VALIDATION OF CATHARE CODE ON THE 3D ROSA-LSTF PRESSURE VESSEL

摘要

The Commisariat a l'Energie Atomique et aux Energie Alternatives (CEA) is performing an important work aimed to validate the 3D modelling for the CATHARE code since the necessity to better simulate the 3D effects observed during nuclear accidents experimental tests. The attention is focused on the reactor vessel behaviour. This paper presents a first validation of the code on the Japanese ROSA-LSTF installation for the test 1 of the OECD/NEA ROSA2 project, an intermediate (17%) hot leg break. An important effort is focused on the 3D modelling of the entire ROSA-LSTF pressure vessel by one single 3D module. Starting from the previous ROSA integral system input deck, the 1D-0D components, generally employed to simulate the entire pressure vessel, are replaced by this single 3D module. A good agreement between calculated and experimental results is obtained and presented in this paper. Furthermore the comparison with the previous 1D-0D results shows a better consistency of the 3D approach with experimental data. It stresses out the importance to better investigate the 3D phenomena and the necessity to carry on with the 3D validation. The non-homogenous temperature distribution at the core exit, the influence of the particular 3D geometry and the presence of the CCFL phenomenon in the core support plate are dealt with in detail. A first validation of CATHARE 3D module is completed and a better understanding of 3D phenomena starting from code results is shown possible, complementary to the experimental evidence.