APEX: an efficient and fast-running simulator for multi-cycle core analysis

Veracity Nuclear has developed an efficient, fast-running three-dimensional simulator for multicycle fuel and core analysis. APEX is a physics-based surrogate model for the high-fidelity VERA core simulator, accurately representing objective functions and constraints for fuel cycle optimization problems. APEX utilizes QPANDA methods for the neutronics solution, ANTS for the subchannel thermal-hydraulics solution, and MPACT-based lattice cross sections. VERA-based discontinuity factors are also used in regions such as the reflector interface. The APEX nodal solution is robust for core analysis problems in full, half, quarter, and eighth core geometries, as well as four-node-per-assembly, one-node-per-assembly, and pin-by-pin geometries.