| 학회 | 한국재료학회 |
| 학술대회 | 2005년 가을 (11/10 ~ 11/11, 한양대학교) |
| 권호 | 11권 2호 |
| 발표분야 | 에너지환경재료 |
| 제목 | 핵분열생성물 타겟 제조 |
| 초록 | I. INTRODUCTION A transmutation technology has been developed to reduce the long-term radiological toxicity of LWR spent fuel due to the long-lived radioactive nuclides such as Pu, MA (Minor Actinide), and some fission products. Among the transmutation technologies, an accelerator driven sub-critical transmutation system named HYPER (HYbrid Power Extraction Reactor) is being developed within the framework of the national mid- and long-term nuclear research plan. The HYPER core has been designed to have a hybrid neutron energy spectrum: a fast neutron spectrum for the TRU burning zone and a highly localized thermal neutron spectrum for the Tc-99 and I-129 burning zone. A hexagonal type array was employed to design a compact core pitch-to-diameter and to achieve a hard neutron energy spectrum for TRU burning. The preliminary results of the basic material studies have shown that a pure metallic form is the most desirable one for Tc-99: a fabrication route for casting the Technetium metal has been developed and irradiation experiments did not show any evidence of the swelling or disintegration of the metal. On the other hand, an elemental form is found to be unacceptable for Iodine because of its volatility and chemical reactivity. Thus, metal iodides are being considered. Sodium iodide (NaI) and calcium iodide(CaI2) are the desirable forms. Sodium iodide is expected to have melting problems when the sodium is liberated from iodide due to the transmutation. Therefore, we fabricated a target consisted of NaI(CaI2) and Ru instead of Tc-99 with HT9 cladding material. Also, the interactions among the materials were observed at elevated temperature in this study. II. EXPERIMENTAL PROCEDURE A simulated target composed of HT9 cladding material, Ru, CaI2, NaI and ZrH2 were prepared to investigate the compositional and structural changes of the solid state reaction layers formed among the interfaces. Tc-99 was replaced by Ru, and sodium iodide(NaI) and calcium iodide(CaI2) were used instead of Iodine because of difficulties in handling and fabrication. The powders of CaI2, NaI and ZrH2 were cold pressed to pellet shape with the diameter size of 6mm, followed by heat treatment. Sample of Ru was arc-melted with pellet shape owing to high melting temperature of Ru, 2250oC, and also HT9 sample with 6mm diameter was fabricated. The diffusion couples assembling ZrH2/CaI2(NaI)/Ru/HT9 were compressed in a stainless steel holder. The inner surface of the holder was lined with tantalum foils to prevent the couple from reacting with the holder. Each of the diffusion couple assemblies was encapsulated in a quartz tube under an atmosphere of Ar under 1atm, and annealed isothermally at 600oC for 100hrs. After annealing, the capsule was taken out of the furnace and quickly broken in a water bath so that the diffusion couple could be quenched rapidly. Each layer in the annealed couple was separated respectively in the middle of taking away contact between holder and annealed layer. The annealed couple was planned to cut perpendicularly to the interface, instead, the surfaces of each layer were investigated on scanning electron microscope. |
| 저자 | 이봉상1, 신민재2, 송태영1 |
| 소속 | 1한국원자력(연), 2한국기계(연) |
| 키워드 | fission product; interfacial reaction |
