• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
• /
• pp.1884-1887
• /
• 1997

The increasing concern over radiation exposure in the nuclear industry has fostered agrressive efforts to reduce the levels of radiation exposure. One area of the effot to reduce the radiation exposure is the development of a remote radiation monitoring system. Remote radiation monitoring can serve many benificaial functions reduce exposure to radiation by plant personnel, impruve the quality of the data that is collected and recognize the radiation environment easily. Radiation mapping system gives a good information that represents radiation level distribution. The system we have developed consists of a data acquistion parts, mobile robot and remote control parts. Data acquisition parts consist of radiation detection module and vision acquistion module which collect radiation data, visiion data and distance information. In remote control parts, the acquision data are processed and displayed. We have constructed radiation mapping image by overlaying the vision and radiation data. The radiation mapping techniques for displaying the results of the survey in an easily comprehendable form will facilitate a better understanding of the radiation environment in the facility. This system can reduce workers radiation exposure and aid to help work plan, so it has significant benifits in cost and safety.

• 대한방사선기술학회지:방사선기술과학
• /
• 제44권2호
• /
• pp.109-115
• /
• 2021

In this study, a physical evaluation of internal radiation exposure in children was conducted using nuclear medicine test(Renal DTPA Dynamic Study) to simulate the distribution and effects of the radiation throughout the tracer kinetics over time. Monte Carlo simulations were performed to determine the internal medical radiation exposure during the tests and to provide basic data for medical radiation exposure management. Specifically, dose variability based on changes in the tracer kinetic was simulated over time. The internal exposure to the target organ (kidney) and other surrounding organs was then quantitatively evaluated and presented. When kidney function was normal, the dose to the target organ(kidney) was approximately 0.433 mGy/mCi, and the dose to the surrounding organs was approximately 0.138-0.266 mGy/mCi. When kidney function was abnormal, the dose to the surrounding organs was 0.228-0.419 mGy/mCi. This study achieved detailed radiation dose measurements in highly sensitive pediatric patients and enabled the prediction of radiation doses according to kidney function values. The proposed method can provide useful insights for medical radiation exposure management, which is particularly important and necessary for pediatric patients.

• Journal of Radiation Protection and Research
• /
• 제46권4호
• /
• pp.213-217
• /
• 2021

Background: Radiation exposure can occur as a result of occupational activities utilizing sources of radiation. The average level of occupational exposure is generally similar to the global average, but some workers receive more than this. In this study, the occupational exposure data for workers in Korea to check the recent trend of radiation exposure. Materials and Methods: The data collection and analysis are carried out by two separate periods based on the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) survey. One is the year 2003 to 2014 for a recent survey, and the other is 2015 to 2019. All available data were collected by annual reports from radiation dose registry organizations. Results and Discussion: The annual dose over the record level to the total workers did not change much compared with the total increasing number of workers in this period. The dose to the nuclear fuel cycle field has a tendency to decrease. It resulted from the efforts of radiation dose reduction with high technology introduced to this area. Also, it is important result that the radiation dose to the workers in radiography is remarkably reduced. Conclusion: The number of radiation workers and average doses were analyzed for occupational categories in Korea. It still needs cooperative efforts between the dose registry organizations for the efficient dose management of Korean radiation workers.

• Journal of Radiation Protection and Research
• /
• 제22권4호
• /
• pp.263-272
• /
• 1997

방사선 작업자의 과피폭을 방지하기 위해 방사선 작업 도중 이상 사태가 발생할 경우 광 음경보가 발생한 후 이상 사태 발생 90분, 발생 30분간의 방사선량과 방사선량율 변화를 저장하고 외부 PC로 데이터를 전송한 후 사고를 분석하여 차후에 같은 유형의 방사선 사고를 사전에 예방할 수 있도록 고안된 방사선 경보장치를 개발하였다. 이 방사선 경보장치의 특징은 넓은 방사선 측정 범위(10mR/h $\sim$ 100 R/h), 방사선 준위의 기록 및 기억, PC와의 data처리 기능, 휴대성, 교정 기능에 의한 높은 정밀도(${\pm}5%$), 인지도가 높은 강력한 경보기능 채택 등이다. 개발된 방사선 경보장치의 물리적 환경 적응시험을 가장 엄격한 ANSI N42.17A의 표준 시험조건에 의거하여 온도, 습도, 진동, 전자기파 간섭 등에 관해 한국표준과학연구원에서 수행하였으며 모든 시험항목을 통과하였다.

• 대한안전경영과학회지
• /
• 제17권4호
• /
• pp.193-198
• /
• 2015

This study analyzed the total number of 19,636 patients and radiation technologists, 11,433 of male and 8,203 of female by examined body parts, age, types of detectors, the using contrast enhancement and working condition of the technologists, regular staffs or rotation-duty staffs, based on the K-DOS program distributed by FDA with the DLP value of diagnostic evaluation. The result shows that the effective radiation dose was 0.7mSv~41.7mSv for each region and male patients had more radiation exposure than females. And the amount of exposure was also affected by the types and the method of detectors. Furthermore, the regular staffs took the role of helping the patient to get reduced amount of radiation exposure than rotation duty-staffs. Computed tomography (CT) use has increased dramatically over the past several decades. In this reason, to support the patients and the workers' health in the field, the hospitals should apply specialized regular working radiation technologist system and manufacturing companies of those CTs should develop low medical radiation exposure devices.

• 한국산업보건학회지
• /
• 제31권4호
• /
• pp.342-352
• /
• 2021

Objectives: This study analyzed the local exposure levels of radiation emitted from the equipment with soft X-ray ionizers to investigate the radiation exposure levels in Liquid Crystal Display(LCD) manufacturing processes. Methods: This study measured the local radiation levels for the equipment installed in two LCD manufacturing companies. The equipment were installed at diverse processes and equipped with various number of ionizers. The local radiation levels were measured on the surface of the equipment by using direct reading equipment, and the measurements were converted into annual effective dose by considering the radiation exposure time of workers. Statistical analyses were performed to investigate the radiation exposure characteristics. Results: Annual effective doses for 97.6% of the equipment being measured were less than 1 mSv. However, the range of annual effective doses was 0.004 mSv ~ 2.167 mSv, which indicated a large variation among the equipment. Statistical analyses of the study found that this large variation was raised due to improper shielding of the equipment rather than process and/or equipment characteristics. To pinpoint the cause of this large variation in annual effective dose, this study improved the shielding of the equipment being radiated over 1 mSv and found that their average effective dose was reduced from 1.604 mSv to 0.126 mSv after shielding improvement. Conclusions: Relatively high exposure levels of radiation were observed in some equipment where their shielding were insufficiently thick and/or sealed. This finding implies that the shielding of the equipment is an important engineering countermeasure to control the radiation exposure levels in industries.

• Journal of Korean Neurosurgical Society
• /
• 제49권1호
• /
• pp.37-42
• /
• 2011

Objective: The author measured levels of fluoroscopic radiation exposure to the surgeon's body based on the different beam directions during kyphoplasty. Methods: This is an observational study. A series of 84 patients (96 vertebral bodies) were treated with kyphoplasty over one year. The patients were divided into four groups based on the horizontal and vertical directions of the X-Ray beams. We measured radiation exposure with the seven dosimetry badges which were worn by the surgeon in each group (total of 28 badges). Twenty-four procedures were measured in each group. Cumulative dose and dose rates were compared between groups. Results: Fluoroscopic radiation is received by the operator in real-time for approximately 50% (half) of the operation time. Thyroid protectors and lead aprons can block radiation almost completely. The largest dose was received in the chest irrespective of beam directions. The lowest level of radiation were received when X-ray tube was away from the surgeon and beneath the bed (dose rate of head, neck, chest, abdomen and knee: 0.2986, 0.2828, 0.9711, 0.8977, 0.8168 mSv, respectively). The radiation differences between each group were approximately 2.7-10 folds. Conclusion: When fluoroscopic guided-KP is performed, the X-Ray tube should be positioned on the opposite side of the operator and below the table, otherwise the received radiation to the surgeon's body would be 2.7-10 times higher than such condition.

• 한국산업보건학회지
• /
• 제27권3호
• /
• pp.170-179
• /
• 2017

Objectives: This study aims to investigate the occupational radiation exposures of emergency medical technicians(EMTs) in emergency medical centers in Korea. The results will provide a basis for developing prevention programs to minimize adverse health effects relating to radiation exposure among emergency medical technicians working in this area. Methods: Radiation exposure doses were measured for twenty-two EMTs working in six emergency medical centers. Thermo Luminescent Dosimeters(TLD) were placed on three representative body parts, including chest, neck, and a finger. Measurements were conducted over the entire working hours of the participants for foor weeks. Dosimeters were analyzed according to a standard method by a KFDA-designated lab. Detection rate, annual radiation exposure dose, and relative levels to dose limit were derived based on the measured doses from the dosimeters. SPSS/Win 18.0 software(IBM, US) was used for statistical analysis. Results: Detection rates were 45.5%, 36.4%, and 45.5% for the dosimeters sampled from chest, neck, and a finger, respectively. The average annual doses were $2.39{\pm}3.44mSv/year$(range 0.38-10.0 mSv/year) for the chest, $2.72{\pm}3.05mSv/year$(2.00-11.34) for the neck, and $20.98{\pm}17.57mSv/year$(1.25-53.50) for the hand dose. The average annual eye dose was estimated to $3.61{\pm}2.37mSv/year$(1.50-8.34). The exposure dose levels of EMTs were comparable to those of radiologists, who showed relatively higher radiation dose among health care workers, as reported in another study. Conclusions: EMTs working in emergency medical centers are considered to be at risk of radiation exposure. Although the radiation exposure dose of EMTs does not exceed the dose limit, it is not negligible comparing to other professionals in health care sectors.

• 대한의용생체공학회:의공학회지
• /
• 제38권5호
• /
• pp.256-263
• /
• 2017

By using the buildup characteristics of the radiophotoluminescence glass dosimeter(RPLGD), it is aimed to help the measurement of the accurate dose by measuring the radiation dose according to the time of the glass element. Five glass elements were arranged on the table and the source to image receptor distance(SID) was set to 100 cm for the build-up radiation dose measurement of the fluorescent glass dosimeter glass element(GD-352M). Radiation doses and saturation rates were measured over time according to irradiation time, with the tube voltage (30, 60, 90 kVp) and tube current (50, 100 mAs) Repeatability test was repeated ten times to measure the coefficient of variation. The radiation dose increased from 0.182 mGy to 12.902 mGy and the saturation rate increased from 58.3% with increasing exposure condition and time. The coefficient of variation of the glass elements of the fluorescent glass dosimeter was ranged from 0.2 to 0.77 according to the X - ray exposure conditions. X - ray exposure showed that the radiation dose and saturation rate were increased with buildup characteristics, and degeneration of glass elements was not observed. The reproducibility of the variation coefficient of the radiation generator was included within the error range and the reproducibility of the radiation dose was excellent.

• 대한방사선기술학회지:방사선기술과학
• /
• 제31권4호
• /
• pp.415-417
• /
• 2008

현재 방사선치료는 선형가속기에 의하여 대다수 이루어지고 있으며 사용되는 방사선인 광자도 의학의 발전에 의해 고에너지화 고선량화 되고 있다. 본 연구에서는 방사선치료 조사면에서 중성자 측정이 가능한 CR-39를 이용한 중성자 검출법을 이용하였다. 선형가속기에서 발생되는 X선(광자)치료 시 발생 되는 중성자의 선량을 CR-39를 이용한 중성자 검출법을 이용하여 측정하고, 임상적 응용으로 고에너지 광자를 이용하여 암 치료에 사용할 때 중성자의 발생이 환자치료 선량과 연관되는 어떤 문제를 발생시키는지를 연구한 결과는 다음과 같다. 속중성자의 경우 광자 1Gy 조사 시 평균 0.35mSv, 2Gy 조사 시 평균 0.65mSv, 5Gy 조사 시 평균 1.82mSv, 열중성자의 경우 광자 1Gy 조사 시 평균 0.26mSv, 2Gy 조사 시 평균 0.56mSv, 5Gy 조사 시평균 1.23mSv의 중성자 발생하였다. Wedge Filter를 사용하여 중성자의 발생을 측정한 결과 Wedge Filter를 사용했을 때 중성자의 발생이 증가하였다. 고선량을 요구하는 SRS Cone을 사용했을 때에는 기존의 실험결과 보다 많은 중성자가 검출되었다. 속중성자의 경우 광자 5Gy 조사 시 평균 2.85mSv, 열중성자의 경우 광자 5Gy 조사 시 평균 1.37mSv의 중성자가 발생하였다. 일반 치료 시 광자 5Gy 조사했을 때 보다 속중성자의 경우 약 1.6배, 열중성자의 경우 약 1.12배 정도의 중성자가 더 발생하는 것으로 나타났다.