Fuel assembly, nuclear power plant and nuclear power plant operation method

The present invention provides a fuel assembly, a nuclear power plant and a method of operating the nuclear power plant for safely and reliably removing radioactive ions and insoluble solid ingredients (cruds) present in coolants in a nuclear power plant. Namely, as a first embodiment, the fuel assembly is adapted to have fuel rods and filter rods comprising means for capturing cruds and radioactive ions in coolants in the nuclear power plant. The cross section of the filter rod may be not greater than that of the fuel rod. As a second embodiment, the fuel assembly further comprises a water rod. The cross section of the filter rod may be not greater than that of the water rod. The capturing means is preferably an adsorbent comprising at least one of oxides of metals selected from the group consisting of Ti, V, Fe, Ni, Nb, Zr, Mo and W. With such a constitution, the capturing means of the filter rod captures cruds and radioactive ions in coolants. The method of the present invention can be applied to existent fuel assemblies. (I.S.)