Uncertainty Analysis of Benchmark Experiments using MCBEND

Uncertainty Analysis of Benchmark Experiments using MCBENDSteve CHUCAS, Malcolm GRIMSTONE and Christopher DEANAEA Technology, Winfrith Technology Centre, Dorchester, Dorset DT2 8DH, UKDifferences between measurement and calculation for shielding benchmark experiments can arise from uncertainties in anumber of areas including nuclear data, radiation transport modelling, source specification, geometry modelling,measurement, and calculation statistics. In order to understand the significance of these differences, detailed sensitivityanalysis of these various uncertainties is required. This is of particular importance when considering the requirements fornuclear data improvements aimed at providing better agreement between calculation and measurement.As part of a programme of validation activity associated with the international JEFF data project, the Monte Carlo codeMCBEND has been used to analyse a range of benchmark experiments using JEF-2.2 based nuclear data together withmodern dosimetry data.This paper describes the detailed uncertainty analyses that have been performed for the following Winfrith materialbenchmark experiments: graphite, water, iron, graphite/steel and steel/water. Conclusions are reported and compared withcalculations using other nuclear data libraries. In addition, the effect that nuclear data uncertainties have on the calculatedresults is discussed by making use of the data adjustment code DATAK. Requirements for further nuclear data ...