| 摘要 |
PURPOSE:To form the coarser grains of uranium dioxide fuel pellets by operating the uranium dioxide fuel pellets freshly loaded into a power reactor continuously for >=5 days at >=400W/cm linear output. CONSTITUTION:The fresh fuel loaded into the reactor is held for at least >=5 days in the state of increasing the output to >=400W/cm linear output. The temp. in the central part of the fuel rises to about 1,600 deg.C in this treatment and the grain size of the fuel pellets increases to about 4 times the initial grain size. The coarser grains are, therefore, formed without using additives or changing a sintering method. The amt. of the fission product gas is thus decreased. |
