Accuracy Evaluation of Pin Exposure Calculations in Current LWR Core Design Codes (Phase 2)

摘要

There improved analysis techniques provided higherrnconfidence in the reference solution of MCNP/ORIGENSrncoupled code system Comparison between thernMCNP/ORIGEN-S calculation and the CASMO-rncalculation reveals a fundamental deviation associatedrnwith the depletion calculation in the cross sectionrngeneration process of the current LWR design codes. Asrnthe burnup increases, the pin exposure difference tends tornpropagate.rnThe pin powers calculated with MCNP are subjectrnto standard deviations. Currently, the average standardrndeviation of the pin powers of this model is about % andrnpropagates with burnup. The propagation of uncertaintyrnwith burnup in the coupled Monte Carlo/depletionrncalculation still need to be addressed. Eventually, therndetail x fuel assembly array model with improvedrnanalysis techniques can be expanded to a bigger nxnrnassembly array model (min-core) with more heterogeneityrnto resemble a typical BWR core.