Development of sensitivity analysis capabilities of generalized responses to nuclear data in Monte Carlo code RMC

• A capability of computing generalized sensitivity coefficients was developed in the Reactor Monte Carlo code (RMC).
• The superhistory algorithm was implemented to reduce memory consumption for generalized sensitivity analysis.
• The generalized sensitivity coefficients computed by RMC agree well with SERPENT2 and TSUNAMI-1D.

Capabilities for nuclear data sensitivity and uncertainty analysis have been recently implemented in numerous continuous-energy Monte Carlo codes, including the Reactor Monte Carlo (RMC) code. Previous work developed the capability for RMC of computing sensitivity coefficients of the effective multiplication factor and related uncertainties, due to nuclear data. In this work, such capability was extended to generalized responses in the form of ratios of linear response functions of the forward flux based on the collision history-based approach as implemented in SERPENT2. The superhistory algorithm was also adopted in RMC to reduce memory consumption for generalized sensitivity calculations. These new capabilities of RMC were verified by comparing results of TSUNAMI-1D in SCALE6.1 code package, and SERPENT2 through Jezebel, Flattop and the UAM TMI PWR pin cell benchmark problems.