Analysis of root-mean-square temperature noise in FBR wire-spacered assembly with local blockage

Abstract We have developed a method to calculate the three-dimensional distribution of root-mean-square (RMS) of temperature noise in a fuel assembly with a bundle region and an upper plenum region. In the bundle region the subchannel method is adopted. In the plenum region the finite difference method is adopted. The precision of this method has been verified by comparing the calculated values of temperature and RMS of temperature noise with experimental data obtained from a sodium loop test experiment using a wire-spacered fuel assembly with and without a local blockage. Furthermore, we have investigated the effects of heating conditions on temperature and temperature noise.