• Journal of Radiation Protection and Research
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• v.42 no.3
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• pp.166-175
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• 2017

Background: This study presents food ingestion standards for radioactivity that can be applied in nuclear emergency exposure situations, and discusses the validity of the current domestic standards. Materials and Methods: This study derived food ingestion standards for radiocesium and radioiodine using domestic food intake rates and intervention levels, which serve as a basis for determining the necessity of public protective actions, and then compared them with the existing guidelines. Operational intervention levels were also derived using domestic food intake rates, and were compared with those of the International Atomic Energy Agency. Results and Discussion: The derived activity concentrations for food ingestion standards of radiocesium for infants were higher than those in the Act on Physical Protection and Radiological Emergency (APPRE) for all food categories, while for adults, the derived activity concentrations for drinking water and milk appeared to be slightly lower. The derived activity concentrations for vegetables, fruits, and grains were greater than those in the guidelines of the APPRE, while the derived activity concentrations for meat and seafood were similar to those in the APPRE. The derived activity concentrations for radioiodine were greater than both domestic and global standards. The calculated operational intervention levels (OILs) based on domestic food intake rates were greater than the IAEA's default OIL6 values for most radionuclides, except for a few ${\alpha}$-radionuclides. Conclusion: The current domestic guidelines turned out to be conservative overall, compared to the present results that were calculated using domestic food intake rates. It is recommended that the domestic guidelines should be revised and complemented transparently through an in-depth review by stakeholders on a solid scientific basis.

• Journal of the Korean Society of Systems Engineering
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• v.14 no.1
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• pp.63-71
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• 2018

This paper discusses decommissioning procedure requirements management using requirement engineering to systematically manage the technical requirements and criteria that are required in decontamination and decommissioning activities, and the regulatory requirements that should be complied with in a decommissioning strategy for research reactors and nuclear power plants. A schema was designed to establish the traceability and change management related to the linkage between the regulatory requirements and technical criteria after classifying the procedures into four groups during the full life-cycle of the decommissioning. The results confirmed that the designed schema was successfully traced in accordance with the regulatory requirements and technical criteria required by various fields in terms of decontamination and decommissioning activities. In addition, the changes before and after the revision of the Nuclear Safety Act were also determined. The dismantling procedure requirement management system secured through this study is expected to be a useful tool in the integrated management of radioactive waste, as well as in the dismantling of research reactor and nuclear facilities.

• Journal of radiological science and technology
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• v.43 no.2
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• pp.123-128
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• 2020

Radiation Following the 2011 Fukushima nuclear accident in Japan, public interest and anxiety about radiation safety increased, and vague anxiety about commonly exposed living radiation was generated. The Atomic Energy Safety Commission has been conducting a survey of processed products that advertise "negative ions" and "far-infrared" emissions under the Living Radiation Safety Management Act. In this study, in-depth analysis was performed from a statistical point of view using the measurement data presented in the Nuclear Safety Committee's actual survey analysis report as secondary data. As a result, there was a statistically significant difference (p<0.005) between latex and civil affairs products. There were also statistically significant differences (p<0.05) in the results of testing whether there were significant differences in the annual exposure dose between groups after categorizing 71 civil products, including radon beds, into bed, bedding, and living and other categories. The correlation analysis results also confirm that, as is commonly known, the annual doses received from processed products are associated with radon derived from U-238 and Th-232.

• Nuclear Engineering and Technology
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• v.55 no.1
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• pp.63-70
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• 2023

Ultrasound-assisted dissolution of U₃O₈ powder in carbonate solution was explored to determine if and how ultrasound act during the dissolution. The variation of U₃O₈ solid particles and uranyl complexes under ultrasound treatment and magnetic stirring was observed in carbonate media. The results show that the use of ultrasound can increase the solubility and dissolution rate of U₃O₈ powder than that under magnetic stirring. The crush of U₃O₈ particles and the reduction of the activation energy (Ea, kJ/mol) of U₃O₈ dissolution reaction were observed, which both play an important role in the ultrasonic-assisted dissolution of U₃O₈ in carbonate-peroxide solution. Meanwhile, there is no observation of the ultrasound effect on the distribution of uranyl species and hydrolysis of uranyl complexes during the ultrasound treatment in carbonate-peroxide solution. Although the generation of ·OH radicals under ultrasound (22 ± 2 kHz) was observed, the oxidation of ·OH had little effect on the dissolution of U₃O₈ in the carbonate-peroxide solution system.

• Journal of Radiation Industry
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• v.18 no.1
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• pp.1-7
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• 2024

The International Commission on Radiological Protection (ICRP) lowered the annual equivalent dose limit of lens of the eye for radiation workers from 150 to 20 mSv in April 2011. This trend of lowering the equivalent dose limit for radiation workers has been observed worldwide, including international organizations such as the International Atomic Energy Agency (IAEA), International Organization for Standardization (ISO) and the European Commission (EC). In 2016, the Nuclear Safety and Security Commission of South Korea published research results that included a proposal for lowering the equivalent dose limit of lens of the eye for radiation workers in line with the ICRP recommendation. However, as of now, South Korea's Nuclear Safety Act and related regulations still specify an annual equivalent dose limit of lens of the eye as 150 mSv for radiation workers. The IAEA and ISO have issued guidelines regarding radiation protection for lens of the eye and recommended a dose level for the lens of the eye at 5 or 6 mSv per year for periodic monitoring of the equivalent dose for the lens of the eye.

• Journal of the Korean Society of Radiology
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• v.7 no.6
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• pp.397-402
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• 2013

This study suggests considerations for legislation of radiopharmaceutical manufacturing practice according as the Korea Pharmaceutical Affairs Act and guidelines on foreign radiopharmaceutical manufacturing practice. Pharmaceuticals should be verified safety, effectiveness, and uniformity. Therefore, it is expected that the efficiency of the administration of radiopharmaceuticals increase and nation's health promote if rational manufacturing management to consider of radiopharmaceutical properties is legislated.

• Nuclear Engineering and Technology
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• v.56 no.8
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• pp.3097-3111
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• 2024

Since the level 2 PSA of OPR-1000 was the requirement for regulatory purposes, Cs-137 release estimation was contained as the Nuclear Safety Act of ROK in which the Cs-137 release frequency exceeding 100 TBq was determined to happen less than 1.0E-6 per year after the Fukushima Daiichi Accident. However, Cs-137 release estimation from the conventional level 2 PSA of OPR-1000 provided uncertainty due to dominant accident sequence consideration. Thus, this study aimed to develop systematic methods through the overall framework to quantify realistic uncertainty concerns of radioactive material release using sensitivity and uncertainty analysis methods and apply them to OPR-1000. This framework helped to quantify confidential value for the Cs-137 release under the BEPU approach using both parametric and non-parametric methods to cover both realistic and conservative points. Uncertainty propagation analysis showed the unexpected uncertainty increase of Cs-137 release exceeding 100 TBq. The non-parametric uncertainty analysis provided higher conservative concerns for safety than the realistic concerns in terms of economics when compared with the parametric uncertainty analysis. Wilks' uncertainty analysis showed the importance to consider conservative Cs-137 release in order to reach the higher safety need. Sensitivity analysis showed reasonable relationships between engineering safety parameters with the Cs-137 release.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.2 no.4
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• pp.231-238
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• 2004

The conditions are obtained for the decomposition of solid radioactive wastes, including ion exchange resin, zeolite, charcoal, and sludge from nuclear power plant. In the process of decomposing the radioactive wastes was used the microwave acid digestion method with mixed acid. The solution after acid digestion by the following method was colorless and transparent. Each solution was analyzed with ICP-AES and AAS and the recovery yield for 5 different elements added into the simulated radioactive wastes were over $94{\%}$. The elemental analysis of destructive low and medium level radioactive wastes by the proposed microwave acid digestion conditions concerning the chemical characteristics of each radioactive waste are expected to be useful basic data for development of optimal glass formulation.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.26 no.4
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• pp.483-491
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• 2016

Precision of theoretical group velocity of waves in shell structures was discussed for the purpose of source localization of loose parts impact in pressure vessels of nuclear power plants. Estimating exact location of loose parts impact inside a reactor or a steam generator is very important in safety management of a NPP. Evaluation of correct propagation velocity of impact signals in pressure vessels, most of which are shell structures, is essential in impact source localization. Theoretical group velocities of impact signals in a plate and a shell were calculated by wave equations and compared to the velocities measured experimentally in a plate specimen and a scale model of a nuclear reactor. The wave equation applicable to source localization algorithm in shell structures was chosen by the study.

• Journal of Radiation Protection and Research
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• v.26 no.3
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• pp.207-214
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• 2001

The KN-12 spent nuclear fuel (SNF) transport cask is designed for transportation of up to 12 assemblies and is in standby status for being licensed in accordance with Korea Atomic Energy Act. To evaluate radiation shielding and criticality safety of the KN-12 cask, each case of study was carried out using MCNP4B Code. MCNP code is verified by performing benchmark calculation for the KSC-4 SNF cask designed in 1989. As a result of radiation safety evaluation for the KN-12 cask, calculated dose rates always satisfied the standards at the cask surface, at 2m from the surface in normal transport condition, and at 1 m from the surface in hypothetical accident condition. Maximum dose rate was always arisen on the side of the cask. For normal transport condition, photons primarily contribute to dose rate between two kinds of released sources, neutrons and photons, from spent nuclear fuel but for hypothetical accident condition, contrary case was resulted. The level of calculated dose rate was 27.8% of the limit at the cask surface, 89.3% at 2 m from the cask surface, and 25.1% at 1 m from the cask surface. For criticality analysis, keff resulting from the criticality analysis considering the condition of optimum partial flooding with fresh water is 0.89708(0.00065. The results confirm the standards recommended by all regulations on radiation safety.