Computer simulation of the three-dimensional temperature history in a multipass filled weldment was attempted by modifying a transient heat transfer code, HEATING5. The model includes temperature-dependent physical parameters, radiation and convection heat losses, turbulent and laminar convection in the molten pool, and variable arc velocity, intensity, and weld geometry. The model requires approximately 28 CPU min to simulate one second of welding. 15 figures, 8 tables.

An evaluation of the proposed design for the first blanket zone of the DEMO fusion device at Oak Ridge National Laboratory was performed by determining temperature profiles for a number of possible design geometries. Only one design configuration was acceptable and further evaluated by determining two-dimensional steady state temperature and tritium concentration profiles within the unit. The transient response of this design during periods of plasma shutdown was also determined to evaluate the maximum and minimum possible stress on the stainless steel cooling tubes. The preponderance of unacceptable designs of those investigated led to the recommendation that future studies consider only modules less than 25 cm thick and coolant temperature rises less than 67/sup 0/C.