In the majority of countries, the upper limit of buffer temperature in a repository is set to below 100℃ due to the possible illitization. This smectite-to-illite transformation is expected to be detrimental to the swelling functions of the buffer. However, if the upper limit is increased while preventing illitization, the disposal density and cost-effectiveness for the repository will dramatically increase. Thus, understanding the characteristics and creating a database related to the buffer under the elevated temperature conditions is crucial. In this study, a strategy to investigate the bentonite found in Korea under the elevated temperatures from a mineral transformation and radionuclides retardation perspective was proposed. Certain long-term hydrothermal reactions generated the bentonite samples that were utilized for the investigation of their mineral transformation and radionuclide retardation characteristics. The bentonite samples are expected to be studied using in-situ synchrotron-based X-Ray Diffraction (XRD) technique to determine the smectite-to-illite transformation. Simultaneously, the ‘high-temperature and high-pressure mineral alteration measurement system’ based on the Diamond Anvil Cell (DAC) will control and provide the elevated temperature and pressure conditions during the measurements. The kinetic models, including the Huang and Cuadros model, are expected to predict the time and manner in which the illitization will become detrimental to the performance and safety of the repository. The sorption reactions planned for the bentonite samples to evaluate the effects on retardation will provide the information required to expand the current knowledge of repository optimization.
The study is about variations in Carbonyl compounds concentration within apartment buildings according to pre-residence and residence.
We consecutively investigated indoor air pollutants in 120 households in 6 cities at pre-residence and residence. Carbonyl compounds were collected using the 2,4-DNPH cartridge and were analyzed using HPLC. The carbonyls concentration of indoor air in the new apartments before occupation measured formadlehyde(76.0㎍/㎥), acetone(85.9㎛/㎥), acetaldehyde(13.8㎍/㎥). The carbonyls concentration of indoor air in the new apartments after occupation measured formadlehyde(233.1㎍/㎥), acetone(128.9㎍/㎥), acetaldehyde(29.8㎍/㎥), respectively.
As a result, the mean concentration of carbonyl compounds within the pre-occupancy stage was lower than those of residence.
Because of the building is made airtight, Indoor Air Quality(IAQ) is go from bad to worse. There are many source of indoor pollution in any home. These include irritation of the eyes, nose, and throat, headaches, dizziness, and fatigue. Such immediate effects are usually short-term and treatable. In this study was measured and analyzed VOCs exposure levels and characteristic of Indoor air pollutant from new apartments in Korea. VOCs were measured indoor pre-residential and residential in new apartment and analyzed GC/MS. The concentration levels of indoor respirable TVOC were found to be higher than those of outdoor TVOC for new apartments. Before occupation, the average indoor and outdoor concentrations were 1498.61 ug/m3 and 468.38 ug/m3, respectively. After being occupied, the average indoor and outdoor concentration were 847.04 ug/m3 and 102.84, respectively. The concentrations of TVOC in new apartments before occupation were shown in the order of Toluene(328.12 ug/m3) > m,p-Xylene(163.67 ug/m3) > Ethylbenzene(80.70 ug/m3)>o-XYlene (67.04ug/m3). In addition, the TVOCs concentrations after occupation were also found in the order of Toluene (272.28 ug/m3) > m.p-Xylene(121.79 ug/m3) > Ethylbenzene(53.92 ug/m3)>O-Xylene(24.94 ug/m3). As a result, the concentrations of VOCs in new apartment houses were shown to be affected by indoor environment according activity patterns. So new apartments need to be controled in indoor air quality so that the residents can have more comfortable and healthier living environment.
The results of particulate matters level and heavy metal concentration, which surveyed in Gwang-Yang, Dang-Jin steel industry area, are as follows; The PM2.5, PM10 of exposure area are 22.3μg/m3, 40.4μg/m3 each in Kum-Ho dong, and 28.1μg/m3, 51.5 each in Jung dong. The PM2.5, PM10 of control area are 16.4μg/m3, 29.5μg/m3 each in Bonggang-myeon. The level is higher in exposure area than control area. In case of Dang Jin, the concentration of PM10 and PM2.5 is higher in exposure area than control area (PM2.5-20.4μg/m3, PM10-39.2μg/m3). The Pb level of Dang Jin area is higher in exposure area(0.13μg/m3) than control area(0.1μg/m3), and both Gwang-Yang and Dang-Jin area lower level than the Guideline level of Korea EPA.
In this study, in order to analyze the air quality of the indoor environments of schools, we measured the indoor, outdoor and personal exposure concentration level of PM10 for 40 classrooms(20 old, 20 new) in chungnam area from June 22 to July 19 and from November 21 to December 30, 2003. 1. Old classrooms contained more dust than new classrooms; the average of respirable dust is 43.27 ㎍/㎥ for new classrooms while 53.38 ㎍/㎥ for old one. The exposure concentration level of respirable dust in new classrooms were in summer higher outdoors than indoors. The values were indoors 46.71 ㎍/㎥, outdoors 50.46 ㎍/㎥, and personal 41.62 ㎍/㎥. Meanwhile in winter indoors had a higher concentration level than outdoors, the values being indoors 39.11 ㎍/㎥, outdoors 34.86 ㎍/㎥, and personal 49.01 ㎍/㎥. 2. Cr concentration level within dust was slightly higher in summer indoors (101.50±32.10 ng/㎥) and outdoors (100.89±35.18 ng/㎥) than winter indoors (85.80±48.95 ng/㎥) and outdoors (74.43±38.93 ng/㎥), but in personal concentration level, winter was higher. The results of this research show insufficient understanding of health risks from indoor air pollution, and shows possible health problems to students from school indoor air pollution. As such, a logical and systematic education program for students about the importance of indoor air quality should be carried out. Also the results of PM10 concentration level measurements emphasize the need for regular measurements of indoor / outdoor and personal concentration level. New classrooms in particular needs to be used after measuring pollutants and safety, and requires installation of a ventilation device in all classrooms to improve air quality.