Many channels are employed for a whole-core representation. The transient fuel and cladding mechanical behavior model, integrated with fission product production, release, and transport models, provides prediction of fuel element dimensional changes and the margin to cladding failure. Thermal-hydraulic models of the reactor and intermediate coolant loops analyze heat removal from both forced and natural circulation, with transient performance of loop components including pumps, heat exchangers, valves, and plena. Reactivity effects from reactor structural temperature changes yielding radial core expansion are modeled. Changes in reactor power level are computed with point kinetics.
Numerical models used in the code modules range from semi-implicit to explicit.
The number of channels is limited only by the size of the computer memory. Earlier versions have been exported to domestic U.S. DOE contractors and to research organizations in foreign countries. System dependent routines may be supplied for dynamic memory allocation, timing, and system and user identification.