| 摘要 |
1. A process for operating a light water moderated and cooled nuclear reactor having a core consisting of fuel assemblies immersed in the moderated and cooling light water and which are at least partially replaced at predetermined intervals, corresponding to operating cycles of the reactor, wherein : during a first phase of the cycle, neutron energy spectrum variation bars which are regularly distributed in the core are maintained within the core for decreasing the ratio between the volume of moderator and the volume of fissile material in the core and for shifting the neutron energy spectrum towards higher energies and, during a second phase of the cycle, the spectrum variation bars are withdrawn for operating with a lower energy spectrum, characterized in that the spectrum variation bars contain fertile material which absorbs the slow or low energy neutrons for locally obtaining an increased shift of the neutron energy spectrum towards higher energies resulting in an increased conversion of fertile fuel material into fissile fuel material. |
