[en] The BWR Core Simulator is a static, three-dimensional coupled nuclear-thermal-hydraulic computer program representing the BWR core exclusive of the external flow loop. Provisions are made for fuel cycle and thermal limits calculations. The program is useful for detailed three-dimensional design and operational calculations of BWR neutron flux and power distributions and thermal performance as a function of control rod position, refueling pattern, coolant flow, reactor pressure, and other operational and design variables. A special power-exposure iteration option is available for target exposure distribution and cycle length predictions. The nuclear model consists of finite-differenced, coarse mesh, one group, static diffusion theory. Eigenvalue iteration yields the fundamental mode solution. This is coupled to static parallel channel thermal-hydraulics containing a modified Zuber-Findlay void-quality correlation. Pressure drop balancing yields the flow distribution. The mathematical models used in the program will be described in general terms. Detailed explanation of the use of this program for core design analysis is not included