• Title/Summary/Keyword: Decontamination Technology

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Effects of Irradiation and Fumigation on Color and Sensory Properties in the Parts of Dried Red Pepper during Storage (방사선과 훈증 처리된 건고추의 저장 중 부위별 색도 및 관능적 특성)

  • Kim Byeong-Keun;Kwon Youngju;Noh Jungeun;Kim Jeong-Sook;Kim Dong-Ho;Kwon Joong-Ho
    • Food Science and Preservation
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    • v.11 no.4
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    • pp.431-436
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    • 2004
  • Associated with microbial decontamination and quarantine treatment of dried red pepper, the samples was gamma-irradiated (5, 10 kGy) and fumigated (methyl bromide/MeBr, phosphine/$PH_3$) to compare their Hunter's color (L, a, b, ${\Delta}E$) and sensory properties by types (whole, powder, pericarp, seed) during storage under room conditions($18{\pm}12^{\circ}C$). Whole pepper maintained higher lightness (L value) than other groups, while powdered pepper showed higher redness (a value) during storage. Immediately after treatments there was little difference in the overall color difference (${\Delta}E$) among the groups. After 8 months, a higher redness was observed in $PH_3$ group of whole pepper and 5 kGy group of powdered pepper, respectively(p<0.05). Redness of irradiated pericarps was apparently reduced following 8 months of storage and a similar pattern was found in fumigated samples. The yellowness (b value) of pepper seed was lowest in 10 kGy sample (p<0.05), but insignificant difference was observed among treatment groups with storage time. Sensory properties of whole and powdered peppery were little changed by both treatments under commercial conditions. Sensory scores of irradiated or fumigated samples were higher than that of non-treated control with storage time, which was more significant in the powdered than in the whole samples.

Photostimulated Luminescence-Thermoluminescence Application to Detection of Irradiated White Ginseng Powder (방사선 조사 백삼분말의 PSL-TL 다중검지법)

  • Chung, Hyung-Wook;Delincee, Henry;Kwon, Joong-Ho
    • Korean Journal of Food Science and Technology
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    • v.32 no.2
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    • pp.265-270
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    • 2000
  • White ginseng powder, permitted to be irradiated in Korea for the purpose of microbial decontamination, was treated with electron beam at doses of $0{\sim}15\;kGy$ for a detection trial whether it is irradiated or not by measuring photostimulated luminescence for whole samples first and then (TL) for the mineral adhering to the samples. PSL values were less than threshold value (700, $T_{1}$) and were negative for nonirradiated samples but more than 5000 $(T_2)$ and were positive for irradiated ones. After PSL measurement mineral was separated from the whole samples using density separation. Mineral of nonirradiated samples was characterized by glow curves which have low intensity and were situated at the high temperature region (about $300^{\circ}C$) by the low level of natural radioactivity. Glow curves of minerals for all irradiated samples were observed at about $200^{\circ}C$. TL ratio by normalization was 0.01 for nonirradiated sample and more than 0.78 for irradiated samples, and it was possible to detect whether white ginseng powders were irradiated or not.

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A Study on Strengthening Consequence Management System Against CBRN Threats (CBRN 위협에 대비한 사후관리체계 강화방안)

  • Kwon, Hyuckshin;Kwak, Minsu;Kim, Kwanheon
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.40 no.4
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    • pp.429-435
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    • 2020
  • North Korea declared itself complete with nuclear force after its sixth nuclear test in 2017. Despite efforts at home and abroad to denuclearize the Korean Peninsula, the prospects for the denuclearization are not bright. Along with political and diplomatic efforts to deter NK's WMD threats, the government is required to strengthen its consequence management capabilities against 'catastrophic situations' expected in case of emergency. Accordingly, this study was conducted to present measures to strengthen follow-up management against CBRN threats. The research model was partially supplemented and utilized by the THIRA process adopted and utilized by the U.S. Department of Homeland Security among national-level disaster management plan development models. Korea's consequence management (CM) system encompasses risk and crisis management on disaster condition. The system has been carried out in the form of a civil, government and military integrated defense operations for the purpose of curbing the spread or use of CBRNs, responding to threats, and minimizing expected damages. The preventive stage call for the incorporation of CBRN concept and CM procedures into the national management system, supplementing the integrated alarm systems, preparation of evacuation facilities, and establishment of the integrated training systems. In the preparation phase, readjustment of relevant laws and manuals, maintenance of government organizations, developing performance procedures, establishing the on-site support systems, and regular training are essential. In the response phase, normal operations of the medical support system for first aid and relief, installation and operation of facilities for decontamination, and development of regional damage assessment and control guidelines are important. In the recovery phase, development of stabilization evaluation criteria and procedures, securing and operation of resources needed for damage recovery, and strengthening of regional damage recovery capabilities linked to local defense forces, reserve forces and civil defense committees are required.

Effects of Gamma Irradiation on the Decontamination of Animal Feeds : Sterilization of Protein Sources (배합사료 원료에 대한 방사선 살균 효과 -단백질원의 살균-)

  • Byun, Myung-Woo;Kwon, Joong-Ho;Cha, Bo-Sook;Cho, Han-Ok;Kim, Young-Bae
    • Korean Journal of Food Science and Technology
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    • v.20 no.1
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    • pp.112-118
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    • 1988
  • The effect of gamma irradiation of microbiological and physicochemical properties of raw ingredients (thirteen kinds of protein sources) for the mixed feed were investigated. The total aerobic bacteria counts in the samples was ranged from $10^2$ to $10^7$cells/g. After 5 to 7 kGy irradiation, the total count was reduced by 3 to 4 log cycles. Coliforms were detected in seven samples and the range was from $10^4$ to $10^6$cells/g. Enteric pathogens were found only in fish meal and poultry byproduct as $10^2$ to $10^6$cells/g. They were sensitive to radiation and completely sterilized by 3 to 5 kGy irradiation. Total fungi count was ranged from $10^1$ to $10^4$cells/g in all samples. They were osmophiles such as Aspergillus, Penicillium, Cladosporium, Aureobasidium and Rhizopus and were destroyed by 3 to 7 kGy irradiation. Five species of potential mycotoxin producers including Aspergillus flavus were also identified. Physicochemical properties, such as total amino acid content, TBA value, POV and color difference showed that irradiation with optimum does was less detrimental than autoclaving.

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A Study on the Assessment of Source-term for PWR Primary System Using MonteCarlo Code (MonteCarlo 코드를 이용한 PWR 일차 계통 선원항 평가에 관한 연구)

  • Song, Jong Soon;Lee, Sang Heon;Shin, Seung Su
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.16 no.3
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    • pp.331-337
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    • 2018
  • The decommissioning of nuclear power plants is generally executed in five steps, including preparation, decontamination, cutting/demolition, waste disposal and environmental restoration. So, for efficient decommissioning of nuclear power plants, worker safety, effects compared to cost, minimization of waste, possibility of reuse, etc., shall be considered. Worker safety and measurement technology shall be secured to exert optimal efficiency of nuclear power plant decommissioning work, for which accurate measurement technology for systems and devices is necessary. Typical In-Situ methods for decommissioning of nuclear plants are CZT, Gamma Camera and ISOCS. This study used ISOCS, which can be applied during the decommissioning of a nuclear power plant site without collecting representative samples, to take measurements of the S/G Water Chamber. To validate the measurement values, Microshield and the GEANT4 code was used as the actual method were used for modeling, respectively. The comparison showed a difference of $1.0{\times}10^1Bq$, which indicates that it will be possible to reduce errors due to the influence of radiation in the natural environment and the precision of modeling. Based on the research results of this paper, accuracy and reliability of measurement values will be analyzed and the applicability of the direct measurement method during the decommissioning of NPPs will be assessed.

Development of Practical Advanced Oxidation Treatment System for Decontamination of Soil and Groundwater Contaminated with Chlorinated Solvents (TCE, PCE): Phase II (염소계 화합물(TCE, PCE)로 오염된 토양 및 지하수 처리를 위한 실용적 고도산화처리시스템 개발 (II))

  • Kim, Sang-Yeek;Sohn, Seok-Gyu;Kong, Sung-Ho
    • Journal of Soil and Groundwater Environment
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    • v.15 no.2
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    • pp.10-17
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    • 2010
  • Advanced oxidation processes (AOPs) have advantages to reduce the processing time and mineralize contaminants dissolved in groundwater. Recently, remediation techniques for organic contamination in groundwater have been studied, and technology using $UV/H_2O_2$ is generally accepted as one of the most powerful and reliable alternative for the remediation of groundwater contamination. In this study, $UV/H_2O_2$ technology, which generates hydroxyl radical ($\cdot$ OH) as known for strong non-selective oxidant, was used to degrade chlorinated solvents (TCE and PCE), and it was expanded to apply continuous stirred tank reactor (CSTR) system (i.e. combinations of three CSTR). The tested parameters for CSTR system were retention time and groundwater/$H_2O_2$ injection volume ratio. To find optimum parameters for CSTR system, various retention time (6 min ~ 90 min) and groundwater/$H_2O_2$ injection volume ratio (5/1 ~ 119/1) were tested. Other conditions for CSTR were adapted from the batch test results, which concentration of $H_2O_2$ and UV dose were 29.4 mM (0.1%) and 4.3 kWh/L, respectively. Based on the experimental results, the optimum parameters for CSTR system were 20 min for retention time and 119/1 for groundwater/$H_2O_2$ injection volume ratio. Applying these optimum conditions, chlorinated solvents (TCE and PCE) were removed at 99.9% and 99.6%. Moreover, the effluent concentrations of TCE and PCE are 0.036 mg/L and 0.087 mg/L, respectively, which are satisfied the regulatory level (TCE 0.3 mg/L, PCE 0.1 mg/L). Consequently, the CSTR system using $UV/H_2O_2$ technology can achieve high removal efficiency in the event of treatment of groundwater contaminated by chlorinated solvents (TCE and PCE).

Effects of Gamma-Irradiation and Fumigation on Microbial Growth, Color and Absorption Properties of Dried Red Pepper during Storage (감마선과 훈증처리가 저장 중 건고추의 미생물 생육, 과피 색도 및 흡광 특성에 미치는 영향)

  • Kim Byeong-Keun;Kausar Tusneem;Kim Dong-Ho;Kwon Joong-Ho
    • Food Science and Preservation
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    • v.12 no.1
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    • pp.48-53
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    • 2005
  • Comparative effects between commercial fumigation (methyl bromide/MeBr, phosphine $gas/PH_3$) and gamma irradiation (5, 10 kGy) on dried red pepper were investigated in terms of it microbiological quality, moisture content Hunter's colors, and UV-visible spectra during storage for 8 months at mom temperature. The non-treated control samples showed total aerobic bacteria as $4.8\times10^5\;CFU/g$ in powdered state and $1.8\times10^2\;CFU/g$ in whole red repper. While yeasts and molds were $1.7\times10^5\;CFU/g$ in powdered pepper and $5.0\times10^2\;CFU/g$ in whole pepper, respectively. The effect of chemical fumigant on microbial decontamination was negligible, whereas irradiation at 5 kGy was proven to reduce the microbial populations by 2 to 3 log cycles that could improve the hygienic quality of powdered pepper. Moisture content of the samples showed no noticeable changes resulting 1mm irradiation or fumigation. Immediately after treatments, irradiation or fumigation reduced Hunter's lightness (L), redness (a), and yellowness (b) of the samples (p<0.05), but there was no difference in color parameters between the control and all treated stoups after 4 months of storage. It was found that storage period was more influential than irradiation or fumigation to changes in moisture and color of dried red pepper and ie powder.

Decontamination of Poultry Feeds by Gamma Irradiation (감마선 조사에 의한 가금용 사료의 살균)

  • Byun, Myung-Woo;Cho, Han-Ok;Lee, Jae-Won;Kwon, Joong-Ho;Kim, Young-Bae
    • Korean Journal of Food Science and Technology
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    • v.19 no.5
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    • pp.403-408
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    • 1987
  • The effects of gamma irradiation on microbiological and chemical qualities of four kinds of poultry feeds were investigated. The viable counts of total bacteria in the samples were $10^5\;to\;10^6/g$. They were reduced by 2 to 3 log cycles after 3 to 5 kGy irradiation, and were completely eliminated with irradiation of 7 kGy. Coliforms and enteric pathogens were contaminated in high levels in all samples, ranging from $1.2{\times}10^4\;to\;1.7{\times}10^5/g\;and\;4.0{\times}10\;to\;2.6{\times}10^3/g$, respectively, They were sterilized by 3 to 5 kGy irradiation. Fungi, ranging from $10^{2}\;to\;10^4/g$, mainly osmophiles were identified as Aspergillus and Penicillium. They were eliminated to a undetectable level by 5 to 10 kGy irradiation. Six kinds of species, including Aspergillus flavus, were potential mycotoxin producers. Chemical components, such as proximate compositions, and mineral contents were not affected by the gamma irradiation. However, TBA values and amino acid content seemed to be affected by gamma irradiation.

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Characteristics of the Decontamination by the Melting of Aluminum Waste (용융에 의한 알루미늄 폐기물의 제염 특성)

  • Song Pyung-Seob;Choi Wang-Kyu;Min Byung-Youn;Kim Hak-I;Jung Chong-Hun;Oh Won-Zin
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.3 no.2
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    • pp.95-104
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    • 2005
  • Effects of the aluminum melting temperature, melting time and a kind of flux agents on the distribution of surrogate nuclide were investigated in the electric furnace at the aluminum melting including surrogate radionuclides(Co, Cs, Sr) in order to establish the fundamental research of the melting technology for the metallic wastes from the decommissioning of the TRIGA research reactor. It was verified that the fluidity of aluminum melt was increased by adding flux agent but it was slightly varied according to the sort of flux agents. The results of the XRD analysis showed that the surrogate nuclides move into the slag phase and then they were combined with aluminum oxide to form more stable compound. The weight of the slag generated from aluminum melting test increased with increasing melting temperature and melting time and the increase rate of the slag depended on the kind of flux agents added in the aluminum waste. The concentration of the cobalt in the ingot phase decreased with increasing reaction temperature but it increased in the slag phase up to 90$\%$according to the experimental conditions. The volatile nuclides such as Cs and Sr considerably transferred from the ingot phase to the slag and dust phase.

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A Study of Measuring the Surface Contamination for Patient's Clothes and Bedclothes after Ablation Therapy (방사성옥소 치료환자의 환의 및 침구류에 대한 표면오염 측정에 관한 고찰)

  • Moon, Jae-Seung;Park, Dae-Seong;Kim, Su-Keun;Jeong, Hee-Il
    • The Korean Journal of Nuclear Medicine Technology
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    • v.12 no.1
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    • pp.3-12
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    • 2008
  • Purpose: Contaminated clothes and bedclothes of patients by mouth or with excrement are produced after Radioisotope $^{131}I$ treatment. In this paper, patient's clothes and bedclothes contaminated by radioactivity measured and radioactive waste wish to calculate optimum storage period. Material and Methods: The whole area of patients' clothes and bedclothes measured 70 patients, 12 males and 58 females, who had radioisotope $^{131}I$ therapy between August 2005 and February 2006. Assuming contamination is evenly distributed, the radioscope used to measure up to social toleration level at 7 day intervals. Results: Each optimum storage period of control group of 60 case and non control group of 10 case were average $44{\pm}16$ days and $32{\pm}13$ days. Decontamination effect of surface contamination for radioactive waste was average $83.66{\pm}15.15%$. Conclusion: It is important that classify radioactive waste according to difference of surface contamination. Result of this research, handling radioactive waste in optimum storage period may be useful.

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