• Proceedings of the Korean Radioactive Waste Society Conference
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• 2016.10a
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• pp.411-412
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• 2016

• Journal of Radiation Protection and Research
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• v.23 no.1
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• pp.7-15
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• 1998

In order to evaluate the effectiveness of some decontamination agents against skin contamination of $^{60}Co$ and $^{137}Cs$, the experiments were carried out in this study. In the experiments, pig skin was used instead of human skin , $^{60}CoC1_2$ and $^{137}CsCl$ were used the liquid sources of skin contamination. To examine the effectiveness of decontamination agents, skin decontamination was tried using soup, EDTA, KAERICON which was developed for decontamination of radionulides on the surface of building structure, and new decontamination agents such as IOCON, TRICON, and CHARCON, which were developed in this study. The absorption of radionuclides through the skin was evaluated by the gamma-tay detection on the surface of sample skin after radionuclides were penetrated into the skin during 16 hour soiling time. The results of this absorption experiment indicated that 11.5% and 3.2% of initial amounts of $^{137}Cs$ and $^{60}Co$, respectively, were panerated into the skin. In the experiment to remove the residual radioactivity fixed on the skin, KAERICON showed the decontamination rates up to 52.1%(decontamination factor of 2.1) and IOCON showed the equivalent decontamination rate (decontamination factor 1.9) for $^{137}Cs$. However, IOCON and CHARCON showed the poor decontamination rates of less than 20%(decontamination factor of 1.2) for $^{60}Co$, and KAERICON showed the poor decontamination rate (decontamination factor 1.1) for $^{60}Co$. For TRICON, the decontamination factors were 1.6 to 1.8 for $^{137}Cs$, and 1.0 to 1.2 for $^{60}Co$, respectively.

• Proceedings of the Korean Nuclear Society Conference
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• 2001.05a
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• pp.470.2-470
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• 2001

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.2 no.4
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• pp.245-251
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• 2004

Soil washing equipment was developed for decontamination of radioactively contaminated soil generated during normal operation or decommissioning and verification experiments were performed. Decontamination effciency above $80{\%}$ was achieved. In case of low radiation level and large particle size, decontamination efficiency was higher. According to the ratio of volume of water to soil quantity, decontamination efficiency was higher in case of high radiation level. Re-decontamination using decontaminated soil was effective in case of small particles. Using soil washing equipment, radioactivity of contaminated soil generated in nuclear power plant can be decreased and volume of soil for disposal can be decreased. And this equipment can be used in decommissioning.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2005.06a
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• pp.21-29
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• 2005

The HANARO, a multi-purpose research reactor of 30 MWth open-tank-in-pool type, has been under normal operation since its initial criticality in February, 1995. Recently, ten years after the initial operation of the HANARO, one of the two primary cooling pumps was decontaminated for overhaul maintenance in 2004. Before decontamination exposure doserate and surface contamination level of primary cooling pump measured at 4 points. After final decontamination exposure doserate and surface contamination level of primary cooling pump remeasured by same method done before. It is easy to decontaminate the out side exposed surfaces of the pump, but it is difficult to approach the inside surface due to double volute installed in the casing. Therefore, a new decontamination facility has been developed to solve this problem. A concentrated de-contaminant (DX-300) is rotated in the closed pump casing by the impeller actuated by a temporary motor. Nuclide particles are removed by the emulsification effect of the de-contaminant and the surface contaminants are chemically removed from the pump by the corrosion and dissolution effect. The inside surfaces of the primary cooling pump have been decontaminated by using the facility. As results, the contamination level of the inside surfaces was maintained below the surface contamination limit.

• Proceedings of the Korean Nuclear Society Conference
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• 2002.05a
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• pp.321.2-321
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• 2002

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2011.05a
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• pp.197-198
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• 2011

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.3 no.4
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• pp.293-300
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• 2005

Ultrasonic decontamination of the type 304 stainless steel specimen loosely contaminated with $Eu_2O_3$ powders was investigated. Decontamination factors (DFs) by the three kinds of ultrasonic media such as water, pure PFC (Pefluorocarbon, $C_7F_{16}$) and a mixed solution of $99.9\;vol\%\;PFC\;and\;0.1\;vol\%$ anionic surfactant were determined. The determined DF values were 20, 50 and 200, respectively. This significant difference in the decontamination factors for the different decontamination solution was well explained by the surface tension of the media as well as the interaction between the positively charged surface of $Eu_2O_3$ powders and the anionic surfactant. Ultrasonic decontamination behavior of the loosely contaminated metal specimens such as plate, pipe, welding specimen and crevice specimen in the mixed solution of PFC and anionic surfactant was also investigated. The contaminants were completely removed for the tested specimens except for the longest specimen. For 6-cm long pipe specimen, however, $98.5\%$ of the contaminants were removed.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2003.11a
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• pp.720-724
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• 2003

In order to develop the decontamination process for self-disposal with authorization of duct waste generated from the decommissioning of retired TRIGA research reactors, the surface characterization of duct specimen taken from TRIGA research reactor was carried out and the adequate decontamination method was selected. It can be known that the paint coated internal surface of duct is contaminated with $^{60}Co$and $^{137}Cs$, which are penetrated into the paint layer and incorporated into zinc plated surface of galvanized iron as the material of duct. Two step chemical decontamination process, in which sodium hydroxide and sulfuric acid solutions are used in turn, is quite successful to remove the surface contamination of duct waste.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2017.05a
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• pp.136-136
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• 2017

화학제염 기술은 산화제, 환원제, 금속이온, 무기산등이 혼합되어 있는 화학용액을 사용하여 원전기기 계통 내부에 생성된 고방사능 준위의 산화막과 오염물질을 제거하는 기술이다. 원전의 해체 및 유지보수에 있어 방사능 피복저감을 위한 필수적인 기술이다. 현재 원전 해체 산업은 잠재성이 높은 고부가가치 창출 산업으로 주목을 받고 있다. 원전 보유국의 경우, 기존 상용 제염기술과는 차별성 있는 제염기술을 확보하고자 노력하고 있다. 기존의 공정과 비교하여 공정비용 및 시간을 감소시킬 수 있어야 할 뿐만 아니라, 화학용액에 의한 원전 계통 금속 부품의 부식 및 손상을 최소화해야 한다. 금속 부품이 화학약품에 의한 부식손상을 받는다면 금속 부품의 수명 및 재활용 가치가 감소하기 때문에, 화학제염 기술 적용에 있어 용액에 대한 재료의 건전성 평가가 사전에 필히 이루어져야 한다. 본 연구에서는 원전 냉각재 펌프용 재료로 주로 사용되는 Stainless 304강을 시험편으로 선정하여, 화학제염 시험공정 3가지에 대한 부식손상 특성을 규명하였다. 산화공정은 과망간산($HMnO_4$) 용액을 공통으로 사용하였으며, 산화공정 종료 후 환원공정은 각 시험공정에 따라 시험공정 1은 옥살산($H_2C_2O_4$) 2000ppm, 시험공정 2는 옥살산($H_2C_2O_4$)1500ppm + 시트르산($H_8C_6O_7$)500ppm, 그리고 시험공정 3은 옥살산($H_2C_2O_4$) 3000ppm 용액을 각각 투입하여 수행하였다. 산화, 환원공정을 1Cycle로 하여, 각 시험공정 별로 총 5Cycle을 실시하였다. 각 시험공정 Cycle종료 후 시험편을 취외하여 무게감량측정, SEM(Scanning electron microscope) 분석, 3D현미경분석 그리고 타펠분극 실험을 실시하였다. 각 분석결과를 토대로 하여, Stainless 304강에 대한 화학제염 시 모델별 시험공정에 따른 부식특성을 규명하였다.