Measurement of Material Buckling of U-H2O Assembly

Abstract

A method of determining the material buckling of a cylindrical subcritical assembly is described. The new technique is an improved "flux shape" method that is based upon the complete orthogonal· ity of the Bessel function. To obtain sufficient accuracy, a scintillation detector with a very thin scintillator has been used. The result indicates that the present method yields a value of buckling free from higher harmonics and end effects, with a standard deviation of 3.0% under centric point source condition. The buckling obtained is -(7.08±0.23) X w-This lies between the values measured by conventional "flux shape" and "variable loading" methods, which are amenable to un· wanted effects.