Evaluation of Prediction Error Reduction for Breeding Ratio by Bias Factor Method with Use of Experimental Result on Basic Reaction Rate Ratio

Abstract

The evaluation technique of prediction error reduction by the bias factor method is extended to the cases where the neutronic property of a target core is related to the properties in critical experiments. This extended procedure can utilize several experimental results, although the conventional procedure utilizes only one experimental result. Calculations were performed where the measured property is the reaction rate ratio of 238U capture to 239Pu fission (C28/F49) in FCA XXII-1 cores and the target core property is C28/F49 or breeding ratio in a breeding light water reactor (BLWR). The prediction error of the breeding ratio in BLWR is reduced from 0.57 to 0.43%, whereas the error of C28/F49 is reduced from 0.72 to 0.19%.

KEYWORDS:

• prediction error
• breeding ratio
• bias factor method
• reaction rate ratio
• sensitivity coefficient