Zr계 합금의 중성자 조사에 따른 미세조직 변화

초록

For evaluation of nuclear fuel cladding applicability, experimental Zr-base alloys with Nb, Sn and Mo additions were neutron irradiated in HANARO at KAERI up to a fluence of 8.85x1023 n/m2 at 290-320°C. Transmission electron microscopy was employed to examine the microstructural characteristics of defects produced by the neutron irradiation. Regardless of the chemical compositions, the alloys studied showed a-type dislocation loops as a result of the irradiation, which were less than 10nm in diameter. A preferential distribution of the defects occurred on the prism planes with a feature of a directional alignment. Mo-addition as an alloying element suppressed the defect production rate in the alloys by reducing the size and the number density of defects. Under the irradiation condition studied, second phase particles were stable against amorphization. The present work supports the feasibility of the experimental Zr-1Nb-1Sn-0.1Fe-0.5Mo alloy for the nuclear application.