Documentation of SPECTROM-55: A finite element thermohydrogeological analysis program

SPECTROM-55 is a finite element computer program for analyses of coupled heat and fluid transfer through fully saturated porous media. The code is part of the SPECTROM (Special Purpose Engineering Codes for Thermal/ROck Mechanics) series of special purpose finite element programs, that address the many unique rock mechanics problems resulting from storage of radioactive waste in geologic formations. This document presents the theoretical basis for the mathematical model, the finite element formulation of the problem, and a description of the input data for the program along with details about program support and continuing documentation. The program is especially suited for analyses of the regional hydrogeology in the vicinity of a heat-generating nuclear waste repository. These applications typically involved forced and free convection in a ground-water flow system. The program provides transient or steady-state temperatures, pressures, and fluid velocities resulting from the application of a variety of initial and boundary conditions to bodies with complicated shapes. The boundary conditions include constant heat and fluid fluxes, convective heat transfer, constant temperature, and constant pressure. Initial temperatures and pressures can be specified. Composite systems of anisotropic materials, such as geologic strata, can be defined in either planar or axisymmetric configurations. Constant or varyingmore » volumetric heat generation, such as decaying heat generation from radioactive waste, can be specified.« less