Orchid® Core Builder (Orchid® CB) is L3 MAPPS’ graphic tool permitting easy creation and validation of cycle-specific fuel data, used by L3 MAPPS’ reactor core model. Orchid® CB provides 2-D and 3-D graphics to fully validate and document the input fuel data and the output model, together with user-defined test reports. Orchid® CB incorporates the Nodal Expansion Method (NEM) to produce advanced reactor kinetics models. The core neutronics model is based on the fundamental equations of time-dependent neutron diffusion theory. Diffusion equations are solved at each time step using reactor design code techniques. The models developed with Orchid® CB are true two-group, three-dimensional, multi-nodal, fully dynamic models computing in real-time the flux for each node at each time step.

More than a high-fidelity core neutronics model, Orchid® CB provides real-time feedback on simulated neutronic parameters through its unified user-friendly graphical interface. Users can select specific fuel assemblies and obtain axial distributions of the following parameters:

• Power
• Fuel temperature
• Moderator temperature
• Moderator density
• Moderator void
• Xenon concentration
• Samarium concentration

Users also can view and rotate a dynamic three-dimensional image of those same parameters at different axial levels. This way, the user to visualize on a 3-D flux map, in real-time, the core dynamics such as the effect of dropping a rod.

Features

• NEM-based simulation
• Automated fuel data conversion for multiple fuel codes
• Capability of fine tuning fuel data
• Graphical user interface showing core neutronics parameters in real time
• 2-D and 3-D flux maps
• Automated reactor model initialization
• Automated updating of initial conditions following burn-up and/or fuel cycle updates
• Considers power history