[en] The database system have already developed is impossible to solve a quantitative evaluation about a various situation from the dismantle activities of the reactor had contaminated with radioactivity. To satisfy the requirements for safety and economical efficiency among a major decommissioning technologies, it need a system that can evaluate and estimate dismantling scheduling, amount of radioactive waste being dismantled, and decommissioning cost. We have review and analyzed status of the digital mock-up system to get a technical guide because we have no experience establishment of one relation to dismantling of research reactor and nuclear power plant

[en] For volume reduction of the wastewater generated on washing the soil contaminated with cobalt, recycling and reuse experiments of the wastewater were executed. Also, the soil remediation efficiency by repetitive washing with fresh citric acid was analyzed. The soil around TRIGA was sampled for the experiment. Results of recycling experiment by replacement-precipitation method were as follows. The remediation efficiency of 1st recycling wastewater was 97% and that of 2nd recycling wastewater was 94%. Aslo, To obtain remediation efficiency over than 90%, the 5th repetitive washing with fresh citric acid was needed

[en] The effect of perfluorocarbon (PFC) and PFC surfactant on the interactive forces between particulate and solid surface measured by atomic force microscopy (AFM) with Si₃N₄ cantilever and silicon wafer was evaluated to understand the role of PFC solution as a decontamination medium in decontamination process for removing radioactive particulates from the substrates. It was obtained that the PFC solution containing perfluoro-1-butanesulfonyl fluoride (Krytox) as a PFC surfactants even in the concentration as low as 0.1 wt% displays a good surface active effect. On the bases of these results, the decontamination technique using PFC solutions was applied to the simulated specimen contaminated with particulates and the decontamination performance was evaluated. As the results of ultrasonic decontamination using PFC medium, decontamination performances in PFC solution containing PFC surfactant was far better than those is pure PFC solution and the particulate contaminants could be removed quite effectively

[en] The performance of dry decontamination using perfluorocarbon fluids for simulated specimen contaminated with radioactive particulate was evaluated to develop the decontamination process for the treatment of high level alpha bearing wastes generated from the dry process of nuclear fuel cycle. The decontamination performance in PFC fluid containing PFC surfactant was far better than those in the pure PFC fluid. The particulate contaminants were removed very effectively by PFC dry decontamination

[en] Daylighting is the efficient use of natural light in order to minimize the need for artificial light in buildings. A well thought out building designed with daylighting can have a number of significant benefits for building owners and occupants. Increasing levels of daylight within rooms can reduce electrical lighting loads by up to 70% in some cases. In this study, the daylighting system using mini dish and optical fiber was analyzed for application to the schoolroom by the simulation of ECOTECT and RADIANCE

[en] The solvent flushing apparatus for in-situ soil remediation was designed. After the soil around nuclear facilities was sampled and compulsorily contaminated by Co solution, the remediation characteristics by solvent flushing were analyzed. Meanwhile, the nonequilibrium sorption code was developed for modelling of the soil remediation by solvent flushing, and input parameters needed for modelling were measured by laboratory experiment. Experimental results are as follows: The soil around nuclear facilities belongs to Silt Loam including a lot of silt and sand. When water was used as a solvent, the higher was the hydraulic conductivity, the higher the efficiency of soil remediation was. The values calculated by the nonequilibrium sorption code agreed with experimental values more exactly than the values calculated by the equilibrium sorption code. When citric acid was used as a solvent, the soil remediation efficiency by citric acid showed 1.65 times that by water

[en] A series of batch scale experiments was conducted to investigated the decontamination efficiency of citric acid on TRIGA soil artificially contaminated with Co²⁺ ion in the concentration range from 0.005M to 0.1M, under the pH solution of 3.0 to 10.0. The fraction diagram was calculated by equilibrium constant of Co²⁺ ion, Fe³⁺ ion and citric acid. The desorption rate of Co²⁺ ion was increased at low pH, but it was decreased at base zone. The dissolution rate of Fe³⁺ ion was same result against the various pH. The desorption reaction of Co²⁺ ion and the dissolution reaction of Fe³⁺ ion by citric acid both in acid solution and in base solution were suggested

[en] The two research reactors (TRIGA MARK II and III) in Korea are to be decommissioned in the near future. When the reactors are completely dismantled, the site may remain contaminated due to the long period of operation. We assume that the site is radioactively contaminated by Co-60. Soils gathered from the research reactor site were artificially contaminated with Co²⁺ ion. The desorption characteristics of Co²⁺ ion from the soil surface by citric acid solution were investigated. Decontamination performances of citric acid and EDTA on soil stored in the radioactive waste drums was examined. The feasibility test of recycling the citric acid was also performed. We concluded that the radioactive waste volume could be reduced significantly by soil washing with a citric acid solution

[en] The electrokinetic apparatus for remediation of the soil contaminated with Sr²⁺was designed. After kaolin clay compulsorily contaminated by Sr²⁺ solution, the remediation characteristics by electrokinetic method were analyzed. Meanwhile, the numerical code for analysis of electrokinetic migration was developed for modelling of the soil remediation. And the input parameters needed for modelling were measured by laboratory experiment, or taken from literature. Experimental results are as follows : After 6 day remediation under 40 V, the front part of experimental cell was almost decontaminated, but the back part didn't almost be decontaminated. Consequently, the total remediation ratio of Sr²⁺ from cell soil was about 84.8 %. The values calculated by the developed code almost agreed with experimental values. When voltages of electrode were increased by 10, 20, 40V, the total Sr²⁺ remediation ratios were about 21.9%. 43.3%, 84.8 % , respectively, after 6 days

[en] After kaolin clay was compulsorily contaminated with Sr²⁺ ion, the remediation characteristics by electrokinetic method were analyzed. Ethanoic buffer was injected in the soil column and CH₃COOH was continuously inputted in cathode reservoir to restrain the pH elevation. The pH of the cathode side of the soil column was only ascended from 4.0 to 6.0 in 3.8 days and Sr(OH)₂ was not formed. The 21% of total Sr²⁺ in the soil column was decontaminated in 0.6 days, and the 33% of total Sr²⁺ in 0.9 days, and the 84% of total Sr²⁺ in 1.6 days, and the 92% of total Sr²⁺ in 2.5 days, and the 97% of total Sr²⁺ in 3.8 days. Meanwhile, the residual concentrations in the column calculated by the developed model were similar to those by experiment