• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.6 no.1
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• pp.45-54
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• 2008

A new proposed repository has a final capacity of 800,000 drums radioactive waste. Most of foreign repositories have a general practice of segregating control zones which mainly contributes to classification of degree of control, whether it is called buffer zone or not. Domestic regulatory requirements of establishment of buffer zone in a repository are not much different from those of nuclear power plants for operation period, in which satisfactory design objective or performance objective is the most important factor in determination of the buffer zone. The meaning of buffer zone after closure is a minimum requested area which can prevent inadvertant intruders from leading to non-allowable exposure during institutional control period. Safety assessment with drinking well scenario giving rise to the highest probability of exposure among the intruder's actions can verify fulfillment of the buffer zone which is determined by operational safety of the repository. At present. for the repository to be constructed in a few years, the same procedure and concept as described in this paper are applied that can satisfy regulatory requirements and radiological safety as well. However, the capacity of the repository will be stepwise extended upto 800,000 drums, consequently its layout will be varied too. Timely considerations will be necessary for current boundary of the buffer zone which has been established on the basis of 100,000 drums disposal.

• Journal of Radiation Protection and Research
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• v.36 no.3
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• pp.148-153
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• 2011

EMRAS-2 (Environmental Modelling for RAdiation Safety, Phase 2) is an international comparison program, which is organized by the International Atomic Energy Agency (IAEA), in order to harmonize the modelling of radionuclide behavior in the environment. To do so, the urban contamination working group within EMRAS-2 has designed the hypothetical scenarios for a specified urban area. In this study, the importance of contaminated surfaces composing an urban environment was analyzed in terms of dose rate using METRO-K, which has been developed to take a Korean urban environment into account. The contribution of contaminated surfaces to exposure dose rate showed distinctly a great difference as a function of specified locations and time following a hypothetical event. Moreover, it showed a distinct difference according to the existence of precipitation, and its intensity. Therefore, if an urban area is contaminated radioactively by any unexpected incidents such as an accident of nuclear power plants or an explosion of radioactive dispersion devices (RDDs), appropriate measures should be taken with consideration of the type of surface composing the contaminated environment in order to minimize not only radiation-induced health detriment but also economic and social impacts.

• Journal of Space Technology and Applications
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• v.4 no.1
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• pp.1-11
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• 2024

Korea Astronomy and Space Science Institute (KASI) developed an satellite laser ranging (SLR) system for tracking space objects using ultra-pulsed lasers. For the safe operation of SLR system, aircraft surveillance radar system (ASRS) was developed to prevent human damage from high power laser transmitted from the SLR system. The ASRS consists of the radar hardware subsystem (RHS) and main control subsystem (MCS), in order to detect flying objects in the direction of laser propagation and then stop immediately the laser transmission. The RHS transmits the radio frequency (RF) pulse signals and receives the returned signals, while the MCS analyzes the characteristics of received signals and distinguishes the existence of flying objects. If the flying objects are determined to be existed, the MCS sends the command signal to the laser controller in SLR system to pause the laser firing. In this study, we address the interface and operational scenarios of ASRS, including the design of RHS and MCS. It was demonstrated in the aircraft experiments that the ASRS could detect an aircraft and then stop transmitting high power laser successfully.

• Journal of Radiation Protection and Research
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• v.40 no.4
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• pp.252-260
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• 2015

This paper describes the technical background for the Korean wildlife radiation dose assessment code, K-BIOTA, and the summary of its application. The K-BIOTA applies the graded approaches of 3 levels including the screening assessment (Level 1 & 2), and the detailed assessment based on the site specific data (Level 3). The screening level assessment is a preliminary step to determine whether the detailed assessment is needed, and calculates the dose rate for the grouped organisms, rather than an individual biota. In the Level 1 assessment, the risk quotient (RQ) is calculated by comparing the actual media concentration with the environmental media concentration limit (EMCL) derived from a bench-mark screening reference dose rate. If RQ for the Level 1 assessment is less than 1, it can be determined that the ecosystem would maintain its integrity, and the assessment is terminated. If the RQ is greater than 1, the Level 2 assessment, which calculates RQ using the average value of the concentration ratio (CR) and equilibrium distribution coefficient (Kd) for the grouped organisms, is carried out for the more realistic assessment. Thus, the Level 2 assessment is less conservative than the Level 1 assessment. If RQ for the Level 2 assessment is less than 1, it can be determined that the ecosystem would maintain its integrity, and the assessment is terminated. If the RQ is greater than 1, the Level 3 assessment is performed for the detailed assessment. In the Level 3 assessment, the radiation dose for the representative organism of a site is calculated by using the site specific data of occupancy factor, CR and Kd. In addition, the K-BIOTA allows the uncertainty analysis of the dose rate on CR, Kd and environmental medium concentration among input parameters optionally in the Level 3 assessment. The four probability density functions of normal, lognormal, uniform and exponential distribution can be applied.The applicability of the code was tested through the participation of IAEA EMRAS II (Environmental Modeling for Radiation Safety) for the comparison study of environmental models comparison, and as the result, it was proved that the K-BIOTA would be very useful to assess the radiation risk of the wildlife living in the various contaminated environment.