Abstracts and Available Papers Presented at the
2002 International RERTR Meeting

Progress of U-Mo dispersion rod fuel qualification program in Korea

Chang-Kyu Kim, Ki-Hwan Kim, Jong-Man, Don-Bae Lee, Seuk-Jin Oh,
Kye-Hong Lee, Hee-Taek Chae, Dong-Sung Sohn

Korea Atomic Energy Research Institute
150 Dukjin-dong Yusong-ku, Taejon, 305-353, Korea

ABSTRACT

In the irradiation test performed in HANARO since June in 2001 relating to a qualification program of atomized U-Mo dispersion rod fuel for HANARO, a failure happened from the cleavage of cladding under the influence of the fuel meat swelling. An examination on the cross sections showed that the Al matrix of fuel meat at high power region had almost interacted with fuel particles. The depletion of the Al matrix deteriorated the thermal conductivity of fuel meat and resulted in the very high temperature around the center region of fuel meat. Swelling calculations using the Al matrix fractions of fuel meats showed a relatively good agreement with the measured swellings by immersion densities. The swelling in the failure region of about 15% does not seem to be enough to affect the rupture of the pure aluminum cladding. A failure reason could be attributed to the fabrication defects of the cladding. The next irradiation test for U-Mo dispersion rod fuels was planned and the fuel fabrication is under way. The loading density was changed from 6.0 g-U/cc to 4.5 g-U/cc and the smaller fuel meat diameter of 5.49 mm was chosen in the viewpoint of the centerline temperature of fuel meat to be lower than 200 °C. The next irradiation will include the various tests for the following rods; 1) a fuel rod containing U-Mo hollow cylinder, 2) two different particle size fuel rods to investigate the particle size effect, 3) a fuel rod coated with Ni to prevent corrosion, 3) a fuel rod added with poison material of Er₂O₃ relating to fuel life extension, 4) a fuel rod dispersed with U-9wt.Mo particles, 5) A U₃Si dispersion fuel rod for a reference. It is scheduled that the loading in HAHARO will be done around the end of November.  

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