• Nuclear Engineering and Technology
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• v.52 no.8
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• pp.1784-1791
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• 2020

The 14 MeV neutron generator facility is being developed by the Institute for Plasma Research India to conduct the lab scale experiments related to Indian breeding blanket system for ITER and DEMO. It will also be utilized for material testing, shielding experiments and development of fusion diagnostics. Occupational radiation exposure control is necessary for the all kind of nuclear facilities to get the operational licensing from governing authorities and nuclear regulatory bodies. In the same way, the radiation exposure for the 14 MeV neutron generator facility at the occupational worker area and accessible zones for general workers should be under the permissible limit of AERB India. The generator is designed for the yield of 10¹² n/s. The shielding assessment has been made to estimate the radiation dose during the operational time of the neutron generator. The facility has many utilities and constraints like ventilation ducts, accessible doors, accessibility of neutron generator components and to conduct the experiments which make the shielding assessment challenging to provide proper safety for occupational workers and the general public. The neutron and gamma dose rates have been estimated using the MCNP radiation transport code and ENDF -VII nuclear data libraries. The ICRP-74 fluence to dose conversion coefficients has been used for the assessment. The annual radiation exposure has been assessed by considering 500 h per year operational time. The provision of local shield near to neutron generator has been also evaluated to reduce the annual radiation doses. The comprehensive results of radiation shielding capability of neutron generator building and local shield design have been presented in the paper along with detailed maps of radiation field.

• Journal of radiological science and technology
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• v.44 no.6
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• pp.591-597
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• 2021

In the present study, we developed virtual reality education contents for radiation generator on radiation education field. The radiation generator was divided by module and even the X-ray exposure part was manufactured in detail for designing 3D models. The mechanical details of the X-ray exposure part, the function of adjusting field size of the X-ray, the function of moving the exposure part, and the demonstrating the principle of the X-ray tube were applied. For developing VR contents, the Unreal Engine was used. To evaluate the usefulness of virtual reality content, we used t-test by SPSS. The group used the simulator showed significantly higher levels of understanding of X-ray generation, X-ray irradiation unit composition, irradiation field size adjustment, irradiation unit position adjustment, and overall composition and function. We believe that this VR contents will be used well with radiation safe environment.

• International Journal of Contents
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• v.14 no.4
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• pp.65-69
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• 2018

The objective of this study was to conduct a radiation shielding analysis for the facility equipped with radiation generator. The analysis was carried out in two aspects. First, from the aspect of the effect caused by primary and leakage radiation. Second, effect of scattered radiation was evaluated by applying a simple calculation method based on a scattering rate concept since effect of scattered radiation is significantly important at maze entrance of the radiation facility. The calculated results obtained using the simple method were compared to the results calculated using Geant4 code and the measured values. The results calculated by the suggested method indicate that slight error exists in a radiation shielding analysis done at the maze entrance comparing to other two results, while the results evaluated at the outside of the maze entrance door are relatively consistent with other values.

• Journal of dental hygiene science
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• v.15 no.3
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• pp.254-258
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• 2015

To compare the stationary dental X-ray generator and the portable dental X-ray generator and to understand spatial radiation dose depended on locations by measuring spatial radiation dose of the portable dental X-ray generator. The researchers used an Ionization chamber to measure spatial radiation dose which was generated while applying X-ray radiation to real bone skull phantom with both portable and stationary dental X-ray generator. There were 4 measurement locations which were immediate anterior, right, left and posterior. Distance of measurement was 50 cm in every location and the recorded result is an average of two applications of X-ray radiation to the maxillary molar area under the condition of 70 kVp, 3 mA, 0.1 sec. Average spatial radiation dose of portable X-ray generator was $37.51{\mu}Sv$, much higher than that of stationary X-ray generator which was $10.77{\mu}Sv$ (p<0.001). The result of the spatial radiation dose of the portable X-ray generator showed a huge difference depending on types of units which varied from $17.77{\mu}Sv$ to $68.90{\mu}Sv$ (p<0.05), also depending on the measurement location, immediate anterior resulted in the highest radiation dose of $54.14{\mu}Sv$ and immediate right was the lowest of $13.60{\mu}Sv$. Immediate left and posterior, however, resulted in similar radiation dose which were $42.12{\mu}Sv$, $40.18{\mu}Sv$ (p<0.01). With this result, we claim that usage of portable dental X-ray generator should be restricted to patients who can't move and exposure to radiation should be minimized by wearing lead-apron.

• Journal of radiological science and technology
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• v.41 no.5
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• pp.397-403
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• 2018

Mobile X-ray generators are used not in the radiation area but in open space, which causes the exposure of secondary radiation to the healthcare professionals, patients, guardians, etc., regardless of their intentions. This study aimed to investigate the shielding effect of the developed radiation restrictor to block the secondary radiation scattered during the use of mobile X-ray generator. Upon setting the condition of mobile X-ray generator with chest AP, spatial doses were measured by the existence of human equivalent phantom and radiation restrictor, and measured by the existences of phantom and radiation restrictor at the same length of 100 cm. Measurements were taken at intervals of 10 cm every $30^{\circ}$ from $-90^{\circ}$ (head direction) to $+90^{\circ}$ (body direction). Upon the study results, spatial doses in all direction were increased by 45% on average when using phantom in the same condition, however, they were decreased by 64% on average when using the developed radiation restrictor. The dose at 100 cm from the center of X-ray was $3.0{\pm}0.08{\mu}Gy$ without phantom and was increased by 40% with $4.2{\pm}0.08{\mu}Gy$ after phantom usage. The dose when using phantom and the developed radiation restrictor was $1.4{\pm}0.08{\mu}Gy$, which was decreased by 66% compared to the case without using them. Therefore, it is considered the scattered radiation can be shielded at 100-150 cm, the regulation of the distance between beds, effectively with the developed radiation restrictor when using mobile X-ray generators, which can lower the radiation exposure to the people nearby including healthcare professionals and patients.

• Progress in Medical Physics
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• v.19 no.1
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• pp.1-8
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• 2008

Technisium $(^{99m}Tc)$ is one of the most widely used radioactive isotopes for diagnosis in nuclear medicine. In general, technisium is produced inside the so called $^{99m}Tc$ generator which is usually made out of lead to shield relatively high energy radiation from $^{99}Mo$ and its daughter nuclide $^{99m}Tc$. In this paper, a GEANT4 simulation is carried out to test the safety of the $^{99m}Tc$ generator, taking the Daiichi product with radioactivity of 500 mCi as an example. According to the domestic regulation on radiation safety, the dose at 10 cm and 100 cm away from the surface of shielding container should not exceed 2.0 mSv/h and 0.02 mSv/h, respectively. The simulated dose turned out to be less than the limit, satisfying the domestic regulation.

• Elastomers and Composites
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• v.55 no.3
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• pp.222-228
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• 2020

Rubber materials, used in nuclear power plants, need high heat-oxidation resistance to curing or cracking under a heat aging environment. This is because they are applied to environments with high temperature, high humidity, and radiation exposure. Nuclear radiation causes additional hardening or degradation, therefore, rubber materials need radiation resistance that satisfies the general and any accidental conditions produced in the power plant. Therefore, in this study, we developed a rubber material with excellent heat and radiation resistance for the diaphragm seal of a nuclear steam generator nozzle dam. The rubber material greatly improved the reliability of the steam generator nozzle dam. In addition, 30 inch and 42 inch diaphragm seals were manufactured using the developed rubber material. A nozzle dam was installed in a nuclear power plant and tested under the same conditions as a steam generator to evaluate safety and reliability. In the future, the performance and safety of diaphragm seals developed through field tests of nuclear power plants will be evaluated and applied to currently operating and new nuclear power plants.

• ETRI Journal
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• v.42 no.6
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• pp.951-964
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• 2020

This paper presents a lightweight true random number generator (TRNG) using beta radiation that is useful for Internet of Things (IoT) security. In general, a random number generator (RNG) is required for all secure communication devices because random numbers are needed to generate encryption keys. Most RNGs are computer algorithms and use physical noise as their seed. However, it is difficult to obtain physical noise in small IoT devices. Since IoT security functions are required in almost all countries, IoT devices must be equipped with security algorithms that can pass the cryptographic module validation programs of each country. In this regard, it is very cumbersome to embed security algorithms, random number generation algorithms, and even physical noise sources in small IoT devices. Therefore, this paper introduces a lightweight TRNG comprising a thin-film beta-radiation source and integrated circuits (ICs). Although the ICs are currently being designed, the IC design was functionally verified at the board level. Our random numbers are output from a verification board and tested according to National Institute of Standards and Technology standards.

• Journal of the Korea Convergence Society
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• v.11 no.4
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• pp.55-61
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• 2020

The various types of radiation-generator devices have been used in animal hospitals, and the safety for radiation workers is becoming important in Korea. This study investigated and analyzed the radiation safety management for diagnostic radiation-generator devices and radiation workers of animal hospital. The number of radiation-generator devices and radiation workers of animal hospital increased from 2,138 to 2,972 and from 2,644 and 5,733 for six years. The number of general X-ray, CT, C-arm, portable and dental X-ray in 2019 were 2,204, 58, 67, 770, and 14. The number of veterinarian, veterinary nurse, veterinary assistant, and others in 2019 were 4,236, 1,080, 404, and 13. The average exposure dose of radiation workers in 2018 were 0.21mSv in surface dose, 0.18mSv in depth doses. This study is expected to be the basic data for the safety management of radiation-generating devices and radiation workers in animal hospital.

• Proceedings of the KIEE Conference
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• 1999.07e
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• pp.2041-2043
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• 1999

In order to investigate the radiation characteristics of unmixed line noise from overhead high voltage AC transmission lines, a gap noise generator was manufactured. Disk size which decides capacitance between the noise generator and earth was selected through preliminary indoor experiments and analysis by charge simulation method. The capacitance is one of principal parameters related to inject a proper noise current into lines. The field experiments were performed with the noise generator installed in Kochang 765 kV full scale test line. As the results, the useful data which can be used to analysis the radiation characteristics of noise from transmission lines was obtained. Those are lateral profiles the directivity of antenna toward lines, frequency spectra and so on.