ALARM-B1: a computer program for boiling water reactor blowdown analysis

The digital computer program ALARM-B1 written in FORTRAN-IV for FACOM 230-75 is for analyzing thermodynamic and thermal-hydraulic phenomena of BWR during a large break LOCA. The outputs are pressure, core inlet flow and enthalpy which affect core heat transfer during transients. In ALARM-B1, the heat transfer from core to coolant during transients is not calculated, but it is given as inputs. ALARM-B1 solves integral forms of fluid conservation and state equations for user-defined volumes (nodes) which are treated as one-dimensional homogeneous elements with interconnecting flow paths (junctions). The numbers of nodes and junctions and their initial fluid conditions are given as inputs. The program is of a variable dimension so there are no limits to the numbers of nodes and junctions. (auth.)