| 摘要 |
<p>The reactor comprises guide tubes (14) some of which can successively receive, when the reactor is successively reloaded, either absorbing pencils or spectrum-shifting pencils (22). To avoid vibrations and impacts of spectrum-shifting pencils in the guide tubes, these pencils (22) comprise radial projections (42) which can be formed directly on the body of the pencil, on a sleeve added onto the body of the pencil or in the form of a wire wound helically onto the body of the pencil. In addition, in the case of a pencil of fertile type, the internal pressure of helium and the thermal insulation of the material of which the sheath is made are chosen so that the clearance between the pellets and the sheath is quickly taken up at the beginning of a cycle. <IMAGE></p> |
