• Journal of Radiation Protection and Research
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• v.20 no.1
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• pp.8-15
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• 1995

An estimate of a change in radioactivity's circumstances around the nuclear power plant is validated with the results of the radioactivity measurements are compared. In this study, to further enhance the reliability of the results obtained from the environmental radioactivity measurements and analysis around the nuclear power plants that have been carried out up to the present. In the korea standard, there is the technical analysis guide for general stable chemical element's, but there is not the technical analysis guide for the radionuclei. therefore the environmental sample collection, the pretreatment of the sample and radionuclide analysis in the sample, the result's of the environmental radioactivity measurements by each organization, etc. are different. It is not sufficient for the database to forecasting a change in radioactivity's circumstances. A comparative study of collection and pretreatment techniques for the soil sample, the results by comparison, the method of minimizing the relative error are proposed. At one side of sample collection, there are going to considered that the surroundings of sample collection like the lay of the land, the provision of the selection standard for the area and pathway of radionuclide adhesion, the coherence of sample collection, etc.. at another side of pretreatment of the sample and measurement in the case of soil sample, how to do homogeneously the soil particle size and the standard tools, i.e. kinds of meshes, must to be selected.

• Journal of the Korean Society of Radiology
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• v.10 no.1
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• pp.53-58
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• 2016

March 11, 2011 Fukushima nuclear power plant accident has occurred, the last four years, his is the current state of anxiety remains on the consumer. Therefore, 2015 the current progress continues to have continued research for the purpose of resolving the insecurity of fishery in the country. We measured the radiation of the origin of fishery products, by 2015, research was carried out through a number of references to get additional data or studies that influence this to some degree. Create a consumer and one for the seller for the survey to find out the thoughts of both consumers and sellers on fisheries was to create the statistics by direct survey in 2014 year survey meter using PM1405 equipment dynamics of several species of aquatic origin in accordance with the (Taiwan, China, Russia), mackerel, pomfret, hairtail, saury, shrimp, squid measurements of radiation were investigated. The measurement in 2014 was $0.043{\sim}0.073{\mu}Sv/h$. The seller influenced the survey (90%) on fishery products sales, consumer safety, without this fishery (90%), radioactive contamination very high (28%) and the polarization was not as nearly 72%. The study of the stability of the radiation determined by the radiation levels of the aquatic marine products in a comparison the radiation levels result was determined in ICRP below the standard value (1 mSv/y).

• Journal of the Korean Society of Radiology
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• v.11 no.2
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• pp.117-122
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• 2017

The purpose of this study is to prevent infection in the hospital by computed radiography portable and to provide basic data on infection-related education by investigating bacterial contamination level of computed radiography portable equipment using IP cassette. The results suggest that IP cassette No. 1 is infected with CNS and VRE, no. 2 with CNS, No. 3 with CNS and Pseudomonas aeruginosa, No. 4 with CNS, No. 5 with CNS and Bacillus sp., and No. 6 with enterococcus faecium. Enterococcus faecium and bacillus sp. were detected from the IP reader and Acinetobacter baumannii was detected on the mobile handle; Bacillus sp. on the control buttons, CNS and Bacillus sp. from the irradiation control handle, Acinetobacter baumannii on the x-ray generation switch, and CNS on the barcode scanner. In addition, Bacillus sp. Acinetobacter baumannii was found on the IP cassette mobile table and CNS and bacillus sp. were found on the lead apron. Acinetobacter baumannii and CNS were detected from the medical gloves worn by a radiological technologist during radiography. This suggests that IP cassette should be sterilized after use as it can hand over bacteria to IP reader and IP mobile table. Medical gloves that are in direct contact with patients should also be replaced after using them once and other supplies such as x-ray generation switch and lead apron should thoroughly be sterilized to prevent infection due to radiography as they are in a lot of contact with patients.

• Progress in Medical Physics
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• v.12 no.1
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• pp.95-102
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• 2001

The intracavitary cones were designed which were made of stainless steel and have scratched inside cone to be generated electron scatter and designed to be attached easily to the LINAC collimator and controlled cones length to be contacted smoothly between the patient and the cone tip. Two types of intracavitary cones were designed. One is the straight end cones with circular opening on the distal end and the other is 30 degree beveled end cones with elliptical opening on the distal end. Each type of intracavitary cone ranged in daimeter from 2.5 cm to 3.5 cm and required a separate set of lower trimmer annulias cone diameter. The film phantom was designed with an internal cassette that accurately aligned the film edge with the film phantom surface. Film optical density data were measured by photodensitometer(Wellhofer 700i) Dosimetry measurements were made to commission the LINAC for 6 - 20 MeV electron using the intracavitary cones. Isodose curves were measured for all energy and cones combinations. Output is defined as the maximum dose per MU along the clinical central axis in water at 113 cm SSD. Calibration output, defined to be the output for the 15cm$\times$15cm diameter straight cone, was adjusted to 1.00 cGy/MU at each energy according to the TG-21 protocol.

• Korean Journal of Food Science and Technology
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• v.30 no.5
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• pp.1209-1213
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• 1998

The gamma-radiation sensitivity of four kinds of Escherichia coli O157:H7 was investigated in frozen cells $(-18^{\circ}C)$ with 0.1 M phosphate buffer and inoculated cells in beef. The maximum populations were observed at 12 hr when E. coli O157:H7 was incubated in the tryptic soy broth at $37^{\circ}C$. In the case of the frozen cells at logarithmic phase, the $D_{10}$ and $12D_{10}$ values of four kinds of E. coli O157:H7 were $0.09{\sim}0.15\;kGy$ and $1.08{\sim}1.80\;kGy$, and inactivation factors were $13.33{\sim}22.22$ and $20.00{\sim}33.33$ at radiation doses of 2 and 3 kGy, respectively. The radiosensitivity of inoculated E. coli O157:H7 in beef showed the $D_{10}$ value of $0.30{\sim}0.47\;kGy$, the $12D_{10}$ value of $3.60{\sim}5.64\;kGy$, and inactivation factor of $4.26{\sim}10.00$. The radiosensitivity of the frozen cells was higher than that of the inoculated E. coli O157:H7 in beef. Gamma irradiation at doses within the range of 1.5 to 3 kGy is considered to be an effective method to control E. coli O157:H7 in beef.

• Journal of the Korean Society of Food Science and Nutrition
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• v.18 no.1
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• pp.14-18
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• 1989

Comparative effects of gamma irradiation and ethylene oxide treatments on the sterilization and physicochemical propperties of the condiment for soup of instant noodle (ramen) were investigated. The number of microorganisms contaminated ranged from $10^3\;to\;10^7\;CFU/g$ in total bacterial count, which were mainly composed of thermophiles and acid tolerant bacteria by over 90%. The yeast & molds were contaminated by $10^2\;to\;10^3\;CFU/g$. In the sterilizing effect of an irradiation on the microorganisms contaminated, 7 to 10 kGy gamma irradiation could eliminated yeast & molds, and also bring about the reduction of total bacterial count to below $10^3\;CFU/g.\;D_{10}$values of total bacteria! count of the samples ranged from 2.33 to 3.33 kGy. In comparative effects of irradiation and ethylene oxide treatments on the physicochemical properties of the sample, both treatments affected more or less rancidity, color, and amino-Ncontent, but less than 10 kGy irradiation was shown to be safe than ethylene oxide.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.14 no.3
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• pp.267-277
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• 2016

For the decommissioning of a nuclear power plant, a site characterization and final status survey require a site-specific suite of radionuclides that could potentially still be present in the site during or after the decontamination processes. The United States Nuclear Regulatory Commission (U.S. NRC) requires a Decommissioning Technical Base Document (DTBD) along with a Site Characterization and Historical Site Assessment (HSA) from the utility for decommissioning to proceed. Both the DTBD and HSA are preliminary components of the Radiological Site Survey investigation process and should be included in the final License Termination Plan (LTP) for site release and reuse consideration from the U.S. NRC and the utility company. This study reviews the United States Nuclear Power Plants (U.S. NPPs) decommissioning cases and is especially focused on the methodologies used for determining a site-specific suite of radionuclides before and during the site characterization and final status surveys. In 2017, Kori-1 will be ready for decommissioning and related preparations are ongoing, this review will help Korea to prepare regulatory guidelines and give technical background for the safe and successful decommissioning of NPPs.

• Journal of Radiation Industry
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• v.9 no.4
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• pp.209-216
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• 2015

It has been about 5 years since the Fukushima nuclear power plant accident, which contaminated large area with radioactive materials. It is necessary to assess radiation dose to establish evacuation areas and to set decontamination goal for the large contaminated area. In this study, we assessed temporal trend of radiation dose to the public living in the large area contaminated with radioactive materials after the Fukushima nuclear power plant accident. The dose assessment was performed based on Chernobyl model and RESRAD model for two evacuation lift areas, Kawauchi and Naraha. It was reported that deposition densities in the areas were $4.3{\sim}96kBq\;m^{-2}$ for $^{134}Cs$, $1.4{\sim}300kBq\;m^{-2}$ for $^{137}Cs$, respectively. Radiation dose to the residents depended on radioactive cesium concentrations in the soil, ranging $0.11{\sim}2.4mSv\;y^{-1}$ at Kawauchi area and $0.69{\sim}1.1mSv\;y^{-1}$ at Naraha area in July 2014. The difference was less than 5% in radiation doses estimated by two different models. Radiation dose decreased with calendar time and the decreasing slope varied depending on dose assessment models. Based on the Chernobyl dosimetry model, radiation doses decreased with calendar time to about 65% level of the radiation dose in 2014 after 1 year, 11% level after 10 years, and 5.6% level after 30 years. RESRAD dosimetry model more slowly decreased radiation dose with time to about 85% level after 1 year, 40% level after 10 years, and 15% level after 30 years. The decrease of radiation dose can be mainly attributed into radioactive decays and environmental transport of the radioactive cesium. Only environmental transports of radioactive cesium without consideration of radioactive decays decreased radiation dose additionally 43% after 1 year, 72% after 3 years, 80% after 10 years, and 83% after 30 years. Radiation doses estimated with cesium concentration in the soil based on Chernobyl dosimetry model were compared with directly measured radiation doses. The estimated doses well agreed with the measurement data. This study results can be applied to radiation dose assessments at the contaminated area for radiation safety assurance or emergency preparedness.

• Journal of the Korean Society of Radiology
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• v.17 no.1
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• pp.79-90
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• 2023

The study is to estimate the social costs of premature deaths due to nuclear power plant(NPP) accidents, by resorting to the contingent valuation method(CVM) which is used to estimate the value of a statistical life(VSL). The VSL estimate is about 3.55 billion won, which is multiplied by some 1.8 million premature deaths due to the accidents in world history of NPP, to get a maximum social cost of 1,952 trillion won. This estimate is equivalent to the 2022 real GDP of Korea. The annual average number of premature deaths and the resulting average social cost is 26,000 and 28 trillion won, respectively. The social cost of premature deaths due not only to accidents, but also the air pollutants from fired power plants(FPP) during 1987~2021 is estimated to be 26,919 trillion won. This is equivalent to 2021 US GDP, and is about 3,000 times higher than that for NPP of 9 trillion won. In 2021, the estimated social costs of FPP and NPP are 1,075 trillion won and 292 billion won, respectively. For South Korea, the study suggests to adapt an energy mix of increased share of electricity production for NPP relative to FPP, given that the 2050 carbon neutrality strategy of Korea is expected to lead to an increased share of renewable energy in electricity production. The study emphasizes accumulating the number of CVM-based VSL studies to ensure efficient energy policies.

• Korean Journal of Food Science and Technology
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• v.31 no.3
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• pp.619-624
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• 1999

This work was to study the potential health food use of germinated colored rice after germinating and drying using microwave under vacuum. Colored rice was soaked in water at $15^{\circ}C$ for 2 days and then germinated at $25^{\circ}C$ for $3{\sim}4\;days$. The germinated colored rice was dried by different drying methods: microwave vacuum drying 1, microwave vacuum drying $2\;(drying{\rightarrow}crushing{\rightarrow}drying)$, hot air drying, vacuum drying and freeze drying. Each drier except freeze drier was set to maintain the sample temperature at $60^{\circ}C$. During microwave vacuum drying 1 or 2, the sample reached $60^{\circ}C$ much faster (within 5 min) and was dried much faster ($2{\sim}3\;hrs$ than the other drying methods. The initial drying rate of microwave vacuum drying was ten times faster than that of hot air drying. The microwave vacuum drying 2 retained the highest ${\alpha}-amylase$ activity, followed by microwave vacuum drying 1, freeze drying, vacuum drying, and hot air drying.