Post-Test Analysis of the Bethsy Experiment 9.1b with ASTEC V1.2 Code for CESAR Thermal-Hydraulic Module Validation
Titre du congrès :International Conference "Nuclear Energy for New Europe 2006"
Ville du congrès :Portorose
Date du congrès :08/09/2006
The CESAR thermal-hydraulic module of ASTEC V1.2 code has been validated by means of the analysis of one experiment carried out in the Bethsy facility which simulates a French 900 MWe PWR reactor. The test under investigation is the loss-of-coolant accident 9.1b test (OECD ISP N°27) which consists in a 2" cold leg break, while the high pressure injection system is assumed to be unavailable.
Starting from a Bethsy nodalisation similar to the one employed in PWR reactor applications with the ASTEC code, the Bethsy 9.1b test has been analyzed in detail with CESAR. In order to reduce the discrepancies found between code results and test measurements, some nodalisation improvements have been identified and implemented in the original model by means of sensitivity studies.
In the present paper, the results of the code are presented in comparison with the experimental data. The occurrence of major events and the time evolution of main thermal-hydraulic parameters of both primary and secondary circuits are well predicted by CESAR.