• Journal of dental hygiene science
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• v.12 no.4
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• pp.335-341
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• 2012

This study conducted a survey targeting at dental hygienists working in medical institutions located in Daegu, Pusan, Ulsan Metropolitan City and Gyeongnam and Gyeongbuk Province from July 18th to August 26th 2011, in order to study factors which affect radiation safety management behaviors and improve levels of those behaviors. The results of this study are as follows. 1. There were significant differences in radiation safety management knowledge of dental hygienists, according to service institutions (p<.001), the current state of defense facilities (p<.006) and the necessity for safety management education (p<.012). 2. There were significant differences in radiation safety management attitudes, according to age (p<.014), service institutions (p<.003), work experience (p<.009), educational level (p<.002), the current state of defense facilities (p<.015), the necessity for safety management education (p<.005) and the intention to take part in the education (p<.036). 3. There were significant differences in radiation safety management behaviors, depending on experience in safety management education (p<.068), measurement of exposed dose (p<.010), the state of defense facilities (p<.001). 4. There were statistically positive correlations between radiation safety management knowledge and attitude, and between radiation safety management attitude and behavior (p<.05). 5. The regular measurement of exposed dose (p<.046) and the present state of defense facilities (p<.001) were found to be factors to affect radiation safety management behaviors. In conclusion, it is considered that building perfect defense facilities of radiology rooms and measuring the exposed does of dental hygienists on a regular basis to alert them to the danger of radiation is considerably important to improve radiation safety management behaviors.

• Journal of dental hygiene science
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• v.10 no.4
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• pp.265-271
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• 2010

This study was to investigate the level of knowledge, recognition, behavior of radiographic safety control and job stress in dental hygienists and to determine the relationship among variables. The subjects were 256(56.9%), who were worked in dental hospital and clinic with mean age of $29.59{\pm}7.30$. Data was collected using a self administrated questionnaire from April 4 to May 15, 2010. Behavior of radiographic safety control was measured using the 15-items and job stress was measured using the 5-items with 5-point likert scale. The data were analyzed with t-test, one-way ANOVA and pearson correlation coefficient using the SPSS WIN 17.0 program. Regarding job stress, the subjects was a mean of 2.63 out of a maximum 5 points. The level of knowledge, recognition, behavior of radiographic safety control a mean of 3.11, 4.08 and 3.43 out of a maximum 5 points. Recognition and behavior of radiographic safety control was negative related job stress in this study. Based on the findings, behavior of radiographic safety control is associated with job stress. These results suggest that various program should be considered for radiation safety control of dental hygienists.

• The Journal of Korean Society for Radiation Therapy
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• v.24 no.2
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• pp.107-114
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• 2012

Purpose: Unlike the existing linear accelerator with photon, proton therapy produces a number of second radiation due to the kinds of nuclide including neutron that is produced from the interaction with matter, and more attention must be paid on the exposure level of radiation workers for this reason. Therefore, thermoluminescence dosimeter (TLD) that is being widely used to measure radiation was utilized to analyze the exposure level of the radiation workers and propose a basic data about the radiation exposure level during the proton therapy. Materials and Methods: The subjects were radiation workers who worked at the proton therapy center of National Cancer Center and TLD Badge was used to compare the measured data of exposure level. In order to check the dispersion of exposure dose on body parts from the second radiation coming out surrounding the beam line of proton, TLD (width and length: 3 mm each) was attached to on the body spots (lateral canthi, neck, nipples, umbilicus, back, wrists) and retained them for 8 working hours, and the average data was obtained after measuring them for 80 hours. Moreover, in order to look into the dispersion of spatial exposure in the treatment room, TLD was attached on the snout, PPS (Patient Positioning System), Pendant, block closet, DIPS (Digital Image Positioning System), Console, doors and measured its exposure dose level during the working hours per day. Results: As a result of measuring exposure level of TLD Badge of radiation workers, quarterly average was 0.174 mSv, yearly average was 0.543 mSv, and after measuring the exposure level of body spots, it showed that the highest exposed body spot was neck and the lowest exposed body spot was back (the middle point of a line connecting both scapula superior angles). Investigation into the spatial exposure according to the workers' movement revealed that the exposure level was highest near the snout and as the distance becomes distant, it went lower. Conclusion: Even a small amount of exposure will eventually increase cumulative dose and exposure dose on a specific body part can bring health risks if one works in a same location for a long period. Therefore, radiation workers must thoroughly manage exposure dose and try their best to minimize it according to ALARA (As Low As Reasonably Achievable) as the International Commission on Radiological Protection (ICRP) recommends.

• Journal of radiological science and technology
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• v.36 no.1
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• pp.11-17
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• 2013

Currently, there are many studies being conducted around the world to reduce exposure dose to radiation for patients to receive medical treatments in a safe environment. We developed and fabricated of this shield that the patients are protected from the radiation and are need of safety control during breast imaging. In this study, for breast imaging, GE Senography 2000D were used and set at SID 65cm, 28kVp, and 63mAs. The measuring instrument was Fluke's Victoreen 6000-529. And we performed Face Block on with 30 patients. The chamber on the actual thyroid glands to take CC and MLO and measure the dosage before and after wearing the Face Block. For the results, after wearing the Face Block, exposure was decreased by 53.8%-100% and 65.8% in average in CC View and by 50%-100% and 60.7% in average in MLO View. The development of the Face Block that practically decreased the exposure dose of thyroid glands, crystalline eyes during breast imaging and reduced the patients' anxiety during breast imaging. The Face Block is expected to improve patients' satisfaction and contribute to reducing patients' exposure dose, but more efforts should be made to reduce exposure dose to medical radiation.

• Journal of Radiation Protection and Research
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• v.18 no.1
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• pp.71-82
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• 1993

It is a fundamental element of the nuclear power plant operation to assess exactly the occupational radiation exposure. And, according to recently published ICRP 60 recommendation, it is needed to reduce individual radiaton exposure limit further. In this paper, an optimization techique was suggested for selection of alternatives for reducing occupational radiation exposure, and used in reviewing alternatives given by a plant utility. After the basic analysis, sensitivity analysis was performed to consider the variabilities of the economic variables. From the result, it was found that an option using steam generator nozzle dam and torquing machine was the best with respect to total benefits, and in case of multi-attribute utility analysis, an option using Co-No seal had the highest utility. Therefore, it was necessary to apply more than one technique togeter in optimization study and to consider qualitative factor, too.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.16 no.3
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• pp.377-387
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• 2018

Korea's first commercial nuclear power plant, Kori Unit 1, was permanently shut down on June 18, 2017, after 40 years of successful operation. Kori Unit 1 plans to construct a waste treatment facility in the turbine building prior to commencement of dismantling in earnest. Various radioactive wastes are decontaminated, disassembled, cut and melted in the waste treatment facility and sent to the radioactive waste repository. The proportion of metal radioactive waste in dismantled waste is about 70%, of which large metal radioactive waste is mainly generated in the primary circuit and has high radioactivity, so radiation exposure must be managed during disassembly. In this study, the steam generators are selected as large metal radioactive waste, the exposure doses of the dismantling workers are calculated using RESRAD-RECYCLE code and the methods for reducing the exposure doses are suggested.

• Journal of the Korean Society of Radiology
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• v.1 no.3
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• pp.23-34
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• 2007

To find how much radiation was exposed the patients who visit emergency room, a measurement study was made for radiation amount toward 200 patients selected randomly among visitors to an emergency room in a university hospital from March 16 to 31st, 2006. The results are as follows ; 1. Among the subjects 50 person(25.0%) were transferred from other hospitals, 24 persons(8.3) come after traffic accident, 50 persons for other accident and 76 persons for general medical care. 2. The average frequency of X-ray taking was calculated as 6.4 time per person among transferred patients, 14.5 times per person among patients with traffic accident and 2.6 times per person among general medical care. 3. The radiation exposure amount by kind of X-ray showed 28.9mGyfor general X-ray diagnosis, 84.2mGy for CT scanning and 1.02mGy for other special radiation study. 4. Average radiation exposure amount was calculated as 24.6mGy by transferred patients, 55.2mGy by patients with traffic accident, 17.1mGy by patients with other accidents and 17.0mGy by general patients. 5. Through the comparison of radiation exposure amount among to subject with maximum allowance threshold by International Commission on X-ray Radium Protection, transferred patients exceeded 6 times than allowance in whole body except extremities and joints, blood forming organ, reproductive system, vitreous body of eye, bone, thyroid gland, skin and etc, Patient suffered from traffic accidents were exposed 10 times more than allowance. In conclusion, the radiation exposure amount during X-rat diagnosis re too much and exceeded allowance standard by International Commission on X-ray Radium Protection. So further study and preventive measure to decrease radiation exposure by patients who visit emergency room.

• The Korean Journal of Nuclear Medicine Technology
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• v.14 no.2
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• pp.65-76
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• 2010

Purpose: he use of PET scanners and the number of patient in Korea have been increased for recent several years dramatically. For this reason, technologists have more possibilities to be exposed to the radiation. The hospitals using PET scanners should make an effort to reduce the radiation exposure dose. The purpose of this study was to evaluate the radiation exposure does when using radiation shielding devices. The evaluation was performed through questionnaire survey and experiment. Materials and Methods: First, the technologists who had experience working in PET center in 2008-2009 were surveyed with questionnaire and TLD Figures, personal opinion of utilization of radiation shielding devices are analyzed. Second, we measured the shielding rate of shielding devices which have been using in PET study procedures. We divided the procedures into four steps; distribution, moving, injection of $^{18}F$-FDG and patient setup. Results: First, the results of this survey, using of L-block+Syringe shield, L-block, Syringe shield, No shield during the injection, were each 58.5%, 20%, 9%, 12.3%. The TLD values according to utilization of radiation shield, using both L-block+Syringe Shield and L-block showed the lower TLD values, and Syringe shield only or No shield showed the higher TLD values. Second, the results of experiments according to PET study procedures measured the shielding rates as follows. The shielding rates during the distribution using L-block, L-block+Apron shield were measured 97.4%, 97.7%. The shielding rates during the $^{18}F$-FDG delivery to the injection room using mobile Syringe shield, Syringe holder, Syringe shield carrier were each 81.7%, 98.9%, 99.7%. The shielding rates during the injection using Syringe shield, L-block, L-block+Syringe shield were measured each 51.9%, 98.3%, 98.7%. The shielding rates of Apron were measured in each 30, 60, 90, 120, 150 cm distance. The measurement were each 16.9%, 14.2%, 16.6%, 17.1%, 18.1%, 18.6%. Conclusion: The most effective method for radiation shielding is to using L-block during the $^{18}F$-FDG distribution and Syringe shield carrier during in moving $^{18}F$-FDG. For the $^{18}F$-FDG injection, L-block+Syringe shield have to be used. The shielding effect of Apron has shown average 16.4%. According to the survey of questionnaire, the operators recognized well risk of the radiation exposure but, tended ignore in working. The radiation dose according to recognition of radiation exposure risk was not relevant. but radiation dose according to utilization of radiation shield lower the more use it. The main reason of no use of shielding devices is cumbersome, 55% of the respondents answered. I'm sure, by use of radiation shield in all PET procedure, radiation exposure will be reduced considerably.

• Journal of Radiation Protection and Research
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• v.9 no.2
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• pp.118-128
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• 1984

The analysis of radiological protection at Kori Nuclear Unit #1, which started commercial operation on April 29, 1978, has been carried out in three areas, namely, radiation exposure, radioactive waste disposal and environmental management. The analysis results for radiation exposure and radioactive effluent releases appear to increase gradually with plant operating years. On the other hand, the apex of radiation exposure and radioactive effluent releases was in 1983 and 1982 respectively and then decreased or stabilized. Also, the operation environmental radioactivity seems to be no higher than preoperation environmental radioactivity.

• Journal of Radiation Protection and Research
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• v.39 no.4
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• pp.159-167
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• 2014

In Korea, July 2012, the law as called 'Act on Safety Control of Radioactive Rays Around Living Environment' was implemented to control the consumer product containing Naturally Occurring Radioactive Material (NORM), but, there are no appropriate database and effective dose calculation system. The aim of this study was to develop evaluation technique of the exposure dose with the use of the consumer products containing NORM and to understand the characteristics of the exposed dose according to the radiation type and energy. For the evaluate of exposure dose, the ICRP reference phantom was simulated by the MCNPX code based on Monte Carlo method, and the minimum, medium, maximum energy of alphas, betas, gammas from the representative NORM of Uranium decay series were used as the source term in the simulation. The annual effective doses were calculated by the exposure scenario of the consumer product usage time and position. Short range of the alpha and beta rays are mostly delivered the dose to the skin. On the other hand, the gamma rays mostly delivered the similar dose to all of the organs. The results of the annual effective dose with $1Bq{\cdot}g^{-1}$ radioactive stone-bed and 10% radioactive concentration were employed with the usage time of 7 hours 50 minute per day, the maximum annual effective dose of alphas, betas, gammas were calculated 0.0222, 0.0836, $0.0101mSv{\cdot}y^{-1}$, respectively.