| 摘要 |
<p>A pressurised water nuclear reator has a number of low neutron- absorbing water displacer elements which can be inserted into and withdrawn from fuel assemblies of the reactor. A certain number of the fuel assemblies may also receive medium neutronabsorbing displacer elements. The elements are inserted into the fuel assemblies to reduce the vol. of water in the reactor core. The arrangement is used in a spectral shift reactor to reduce fuel costs and extend core lifetime. The medium elements give greater reactivity charge than the low absorbing elements, but can be arranged in clusters to give a smaller effect. By using different combinations, numerous reactivity levels can be achieved in the core.</p> |
