Safety Evaluation of Clearance of Radioactive Metal Waste After Decommissioning of NPP (원전해체후 규제해제 대상 금속폐기물에 대한 자체처분 안전성 평가)
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- Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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- v.18 no.2_spc
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- pp.291-303
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- 2020
The Kori-Unit 1 nuclear power plant, which is scheduled to be decommissioned after permanent shutdown, is expected to generate large amounts of various types of radioactive waste during the decommissioning process. Among these, nuclear reactors and internal structures have high levels of radioactivity and the dismantled structure must have the proper size and weight on the primary side. During decommissioning, it is important to prepare an appropriate and efficient disposal method through analysis of the disposal status and the legal restrictions on wastes generated from the reactors and internal structures. Nuclear reactors and internal structures generate radioactive wastes of various levels, such as medium, very low, and clearance. A radiation evaluation indicates that wastes in the clearance level are generated in the reactor head and upper head insulation. In this study, a clearance waste safety evaluation was conducted using the RESRAD-RECYCLE code, which is a safety evaluation code, based on the activation evaluation results for the clearance level wastes. The clearance scenario for the target radioactive waste was selected and the maximum individual and collective exposure doses at the time of clearance were calculated to determine whether the clearance criteria limit prescribed by the Nuclear Safety Act was satisfied. The evaluation results indicated that the doses were significantly low, and the clearance criteria were satisfied. Based on the safety assessment results, an appropriate metal recycle and disposal method were suggested for clearance, which are the subject of the deregulation of internal structures of nuclear power plant.
The Korea Radioactive Waste Agency plans to expand the storage capacity of radioactive waste by constructing a radioactive waste inspecting building to solve the problem of the lack of inspection space and drum-handling space in the radioactive waste receipt and storage building for the first-stage disposal facility. In this study, the exposure doses of radiation workers that handle new disposal containers for decommissioning waste in the storage areas of the radioactive waste inspecting building were calculated using the Monte Carlo N-particle transport code. The annual collective dose was calculated as a total of 84.8 man-mSv for 304 new disposal containers and an estimated annual 306 working hours for the radiation work. When the 304 new disposal containers (small/medium type) were stored in the storage areas, it was found that 25 radiation workers should be involved in acceptance/disposal inspection, and the estimated exposure dose per worker was calculated as an average annual value of 3.39 mSv. When the radiation workers handle the small containers in high-radiation dose areas, the small containers should be shielded further by increasing the concrete liner thickness to improve the work efficiency and radiation safety of the radiation workers. The results of this study will be useful in establishing the optimal radiation working conditions for radiation workers using the source term and characteristics of decommissioning waste based on actual measurements.
The purpose of this study was to compare the nutritional status of children aged 5 or under and women aged 20 to 34 years between the Republic of Korea (South Korea) and the Democratic Peoples' Republic of Korea (DPRK: North Korea). For the source of nutritional status of North Koreans, the DPRK 2004 Nutrition Assessment-Report of Survey Results was used. As the comparable data of South Koreans, the anthropometric data for children and women were obtained from the reports of the Korean Pediatric Society and the Korean Agency for Technology and Standards, respectively. The blood hemoglobin data of South Korean women were obtained from the data file of the 2001 National Health and Nutrition Survey and analyzed. In regard to the North Korea, the Prevalence of underweight (weight for age Z-score < -2.0) in children under 12 months was about
High price equipment is one of the major factors that increases national health expenditure in developed countries. Computerized Tomography(CT), one of the important high price equipment, has been concerns of health service researchers and policy makers in many countries. In Korea, CT, first introduced in 1984, have spreaded nationwide with rapid speed. Though the Committee for Approving Import of High Price Medical Equipment, founded in 1981, tried to regulate the introduction of high price medical equipment including CT, the effort resulted in failure. The exact situation of diffusion of the high price equipment, however, was not yet investigated. We aimed at the description of the diffusion of CT in Korea and analysis of influencing factors on hospitals for the adoption of CT. We mainly used the database of CT, made in 1996 by the National Federation of Medical Insurance for the purpose of insurance payment for CT. Also characteristics of hospitals were gathered from yearbooks published by the central and local governments and by the Korean Hospital Association. We calculated the cumulative number of the CT per one million population year by year. In turn, multiple linear logistic regression was done to find out the contributing factors for the adoption of CT by each hospital. In the logistic regression model, it is regarded as dependent factor whether a hospital retained CT or not in 1988 and 1993. The major categories of the independent factors were hospital characteristics, environmental factors and competitive conditions of hospitals at the period of the adoption. The results are as follows: Number of CT scanners per one million persons in Korea marked more higher level compared with those of most OECD countries. Major influencing factors on the adoption of CT scanners were hospital characteristics, such as hospital referral level, and competitive condition of hospitals, such as number of CT scanners per 10,000 persons in each district where the hospital was located. In Korea, CT diffused with rather rapid speed, comparable with those of the United States and Japan. The major factors contributing on the adoption of CT for hospitals were competitive condition and hospital characteristics rather than regional health care need for CT. In conclusion, a kind of regulating mechanism would be necessary for the prevention of the indiscreet adoption and inefficient use of high price equipment including CT.
The subjects of the study were the 120 mothers who had children hospitalized in 6 hospitals in P city during the period from Feb. 1. to May 30. 1996. The purpose of the study are(1) the problems encountered when they carried out Home Care after discharge and (2) the degrees of demand that they had against Home Care Services. In order to investigate the purposes above-mentioned the researchers used the 55 items of Home Care services belonging to 10 areas selected by Korea Home-Care Association in 1994. The items were modified and supplemented to 4-point scale. The selected data were analyzed by SPSS : PC+ and the following results were derived. 1. The subjects payed great attention to 5 items such as 'pain control, OPD visits, diet-control problems' among the 15 sources of anxiety that they had against Home Care services after discharge. Especially, 'OPD visits and knowledge deficit' would to be overcome by the nursing activities of the Home Care Nurses. 2. The acknowledge level of the subjects to the Home Care Project that governmental plans to carry out was surveyed and found as under 50. 0% responded they heard about Home Care Nursing System. 60.8% said that they thought the system was 'very necessary' and 'somewhat necessary'. 65.0% said they would like to use the system. However, the acknowledge level of 50.0% is still low and is thought to need further national promotion and propagation. 3. The demand of the subjects against 55 Home Care Services was investigated and found as