CATNET, Computer Aided Thermalhydraulic Network

Thermalhydraulic networks are usually one-D systems characterized by a relatively small number of fundamental components (pumps, valves, heat exchanger, etc.) connected by pipes and limited spatially by a defined number of boundary conditions (tanks, atmosphere, etc.). In the present application the network system has been simulated by the well known computer program RELAP5/mod3. Information concerning the network geometry, components behavior, initial and boundary conditions are usually supplied to the RELAP5 code using an ASCII input file by means of 'input cards'. CATNET is a graphical user interface that, under specific user guidelines which completely define its range of applicability, permits a very high level of standardization and simplification of the RELAP5/mod3 input deck development process as well as the output processing. The characteristics of the components (pipes, valves, pumps, etc.) defining the network system can be entered through CATNET. The CATNET interface is provided by special functions to compute form losses in the most typical bending and branching configurations. When the input of all system components is ready, CATNET is able to generate the RELAP5/mod3 input file. Finally, by means of CATNET, the RELAP5/mod3 code can be run and its output results can be transformed to an intuitive display for using the chosen measurement units. (authors)