Development and verification of PWR-core fuel management calculation code system NECP-Bamboo: Part I Bamboo-Lattice

PWR-core fuel management calculation code system named NECP-Bamboo is designed to meet different requirements from engineering application, scientific research and nuclear force education simultaneously. In its two-dimensional lattice calculation code Bamboo-Lattice, the one-step direct heterogeneous calculation scheme based on fine-group structure is employed. A series of approximations were eliminated, including the empirical experience based nuclear depletion data library compression, the averaged fission spectrum, the equivalence resonance theory, the pin-cell homogenized lattice calculation, the combined neutron capture energy release, the linear microscopic reaction rate for burnable absorber, and etc. Numerical verification results from single fuel pin-cell, single fuel assembly, multiple assembly and two-dimensional BEAVRS whole-core calculations indicate its good accuracy.