| 摘要 |
<p>The rod has a metal sleeve; and the pellet is made of a material based on at least one fissile or fertile cpd. The pellet has a symmetrical barrel shape with a dia. (D5) at the middle of its height which is larger than the dia. (D6) at each end of the pellet. The pref. pellet consists of two truncated cones tapering towards the ends of the barrel, the cones being inclined at an angle (alpha) of 0.2-3 deg. w.r.t. the axis of the barrel. In a pref. modification, the barrel may have a cylindrical middle zone. Conventional pellets have a cylindrical shape, which distorts in the metal sleeve when used in the reactor core, and can crack the sleeve. The invention provides a pellet profile which distorts much more slowly, so the life of fuel rods is increased.</p> |
