Comet™/Comet Plus™

Advanced reactor kinetics models

L3 MAPPS’ Comet™ and Comet Plus™ are advanced models for the simulation of reactor neutron kinetics based on a rigorous application of first principle physics and advanced numerical techniques. The models have been installed worldwide on numerous simulators currently certified for training.

Comet, primarily applied to the simulation of heavy water reactors (PHWRs), solves diffusion equations by using the Mesh-Centered Finite Difference (MCFD) method modified by the application of the Generalized Equivalence Theory in the calculation of homogenized parameters.

Comet Plus, used for simulating light water reactors (LWRs) and gas-cooled reactors (AGRs), solves the diffusion equations by using the Nodal Expansion Method (NEM). The NEM represents the flux by a fourth-order polynomial and yields unprecedented accuracy.
Both Comet and Comet Plus are true three-dimensional models. A minimum of one radial node per fuel assembly/channel is used. The neutron diffusion equations are solved at each node at each time step without relying on approximate methods based on a space-time factorization


Advanced Steam Supply System Model

L3 MAPPS’ advanced thermal-hydraulic model (ANTHEM™) is based on a rigorous application of the equations of mass, momentum, and energy conservation and implicit numerical techniques. ANTHEM has been successfully installed and validated on numerous simulators and simulator upgrades currently certified for training.

Severe Accident Simulation

Modular Accident Analysis Program (MAAP) on Real-time Simulators

L3 MAPPS can address your severe accident simulation needs. The L3 MAPPS solution is backed by proven results on full scope real-time simulators.