• Journal of Radiation Protection and Research
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• v.20 no.2
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• pp.97-102
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• 1995

Adaptive response induced by low dose ${\gamma}-ray$ irradiation in human peripheral lymphocytes was examimed. Human lymphocytes were exposured to low dose of ${\gamma}-ray$ (priming dose, 0.01Gy) followed by high dose (challenging dose, 1.5Gy) after various time intervals (4, 7, 20 hours). Frequencies of micronuclei were enumerated in both primed and unprimed groups. Maximum reduction in frequency of micronuclei was observed when challenging dose irradiation was followed by priming dose after 4hr incubation period. When challenging doses were irradiated 7 or 20hr after priming dose, frequencies of micronuclei were reduced slighty. However, these reduction were not statistically significant. In this study, human peripheral lymphocytes were irradiated at Go phase and they showed adaptive response induced by low dose radiation. Since micronucleus assay is relatively simpler and faster than other methods, it may be a good tool for evaluating radiation-induced adaptive responses.

• Journal of Radiation Protection and Research
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• v.35 no.1
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• pp.21-25
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• 2010

Burnup of spent fuel should be determined accurately for the safety control of spent fuel. Especially, it is necessary to measure the burnup profile along the nuclear fuel axis. In the present work, an ionization chamber was designed and fabricated to measure the gamma ray profile inside the guide tube of spent fuel. The ionization chamber was composed of three parts; induction part, gas-inlet part, and sensor part. The sensor part had two electrodes; cathode and anode. A guide electrode was considered in the ionization chamber design to make the ionization chamber to be inserted easily into the guide tube. Pure gas (argon and xenon) was inserted into the ionization chamber, and the leakage current and saturation curve were measured to determine the operation characteristics of the ionization chamber. The gamma ray radiation was also measured in relatively high dose environment. The gamma ray profile of the spent fuel will be measured with the ionization chamber.

• Journal of Radiation Protection and Research
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• v.34 no.3
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• pp.107-114
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• 2009

A Compton camera, which is based on Compton kinematics, is a very promising gamma-ray imaging device in that it could overcome the limitations of the conventional gamma-ray imaging devices. In the present study, the image quality of a rotating Compton camera was evaluated by using 4-D Monte Carlo simulation technique and the applicability to nuclear industrial applications was examined. It was found that Compton images were significantly improved when the Compton camera rotates around a gamma-ray source. It was also found that the 3-D imaging capability of a Compton camera could enable us to accurately determine the 3-D location of radioactive contamination in a concrete wall for decommissioning purpose of nuclear facilities. The 4-D Monte Carlo simulation technique, which was applied to the Compton camera fields for the first time, could be also used to model the time-dependent geometry for various applications.

• Journal of Radiation Protection and Research
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• v.47 no.1
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• pp.16-21
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• 2022

Background: Epidemiological observations such as mental retardation, physical deformities, etc., in children besides different types of cancer in the adult population of the Malwa region have been reported. The present study is designed to get insight into the role of naturally occurring radioactive material (NORM) in causing detrimental health effects observed in the general population of this region. Materials and Methods: Deep soil samples were collected from different locations in the Malwa region. Their activity concentrations were determined using low-level background gammaray spectrometry. High efficiency and high purity germanium detector capped in a lead-shielded chamber having a resolution of 1.8 keV at 1,173 keV and 2.0 keV at the 1,332 keV line of ⁶⁰Co was used in the present work. Data were evaluated with Genie-2000 software. Results and Discussion: Mean activity concentrations of ²³⁸U, ²³²Th, and ⁴⁰K in deep soil were found to be 101.3 Bq/kg, 65.8 Bq/kg, and 688.6 Bq/kg, respectively. The mean activity concentration of ²³⁸U was found to be three and half times higher than the global average prescribed by the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR). It was further observed that the activity concentration of ²³²Th and ⁴⁰K has a magnitude that is nearly one and half times higher than the global average prescribed by UNSCEAR. In addition, the radioisotope ¹³⁷Cs which is likely to have its origin in radiation fallout was also observed. It is postulated that the NORM present in high quantity in deep soil somehow get mobilized into the water aquifers used by the general population and thereby causing harmful health problems. Conclusion: It can be stated that the present work has been able to demonstrate the use of low background gamma-ray spectrometry to understand the role of NORM in causing health-related effects in a general population of the Malwa region of Punjab, India.

• Journal of Radiation Protection and Research
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• v.19 no.1
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• pp.37-50
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• 1994

The experimental evaluation of exposure conversion formula using the relationship between optical photo-density, exposure dose and the quality of radiation characteristics of radiation energy to X-ray and ${\gamma}-rays$. The film badge dosimeter is analysed by exposure conversion formula which evaluate image fading characteristics for development time and directional characteristics for incident beam angle. In conclusion, exposure conversion formula evaluated of this study is satisfied with quality decision criterion of the film badge dosimeter.

• Korean Journal of Plant Resources
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• v.27 no.5
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• pp.429-438
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• 2014

This study was designed to investigate the effects on anti-oxidative activities and increasing extraction yield of Aralia elata Cortex by gamma irradiation. Electron spin resonance (ESR) analysis as physical techniques for irradiation identification of Aralia elata showed that a pair of peak appeared on a space of 6.0 mT at the left and right of symmetric unspecific central ESR spectrums, confirming that the plant was gamma-irradiated. The optimum extracting conditions for preparing gamma irradiated samples from Aralia elata Cortex were to extract with 50% ethanol for 15 hrs after 10 kGy irradiation. DPPH scavenging activity and ABTS radical cation inhibitory activity of the water and 50% ethanol extracts from non irradiated and irradiated Aralia elata Cortex was very high as over 80% and 98%, respectively, at tested low concentration of $50{\mu}g/mL$. Antioxidant protection factor (PF) as anti-oxidation indicator of lipophilic compounds showed a very high level of activity as 2.18~2.78 PF. As for TBARs, water and ethanol extracts showed high level. Increase of TBARs inhibitory activity of water extracts was not shown by gamma-ray irradiation but ethanol extracts showed slight increasement of TBARs inhibitory activity with 10 kGy gamma-ray irradiation. These results shown confirmed increasement of extraction yield for phenolic compounds and anti-oxidative activity from Aralia elata. Thus, the treatment of gamma-irradiation can be used a way to amplify a solubility for biological active compounds and anti-oxidative activity in plants.

• Nuclear Engineering and Technology
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• v.55 no.1
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• pp.278-284
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• 2023

The synthetic B₂O₃-As₂O₃ glass ceramic are prepared to investigate the physical properties and the radiation shielding capabilities with the variation of concentration of the As₂O₃ with 10, 20, 30, and 40%, respectively. XRD analyses are performed on the fabricated glass-ceramic and depicted the improvement of crystallinity by adding As₂O₃. The radiation shielding properties are studied for the B₂O₃-As₂O₃ glass ceramic. The values of linear attenuation coefficient (LAC) are varied with the variation of incident photon gamma energy (23.1-103 keV). The LAC values enhanced from 12.19 cm^-1-37.75 cm^-1 by raising the As₂O₃ concentration from 10 to 40 mol% at low gamma energy (23.1 keV) for BAs10 and BAs40, respectively. Among the shielding parameters, the half-value layer, transmission factor, and radiation protection efficiency are estimated. Furthermore, the fabricated samples of glass ceramic have low manufacturing costs and good shielding features compared to the previous work. It can be concluded the B₂O₃-As₂O₃ glass ceramic is appropriate to apply in X-ray or low-energy gamma-ray shielding applications.

• Journal of Radiation Protection and Research
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• v.40 no.1
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• pp.25-35
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• 2015

We analyzed the differential effects of histopathology, apoptosis and expression of radiation response genes after chronic low dose rate (LDR) and acute high dose rate (HDR) radiation exposure in spleen, lung and liver of rats. Female 6-week-old Sprague-Dawley rats were used. For chronic low-dose whole body irradiation, rats were maintained for 14 days in a $^{60}Co$ gamma ray irradiated room and received a cumulative dose of 2 Gy or 5 Gy. Rats in the acute whole body exposure group were exposed to an equal dose of radiation delivered as a single pulse ($^{137}Cs$-gamma). At 24 hours after exposure, spleen, lung and liver tissues were extracted for histopathologic examination, western blotting and RT-PCR analysis. 1. The spleen showed the most dramatic differential response to acute and chronic exposure, with the induction of substantial tissue damage by HDR but not by LDR radiation. Effects of LDR radiation on the lung were only apparent at the higher dose (5 Gy), but not at lower dose (2 Gy). In the liver, HDR and LDR exposure induced a similar damage response at both doses. RT-PCR analysis identified cyclin G1 as a LDR-responsive gene in the spleen of rats exposed to 2 Gy and 5 Gy gamma radiation and in the lung of animals irradiated with 5 Gy. 2. The effects of LDR radiation differed among lung, liver, and spleen tissues. The spleen showed the greatest differential effect between HDR and LDR. The response to LDR radiation may involve expression of cyclin G1.

• Journal of radiological science and technology
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• v.44 no.2
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• pp.117-122
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• 2021

This study is desinged to examine for radiation protection effect of Protaetia Brevitarsis Larvae extracts on the blood and prostate of male rat as a natural radiation protection agent. 5 groups were classified using 90 male rat as experimental animals. Each group was clssified as normal control group (NC Group), the group administered protaetia brevitarsis larvae extracts (PBE Group), irradiated group (IR Group), irradiated group after administration of protaetia brevitarsis larvae extracts (PBE+IR Group), the group administered protaetia brevitarsis larvae extracts after irradiaton (IR+PBE Group). In IR Group, 7 Gy/h of Co-60 gamma ray was irradiated to SD rats. In PBE+IR Group, protaetia brevitarsis larvae extacts wewe injected at 200 mg/kg/day for 14 days before irradiation, In IR+PBE Group, protaetia brevitarsis larvae extract was injeted after irradiation. On the 1, 7 and 21 days after irradiation, the experimental animals were sacrificed to evaluate the changes in blood cell component, superoxide dismutase (SOD) activity, histopathological evaluation of the liver and prostate gland. As a result, the PBE+IR Group and IR+PBE Group showed a significantly recovery of white blood cell (p<0.01, p<0.01), platelet (p<0.01, p<0.01) than the IR Group. It was also confirmed that SOD activity of PBE+IR Group (p<0.01) and IR+PBE Group (p<0.01) was significantly increased than the IR Group. Also PBE+IR Group and IR+PBE Group showed less inflammatory reactions of cystoplasm in the prostate gland than the IR Group. In conclusion, the protaetia brevitarsis larvae have radioprotection effect against blood and prostate gland. It is expected to be useful for research of radiation protection agent.

• Journal of Radiation Protection and Research
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• v.12 no.1
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• pp.34-39
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• 1987

Radiation shielding analysis for a 6MeV X-ray facility was carried out. The primary and leakage radiation for the facility can be evaluated based on the methodology in NCRP No. 49 and 51. The present study deals with radiation scattering analysis for the outside and inside door of the facility based on the albedo concept. The calculated dose rates were compared with the results of MORSE-CG code calculation and the measured data, resulting in a good agreement, even though there existed some deviation for the inside door. These results can be utilized to the radiation shielding design of the medical and industrial X and gamma ray facilities, and to the safety evaluation of these facilities.