• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.3 no.2
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• pp.113-123
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• 2005

The removal of radioactive corrosion products from the reactor coolant through a magnetic filter system is one of the many approaches being investigated as a means to reduce radiation sources and exposures to the operational and maintenance personnel in a nuclear power plant. Many research activities in water chemistry, therefore, have been performed to provide a filtration system with high reliability and feasibility and are still in process. In this study, it was devised the magnetic filter system with permanent and electric magnets to remove the corrosion products in the coolant stream taking an advantage of the magnetic properties of corrosion particles. Permanent magnets were used for separation of corrosion products and electric magnets were utilized for flocculation of colloidal particles to increase in their size. Experiments using only permanent magnets, in the previous study, displayed the satisfactory outcome of filtering corrosion products and indicated that the removal efficiency was more than 90 $\%$ for above 5 $\mu$m particles. Experiments using electric magnets also showed the good performance of flocculation without chemical agents and exhibited that most corrosion particles were flocculated into larger aggregates about 5 $\mu$m and over in diameter. It is, thus, expected that the magnetic filter system with the arrangement of permanent and electric magnets will be an effective way for the removal of radioactive corrosion products with considerably high removal efficiency.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.17 no.4
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• pp.437-445
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• 2019

After the permanent shutdown of K1 in 2017, decommissioning processes have attracted great attention. According to the current decommissioning roadmap, the dismantling of the activated components of K1 may start in 2026, following the removal of its spent fuel. Since the reactor vessel (RV) and reactor vessel internal (RVI) of K1 contain massive components and are relatively highly activated, their decommissioning process should be conducted carefully in terms of radiological and industrial safety. For achieving maximum efficiency of nuclear waste management processes for K1, we present activation analysis of the segmentation process and waste classification of the RV and RVI components of K1. For RVI, the active fuel regions and some parts of the upper and lower active regions are classified as intermediate-level waste (ILW), while other components are classified as low-level waste (LLW). Due to the RVI's complex structure and high activation, we suggest various underwater segmentation techniques which are expected to reduce radiation exposure and generate approximately nine ILW and nineteen very low level waste (VLLW)/LLW packages. For RV, the active fuel region and other components are classified as LLW, VLLW, and clearance waste (CW). In this case, we suggest in-situ remote segmentation in air, which is expected to generate approximately forty-two VLLW/LLW packages.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.23
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• pp.10193-10198
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• 2015

Background: Cancer is a major cause of mortality in developing countries and correct and valid information about the epidemiology of this disease is the first step in the planning of health care in each region. The aim of this study was to determine the relative frequency, mean age and sex ratio of the most 10 common non-skin cancers in the world and Iran, among patients referred to an oncology clinic. Materials and Methods: This descriptive study was conducted in Mashhad, north east of Iran. The data obtained from the records of patients referred to the private oncology center between the years of 1985-2012". According to the latest report of GLOBOCAN study commonest malignancies included were lung, breast, colorectal, prostate, stomach, liver, cervix, esophageal, bladder cancers and Non-Hodgkin lymphoma. Results: A total of 4,606 cases were analyzed. The mean age was $55.5{\pm}13.8years$ (male: $59.5{\pm}13.9$, female: $52.6{\pm}12.9$). Overall, breast cancer (1,264 cases, relative frequency of 27.4%) was the most prevalent cancer; however the mean ages of diagnosis were not significantly different between 5-year time period divisions (p=0.290). The most common cancer in men was esophageal cancer (26.3%).The lowest mean age was related to women diagnosed with breast cancer ($48.5{\pm}11.8$) and men with non-Hodgkins lymphoma ($48.4{\pm}17.8$). There were statistically significant differences between the mean age of men and women with gastric (p=0.003) and esophageal cancers (p<0.001). Male to female sex ratios in our study for bladder, lung and stomach cancers were 6.57, 2.60 and 2.50 respectively. Conclusions: The results showed that breast cancer tends to be found in younger female patients and bladder cancer appears more often in men. Screening in target population in addition to early diagnosis may reduce death and disability.

• Journal of the Korean Association of Geographic Information Studies
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• v.22 no.4
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• pp.131-145
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• 2019

Korea has set up a radiation emergency planning zone based on the 「Act on Physical Protection and Radiological Emergency」 to protect residents living near nuclear power plants in the event of nuclear disasters. Little research has been conducted on the appropriateness of existing nuclear evacuation facilities because of a general lack of interest in nuclear accidents. This research addresses this gap by analyzing the location adequacy of evacuation facilities in Busan's emergency protection planning area based on vulnerable populations and accessibility analyses. The Gijang-gun which has the greatest risk, shows that only 4.05% of the total urban area was included in the evacuation service area within 5 minutes while only 36.93% of Geumjeong-gu and 37.23% of Haeundae-gu were included in the evacuation-enabled area. In addition, evaluation facilities in the elderly population hotspots were lacking, and there was a wide gap between dongs within the same Gu. Thus, additional evacuation facilities need to be designated and installed considering the spatial equity between areas and safety of both the public and vulnerable populations.

• Journal of electromagnetic engineering and science
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• v.15 no.3
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• pp.142-150
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• 2015

Several reports supported that continuous exposure to 60 Hz magnetic field (MF) induces testicular germ cell apoptosis in vivo. We recently evaluated duration- and dose-dependent effects of continuous exposure to a 60 Hz MF on the testes in mice. BALB/c male mice were exposed to a 60 Hz MF at $100{\mu}T$ for 24 hours a day for 2, 4, 6, or 8 weeks, and at 2, 20 or $200{\mu}T$ for 24 hours a day for 8 weeks. To induce the apoptosis of testicular germ cell in mice, the minimum dose is $20{\mu}T$ at continuous exposure to a 60 Hz MF for 8 weeks, and the minimum duration is 6 weeks at continuous exposure of $100{\mu}T$. Continuous exposure to a 60 Hz MF might affect duration- and dose-dependent biological processes including apoptotic cell death and spermatogenesis in the male reproductive system of mice. The safety guideline of the International Commission on Non-Ionizing Radiation Protection (ICNIRP) indicates that the permissible maximum magnetic flux density for general public exposure is $200{\mu}T$ at 60 Hz EMF (ICNIRP Guidelines, 2010). In the present study, we aimed to examine the expression of pro- and anti-apoptotic genes regulated by the continuous exposure to 60 Hz at $200{\mu}T$ in Sprague-Dawley rats for 20 weeks. The continuous exposure to 60 Hz at $200{\mu}T$ does not affect the body and testicular weight in rats. However, exposure to 60 Hz MF significantly affects testicular germ cell apoptosis and sperm count. Further, the apoptosis-related gene was scrutinized after exposure to 60 Hz at $200{\mu}T$ for 20 weeks. We found that the message level of endonuclease G (EndoG) was greatly increased following the exposure to 60 Hz at $200{\mu}T$ compared with sham control. These data suggested that 60 Hz magnetic field induced testicular germ cell apoptosis through mitochondrial protein Endo G.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.10
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• pp.1588-1593
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• 2014

This study evaluated the genotoxic effects of 30 kGy of X-ray irradiation to four foods (chicken, egg powder, dried green onion, and black pepper). In bacterial reversion assay with Salmonella Typhimurium TA98, TA100, TA1535, and TA1537, the X-ray irradiated foods did not show a significantly increased number of revertant colonies in the presence or absence of the S9 metabolic activation system. In chromosomal aberration tests with Chinese hamster ovary (CHO) cells, the X-ray irradiated foods showed no increase in the frequency of chromosomal aberrations. In in vivo mouse micronucleus assay, the X-ray irradiated foods did not show any increase in the frequency of polychromatic erythrocytes with micronuclei. These results indicate that 30 kGy of X-ray irradiation to four foods (chicken, egg powder, dried green onion, and black pepper) showed no genotoxic effects under these experimental conditions.

• Journal of the Korean Society for Nondestructive Testing
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• v.22 no.5
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• pp.490-499
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• 2002

Recently, gamma radiographic equipments have been used about 1,000 sets manually and operated by about 2,500 persons in Korea. In order for a radiography to work effectively with avoiding any hazard of the high level radiation from the source, many field workers have expected developing a wireless automatic remote exposure controller. The KlTCO research team has developed an automatic remote exposure controller that can regulate the speed of $0.4{\sim}1.2m/s$ by BLDC motor of 24V 200W which has output of $54kgf{\cdot}cm$, suitable torque and safety factor for the work. And the developed automatic remote exposure controller can control rpm of motor, pigtail position by photo-sensor and exposure time by timer to RF sensor. Thus, the developed equipment is expected that the unit can be used in many practical applications with benefits in economical advantage to combine the use of both automatic and manual type because attachment is possible existent manual remote exposure controller, AC and DC combined use.

• Journal of the Korea Concrete Institute
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• v.25 no.5
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• pp.497-508
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• 2013

This paper introduces a numerical model which can evaluate the fire-resistant capacity of reinforced concrete members. On the basis of the transient heat transfer considering the heat conduction, convection and radiation, time-dependent temperature distribution across a section is determined. A layered fiber section method is adopted to consider non-linear material properties depending on the temperature and varying with the position of a fiber. Furthermore, effects of non-mechanical strains of each fiber like thermal expansion, transient strain and creep strain are reflected on the non-linear structural analysis to take into account the extreme temperature variation induced by the fire. Analysis results by the numerical model are compared with experimental data from the standard fire tests to validate an exactness of the introduced numerical model. Also, time-dependent changes in the resisting capacities of reinforced concrete members exposed to fire are investigated through the analyses and, the resisting capacities evaluated are compared with those determined by the design code.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.12
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• pp.99-108
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• 2015

The embedded microcontroller which is operated by the logic gates synchronized on the clock pulse, is gradually used as main controller of mission-critical systems. Severe electrical situations such as high voltage/frequency surge may cause malfunctioning of the clock source. The tolerant system operation is required against the various external electric noise and means the robust design technique is becoming more important issue in system clock failure problems. In this paper, we propose on-chip backup clock change architecture for the automatic clock failure detection. For the this, we adopt the edge detector, noise canceller logic and glitch-free clock changer circuit. The implemented edge detector unit detects the abnormal low-frequency of the clock source and the delay chain circuit of the clock pulse by the noise canceller can cancel out the glitch clock. The externally invalid clock source by detecting the emergency status will be switched to back-up clock source by glitch-free clock changer circuit. The proposed circuits are evaluated by Verilog simulation and the fabricated IC is validated by using test equipment electrical field radiation noise

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.5
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• pp.725-731
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• 2015

Electron spin resonance (ESR) analysis was conducted for eight different kinds of dried seafood products to investigate their gamma-irradiation status. The specimens consisted of 0~10 kGy-irradiated bones, which included five dried fishes (plaice, hairtail, saury, herring, and dried filefish) and three dried mollusks (beca squid, dried squid, and mitra squid) without flesh or marrow. ESR analysis showed that irradiated specimens exhibited typical asymmetric signals as compared to non-irradiated specimens. ESR signal intensities of all dried fishery samples significantly increased depending on irradiation dose, whereas hydroxyapetite radicals clearly appeared in irradiated plaice, saury, and hairtail. In comparing hydroxyapatite (HA) ratio, irradiated hairtail showed a greater hydroxyapatite-radical generation rate than plaice and saury, and the HA ratio significantly increased with elevated irradiation dose. However, all irradiated plaice and hairtail samples, including 5 and 10 kGy-irradiated saury, showed radiation-derived radicals, whereas filefish and mollusks did not. From the results, ESR spectroscopy was found to have potential to be applied for identifying irradiated plaice, hairtail, and saury, which all contained bones.