SAS2A LMFBR accident-analysis computer code

The SAS2A code is an integrated accident-analysis code that calculates the initial consequences of an accident, from steady-state, preaccident conditions up to the point of large-scale fuel motion or disassembly. The code starts with a steady-state thermal-hydraulics calculation to initialize the fuel temperatures, fuel and cladding thermal expansion, and the coolant temperatures, pressures, and flow rates. The code then starts a user-specified perturbation in power level or flow rate, and calculates transient temperatures in fuel, cladding, and coolant. Transient stresses and strains in the fuel and cladding, and transient coolant pressures and flow rates are also calculated, as well as sodium boiling, film dryout, cladding melting, and fuel melting. Neutron kinetics is handled with a point-kinetics approximation, with reactivity feedback from the Doppler effect, fuel thermal expansion, sodium voiding, user-supplied table-lookup fuel slumping, and scram reactivity, as well as user-specified programmed reactivity. 18 references. (U.S.)