• Title/Summary/Keyword: Radioactive

Search Result 7,970, Processing Time 0.039 seconds

Evaluation of Capillary Barrier Effect of Multi-layer Cover System (다중 덮개시스템의 모세관 방벽 효과 평가)

  • Lee, Jeong-Hwan;Cho, Hyun-Jin;Cheong, Jae-Yeol;Jung, Haeryong;Yoon, Jeong Hyoun
    • Journal of Soil and Groundwater Environment
    • /
    • v.21 no.1
    • /
    • pp.1-5
    • /
    • 2016
  • Capillary barriers, consisting of relatively fine-over-coarse materials, have been suggested as an alternative to traditional compacted soil covers. So, We were analysed to capillary barrier effect according to five cases of multi-layer cover systems. Water balance simulation was conducted with unsaturated flow model HELP to assess unsaturated hydraulic parameters such as hydraulic conductivity, climate affecting the performance of capillary barriers. Simulation were conducted for 5 Cases in the Ulsan area. Result of simulation indicated that three cases was formed unsaturated condition and capillary barrier effect.

Fundamental study on volume reduction of cesium contaminated soil by using magnetic force-assisted selection pipe

  • Nishimura, Ryosei;Akiyama, Yoko;Manabe, Yuichiro;Sato, Fuminobu
    • Progress in Superconductivity and Cryogenics
    • /
    • v.23 no.3
    • /
    • pp.26-31
    • /
    • 2021
  • Advanced classification of Cs contaminated soil by using a magnetic force-assisted selection pipe was investigated. A selection pipe is a device that sort particles depending on their particle size, based on the relationship between buoyancy, drag, and gravity force acting on the particles. Radioactive cesium is concentrated in small-particle size soil components with a large specific surface area. Hence, the volume of the Cs contaminated soil can be reduced by recycling the large-particle size soil components with low radioactive concentration. One of the problems of the selection pipe was that the radioactive concentration of the stayed soil in the selection pipe exceeds 8000 Bq/kg, which is the standard value of recycling of Cs contaminated soil, due to low classification accuracy. In this study, magnetic fields were applied to the lab-scale selection pipe from upper side to improve the classification accuracy and to reduce the radioactive concentration of the stayed soil.

Safety Assessment for the Landfill Disposal of Decommissioning Waste Solidified by Magnesium Potassium Phosphate Cement

  • Jeong, Jongtae;Baik, Min-Hoon;Lee, Jae-Kwang;Pyo, Jae-Young;Um, Wooyong;Heo, Jong
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
    • /
    • v.20 no.1
    • /
    • pp.13-22
    • /
    • 2022
  • The decommissioning of a nuclear power plant generates large amounts of radioactive waste, which is of several types. Radioactive concrete powder is classified as low-level waste, which can be disposed of in a landfill. However, its safe disposal in a landfill requires that it be immobilized by solidification using cement. Herein, a safety assessment on the disposal of solidified radioactive concrete powder waste in a conceptual landfill site is performed using RESRAD. Furthermore, sensitivity analyses of certain selected input parameters are conducted to investigate their impact on exposure doses. The exposure doses are estimated, and the relative impact of each pathway on them during the disposal of this waste is assessed. The results of this study can be used to obtain information for designing a landfill site for the safe disposal of low-level radioactive waste generated from the decommissioning of a nuclear power plant.

Selection of a carrying agent for obtaining radioactive methyliodide vapors under dynamic conditions

  • Obruchikov, Alexander V.;Merkushkin, Aleksei O.;Magomedbekov, Eldar P.;Anurova, Olga M.;Vanina, Elena A.
    • Nuclear Engineering and Technology
    • /
    • v.53 no.8
    • /
    • pp.2761-2766
    • /
    • 2021
  • A method for preparing "reagent" for radioactive methyliodide vapors production using an isotopic exchange reaction has been developed. Based on the obtained data of the isotopic exchange efficiency and hydraulic resistance, white fused alumina (700-840 ㎛) was selected as the carrying agent material for "reagent" production. The radioiodine isotopic exchange dependences on such parameters as temperature, gas flow velocity, and the methyliodide concentration in it were determined. Optimal conditions have been selected to achieve 85% of the isotopic exchange rate in 1 h of the experiment. The obtained data allowed to develop an approach to the test of iodine filters for nuclear power plants and to determine their efficiency.

Design and Graphic Simulation of a Cleaning Robot for a Radioactive Environment Application

  • Kim, K.;Park, J.;M. Yang;C. Oh
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 2001.10a
    • /
    • pp.161.3-161
    • /
    • 2001
  • This paper describes design features of a cleaning robot for use in a radioactive zone of the Isolation room of the Irradiated Material Examination Facility (IMEF) at Korea Atomic Energy Research Institute (KAERI). This cleaning robot is intended to completely eliminate human interaction with hazardous radioactive contaminants. The clean ing robot that is operated either by manual mode or by autonomous mode is designed to be capable of cleaning the isolation room´s floor surface and collecting dry nuclear fuel debris and other radioactive waste placed on the floor. The functional, mechanical and electrical design considerations of the cleaning robot in terms of remote cleanup operation and remote maintenance at a radioactive environment are presented. A graphical representation of the cleaning ...

  • PDF

A Teleoperated Cleaning Robot for a High Radioactive Environment

  • Kim, Ki-Ho;Park, Jang-Jin;Yang, Myung-Seung;Oh, Chae-Youn
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 2003.10a
    • /
    • pp.849-854
    • /
    • 2003
  • The Korea Atomic Energy Research Institute has developed a teleoperated cleaning robot for use in the radioactive zone of the isolation room of the Irradiated Material Examination Facility where direct human access to the interior is strictly limited. The teleoperated cleaning robot that was designed to completely eliminate human interaction with the hazardous radioactive contaminants has five remotely replaceable submodules - a mobile module for navigation, a cleaning module for dislodging and sucking contaminated waste, a sensing module for obstacle avoidance, a collection module for storing the acquired waste, and a cover module for protecting the collection module. This cleaning robot is capable of cleaning the contaminated floor surface of the isolation room and collecting loose dry spent nuclear fuel debris and other radioactive waste fixed or scattered on the floor surface. The developed cleaning robot is operated either by a manual control or by autonomous control in conjunction with a graphical simulator, by which the human operator can monitor and intervene the robot performing cleanup tasks in the isolation room. In this paper, we present the mechanical and environmental design considerations and development of the teleoperated cleaning robot for radioactive isolation room use. We also demonstrate its mock-up performance test results from the viewpoint of a remote cleanup operation and remote maintenance.

  • PDF

The Experience of Receiving Radioactive Iodine Therapy among Thyroid Cancer Patients (갑상선암 환자의 방사성요오드 치료경험)

  • Kang, Kyung Ok;Kim, Hyun Kyung;Kim, Ji Young;Lim, Seok Tae
    • Journal of East-West Nursing Research
    • /
    • v.22 no.2
    • /
    • pp.148-157
    • /
    • 2016
  • Purpose: The purpose of this study was to explore the meaning of the experience of receiving radioactive iodine therapy among patients with thyroid cancer. Methods: A qualitative research design was adopted. The participants were ten women diagnosed with thyroid cancer who had received radioactive iodine therapy within one year. Data were collected through in-depth interviews from October of 2015 to April of 2016. Individual interviews were recorded, and transcribed data were analyzed using Colaizzi's method. Results: The six categories of the experience of receiving radioactive iodine therapy were "Finally realizing having cancer," "The lonely fight that feels like prison life," "Narrower scope of life," "Lack of understanding by others," "Enduring a short, yet difficult journey," and "A turning point for a new life." Conclusion: This study provides deep insight into the experience of thyroid cancer patients who had received radioactive iodine therapy. Nurses should concern their distress during radioactive iodine treatment and manage psychological difficulties as well as physical symptoms. Support from family and health care providers may help them to overcome the hard journey.

Options Manageing for Radioactive Metallic Waste From the Decommissioning of Kori Unit 1 (고리1호기 해체시 발생할 방사성금속폐기물 관리 옵션 연구)

  • Kessel, David S.;Kim, Chang-Lak
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
    • /
    • v.15 no.2
    • /
    • pp.181-189
    • /
    • 2017
  • The purpose of this paper is to evaluate several leading options for the management of radioactive metallic waste against a set of general criteria including safety, cost effectiveness, radiological dose to workers and volume reduction. Several options for managing metallic waste generated from decommissioning are evaluated in this paper. These options include free release, controlled reuse, and direct disposal of radioactive metallic waste. Each of these options may involve treatment of the metal waste for volume reduction by physical cutting or melting. A multi-criteria decision analysis was performed using the Analytic Hierarchy Process (AHP) to rank the options. Melting radioactive metallic waste to produce metal ingots with controlled reuse or free release is found to be the most effective option.

New mathematical approach to calculate the geometrical efficiency using different radioactive sources with gamma-ray cylindrical shape detectors

  • Thabet, Abouzeid A.;Hamzawy, A.;Badawi, Mohamed S.
    • Nuclear Engineering and Technology
    • /
    • v.52 no.6
    • /
    • pp.1271-1276
    • /
    • 2020
  • The geometrical efficiency of a source-to-detector configuration is considered to be necessary in the calculation of the full energy peak efficiency, especially for NaI(Tl) and HPGe gamma-ray spectroscopy detectors. The geometrical efficiency depends on the solid angle subtended by the radioactive sources and the detector surfaces. The present work is basically concerned to establish a new mathematical approach for calculating the solid angle and geometrical efficiency, based on conversion of the geometrical solid angle of a non-axial radioactive point source with respect to a circular surface of the detector to a new equivalent geometry. The equivalent geometry consists of an axial radioactive point source with respect to an arbitrary elliptical surface that lies between the radioactive point source and the circular surface of the detector. This expression was extended to include coaxial radioactive circular disk source. The results were compared with a number of published data to explain how significant this work is in the efficiency calibration procedure for the γ-ray detection systems, especially in case of using isotropic radiating γ-ray sources in the form of point and disk shapes.

Evaluation of Percolation Rate of Bedrock Aquifer in Coastal Area (해안지역 암반대수층의 침누수량 평가)

  • Lee, Jeong-Hwan;Jung, Haeryong;Park, Joo-Wan;Yoon, Jeong Hyoun;Cheong, Jae-Yeol;Park, Sun Ju;Jun, Seong-Chun
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
    • /
    • v.14 no.1
    • /
    • pp.21-33
    • /
    • 2016
  • Estimation of groundwater hydrologic cycle pattern is one of the most critical issues in sustainable management of groundwater resources in coastal area. This study estimated groundwater percolation by using the water balance methodology and hydrogeological characteristics of land use and soil. Evapotranspiration was computed by using the Thornthwaite method, and surface runoff was determined by using the SCS-CN technique. Groundwater storage change was obtained as 229 mm/a (17.8% of the average annual rainfall, 1286 mm/a), with 693 mm/a (60.1%) of evapotranspiration and 124 mm/a (9.6%) of surface runoff. Rainfall and groundwater storage change was highly correlated, comparing with the relationships between rainfall and evapotranspiration, and between rainfall and surface runoff. This result indicates that groundwater storage change responds more sensitively to precipitation than evapotranspiration and surface runoff.