LAUSR

Abstract Based on the idea of uncertainty propagation, global relative covariance matrices of few-group cross sections representing the uncertainties propagated from the basic nuclear data and manufacturing tolerance were built by using statistical method. Then the twice critical calculation coupled with efficient sampling (TCCES) method based on the innovative efficient sampling method of Latin hypercube sampling combined with singular value decomposition conversion (LHS-SVDC) was chosen to quantify the CRW uncertainty. A simplified Mini-core model in a 3 × 3 checker board pattern based on the CASL benchmark and the steady-state BEAVRS benchmark were chosen for the CRW uncertainty analysis. For the purpose of verifying the modeling and simulation, lattice calculations, keff calculation and control rod worth calculation for different types of control rod banks were all performed and compared with the published results obtained by other MC codes and deterministic method codes. Finally, the uncertainties of the differential and integral CRW for different types of control rod banks were quantified and the contributions of nuclear data and manufacturing tolerance were also identified.