[en] A hazardous material treatment system utilizing photochemical reaction is a new technology which does not produce any secondary pollutants after dissolving treatment because it is activated by solar photo energy. Photo catalysis reaction apparatus using photo catalytic reaction of TiO₂ was fabricated and installed to food waste treatment system for removing bad smell during treatment of food waste. Evolved gas was analysed by gas chromatograph and active carbon fiber sheet and yarn were used as adsorption media for photo catalysis in order to increase the effectiveness of filter system. (author)

[en] Since the high-temperature superconductor of oxide type was founded in 1986, many researches and efforts have been performed for finding its application field. First of all, the improvement of critical current property as well as the mechanical property is important for the application. The improvement of the critical current can be achieved by forming the nano-size defect working as a flux pinning center inside the superconductor. The nano-size defect can be effectively formed by using neutron irradiation of HANARO in KAERI. All properties of most of materials after irradiation become bad. On the contrary, the critical current property of the superconductor is largely improved after irradiation. In this report, the literature survey on the neutron and (heavy) ion irradiation of the superconductor was summarized, and the emission property of superconductor was evaluated using neutron flux in HANARO

[en] Based on our own ceramic fabrication technologies, the development of SiC based materials and sub-scale mock-up will be carried out by developing the following technologies for high temperature ceramic process heat exchanger and intermediate heat exchanger, which will be applied in the operating temperature ranges of 400-900 .deg. C : - Optimum fabrication technologies for high temperature compact heat exchanger - Design, machining and bonding of heat exchanger unit cell - Analysis of corrosion and long term degradation behaviors of SiC based ceramics in a high temperature sulfuric acid - Analysis and simulation of heat transfer and stress distribution of heat exchanger mock-up · The unit heat transfer plate of the compact SiC heat exchanger with a density of more 98% TD and the size of 100 x 100 mm was successfully fabricated and related technologies such as compaction, reaction sintering, machining were established. · The fabrication technologies such as design, stacking, sinter-forging, bonding of the sub-scale mock-up of a plate-type SiC heat exchanger were also developed. And the sub-scaled mock-up heat exchanger with a size of 100 x 100 x 60 mm were successfully fabricated. · The long term corrosion test in sulfuric acid were carried out for 200 days. The amounts of the weight changes were less than 0.3 g/cm². The tendency of the weigh gain from corrosion was saturated after 100 days. · The development of the bonding technologies between SiC plates were also performed. Various bonding technologies like forming bonding, pyro bonding and sinter bonding were compared. Based on analyses of the strength, microstructures and fracture behaviors, the sinter bonding was considered as a best candidate process. · For sinter bonding, a feasibility study on a new bonding technology using nano SiC powder and hot pressing were being performing

[en] There are some ceramic materials being used in the nuclear energy such as nuclear fuel, coolant pump seals, tritium breeder materials, a high temperature absorber, and the solid electrolyte for recovering tritium. In addition, lots of researches recently have been conducted on the development of highly functional ceramics such as highly efficient shielding materials, functional graded materials and radioactive isotopes-separating materials. Therefore, one of the objectives of this project is to develop ultra-fine and pure powder manufacturing technology. Tritium breeder materials, LiAlO₂, Li₂ZrO₃ and Li₂TiO₃ were made with a combustion process of mixed fuels that is developed indigenously in this project. Additionally, this study also focused on the development of promising low temperature electrolytes of ceria. By using the ceria powder made by the combustion process of GNP was investigated their sinterability and the electrolytic characteristics. (author). 167 refs., 74 tabs., 91 figs

[en] In order to operate the nuclear system at high temperatures, core materials with a good irradiation resistance at high temperatures must be developed. SiC composite is one of candidates for high temperature structural materials. Among several fabrication processes, the PIP process includes the curing and pyrolysis process. Generally, the thermal oxidation curing method has some disadvantages; difficulty in the control of oxygen contents and volatilization of many constituents. To overcome these disadvantages and reduce the process time, a new and improved method like the beam curing process has been proposed as one of the effective methods for the fabrication of SiC composite. In this study, the electron beam curing method in the PIP process was optimized to develop SiCf/SiC composite with low oxygen contents. Using the electron beam curing method with full doses of 2∼10 MGy and the pyrolysis process at 1300∼1400 .deg. C, composite with the oxygen content of less than 1 wt% could be obtained. Additionally, if the slurry impregnation and curing/pyrolysis processes were repeated several times, dense composite could be produced

[en] The studies have shown that crystalline ceramics are better hosts compared to glass matrix due to their superior chemical durability and higher density. Synroc, atitanate based ceramic containing hollandite, perovskite, zirconolite and rutile phases, is considered as the most effective and durable means of immobilizing various forms of high-level radioactive wastes for disposal. The oxide-route (solid state reaction) is the most known process to form a solid solution. However, the synthesis of nano crystalline powders using an exothermic redox reaction between nitrate and organics in an aqueous solution has been reported. In this study, the SCS and oxide route was compared to form the solid solution of Synroc-B nano crystalline powders. TEM mapping results on combustion synthesized powder has been confirmed that it contains the fully solid solution occurred on constituent elements for the composition Synroc-B in all powders. TEM analyses also show that particle size is very homogeneous and evenly distributed in 20257-258⁓30 nm. By a combustion synthesis method Synroc-B nano powder of a multi-phase is could be produced in a relatively easy way. Solidified in the Synroc-B complex, radioactive elements contained in waste can easily be immobilized

[en] A State of Art Report on Study of ZrC coating methods for TRISO coating process has been reviewed. The fabrication and characteristics of coated ZrC layer instead of SiC layer are introduced and mechanism and parameters for deposition process are described. Additionally, the thermal dynamic properties of chemical species with temperature were investigated using SOGASMIX-PV program

[en] As a part of a project of high temperature materials characterization and advanced materials development, we are establishing integrated database systems for activation of R and D nuclear materials. The database constructions using the raw data produced from research experiment can increase the applications of final results. Also, we can easily obtain the basic and raw data from database system when we have plan the new and creative experiment and can produce high quality results by compare the previous data. In this present, the DBs of seven kinds of materials property were developed by internet method using Oracle 9i and JSP (Java Server Pages) tools

[en] One of the promising methods in the hydrogen production is nuclear technologies based on the use of VHTR. This reactors are being under development should provide a core-output He temperature at a level of 1000 .deg. C. To realize this requirement, the present R and D of materials programs on VHTR are emphasized on development of metallic materials for the core as well as on advanced fuel development and tests. The development of advanced coated fuel particles with the use of ZrC instead of SiC is needed because SiC has good properties for a TRISO fuel, however, it gradually loses its mechanical integrity at very high temperatures, above 1700 .deg. C, by a thermal dissociation. Zirconium carbide (ZrC) is well known as a refractory and chemically stable compound, with a melting point of 3540 .deg. C. Therefore, ZrC could have a higher resistance to a chemical attack by fission product elements such as Pd and Cs and it is reported that ZrC is a better barrier for Cs than SiC by post-irradiation heating experiments. For this reason, ZrC has been focused on for replacing the material of the SiC layer in the TRISO coating layers, and many researchers have reported ZrC coating methods with various Zr-salts-CH₄ as a source material for fluidized bed chemical vapor deposition (FBCVD) equipment. Among these methods, a chloride process is a preferred process because of its less hazardous and better stoichiometric composition than the other processes. KAERI has been developing ZrC-coated fuel particles as an advanced particle. In this study, coating technique of ZrC on the surface of the ZrO₂ particle by chloride process has been developed. The purpose of the present work is to investigate the coating conditions and deposition parameters of ZrC coatings on their composition and some characteristics

[en] A feasibility study on the coating process of ZrC for the TRISO nuclear fuel and applications of SiC as high temperature materials for the core components has performed to develop the fabrication process for the advanced ZrC TRISO fuels and the high temperature structural components for VHTR, respectively. In the case of ZrC coating, studies were focused on the comparisons of the developed coating processes for screening of our technology, the evaluations of the reactions parameters for a ZrC deposition by the thermodynamic calculations and the preliminary coating experiments by the chloride process. With relate to SiC ceramics, our interesting items are as followings; an analysis of applications and specifications of the SiC components and collections of the SiC properties and establishments of data base. For these purposes, applications of SiC ceramics for the GEN-IV related components as well as the fusion reactor related ones were reviewed. Additionally, the on-going activities with related to the ZrC clad and the SiC composites discussed in the VHTR GIF-PMB, were reviewed to make the further research plans at the section 1 in chapter 3