Computer aided nuclear reactor modeling

Abstract

Nuclear reactor modeling is an important activity that lets us analyze existing as well as proposed systems for safety, correct operation, etc. The quality of a analysis is directly proportional to the quality of the model used. In this work we look at a thermal hydraulic analysis program, CENTAR, and present the problems encountered in the tra ditional modeling process. These problems are the difficulty the modeler faces to cope with the model size, complexity, rigidity, correctness, long modeling time, and large resource demand for testing. The problems are mainly due to three factors: lack of automation, lack of model abstraction (the CENTAR model is too distant from the physical system), and batch nature of modeling (problems uncovered only after model has been sent to CENTAR). We then present an interactive, graphical, icon based modeling program, Alpha, that lets the user "draw" the model on screen and translates it into a syn tactically correct CENTAR input model which is also free of most common semantic errors. Alpha overcomes the modeling problems of traditional modeling practice by providing automation of modeling, by providing a more abstract model ("Alpha model") that is closer to the physical system and can be translated to a CENTAR model), and by interacting with the user and providing feedback by checking for errors and advising corrections. The architecture of Alpha is presented with its constituent libraries explained in their internal working and external interactions with other libraries.