Coarse-node computations with an adaptive node structure

The analysis with COMMIX of liquid-metal reactor (LMR) intermediate heat exchanger (IHX) transients characterized by low flows, especially imbalanced low flows, shows that if a coarse-node structure is used, the predicted temperatures are significantly different than those given by a fine-node structure. If a fine-node structure is used for problems that involve a large part of the plant, the computation time becomes excessive. A method of adaptive node structure that resolves such difficulties was presented earlier. This paper presents an improved version of this method. At this stage, this version has been applied only to one-dimensional problems