Application of deterministic sampling methods for uncertainty quantification in manufacturing tolerances in neutron physics

摘要

In this work, an application of the deterministic sampling (DS) methodology for uncertainty quantification of manufacturing tolerances is assessed. The DS methodology is applied to eight benchmark cases, from two criticality safety benchmark series, extracted from the International Handbook of Evaluated Criticality Safety Benchmark Experiments (i.e., LCT-007 & LCT-039). The DS results are compared to two other sampling techniques: Random Sampling and Latin Hypercube Sampling. Ten input parameters such as isotopic composition of the fuel, geometry properties of the assembly, pitch array, etc. were considered. Only the multiplicative factor (k(eff)) was considered as output quantity. Evaluation of the k(eff) was obtained using the Monte Carlo code MCNP for the LCT-007 case, and the Serpent code for LCT-039.Results show very good agreement among all methodologies for the calculated k(eff) values and their corresponding uncertainties. The largest uncertainty difference with DS, compared to the reference values, is 46 pcm for LCT-007 and 9 pcm for LCT-039. The use of DS remarkably reduces the number of samples needed to perform an accurate uncertainty quantification (from thousands of samples down to a dozen).This study provides insights in the application of DS methodology in the neutron physics domain and showcases its benefits and limitations.