• Title/Summary/Keyword: Decontamination Technology

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Comparison of the effects of gamma ray, electron beam, and X-ray irradiation to improve safety of black pepper powder (후춧가루의 위생화를 위한 감마선, 전자선 및 X-선 조사 효과 비교)

  • Park, Jae-Nam;Jung, Koo;Yoon, Young-Min;Choi, Soo-Jeong;Kim, Jae-Hun;Lee, Ju-Woon;Song, Beom-Seok
    • Food Science and Preservation
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    • v.21 no.3
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    • pp.315-320
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    • 2014
  • This study evaluated the effects of a gamma ray (GR), electron beam (EB), and X-ray (XR) to improve the safety of black pepper powder. The black pepper powder was irradiated by GR, EB, and XR at 2, 4, 6, 8, and 10 kGy. The results of the total bacterial populations in the black pepper power sample showed a similar effect on microbial decontamination for radiation sources. Radiation sensitivity ($D_{10}$ value) on the initial bacteria loads in the sample was 2.24 kGy in GR, 2.37 kGy in EB, and 2.75 kGy in XR. In addition, there were no differences among the radiation sources. The color values, such as L (lightness), a (redness), and b (yellowness), were not changed significantly. The sensory characteristics of GR, EB, and XR irradiated black pepper powder were decreased when the radiation dose increased, but there was no significant changes among the radiation sources. The results can be applied to investigate the effects of radiation sources on the microbiological and sensory characteristics of black pepper powder.

Effects of Combined Treatment of Aqueous Chlorine Dioxide and Fumaric Acid on the Microbial Growth in Fresh-cut Paprika (Capsicum annuum L.) (신선편이 파프리카의 미생물 생장에 있어서 이산화염소수와 푸마르산 병합처리의 효과)

  • Jung, Seung-Hun;Park, Seung-Jong;Chun, Ho-Hyun;Song, Kyung Bin
    • Journal of Applied Biological Chemistry
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    • v.57 no.1
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    • pp.83-87
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    • 2014
  • The effects of combined treatment of aqueous chlorine dioxide ($ClO_2$) and fumaric acid on the microbial growth in fresh-cut paprika were investigated. After the combined treatment, the populations of total aerobic bacteria and inoculated Listeria monocytogenes in the paprika sample were reduced by 0.82 and 1.21 log CFU/g, respectively, compared to those of the control. In addition, after 10 d of storage at $10^{\circ}C$, the populations were decreased by 1.21 and 2.10 log CFU/g, respectively. The predictive model for the populations of total aerobic bacteria and L. monocytogenes in the paprika was applied during storage. The prediction equation using Gompertz model was appropriate, based on the statistical analysis such as accuracy factor and bias factor. These results suggest that the combined treatment of aqueous $ClO_2$ and fumaric acid can be an effective technology for microbial decontamination and it can improve microbial safety by decreasing maximum growth rate and increasing lag time of bacteria in the fresh-cut paprika.

Helium dielectric barrier discharge-cold plasma treatment for microbiological safety and preservation of onion powder (유전체 방벽 방전 콜드 플라즈마 기술을 이용한 양파 분말 미생물 안전성 향상 및 품질 보존)

  • Won, Mee Yeon;Choi, Ha Young;Lee, Kwang Sik;Min, Sea Cheol
    • Korean Journal of Food Science and Technology
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    • v.48 no.5
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    • pp.486-491
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    • 2016
  • Efficacy of dielectric barrier discharge-cold plasma treatment (DBD-CPT) for microbial decontamination of onion powder was evaluated. Onion powder, inoculated with Escherichia coli O157:H7, Salmonella Enteritidis, or Listeria monocytogenes, was treated with helium DBD-CPT. DBD-CPT (9 kV, 20 min) inhibited E. coli O157:H7, S. Enteritidis, and L. monocytogenes by $1.4{\pm}0.5$, $2.3{\pm}0.3$, and $1.2{\pm}0.0log\;CFU/cm^2$, respectively. The inactivation levels of E. coli O157:H7, S. Enteritidis and L. monocytogenes increased by $2.2{\pm}0.1$, $2.5{\pm}0.1$ and $1.9{\pm}0.3log\;CFU/cm^2$, respectively, as water activity increased from 0.4 to 0.8, and increased by $2.3{\pm}0.4$, $2.1{\pm}0.1$ and $1.6{\pm}0.1log\;CFU/cm^2$, respectively, as the particle size increased from 0.3 to $1.0cm^2$. Neither the ascorbic acid and quercetin concentrations nor the color of onion powder was changed by DBD-CPT (p>0.05). These results demonstrate the potential for application of DBD-CPT in improving microbiological safety of onion powder while preserving the physicochemical properties.

Heavy Metal Adsorption Characteristics and Produced of Food Waste Activated Carbon (음식물류 폐기물 활성탄의 제조 및 중금속 흡착특성)

  • Lee, Jun-Hee;Lee, Seung-Chul;Ju, Min;Kim, Ji-Hye;Lee, Don-Gil
    • Journal of Environmental Science International
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    • v.24 no.12
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    • pp.1601-1608
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    • 2015
  • This study evaluates heavy metal(Cu and Cr) adsorption characteristics produced from food waste charcoal extracted in an optimal operation condition after analyzing activated charcoal of iodine adsorption and heavy metals that derived from an activation process of carbide by the developed by-products of food waste treatment facility using the methods from previous studies. As experiment apparatus, this study used a tube-shaped high temp furnace. The mixing ratio of by-products of food waste treatment facility, carbide, and activation component($ZnCl_2$) was 1:1. The experiment was proceeded as adjusting the activation temperature from 400 to $800^{\circ}C$ and activation time from 30 to 120 minutes. The optimal activation condition for iodine absorption was 90 minutes at $700^{\circ}C$ and by using the produced food waste charcoal, this study conducted an experiment on absorption of heavy metals (Cu and Cr) as changing pH of artificial wastewater and stirring time. As a result, pH 7 showed the highest heavy metal decontamination ratio and in terms of stirring time, it revealed balance adsorption after 10 minutes. This result can be particularly applied as basic data for recyclability of high concentration organic waste, by-products of food waste treatment facility, as an food waste charcoal.

A Study on the Natural Uranium Contamination Measuring Technology (천연우라늄 오염에 관한 방사선/능 측정기술 연구)

  • 정운수;홍상범;서범경;박진호;조용우;조성원;이정민
    • Proceedings of the Korean Radioactive Waste Society Conference
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    • 2004.06a
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    • pp.407-417
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    • 2004
  • This study is to verify radiation detection method by using $\alpha$-spectroscopy and ${\gamma}$-spectroscopy for concretes and components which will be generated during the decommissioning of the uranium conversion plant. Components and inside walls of the building were contaminated with natural uranium materials. Some parts of the stainless steel pipes and concretes of the walls were sampled and analyzed their alpha and gamma activities respectively. Alpha and gamma activities are well matched each other in the range of high activity region to 0.01 Bq/g and gamma activities are over estimated comparing alpha activities corresponded in below 0.005 Bq/g region for the natural uranium of AUC sample. The $^{238}U$ originated from natural products of conversion process could be distinguished by measuring $^{214}Pb$ or $^{214}Bi$ and $^{234}Th$ or $^{234m}Pa$. Uranium contaminations mainly are in the wall surface of the plant. Decontamination process of generating wastes which can be reached tp background level gamma activities measured by gamma spectroscopy can also be used to conservative assessment data.

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Effects of Antithyroid Drugs on Accidentally Internal Contamination of Iodine-131 (Iodine-131 체내오염 사고에 대한 항갑상선제의 효과)

  • Chung, In-Yong;Kim, Tae-Whan;Chin, Soo-Yil;Yun, Taik-Koo
    • Journal of radiological science and technology
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    • v.11 no.1
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    • pp.63-69
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    • 1988
  • In case of occuring the atomic energy accidents the proper medical treatments should be necessary. As the aim of the basic data for protective actions, the present studies were carried out to evaluate the decontamination of radioiodine by the administration of the antithyroid drugs (KI, NaI) and isotonic saline. Some recommended methods of decorporating radioiodine were investigated using 450, NIH-GP mice, each injected intraperitoneally with $1{\mu}Ci$ of $NaI^{131}$ as the internal contamination and treated with 2mg/0.2ml-saline of NaI and 2.6mg/0.2ml-saline of KI as the antithyroid drugs. Accordingly, effects of antithyroid drugs for internal contamination were: 1. Administration of NaI and KI caused to rapidly excrete internal radioiodine as the antithyroid drugs and decrease in whole body retention was reduced than in the saline group. 2. After internal contamination NaI and KI were to be administered for radioprotective effects as quickly as possible. 3. Decrease in body-retention made temporary shifts with enough fluids (water), however, as far as radioprotective effects is concerned, saline was not more significant than in the other group (NaI and KI). 4. Regarding to thyroid protective effects NaI, KI and saline were significant in effectively order.

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Systems Engineering Approach for the Reuse of Metallic Waste From NPP Decommissioning and Dose Evaluation (금속해체 폐기물의 재활용을 위한 시스템엔지니어링 방법론 적용 및 피폭선량 평가)

  • Seo, Hyung-Woo;Kim, Chang-Lak
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.15 no.1
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    • pp.45-63
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    • 2017
  • The oldest commercial reactor in South Korea, Kori-1 Nuclear Power Plant (NPP), will be shut down in 2017. Proper treatment for decommissioning wastes is one of the key factors to decommission a plant successfully. Particularly important is the recycling of clearance level or very low level radioactively contaminated metallic wastes, which contributes to waste minimization and the reduction of disposal volume. The aim of this study is to introduce a conceptual design of a recycle system and to evaluate the doses incurred through defined work flows. The various architecture diagrams were organized to define operational procedures and tasks. Potential exposure scenarios were selected in accordance with the recycle system, and the doses were evaluated with the RESRAD-RECYCLE computer code. By using this tool, the important scenarios and radionuclides as well as impacts of radionuclide characteristics and partitioning factors are analyzed. Moreover, dose analysis can be used to provide information on the necessary decontamination, radiation protection process, and allowable concentration limits for exposure scenarios.

The Assessment and Reduction Plan of Radiation Exposure During Decommissioning of the Steam Generator in Kori Unit 1 (고리1호기 증기발생기 제염해체 시 작업자 피폭선량 평가 및 저감화 방안)

  • Son, Young Jik;Park, Sang June;Byon, Jihyang;Ahn, Seokyoung
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.16 no.3
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    • pp.377-387
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    • 2018
  • Korea's first commercial nuclear power plant, Kori Unit 1, was permanently shut down on June 18, 2017, after 40 years of successful operation. Kori Unit 1 plans to construct a waste treatment facility in the turbine building prior to commencement of dismantling in earnest. Various radioactive wastes are decontaminated, disassembled, cut and melted in the waste treatment facility and sent to the radioactive waste repository. The proportion of metal radioactive waste in dismantled waste is about 70%, of which large metal radioactive waste is mainly generated in the primary circuit and has high radioactivity, so radiation exposure must be managed during disassembly. In this study, the steam generators are selected as large metal radioactive waste, the exposure doses of the dismantling workers are calculated using RESRAD-RECYCLE code and the methods for reducing the exposure doses are suggested.

Current Status of Infection Prevention and Control Programs for Emergency Medical Personnel in the Republic of Korea

  • Oh, Hyang Soon;Uhm, Dong Choon
    • Journal of Preventive Medicine and Public Health
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    • v.48 no.6
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    • pp.330-341
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    • 2015
  • Objectives: Emergency medical personnel (EMPs) are pre-hospital emergency responders who are at risk of exposure to infections and may also serve as a source for the transmission of infections. However, few studies of infection control have specifically addressed EMPs in the Republic of Korea (hereafter Korea). The goal of this study was to assess the current status of infection prevention and control programs (IPCPs) for EMPs in Korea. Methods: A cross-sectional survey was conducted to quantitatively assess the resources and activities of IPCPs. A total of 907 EMPs in five metropolitan cities completed a structured questionnaire from September 2014 to January 2015. The data were analyzed using descriptive statistics, multi-response analysis, and the chi-square test. Results: The mean age of the participants was $34.8{\pm}15.1years$. IPCPs were found to have weaknesses with regard to the following resources: the assignment of infection control personnel (ICP) (79.5%), hand hygiene resources such as waterless antiseptics (79.3%), the use of paper towels (38.9%), personal protective equipment such as face shields (46.9%), and safety containers for sharps and a separated space for the disposal of infectious waste (10.1%). Likewise, the following activities were found to be inadequately incorporated into the workflow of EMPs: education about infection control (77.5%), post-exposure management (35.9%), and the decontamination of items and spaces after use (88.4%). ICP were found to have a significant effect on the resources and activities of IPCPs (p<0.001). The resources and activities of IPCPs were found to be significantly different among the five cities (p<0.001). Conclusions: IPCPs for EMPs showed some limitations in their resources and activities. IPCPs should be actively supported, and specific IPCP activities for EMPs should be developed.

A Study on the mineral control and salt manufacture technology using higher concentration in the MVR desalination plant (MVR해수담수화플랜트의 고농도 농축수를 활용한 미네랄 제어 및 제염기술 연구)

  • Kim, Yeongmin;Chun, Wongee;Kim, Dongkook
    • Journal of Energy Engineering
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    • v.25 no.4
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    • pp.1-6
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    • 2016
  • Seawater desalination plants generally have two inherent problems which stem from energy inefficiency and desalination concentrate management. The former has been somewhat resolved thanks to the innovative methods in utilizing new and renewable energy resources whereas the latter still has much issues to be dealt with. This paper introduces the application of a desalting process for the disposal of desalination concentrate (especially, Mg) and to improve its cost effectiveness of a MVR seawater desalination plant built in Jeju. Principal component analysis on the desalination concentrate has revealed a steady reduction of Mg with the application of the desalting process verifying its functional reliability. Also, it was found that our MVR seawater desalination plant is not only energy efficient but also could be effectively applied for the dual purpose of fresh water production and concentrate management.