• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
• /
• v.13 no.1
• /
• pp.63-72
• /
• 2015

The low and intermediate-level radioactive waste generated in Korea is disposed of at Wolsong Disposal Facility. For the safety of a disposal facility, it must be assessed by considering some abnormal scenarios including human intrusion as well as those by natural phenomena. The human intrusion scenario is a scenario that an incognizant man of the disposal facility will be occurred by the drilling. In this paper, the well usage scenario was classified into the human intrusion event as the probability of the well drilling is very low during the man's lifecycle and then was assessed by using conservative assumptions. This scenario was assessed using the dilution factor of contaminants released from a disposal facility and then it was introduced the applied methodology in this study. The assessed scenario using this methodology is satisfied the regulatory limits.

• Proceedings of the Korean Radioactive Waste Society Conference
• /
• 2003.11a
• /
• pp.141-148
• /
• 2003

A data collection of a liquid radioactive waste treatment process of a research organization became necessary while developing the RAWMIS(Radioactive Waste Management Integration System) which it can generate personal history management for efficient management of a waste, documents, all kinds of statistics. This paper introduces an input and output application program design to do to database with data in the results and a stream process of a treatment that analyzed the waste occurrence present situation and data by treatment process. Data on the actual treatment process that is not limited experiment improve by a document, human traces, saving of material resources and improve with efficiency of tracking about a radioactive waste and a process and give help to radioactive waste material valance and inventory study.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.8 no.1
• /
• pp.29-36
• /
• 1994

Exhibitlon lighting design be done after due consideration of the photochemical reaction and heating effcts upon exposure to light In this study the balanced judgement is as follows. 'The most light-susceptible material should be illustrated less than 5O(lx](illumlnance-hours per year: 120,OOOlx.h)and the illuminance of moderately sensitive material is 200(lx] (illuminance hours per year: 480,OOOlx.h). Moreover to minimize damage the sources of light should not only contribute as little as heat possible but remove ultraviolt radiation by filters. Also the sources of light must have good color rendering and low color temperature.

• The Journal of Engineering Geology
• /
• v.22 no.1
• /
• pp.95-111
• /
• 2012

This study investigated the relationship between the geochemical environment and the occurrence of natural radioactive materials (uranium and Rn-222) in borehole groundwater at an Icheon site. The drill core recovered from the study site consists mainly of biotite granite with basic dykes. The groundwater samples were collected at four different depths in the borehole using the double-packed system. The pH range of the groundwater was 6.5~8.6, and the chemical type was Ca-$HCO_3$. The ranges of uranium and Rn-222 concentrations in the groundwater were 8.81~1,101 ppb and 5,990~11,970 pCi/L, respectively, and concentrations varied greatly with depth and collection time. The ranges of uranium and thorium contents in drill core were 0.53~18.3 ppm and 6.66~17.5 ppm, respectively. Microscope observations and electron microprobe analyses revealed the presence of U and Th as substituted elements for major composition of monazite, ilmenite, and apatite within K-feldspar and biotite. Although the concentration of uranium and thorium in the drill core was not high, the groundwater contained a high level of natural radioactive materials. This finding indicates that physical factors, such as the degree of fracturing of an aquifer and the groundwater flow rate, have a greater influence on the dissolution of radioactive materials than does the geochemical condition of the groundwater and rock. The origin of Rn-222 can be determined indirectly, using an interrelationship diagram of noble gas isotopes ($^3He/^4He$ and $^4He/^{20}Ne$).

• Proceedings of the Korean Radioactive Waste Society Conference
• /
• 2003.11a
• /
• pp.101-104
• /
• 2003

In this study based on the mass transfer theory, experiments for the evaporation rates depending on various conditions were carried out through the operation of the existing Natural Evaporation Facility in KAERI. Evaporation media were made of the cotton and polyester. Air circulation in the facility was forced by exhausting fans. The evaporation rate and the decontamination factor were calculated by the result of experiment. The evaporation rate increased as the flow rate of air supply, the feed rate of liquid waste, and the temperature of supplied air increased. As for the humidity of supplied air, the evaporation rate was getting higher as the humidity was getting lower. As the result of this study, operation conditions of the Natural Evaporation Facility are optimized as follows : The air temperature above $8^{\circ}C$, the air humidity below 70%, the air flow rate 1.14-1.47 m/sec, and the liquid waste feed rate $4.6{\ell}/hr\cdotm^2$. The decontamination factor and the radioactivity are $5.1{\times}10^3$and $4.7{\times}10^{-13}{\mu}Ci/\textrm{m}{\ell}$ respectively, at the above mentioned optimum operation conditions. The air factor in the Dalton's equation for evaporation was determined from results of experiment on the temperature, the humidity, and the flow rate of supplied air as following : $[\textit{Eh}=(0.018 + 0.0141\textitv) {\delta}textitH]$

• Proceedings of the Korean Nuclear Society Conference
• /
• 1998.05b
• /
• pp.725-729
• /
• 1998

방사성 동위원소를 이용한 체외진단 측정법으로 RIA가 가장 널리 쓰여져 왔으나, 결합분획과 유리분획의 분리과정에서 오는 번거로운 단점을 개선하기 힘들었다. 1979년 Hart와 Greenwald에 의해 소개된 섬광근접측정법(Scintillation Proximity Assay, SPA)을 이용하여 RIA의 단점을 극복하고자 하는 연구가 시작되었다 주로 사용되는 방사성동위원소로 $^3$H, $^{125}$/I이 추천되는 핵종이며, 이 중에서 $^{125}$/I을 이용한 hCG(human chorionic gonadotropin) 체외진단법으로서 SPA의 기초연구를 수행하였다. SPA bead와 방사능 크기에 따라 측정되는 자연계수치의 증가와 hCG 표준물질을 농도별로 희석하여 유의성을 가지고 있는지 확인하였고, hCG 농도가 높은 것으로 판명된 환자의 혈청을 측정하여 임상적용의 가능성을 확인하였다.

• Proceedings of the Korea Air Pollution Research Association Conference
• /
• 2000.04a
• /
• pp.279-281
• /
• 2000

발암성 물질로 알려진 라돈($^{222}Rn$)은 원래 불활성기체로 자연계에 널리 존재하는 자연방사능으로 암석이나 토양 같은 지각물질에서 발생하는 우라늄($^{238}U$) 붕괴계열인 라듐($^{226}Ra$)의 붕괴과정에서 생성되는 방사성 가스이다. 라돈($^{222}R$)은 $\alpha$붕괴에 의하여 $^{218}Po$, $^{214}Po$등의 자핵종(Radon daughter)을 생성하며, 최종적으로 납($^{210}Pb$)으로 변한다 라돈이 폐에 흡입되면 붕괴하면서 $\alpha$방사선을 방출하는데, 이것이 인체의 세포를 죽이거나 염색체를 손상시킬 수 있으며, 폐암의 발생 위험률을 높이는 것으로 보고되었다. (중략)

• Nuclear Engineering and Technology
• /
• v.2 no.4
• /
• pp.273-278
• /
• 1970

The Contents of uranium and thorium in radioactive ores produced in Korea were determined by gamma-ray spectrometry utilizing Ge (Li) diode detector. Both methods, namely, gamma-ray spectrometries of activated samples and non-activated samples, were tested and compared for their accuracies and rapidness in determination of contents. Also the useful-ness of application of Ge(Li) diode detector to the determination of uranium and thorium contents in ores was discussed in detail.

• Environmental Analysis Health and Toxicology
• /
• v.17 no.4
• /
• pp.273-284
• /
• 2002

At present, the health risks associated with the natural radionuclides of ground water have become a concern as potential social problems. However, there are no regulatory actions or control strategies for such risks. Therefore, we have investigated and discussed the risks and associated management strategies for radionuclides in other countries. US EPA has proposed MCL (300 pCi/L) and AMCL (4,000 pCi/L) for radon, and 30 ppb for uranium, 15 pCi/L for gross-alpha and 5 pCi/L for radium as final MCLs. Also, Canada, WHO and European countries have their inherent management levels. Finally, we suggested several criteria for setting guidelines in our countries including exposure related criteria such as geological distribution, occurrence, exposure probability distribution, exposure population and multimedia exposure assessment, acceptable risk, and cost -benefit analysis. The national-scale exposure and risk assessment, and economic analysis should be conducted for producing and aggregating the representative information on these criteria.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
• /
• v.4 no.1
• /
• pp.9-15
• /
• 2006

For the accurate safety assessment of potential radioactive waste disposal site which is located in the crystalline rock it is important to simulate the mass transportation through engineered and natural barrier system precisely, characterized by porous and fractured media respectively. In this work the methods to construct discrete fracture network for the analysis of flow and mass transport through fractured-porous medium are described. The probability density function is adopted in generating fracture properties for the realistic representation of real fractured rock. In order to investigate the intersection between a porous and a fractured medium described by a 2 dimensional rectangular and a cuboid grid respectively, an additional imaginary fracture is adopted at the face of a porous medium intersected by a fracture. In order to construct large scale flow paths an effective method to find interconnected fractures and algorithms of swift detecting connectivities between fractures or porous medium and fractures are proposed. These methods are expected to contribute to the development of numerical program for the simulation of radioactive nuclide transport through fractured-porous medium from radioactive waste disposal site.