Abstract: Sintered nuclear fuel bodies are manufactured by pressing a powder of UO.sub.2 containing 1-20 percent by weight Gd.sub.2 O.sub.3 and up to 20 percent by weight U.sub.3 O.sub.8 into a pressed body and sintering the pressed body, the Gd.sub.2 O.sub.3 at least partly consisting of monoclinic Gd.sub.2 O.sub.3. The monoclinic Gd.sub.2 O.sub.3 used can be manufactured by heat treatment of cubic Gd.sub.2 O.sub.3 at a temperature of at least 1250.degree. C. By employing monoclinic Gd.sub.2 O.sub.3 a considerably increased homogeneity with respect to solid solution of gadolinium in the UO.sub.2 structure is obtained. Particularly favorable results are obtained if the sintering is carried out in a sintering atmosphere which, at 1750.degree. C., has an oxygen partial pressure which is higher than 10.sup.-7 atm.

Abstract: An absorber plate designed to be located in a gap between fuel rod bundles in the core of a boiling water reactor is manufactured by anchoring a burnable neutron-absorbing material to at least one sheet by spraying the absorbing material in finely-divided melted or plastically-formable state onto the sheet, to create a solidified layer of the absorbing material, and by enclosing the absorbing material, thus anchored, in a protective casing.