Abstract
The concept of hot chonnel factor or peaking factor is generally used in the thermal design of reactor cores. The present poper defines a hot spot factor, and presents a method of calculding this factor. The uncertainties in the design variobles are classified. Statistical and cumulative treatments of the hot spot factor are discussed. Then, the method of calculating the hot spot factor is obtained for the case where the design variable does not agree wirh the mean value of the stochstic variable, and it is verified that a procedure analogous to the normal statistical treatment is applicable. As one example, the hot spot factor for a fuel element of pellets in a cladding tube is calculated by the statistical technique. In this case, a correction is necessary for the index of the variable; this correction factor is obtained for the case of a sine or cosine power distribution in the axial direction.
