regular lathe and this experiment was conducted in order to get a best surface roughness with low cost. Beside the subsidiary experiment was performed using the mixed magnet-abrasive with general alumina, barium. This paper introduced the main reason for difficulty using this method in industrial field. It needs more continues research on it. This paper contains the result of experiment to acquire the best surface roughness, not using the high-cost polishing material in processing. The average diameters of magnet-abrasive are the particles of 150 $\mu\textrm{m}$, 250 $\mu\textrm{m}$.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.38 no.8
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• pp.887-892
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• 2014

In a conventional magnetic abrasive polishing process, the polishing abrasives are mixed with ferrous particles and slight cutting oil to form a cluster of abrasives. However, when a tool rotates at a high revolution speed, most of the polishing abrasives are scattered away from it due to the increase in centrifugal force. This phenomenon directly reduces the polishing efficiency. The use of a highly viscous matter such as silicone gel instead of cutting oil for mixing is one method to solve this problem and increase abrasive adhesion. Another method to avoid high abrasive scattering is the application of wet magnetic abrasive polishing (WMAP). In WMAP, abundant mineral oil is preliminarily applied to the workpiece surface. This study experimentally evaluated the effect of WMAP on abrasive adhesion. The relationship between the amount of working abrasives and polishing conditions was characterized. Despite the lower adhesion ratio of polishing abrasives, the surface roughness was found to be significantly improved as the result of WMAP.