Comparison of RELAP5 and CATHARE predictions in Simulation of Natural Circulation in a Test Facility

RELAP 5 and CATHARE are the two best estimate codes used for design and safety analysis of Light water reactors. Although the basic models for solving the conservation equations are same for both the codes however the constitutive relationships which are empirical models may be different in both the codes, which can have significant influence on the predictions of the different phenomenon involved in water cooled reactors. Natural circulation is extensively used as the mode of heat removal in many reactors not only during the accidental conditions but also during the normal power operation An attempt has been made here to compare the predictions of natural circulation behavior of an experimental test facility using both the codes. The steady state and transient natural circulation flow behavior of the test facility for power raising process has been predicted by the codes and compared with each other as well as with the experimental data available. (author)