[en] NaFeAs recently observed superconductivity with the maximum T_c ∼ 25 K is investigated using first principles approach. We will address briefly the electronic structure and contrast other superconducting pnictides. This system shows strong two-dimensionality and reduction of flatness in the Fermi surfaces undermines tendencies of magnetic or charge instabilities. As observed in other superconducting pnictides, Q_M=(π,π,0) antiferromagnetic ordering, which has not been observed clearly yet in this compound, is energetically favored. However, contrast to other superconducting pnictides, the density of states in this ordering shows considerable electron-hole asymmetry, implying efficiency of hole-doping than electron-doping to enhance T_c.

[en] In order to obtain the licence for operating of the radioactive treatment facility, the documents as below must be submitted. Any person, who intends to construct and operate a storage, processing and disposal facility of radioactive wastes and accessory facility shall obtain permit of the Minister of Education, Science and Technology under the conditions as prescribed by the Presidential Decree. The same shall also apply in a case where he wishes to change any permitted matters. Provided, that if he wishes to change any minor matters as prescribed by the Ordinance of the Ministry of Education, Science and Technology, he shall report it

[en] The evaluation technology of decommissioning process must be developed and will be used for the ALARA planning tool of decommissioning process and demonstrated for tools of decommissioning equipment. Also, this technology can be used for tools workplaces with high work difficulty such as large-scale chemical plant, under water and space. The monitoring system for high alpha radioactive contamination measurement will be use in the high radioactivity decommissioning sites such as hot-cell or glove box. Also, it will be use in the general nuclear facilities as the radiation monitoring unit. The preparation technology of the radiation sensor for high radioactive contamination measurement will be transferred to the company for the industrialization. The remote monitoring system can prevent the workers exposure using the optical fiber to separate the sensor and electronics

[en] Although it is expected that the decommissioning of a nuclear power plant will happen since 2020, the need of partial decommissioning and decontamination for periodic inspection and life extension has been on an increasing trend and domestic market has gradually been extended. Therefore, in this project the decommissioning DB system on the KRR-1 and 2 was developed as establishing the information classification system of the research reactor dismantling and the structural design and optimization of the decommissioning DB system. Also in order to secure the reliability and safety about the dismantling process, the main dismantling simulation technology that can verify the dismantling process before their real dismantling work was developed. And also the underwater cutting equipment was developed to remove these stainless steel parts highly activated from the RSR. First, the its key technologies were developed and then the design, making, and capability analysis were performed. Finally the actual proof was achieved for applying the dismantling site. an automatic surface contamination measuring equipment was developed in order to get the sample automatically and measure the radiation/radioactivity

[en] - Incinerating generated decommissioning waste from KRR-1 and 2 and UC plant by using incineration facility for rad-waste. - Induce metallic decommissioning waste to reduce volume and reusing them by using vitrification facility. - To prevent radiation release from no longer use or deteriorated research facility, such as mock-up facility for UF4 fabrication, by done decommissioning safely, then convert to research laboratory for reusing it. - Prepare for the decommissioning of nuclear facility by establish decommissioning engineering system which based on decommissioning experiences of KRR-1 and 2 and UC plant. - Establishing research facility for the treatment of very low level rad-waste from decommissioning after completion of lagoon facility decommissioning. - To secure transparency on nuclear material accounting and to prevent possibility of lose of nuclear material done by central management of no longer using nuclear material being scattered in KAERI

[en] It is predicted that the decommissioning of a nuclear power plant would happen in Korea since 2020 but the need of partial decommissioning and decontamination for periodic inspection and life extension still has been on an increasing trend and its domestic market has gradually been extended. Therefore, in this project we developed following several essential technologies as a decommissioning R and D. The measurement technology for in-pipe radioactive contamination was developed for measuring alpha/beta/gamma emitting nuclides simultaneously inside a in-pipe and it was tested into the liquid waste transfer pipe in KRR-2. And the digital mock-up system for KRR-1 and 2 was developed for choosing the best scenarios among several scenarios on the basis of various decommissioning information(schedule, waste volume, cost, etc.) that are from the DMU and the methodology of decommissioning cost estimation was also developed for estimating a research reactor's decommissioning cost and the DMU and the decommissioning cost estimation system were incorporated into the decommissioning information integrated management system. Finally the treatment and management technology of the irradiated graphites that happened after decommissioning KRR-2 was developed in order to treat and manage the irradiated graphites safely

[en] The various requirements of the staffs were verified to be accident insurance, school expense support, cultural life, lesson, medical check-up and tour. The welfare items were largely classified into basic and optional one. Basic one was composed of legal welfare of four insurance, medical check-up and security insurance. Welfare points were divided into basic and optional one. First of all, the portion between basic and optional one was designated to be 5 to 5 and is subject to the investigation for the settlement in case of the necessity. The optional point was continuous service one with the maximum period of 20 years. The user's interface was established for user's convenience through the basic and detail design on the welfare items. The operation regulation of the welfare system was set and the guideline was specified on welfare items. As a result, the optional welfare system was confirmed to commence from January 2005

[en] In the decommissioning planning stage, it is important to select the optimized decommissioning process considering the cost and safety. Especially the selection of the optimized decommissioning process is necessary because it affects to improve worker's safety and decommissioning work efficiency. The decommissioning process evaluation technology can provide the optimized decommissioning process as constructing various decommissioning scenarios and it can help to prevent the potential accidents as delivering the exact work procedures to workers and to help workers to perform decommissioning work skillfully. It's necessary to measure the radioactive contamination in the highly contaminated facilities such as hot-cells or glove-boxes to be decommissioned for decommissioning planning. These facilities are very high radiation level, so it is difficult to approach. In this case the detector system is preferable to separate the sensor and electronics, which have to locate in the facility outside to avoid the electric noise and worker's radiation exposure. In this project, we developed the remote detection system for radiation measurement and signal transmission in the high radiation area. In order to minimize worker's exposure when decommissioning highly activated nuclear facilities, it is necessary to develop the remote handling tool to perform the dismantling work remotely. Especially, since cutting, measuring, and decontamination works should be performed remotely in the highly activated area, the remote handling tool for conducting these works should be developed. Therefore, the multi-purpose dismantling machine that can measuring dose, facility cutting, and remote handling for maintenance and decommissioning of highly activated facility should be needed

[en] The power system and cooling system for 20MeV low energy proton accelerator have been developed, tested and operated. And basic studies on the superconducting RF technology were carried out. The requirements of the high voltage power supply are 100kV, 20A, < 20J and semiconductor opening switch was used to limit the load arc energy. The Mod. anode power supply consisted of voltage dividing resistors and tetrode. The cooling capacity of the cooling system is 2MW. A 3 way valve was used to control the temperature of the cooling water. The test results of the power system and cooling system showed that the both systems satisfied the requirements and have been operated for 20MeV accelerator. Up to now, the total electrical power consumption of RFQ and DTL power supply are 53,000kWh, 30,000kWh respectively, and the total operation time of the RFQ and DTL cooling system are 520 hours, 220 hours respectively. The study on the power system for SCRF showed that the superconducting accelerator has an advantage over warm linac when the operating rate per year is above 10%, and with this data, comparisons depending on linac configuration and RF source layout were performed. In addition, studies on the single cell cavity and power coupler were carried out which will be used as basic data for the development of superconducting accelerator

[en] Recently, Korea has launched the world's top class heavy ion accelerator project, and for the machine it is necessary to develop related physic and technology for the high charge state beam including a 28 GHz superconducting ECR ion source. This study is prepared to support this activity including transport of TRIAC(Tokai Radioactive Accelerator Complex) and development of ECR ion source technology. TRIAC, which was developed by KEK Japan, was a one of a heavy ion accelerator. This work is especially necessary to support the originality of the experiments with the heavy ion accelerator in the future in Korea. New accelerator DIAC will be used to support Korea Rare Isotope Accelerator project, and also will be applied to other heavy ion beam physics and engineering research. Based on the conceptual design results of the 28 GHz superconducting ECR ion source, an engineering design and construction will be started from next fiscal year