• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.21 no.2
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• pp.183-191
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• 2023

The potential impact of hypothetical accidents that occur during the immediate and deferred dismantling of the Kori Unit 1 steam generator has been comprehensively evaluated. The evaluation includes determining the inventory of radionuclides in the Steam Generator based on surface contamination measurements, assuming a rate of release for each accident scenario, and applying external and internal exposure dose coefficients to assess the effects of radionuclides on human health. The evaluation also includes calculating the atmospheric dispersion factor using the PAVAN code and analyzing three years of meteorological data from Kori NPP to determine the degree of diffusion of radionuclides in the atmosphere. Overall, the effective dose for residents living in the Exclusion Area Boundary (EAB) of Kori NPP is predicted, an it is found that the maximum level of the dose is 0.034% compared to the annual dose limit of 1 mSv for the general public. This implies that the potential impact of hypothetical accidents on human health discussed above is within acceptable limits.

• Analytical Science and Technology
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• v.26 no.1
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• pp.67-72
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• 2013

This study has been conducted to provide a management plan for recycled products (plastic wastes) by identifying hazardous substances present in it and conducting exposure assessment. The concentration of 7 heavy metals (Cd, Cr, Cu, Fe, Hg, Pb, Zn) was analyzed. Exposure scenario was assumed by the consumption of kimchi made in a recycled plastic bucket. According to the analysis, all of the analyzed samples were within the food code standard level except one sample (137.03 mg/kg, sum of Cd, $Cr^{6+}$, Pb and Hg). In leaching test, all of heavy metals were within the leaching standard (Standards specifications of utensil and container-Packing). In an oral exposure test, Fe, Pb and Zn were detected in cabbages and were below PMTDI (Provisional Maximum Tolerable Daily Intake). As one of the recycled plastic buckets exceeded the standard level, we conclude not to recommend the recycled plastic buckets for cooking purpose.

• Journal of Korean Society of Environmental Engineers
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• v.37 no.11
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• pp.619-630
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• 2015

This study was conducted to propose the methodology of human risk assessment specialized to domestic mine areas and to quantify the human risk of heavy metal (As, Cd, Cu, Pb, and Zn) contamination around two abandoned metal mines. To attain the goals, we established a relevant exposure scenario, including 7 exposure pathways and extracted a variety of exposure factors reflecting the characteristics of inhabitants around abandoned metal mine areas. Finally, carcinogenic and non-carcinogenic risks were compared between two areas, exposure pathways, heavy metal contaminants, and receptors. The total excess carcinogenic risks of two mine areas of concern were calculated to be larger than the acceptable carcinogenic risk ($1{\times}10^{-6}$), indicating those two areas are not safe for carcinogenic hazard. In addition, the hazard indices of two areas were computed to be higher than unit risk (1), suggesting that the areas of concern have non-carcinogenic risk. Ingestion of crop and intake of groundwater were evaluated to be main exposure pathways contributing to carcinogenic and non-carcinogenic risks within the areas. Also, the results show that carcinogenic and non-carcinogenic hazards were mostly attributed to As and As, Cd, and Pb, respectively.

• Journal of Radiation Protection and Research
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• v.30 no.2
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• pp.91-97
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• 2005

Bayesian methodology is appropriated for use in PRA because subjective knowledges as well as objective data are applied to assessment. In this study, radiological risk based on Bayesian methodology is assessed for the loss of source in field radiography. The exposure scenario for the lost source presented in U.S. NRC is reconstructed by considering the domestic situation and Bayes theorem is applied to updating of failure probabilities of safety functions. In case of updating of failure probabilities, it shows that 5 % Bayes credible intervals using Jeffreys prior distribution are lower than ones using vague prior distribution. It is noted that Jeffreys prior distribution is appropriated in risk assessment for systems having very low failure probabilities. And, it shows that the mean of the expected annual dose for the public based on Bayesian methodology is higher than the dose based on classical methodology because the means of the updated probabilities are higher than classical probabilities. The database for radiological risk assessment are sparse in domestic. It summarizes that Bayesian methodology can be applied as an useful alternative lot risk assessment and the study on risk assessment will be contributed to risk-informed regulation in the field of radiation safety.

• The Journal of Korean Society for Radiation Therapy
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• v.26 no.2
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• pp.289-295
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• 2014

Purpose : Cone Beam Computed Tomography(CBCT) in Image Guided Radiation Therapy(IGRT), Set-up error can be reduced but exposure dose of the patient due to CBCT will increase. Through this study, we are to evaluate by making a scenario with the implementation period of CBCT as every other day. Materials and Methods : Of prostate cancer patients, 9 patients who got a Intensity Modulated Radiation Therapy(IMRT) with CBCT in IGRT were analyzed. Based on values corrected by analyzing set-up error by using CBCT every day during actual treatment, we created a scenario that conducts CBCT every other day. After applying set-up error values of the day not performing CBCT in the scenario to the treatment planning system(Pinnacle 9.2, Philips, USA) by moving them from the treatment iso-center during actual treatment, we established re-treatment plan under the same conditions as actual treatment. Based on this, the dose distribution of normal organs and Planning Target Volume(PTV) was compared and analyzed. Results : In the scenario that performs CBCT every other day based on set-up error values when conducting CBCT every day, average X-axis : $0.2{\pm}0.73mm$, Y-axis : $0.1{\pm}0.58mm$, Z-axis : $-1.3{\pm}1.17mm$ difference was shown. This was applied to the treatment planning to establish re-treatment plan and dose distribution was evaluated and as a result, Dmean : -0.17 Gy, D99% : -0.71 Gy of PTV difference was shown in comparison with the result obtained when carrying out CBCT every day. As for normal organs, V66 : 1.55% of rectal wall, V66 : -0.76% of bladder difference was shown. Conclusion : In case of a CBCT perform every other day could reduce exposure dose and additional treatment time. And it is thought to be able to consider the application depending on the condition of the patient because the difference in the dose distribution of normal organs, PTV is not large.

• Journal of Radiation Protection and Research
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• v.32 no.1
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• pp.1-8
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• 2007

A model for radiological dose assessment in an urban environment, METRO-K has been developed. Characteristics of the model are as follows ; 1) mathematical structures are simple (i.e. simplified input parameters) and easy to understand due to get the results by analytical methods using experimental and empirical data, 2) complex urban environment can easily be made up using only 5 types of basic surfaces, 3) various remediation measures can be applied to different surfaces by evaluating the exposure doses contributing from each contamination surface. Exposure doses contributing from each contamination surface at a particular location of a receptor were evaluated using the data library of kerma values as a function of gamma energy and contamination surface. A kerma data library was prepared fur 7 representative types of Korean urban buildings by extending those data given for 4 representative types of European urban buildings. Initial input data are daily radionuclide concentration in air and precipitation, and fraction of chemical type. Final outputs are absorbed dose rate in air contributing from the basic surfaces as a function of time following a radionuclide deposition, and exposure dose rate contributing from various surfaces constituting the urban environment at a particular location of a receptor. As the result of a contaminative scenario for an apartment built-up area, exposure dose rates show a distinct difference for surrounding environment as well as locations of a receptor.

• Journal of Food Hygiene and Safety
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• v.33 no.4
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• pp.248-254
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• 2018

To assess the risk of V. parahaemolyticus infection caused by consumption of raw oysters in Korea, contamination levels during the retail-to-table route of oysters was modeled to predict V. parahaemolyticus growth based on temperature and time. The consumed amount data of the KNHANES and the standard recipe of RDA were applied. A consumption scenario for exposure assessment was developed and combined with a Beta-Poisson dose-response model. The estimated probability of illness from consumption of pathogenic V. parahaemolyticus in raw oysters during three separate months (April, October, and November) was $5.71{\times}10^{-5}$ (within the 5th and 95th percentile ranges of $2.71{\times}10^{-8}$ to $1.03{\times}10^{-4}$). The results of the quantitative microbial-risk assessment indicated that the major factors affecting the probability of illness were the initial contamination level at the retailer, the consumed amount, the prevalence of pathogenic strains [tdh or trh genes], and exposure temperature and time.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.11
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• pp.4951-4957
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• 2016

Background: Apart from reducing occupational exposure to cytotoxic hazards, the PhaSeal(R) closed-system transfer device (CSTD) can extend the beyond-use dates (BUDs) of unfinished vials of antineoplastic drugs for up to 168 hours (seven days). In this study, the total material cost incurred by its use in a Malaysian government-funded hospital was calculated. Methods: A list of vial stability following initial needle punctures of 29 commonly-used antineoplastic drugs was compiled. The amount of the materials used, including drugs, infusion bottles, the PhaSeal(R) CSTD and other consumables, was recorded on a daily basis for three months in 2015. The total cost was calculated based on the actual acquisition costs, and was compared with that of a hypothetical scenario, whereby conventional syringe-needle sets were used for the same amounts of preparations. Results: The use of the PhaSeal(R) CSTD incurred a cost of MYR 383,634.52 (USD 92,072.28) in three months, representing an average of MYR 170.5 (USD 40.92) per preparation or an estimated annual cost of MYR 1,534,538.08 (USD 368,289.14). Compared with conventional syringe-needle approach, it is estimated to lead to an additional spending of MYR 148,627.68 (USD 35,670.64) yearly. Conclusion: Although there was a reduction of drug wastage achieved by extending BUDs of unfinished vials using the PhaSeal(R) CSTD, cost saving was not observed, likely attributable to the wide use of lower-priced generic drugs in Malaysia. Future studies should further evaluate the possibility of cost saving, especially in health settings where branded and high-cost antineoplastic drugs are more commonly used.

• Proceedings of the Korea Society for Simulation Conference
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• 2001.10a
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• pp.231-236
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• 2001

Virtual Reality (VR) is a new technology that enables humans to communicate with a computer, It allows the user to see, hear, fuel and interact in a three-dimensional virtual world created graphically. Virtual Reality Therapy (VRT), based on this sophisticated technology, has been recently used in the treatment of subjects diagnosed with acrophobia. Acrophobia is a disorder that is characterized by marked anxiety upon exposure to heights, avoidance of heights, and a resulting impairment in functioning. Conventional virtual reality systems for the treatment of acrophobia have limitations, such as overly expensive devices or somewhat unrealistic graphic scenes. The goal of this study is to develop an inexpensive and more realistic virtual environment in which to perform an exposure therapy fur acrophobia. It runs on a personal computer, and a virtual scene ova bunge-jump tower in the middle of a large city. The virtual scenario includes an open tin surrounded by props beside a tower, which allows the patient to feel a sense of heights. The effectiveness of the VR environment was evaluated through the clinical treatment of a subject who was suffering from the fear of heights. Based on pre- and post- questionnaires and subjective comments from the subject. This virtual reality environment proved to be an effective and realistic tool fur the treatment of acrophobia.

• Journal of Environmental Health Sciences
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• v.37 no.4
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• pp.250-257
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• 2011

Objectives: This study was aimed at re-assessing the environmental burden of disease attributable to waterrelated diseases using available local data from Korea. Methods: The general methods and the operational definitions for water, sanitation and hygiene applied to the study were based on an environmental burden of disease study conducted by WHO. Eleven water-related diseases were selected. The attributable fraction for diarrhea was calculated by assessing local exposure levels to drinking water, sanitation and hygiene according the scenario-based approach. The attributable fractions for the other ten diseases were derived from the results of the environmental burden of diseases study. The attributable DALYs were measured by using the attributable fractions and local health statistics. Results: The total environmental burden of disease attributable to water, sanitation and hygiene for Korea was 0.9210 DALY per 1000 capitals. Of the total burden of disease, the attributable burden of diarrhea was 0.8863 (96.1%), the attributable burden of malaria and malnutrition was 0.0236 and 0.0063 DALY per 1000 capitals, respectively. There was little burden of disease measured for other diseases. Conclusions: This study is meaningful in re-assessing the environmental burden of disease using available local exposure data and health statistics. Quantitative analysis of the environmental risk factors and a health impact assessment would be helpful to prioritize health policies or interventions in the future.