Calculational method error correlation effect in data adjustment for large LMFBFs [liquid metal fast breeder reactors]

The analysis of JUPITER experiments, in a cooperative effort between the United States and Japan using the zero-power plutonium reactor (ZPPR), showed a discrepancy for the ratio of calculated experimental (C/E) values of control rod worth. The C/E value at the core edge was larger by ∼12% than that at the core center. This discrepancy has a strong effect on the design of control rods. To reduce the discrepancy, many effort have been made from the calculational point of view; however, a drastic improvement has not been achieved. The purpose of this paper is to clarify that the discrepancy is drastically improved by the cross-section adjustment if we consider the cross correlation between the calculational method's errors for individual control rods