감마선을 이용한 Metronidazole이 함유된 Poly(vinyl alcohol) 하이드로겔 제조 및 특성

백재,박종석,정진오,정성인,권희정,안성준,임윤묵 (사)한국방사선산업학회 2016 방사선산업학회지 Vol.10 No.1

Periodontitis is disease of damaged gum tissue that is not removed the plaque ontoteeth. In case that the symptoms of disease get pain worse, it will have to extract tooth because oftumefy or bleeding at gums so treatment of drug was required to periodontitis. In this study, thehydrogel was prepared by including superior viscous, excellent elastic, and biocompatibility ofPoly(vinyl alcohol, PVA) and antimicrobial drug of Metronidazole (MD). The 15 wt% PVA wasdissolved in deionized water and then prepared PVA solution was irradiated using gamma-ray at25 kGy (10 kGy hr-1). In addition, PVA hydrogel was immersed in each 0.1, 0.25 and 0.5 wt% MDsolution using stirrer for 24 hr. The result of the gelation, 0.5 wt% MD loaded PVA hydrogel (76%)was lower than PVA hydrogel (88.2%). The swelling ration of 0.5 wt% MD loaded PVA hydrogel(294.8%) was higher than PVA hydrogel (105.2%). The compressive strength and thermal propertiesof MD loaded PVA hydrogel was gradually lower. The drug release test of 0.5 wt% MD loadedPVA hydrogel (61%) was higher than 0.1 wt% MD loaded PVA hydrogel (12%). Therefore, MDloaded PVA hygrogel may be a promising tool for periodontitis medicine by gamma-ray.

전자선 조사에 따른 수질별 수온변화 비교

홍창용,김희수,박해준 (사)한국방사선산업학회 2021 방사선산업학회지 Vol.15 No.4

Some field cases showed that electron beams irradiated samples showed hightemperature increases compared to gamma rays irradiated samples. These cases of temperaturechanges were also estimated to be affected by various water qualities. The aims of this studywere to evaluate demonstratively about temperature changes of electron beams irradiated watersamples and to compare these changes by various water qualities. Sea water samples, freshwater samples and distilled water samples were evaluated in this study, and electron beams wereirradiated with 10 kGy, 25 kGy, 50 kGy, 100 kGy absorbed dose. As a result, high increases ofwater temperature were observed by absorbed dose increases, but were not significantly observedthese increases by various water qualities. Therefore, the stability of the electron beam irradiationfor the moisture-saturated sample, like flooded cultural heritage, should be evaluated with watertemperature increase. Furthermore, variables such as water qualities and irradiation speedsshould be carefully considered in subsequent studies.

X선 촬영실 내에서 피사체가 있을 때와 없을 때의 콜리메이션 최소화에 따른 공간선량의 감소효과

최성관,동경래,곽종길 (사)한국방사선산업학회 2019 방사선산업학회지 Vol.13 No.1

This study was investigated the reduction of space dose at 50 cm, 1 m, 2 m distance fromthe center of source when the collimation size was minimized based on with subject and withoutsubject in X-ray general test. As a result of the experiment using X-ray generator and dosimeter,the space dose when with the subject was investigated at least 1.2 times to 1.4 times higher thanwhen there is no subject, and minimizing the collimation size has reduced the space dose from 1.2to 5 times than when maximizing. This means that when the X-ray test is minimized to the rangeof the target site without opening the collimator size to the maximum, it is possible to reduce thespace dose from 1.2 to 5 times.

해양시료 방사성스트론튬 신속분석법 연구

정원선,이경진,강영근 (사)한국방사선산업학회 2022 방사선산업학회지 Vol.16 No.3

The experiment was conducted to minimize the methods and chemical procedures ofthe existing maritime specimen radiostrontium analytic method. Fish specimen among the maritimespecimens were selected, and extraction chromatography and carbonate extraction chromatographyamong the chemical separation stages were executed. 85Sr radioactive standard was used for themeasurement of the retrieval rate, and the retrieval rates of extraction chromatography and carbonateextraction chromatography were 85.3±0.7% and 95.0±1.7%, respectively. The verification of eachanalytic method was executed by using 90Sr radioactive standard. As the results of verification, bothextraction chromatography and carbonate extraction chromatography were found to be within ±5%of the corresponding standards. Time taken for preliminary processing, including the ashing time, foreach analytic method was approximately 2 days and 2 hours as well as 2 days and 6 hours for extractionchromatography and carbonate extraction chromatography, respectively. It is anticipated that it can beutilized as the rapid radiostrontium analytic method in the future since it is possible to reduce the timetaken for the analysis to approximately 1/5~1/6 of that for the fuming nitric acid method, and to executethe analysis of more specimens within a short period of time.

CT 장비별 관전압의 변화에 따른 노이즈, SNR 평가 - 자동노출제어방법과 수동노출제어방법 비교 -

문일봉,곽종길,성호진,박상원,김미현,동경래 (사)한국방사선산업학회 2018 방사선산업학회지 Vol.12 No.3

Advances in medical technology to evaluate the variety and frequency of the diagnostictest to learn the change of the noise value and the SNR according to the change in the tube voltageas a target in the MDCT trend to increase throughout the world for the high image acquisition andappropriate patient dose. This study in both the scan time, slice thickness, kernel value of Sʼs andthe same equipment Somatom Definition Flash Tube voltage 80, 100, 120, is changed to 140 kVp tomeasure the noise and SNR. Noise and SNR measurement is measured 10 times for each condition by setting the ROI in Clibration QC Phantom of the same size are shown as mean. Change in thenoise in the first Care Dose 4D decreased 60.8% increase relative to 80 kVp to 100 kVp to, decreased46.3% increase in 120 kVp, increasing to 39.8% and decreased to 140 kVp. And mA Fix (200 mA)decreased 63.1% increase in the 100 kVp based 80 kVp, decreased 48.7% increase in 120 kVp,decreased to 41.7% increase in when 140 kVp. First, the change in SNR Care Dose 4D decreasedby - 100% increase in 100 kVp based 80 kVp, 120 kVp to increase during - 366.7% decrease,decreased to - 433.3% increase in when 140 kVp and mA fix (200 mA) The 83.3% increase relativeto the increase in 100 kVp, 80 kVp, increase 120 kVp increased by 250%, increased from 383.3%increase in when 140 kVp. In this study with an increase in the tube voltage was found with theNoise SNR is reduced, the noise proper to valuable diagnostic image acquisition, with the tube voltagevalue and the optimum SNR is believed to minimize patient dose.

일개 대학 강의실의 실내 라돈농도 및 연간유효선량 평가

이재승,양성환,권대철 (사)한국방사선산업학회 2018 방사선산업학회지 Vol.12 No.3

The purpose of this study is to evaluate the effective dose of radon by radon exposureby measuring the concentration of radon in university lecture room. The measurement of radonconcentration was made in two lecture rooms on the first floor of reinforced concrete structurefrom March to May, 2018. On weekends when there was no use of the lecture room, it wasmeasured for 24 hours in a closed state for 12 hours before measurement, and continued for 12hours in 12 hours and 12 hours in continuous for 5 weeks. The indoor radon concentration wasmeasured by a radon meter and an analysis program, and the indoor radon concentration per unittime was converted in real time. The annual effective dose and the continuously measured radonconcentration due to radon inhalation were analyzed for mean and standard deviation, coefficientof variation, indoor radon concentration range, and quartile range. The closed lecture room radonconcentration was estimated to be 67~81.8 Bq·m-3 (mean 74.5±6.65 Bq·m-3) and the effectivedose per year was 0.289~0.353 mSv·y-1. The average radon concentration in normal operationwas 26.6~54 Bq·m-3 (mean 40.2±8.34 Bq·m-3), which was 54% lower than the closed room. Themean radon concentration was 48.3±5.94 Bq·m-3 before the start of the academic year, 31.3±6.64Bq·m-3, the average radon concentration was 41.9±9.64 Bq·m-3, 0.115~0.233 mSv·y-1. Radonconcentration 32.2~54 Bq·m-3 (average 45.7±5.2 Bq·m-3) at 18:00 o’clock without the lecture at09:00 the following day, quaternary range 43.9~48.8 Bq·m-3, annual effective dose 0.190~0.211mSv·y-1 respectively. Radon concentration was 26.6~40 Bq·m-3 (average 31.3±6.64 Bq·m-3) from09:00 am to 18:00 pm, which was reduced by 68.5% compared to the classroom without class, andthe quartile range was 28.3~33.8 Bq·m-3, and annual effective dose was 0.122~0.146 mSv·y-1. The average radon concentration in the lecture room was 10 min resting time (31.8±6.54 Bq·m-3)after lecture 50 minutes, 10 minutes resting time (32.3±7.18 Bq·m-3) after 1 hour and 50 minuteslecture, and 0.008~0.013 mSv·y-1. The average indoor radon concentration of 40.2±8.92 Bq·m-3 for 2 hours and 50 minutes of continuous use in classroom, the annual effective dose of 0.01~0.016mSv·y-1 for 50 minutes or 1 hour 50 minutes, indoor radon concentration and annual effectivedose of about 30% respectively. The radon concentrations in the lecture room were measured atlower levels than the indoor radon concentration control standards, and the hazard coefficientsfrom the radon inhalation in these environments were evaluated to be lower than the populationmean life time cancer risk.

원전 사고 시 RASCAL과 HYSPLIT 전산코드를 이용한 대기확산 모델별 방사성물질의 지표면 침적농도 분석

이진오,권재,류강우,장정환,김광표 (사)한국방사선산업학회 2019 방사선산업학회지 Vol.13 No.2

Introduction of the Lagrangian atmospheric dispersion model was considered insteadof the existing Gaussian atmospheric dispersion models for the level 3 probabilistic safety assessmentto reduce uncertainty in the atmospheric dispersion. The objective of the present study was toanalyze atmospheric dispersion behavior, surface deposition, and atmospheric dispersion models. The study was performed using RASCAL computer code, which employs Gaussian plume modeland Gaussian puff model and HYSPLIT computer code, which employs Lagrangian model. Forthe analysis, long-term station blackout accident was assumed. Released radionuclides includedparticle type 137Cs and gaseous type 131I, which are dispersed widely and extensively for nuclearaccident case. Radionuclide emission rate by time resulting from State-of-the-Art Reactor ConsequenceAnalyses project was used as a source term. The atmospheric dispersion behavior and surfacedeposition was analyzed for two case dates, which include a date with average wind speed ofmore than 3 m·s-1 and a date with wind speed of less than 3 m·s-1. For both 137Cs and 131I, atmosphericdispersion directions were roughly similar among three models. However, deposition concentrationof 131I compared with 137Cs was higher by about 100 folds for the Gaussian models andby about 1,000 folds for the Lagrangian model. For 137Cs, deposition concentrations were higherfor Gaussian plume model, Gaussian puff model, and Lagrangian model, in that sequence. For131I, deposition concentrations were generally higher for the Lagrangian model. The difference inthe deposition concentrations can be attributed to differences in the atmospheric concentration byatmospheric dispersion model and dry deposition velocity of released radionuclides. Therefore, it isrequired to study the physico-chemical characteristics of the released radionuclides for more realisticprediction of surface deposition concentration in applying the Lagrangian model instead of theexisting Gaussian plume models in the level 3 PSA. This study results is expected to contribute asan important base data for more realistic prediction of atmospheric

한국과 미국의 원전 중대사고 시 소외 사고결말평가 시스템 비교 연구

윤상혁,김민성,김광표 (사)한국방사선산업학회 2022 방사선산업학회지 Vol.16 No.3

Having experienced the TMI, the Chernobyl, and the Fukushima accident, NPPs are beingforced to follow stricter safety procedures. Korea and the US are using S-REDAP and RASCAL offsiteconsequence assessment systems based on relevant laws. In accordance with the Act on PhysicalProtection and Radiological Emergency, domestic NPP operators use the assessment system to determineemergency resident protection measures. For accurate resident protection measures, high reliability ofthe domestic consequence assessment system and methodology is important. The purpose of this studyis to compare methodologies of consequence assessment systems in Korea and US and to compare andanalyze assessment results. In this case, the result comparison analysis used an assessment code thatuses the domestic consequence assessment methodology. To achieve this, first, the methodologies of thetwo countries were compared. Second, a simulation scenario was established. Finally, assessment wasconducted based on the simulated scenario. It was found that there are differences in the source termassessment in the inventory and radioactive decay method, the core emission fraction applied unit, and thecore damage input method. In the atmospheric diffusion assessment, the diffusion model was the same asthe Gaussian model, but the domestic assessment models were AERMOD and CALPUFF, and the US wasTADPLUME and TADPUFF. In the dose assessment, there were differences in the duration of the derivedresults and the dose conversion factor. The simulation scenario was set as a scenario in which radioactivematerial was released outside the NPP, and the leakage rate at the time of release was set at 5% hr-1, andthe core damage was set at 5% of the core melt. As a result of the total emission amount, assessment codewas evaluated 1.8 times more conservatively than RASCAL. The initial dose was evaluated 5 to 9 times moreconservatively on assessment code, and 2 to 4 times more conservatively on RASCAL for the mid- to longtermdose. The initial dose was due to the difference between the emission amount and the assessmentperiod, and the mid- to long-term dose was considered to be due to the difference in the terrain effect. The results of this study are expected to prove the reliability of domestic accident assessment system andmethodologies and to be used in the prediction of doses in case of severe accidents.

언론 보도 및 인지도 조사를 통한 방사선량 인식 개선

김상현,홍동희,김호성,곽종길 (사)한국방사선산업학회 2019 방사선산업학회지 Vol.13 No.3

The purpose of this study is to analyze the trends of public and radiological technologistsperception of radiation dose and the trend of media reports and to find a way to change theradiation dose into a correct perception of the public. Press reports have increased since theFukushima nuclear accident. The public is first aware of social thoughts through media reports, andthe press has a great impact on the public because it communicates information and perspectives tothe public. The report trend analysis analyzed the radiation dose in the articles of daily newspapersand broadcasting companies during the last one year. The questionnaire was distributed to theradiological technologists and the general public, and the results were analyzed. Press reports tendto be negative and show that the influence of related articles has a negative impact on radiationrelatedproducts. Radiological Technologists responded that the response to the press was lackingand the official report of The Korean Radiological Technologists Association was an alternative. Therefore, it is expected that public awareness of radiation dose will be improved if the public isable to accurately communicate the positive amount of radiation dose through the media.

방사선 검사 시 2차 누출 방사선에 대한 연구

박환규,구은회 (사)한국방사선산업학회 2022 방사선산업학회지 Vol.16 No.4

During radiological examination, exposure should be minimized, and there should be nounnecessary exposure. But, 93 out of 100 radiation workers who examine with the control room dooropen were identified. The purpose of this study was to investigate the effect on radiation workers bymeasuring the scattering ray, leakage ray with an active dosimeter during radiological examination withthe control room door open. Among the five tests frequently performed in upper hospitals, two wereidentified, chest and spine. To study the difference according to the equipment, Listem’s Analog andGemss-medical’s Digital Radiography equipment were used. Control room door opening angles of 25°,50°, 75°, 100°, Measurements were made by changing the conditions by setting the distance from thedoor to 25 cm, 50 cm, and 100 cm. It was measured 10 times and represented by standard deviation, andChest, both instruments measured values below the radiation control area. Spine measurement result25 cm, 100 degree A device 2,325±33.6 μSv w-1, D device 2,572±38.4 μSv w-1 maximum measurement, Theminimum value was measured at 100 cm 25 degrees A device 159±16.4 μSv w-1 and D device 325±27.6. Except for 5 of the 24 conditions, all of them exceed the radiation control area. As a result of the study, it canbe seen that the annual dose limit is exceeded by converting the unit of the maximum value to 128.6±1.92mSv y-1. As the distance increases and the opening angle of the control room door decreases, the scatteringray, leakage ray decreases. Considering the probabilistic effects recommended in ICRP 103, it isjudged that continuous education for radiation workers is necessary.