Evaluation on the Conservative Critical Flow Model in SPACE Code using Marviken Test

The alpha version of the SPACE code, which is the best-estimate safety analysis code, has been developed, and its verification and validation are in progress. The SBLOCA (Small Break Loss-of-Coolant Accident) evaluation methodology for the APR1400 (Advanced Power Reactor 1400) is also under development using the SPACE code. The goal of the development is to set up a conservative evaluation methodology in accordance with Appendix K of 10CFR50 by the end of 2012. To develop the Appendix K version of the SPACE code, modification of the code is considered through the implementation of the required evaluation models. At present, the Moody model for the conservative prediction of the discharge flow under a two-phase condition is in effect as a look-up table in the SPACE code. In this paper, the implemented conservative critical flow model in the SPACE code is preliminarily assessed against Marviken test