• Progress in Medical Physics
• /
• v.31 no.2
• /
• pp.9-19
• /
• 2020

Purpose: This study aims to develop a multi-purpose electron beam irradiation device for preclinical research and material testing using the research electron linear accelerator installed at the Dongnam Institute of Radiological and Medical Sciences. Methods: The fabricated irradiation device comprises a dual scattering foil and collimator. The correct scattering foil thickness, in terms of the energy loss and beam profile uniformity, was determined using Monte Carlo calculations. The ion-chamber and radiochromic films were used to determine the reference dose-rate (Gy/s) and beam profiles as functions of the source to surface distance (SSD) and pulse frequency. Results: The dose-rates for the electron beams were evaluated for the range from 59.16 Gy/s to 5.22 cGy/s at SSDs of 40-120 cm, by controlling the pulse frequency. Furthermore, uniform dose distributions in the electron fields were achieved up to approximately 10 cm in diameter. An empirical formula for the systematic dose-rate calculation for the irradiation system was established using the measured data. Conclusions: A wide dose-rate range electron beam irradiation device was successfully developed in this study. The pre-clinical studies relating to FLASH radiotherapy to the conventional level were made available. Additionally, material studies were made available using a quantified irradiation system. Future studies are required to improve the energy, dose-rate, and field uniformity of the irradiation system.

• Journal of the Korean Society of Safety
• /
• v.27 no.6
• /
• pp.192-204
• /
• 2012

For a severe accident of nuclear power plant, an approach to estimation of the radiological source term using a severe accident code(MELCOR) has been proposed. Although the MELCOR code has a capability to estimate the radiological source term, it has been hardly utilized for the radiological consequence analysis mainly due to a lack of understanding on the relevant function employed in MELCOR and severe accident phenomena. In order to estimate the severe accident source term to be linked with the radiological consequence analysis, this study proposes 4-step procedure: (1) selection of plant condition leading to a severe accident(i.e., accident sequence), (2) analysis of the relevant severe accident code, (3) investigation of the code analysis results and post-processing, and (4) generation of radiological source term information for the consequence analysis. The feasibility study of the present approach to an early containment failure sequence caused by a fast station blackout(SBO) of a reference plant (OPR-1000), showed that while the MELCOR code has an integrated capability for severe accident and source term analysis, it has a large degree of uncertainty in quantifying the radiological source term. Key insights obtained from the present study were: (1) key parameters employed in a typical code for the consequence analysis(i.e., MACCS) could be generated by MELCOR code; (2) the MELOCR code simulation for an assessment of the selected accident sequence has a large degree of uncertainty in determining the accident scenario and severe accident phenomena; and (3) the generation of source term information for the consequence analysis relies on an expert opinion in both areas of severe accident analysis and consequence analysis. Nevertheless, the MELCOR code had a great advantage in estimating the radiological source term such as reflection of the current state of art in the area of severe accident and radiological source term.

• Journal of radiological science and technology
• /
• v.24 no.2
• /
• pp.59-64
• /
• 2001

The purpose of this study was to examine the general health status of radiological technologists by using Todai Health Index(THI) that has been employed as a standard health assessment tool for a specific group. The subjects in this study were 800 radiological technologists who were working in clinics, hospitals and university hospitals in and around Seoul and in some provincial cities. A survey was conducted directly or by mail in June and July, 2001. And the response rate was 68%. Using THI, the following findings were acquired: 1. By gender, both male and female radiological technologists complained about multiple subjective symptom(I) the most. And the women made more significant complaint of eight items including irregular life. 2. By age group, the radiological technologists whose age ranged from 20 to 24 got higher marks in most of the items, including multiple subjective symptom(I) and symptoms related to eyes and skin. 3. For career, those who had worked for a year or less or for one to five years got higher marks in most of the items. 4. Concerning marital status, the unmarried people complained about many items more, and the married people's symptom was more associated with live scale(L). 5. By the type of medical institution, the radiological technologists in the university hospitals got higher marks in two items including aggressiveness(F), but those in the clinics complained about the others more. 6. Regarding a place of service, there were little differences between the radiological technologists in basement and on the ground.

• Journal of radiological science and technology
• /
• v.41 no.6
• /
• pp.617-626
• /
• 2018

This study aims to provide the basic data helpful for the improvement of rights and interests of radiological technologists, by understanding the current working environment and if they get the proper reward through the analysis on the perception of appropriateness of current wage and job satisfaction of radiological technologists. Survey was conducted to evaluate the perception of satisfaction with job and wage system, work intensity, necessity of the radiological technologist limit system, and turnover in accordance. The appropriate starting salary was low in case of women and non-capital area, and when the age, academic background, career, and hospital size were lower. The appropriate wage was low in case of women and non-capital area, and when the academic background and hospital size were lower. The negative perception of the necessity to change the wage system was shown in university hospitals. Regarding the work intensity, in case of women and low career, and when the age, academic background, and hospital size were higher, the work intensity was perceived as high. When the academic degree and hospital size were lower, the positive perception of the radiological technologist limit was shown. The turnover intention was high in case of women, and when the age, academic background, career, and hospital size were lower. In order to increase the job satisfaction of radiological technologists, it would be necessary to the appropriate reward and the environment where they could concentrate on work.

• Journal of radiological science and technology
• /
• v.44 no.3
• /
• pp.247-252
• /
• 2021

As the number of single-person households increases, the consumption of bottled water is increasing. In addition, as the public's interest in radioactivity increases, interest in the field of living radioactivity is also increasing. Since drinking water is an essential element in our daily life, it must be safe from radioactivity. In this study, gamma radiation of drinking spring water was measured and internal exposure dose evaluation was performed to determine its harmfulness. K-40 and uranium-based radioactivity analysis was performed through a high-purity germanium detector, and as a result, drinking water was detected somewhat higher than that of mixing water. Since there is no regulation on the natural radioactivity concentration in Korea, it was compared with the U.S. Environmental Protection Agency Drinking Water Regulations and World Health Organization standard. As a result, there were some items that exceeded standards. Internal exposure was evaluated according to the effective dose formula of ICRP 119. As the result was derived that a maximum of 1.17 mSv per year could be received. This result means that the dose limit for the general public may be exceeded, and it was judged that it is necessary to set an appropriate standard value and present a recommendation value through continuous monitoring in the future.

• Journal of radiological science and technology
• /
• v.28 no.1
• /
• pp.45-53
• /
• 2005

This study is aimed at analyzing the relationship between personal factors of radiological technologists and their job stressors. For this aim, a survey was conducted by means of 890 questionnaires from the middle of July to the end of August 2003 to the subjects of radiological technologists who are working for 44 general hospitals in 16 cities and provinces across the country. The results of the survey could be summed up as follows: 1. The biggest stressor that affects a radiological technologist personally under the working situation turned out to be position, job satisfaction and physical symptom(p<0.001), while job satisfaction and physical symptom also played an important role in personal relationship(p<0.001). 2. In terms of job conflicts, colleagues, immediate seniors, job satisfaction and physical symptoms appeared to exercise great impact(p<0.001), As for job autonomy, age, position and job satisfaction were known to be heavily influential(p<0.001). 3. With regard to job load, job satisfaction and behavioral symptom turned out to have great influence while, in job stability, position and job satisfaction seemed to be immensely influential(p<0.001). The present study has a limit in that it covers only radiological technologists who are working at the 3rd reference hospitals but excludes those who are working at the first and second reference hospitals. The findings, however, are surely believed to be able to serve as basic data to improve the medical service quality as they will help reduce the stressors of and enhance mental and physical health for radiological technologists who play important roles as teammates with expertise in the medical field. These outcomes could also be referred to in future studies in this area.

• Proceedings of the Korean Nuclear Society Conference
• /
• 2004.10a
• /
• pp.1210-1210
• /
• 2004

• 대한핵의학회:학술대회논문집
• /
• 2005.11a
• /
• pp.322.2-322.2
• /
• 2005

• 대한핵의학회:학술대회논문집
• /
• 2005.11a
• /
• pp.328.1-328.1
• /
• 2005

• Proceedings of the PSK Conference
• /
• 2003.04a
• /
• pp.208.2-209
• /
• 2003

Ginsan. a new polysaccharide isolated from Panax ginseng, has been previously reported as a good immunomodulator. In this study, we investigated the protective effect of Ginsan against a lethal sepsis induced by Staphylococcus aureus infection. The survival rate of mice treated with Ginsan 24 h prior to S. aureus infection was 80％ whereas PBS-treated mice showed 20％ of survival in the same infection. (omitted)