• Proceedings of the Korean Nuclear Society Conference
• /
• 2005.05a
• /
• pp.183-184
• /
• 2005

• Proceedings of the Korean Nuclear Society Conference
• /
• 2005.05a
• /
• pp.205-206
• /
• 2005

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
• /
• v.17 no.2
• /
• pp.139-165
• /
• 2019

The current status and prospect of decommissioning technology development at KAERI are reviewed here. Specifically, this review focuses on four key technologies: decontamination, remote dismantling, decommissioning waste treatments, and site remediation. The decontamination technologies described are component decontamination and system decontamination. A cutting method and a remote handling method together with a decommissioning simulation are described as remote dismantling technologies. Although there are various types of radioactive waste generated by decommissioning activities, this review focuses on the major types of waste, such as metal waste, concrete waste, and soil waste together with certain special types, such as high-level and high-salt liquid waste, organic mixed waste, and uranium complex waste, which are known to be difficult to treat. Finally, in a site remediation technology review, a measurement and safety evaluation related to site reuse and a site remediation technique are described.

• Korean journal of food and cookery science
• /
• v.26 no.5
• /
• pp.665-675
• /
• 2010

This study applied high-pressure extraction cooking, which has been proven superior in processibility and stock extraction, for the preparation of stock, which is widely used as a basic material of dishes, and examined the physicochemical and sensory properties of the extracted stock by adding salt. We observed changes in the chromaticity of brown stock according to salt content, and pH decreased with increased the salt content, suggesting that stock was acidified. Regarding the mineral content, Na was the highest, followed by K and P. Regarding total free amino acid content, the content of essential amino acids, enhancing free amino acids, and other amino acids also showed the highest level in S2, which contented 0.3% salt. In the sensory test, saltiness grew stronger with an increase in salt content, and overall palatability was highest in S2. Regarding ranking, preference was highest for S2. Utilize to data that study finding of above is actual in development for mass production of brown stock product licensed cooks' traditional mesh dipper technology quality that make mass production direction that change and normalizes product that can keep excellent taste and improve conservative property develop. Culture formation and our country foodservice industry development that reduce damage of informed people ashes through development of brown stock product that is changed in large quantity, and improve quality of food more positively contributing to reappear diversification of menu, systematization and taste of specialty store as well as can contribute in rationalization of informed people ashes purchase, personnel expense (labor power) curtailment, waste decrease etc. but is developed still more being utilized.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
• /
• v.12 no.3
• /
• pp.179-189
• /
• 2014

Pyroprocessing has been developed for the purpose of resolving the current spent nuclear fuel management issue and enhancing the recycle of valuable resources. An electrolytic reduction of the pyroprocessing is a process to reduce oxides into metals using LiCl as an electrolyte and requires a post-treatment process due to the inclusion of residual salt in porous metal products. A vacuum distillation has been adopted for various molten salt systems and could be applied to the post-treatment process of the electrolytic reduction. The residual salt in the metal products includes LiCl, alkali chlorides, and alkaline earth chlorides. In this paper, vapor pressures of chlorides have been estimated and the composition changes on the residual liquid during the vacuum distillation process have been calculated. A model combining a material balance and vapor-liquid equilibrium relations has been proposed under a constant vapor discharging flow rate and liquid composition changes have been calculated using the vapor pressures with respect to a dimensionless time. The behaviors have been compared with temperature and molten salt composition changes to simulate the process condition variation. The distillation of the residual salt has been dominated by LiCl which is the main component of the salt and CsCl of which vapor pressure is higher than that of LiCl would be readily removed. RbCl exhibits similar vapor pressure with LiCl and maintains its composition. However, $SrCl_2$ and $BaCl_2$ of which vapor pressures are much lower than that of LiCl are concentrated with time and expected to be possibly precipitated during the distillation when the initial compositions are increased.

• Proceedings of the Korean Radioactive Waste Society Conference
• /
• 2004.06a
• /
• pp.285-291
• /
• 2004

As a part of assessment of the structural material for the molten salt handling system, corrosion behavior of Inconel 718, X-750, Haynes 75 and Haynes 263 alloys in the molten salt of LiCl-Li$_2$O-O$_2$was investigated in the range of temperature; $650^{\circ}C$, time; 24~168h, $Li_2O$; 3wt%, mixed gas; Ar~10%$O_2$. In the molten salt of LiCl-$Li_2O-O_2$, the order corrosion rate was Haynes 263 ＜ Haynes 75 ＜ Inconel X-750 ＜ Inconel 718. Haynes 263 alloy showed the highest corrosion resistance among the examined alloys. Corrosion products of alloys were as fellows: Haynes 75: $Cr_2O_4$, $NiFe_2O_4$, $LiNiO_2$, $Li_2NiFe_2O_4$, Inconel 718; $Cr_2O_4$, $NiFe_2O_4$, Haynes 263; $Li(Ni,Co)O_2$, $NiCr_2O_4$, $LiTiO_2$, Inconel X-750; $Cr_2O_3$, $NiFe_2O_4$,$FeNi_3$, (Al,Nb,Ti)$O_2$. Haynes 263 showed local corrosion behavior and Haynes 75, Inconel 718 and Inconel X-750 showed uniform corrosion behavior.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
• /
• v.8 no.1
• /
• pp.65-70
• /
• 2010

The distillation rate on LiCl-KCl eutectic salt under different vacuums from 0.5-50 mmHg was first investigated by using both a non-isothermal and a isothermal thermogravimetric (TG) analysis. Based on the non-isothermal TG data, distillation rate equations as a function of the temperature could be derived. Calculated flux by these model flux equations was in agreement with the distillation rate obtained from isothermal TG analysis. A distillation rate of $10^{-4}-10^{-5}$ mole $cm^{-2}sec^{-1}$ is obtainable at temperatures less than 1300K and vacuums of 0.5-50 mmHg. About a 99% salt distillation efficiency was obtained after an hour at a temperature above 1150 K under 50 mmHg in a small scale distillation test system. An increase in the vaporizing surface area is relatively effective for removing residual salt in the remaining particles, when compared to that for the vaporizing time. Over 99.95% of total distillation efficiency was obtained for a 1-h distillation operation by increasing the inner surface area from $4.52cm^2$ to $12.56cm^2$.

• Resources Recycling
• /
• v.12 no.5
• /
• pp.10-15
• /
• 2003

In this study, the separation of rare earths and aluminium from the dried powder of waste cerium polishing slurry was investigated. Since cerium oxide, 40％ of rare earths, is the most stable state in rare earth, the dissolution of cerium oxide in acid solution is not easy. Therefore the dissolution process of cerium oxide by sulfation was examined in order to increase the recovery of rare earth. The rare earths could be separated from aluminum by double salt precipitation using sodium sulfate.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
• /
• v.18 no.1
• /
• pp.1-18
• /
• 2020

Molten salt solutions consisting of eutectic LiCl-KCl and concentrations of samarium chloride (0.5 to 3.0 wt%) at 500℃ were analyzed using both cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The CV technique gave the average diffusion coefficient for Sm³⁺ over the concentration range. Equipped with Sm³⁺ diffusion coefficient, the Randles-Sevcik equation predicted Sm³⁺ concentration values that agree with the given experimental values. From CV measurements; the anodic, cathodic, and half-peak potentials were identified and subsequently used as a parameter to acquire EIS spectra. A six-element Voigt model was used to model the EIS data in terms of resistance-time constant pairs. The lowest resistances were observed at the half-peak potential with the associated resistance-time constant pairs characterizing the reversible reaction between Sm³⁺ and Sm²⁺. By extrapolation, the Voigt model estimated the polarization resistance and established a polarization resistance-concentration relationship.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
• /
• v.8 no.1
• /
• pp.77-84
• /
• 2010

Reduction of oxides has been investigated for the volume reduction and recycling of the spent oxide fuel from commercial nuclear power plants. Various oxide reduction methods were proposed and KAERI (Korea Atomic Energy Research Institute) is currently developing an electrochemical reduction process using a LiCl-$Li_2O$ molten salt as a reaction medium. The electrochemical reduction process, the front end of the pyroprocessing, can connect the PWR (Pressurized Water Reactor) oxide fuel cycle to a metal fuel cycle of the sodium cooled fast reactor. This paper summarizes KAERI efforts on the development, improvement, and scale-up of the oxide reduction process.