Since the counter current flow limitation (CCFL) of two-phase has an important influence on safety analysis reactor, it is also great significance to study some characteristics and pattern transitions flow. In order explore influencing factors in hot leg under condition Loss Coolant Accident, this research, using RELAP5 simulation calculation, analyzed effect lengths path leg, shapes upper outl...

Despite system thermal–hydraulic codes were extensively validated for transient simulations of LWR, several activities highlighted limited capabilities these tools to model heat transfer within in-pool passive power removal system. Discrepancies with experimental results related the underestimate pool boiling and film condensation coefficients. Thus, DIAEE “Sapienza” University Rome developed a...

The presented article discusses developing and validation of a VVER 1000 TRACE V5.0p5 model. Developing such model for computer code is important as it increases the capability analyses in simulating nuclear power plant behaviour different accidents including capabilities 3D thermal hydraulic phenomena reactor core simultaneously with physics calculations. In this way, possible to conduct trans...

The Pebble Bed Advanced High Temperature Reactor (PB-AHTR) is a liquid-salt cooled reactor that uses conventional TRISO fuel. Due to the high thermal inertia of the liquid salt coolant, the PB-AHTR allows for a much higher power-density core than traditional gas-cooled high temperature reactors. High power density has a favorable economic impact. In 2007, the baseline design 2400MWth PB-AHTR wa...

The Slovenian Krško Nuclear Power Plant (NEK) model was built in using APROS - Advanced PROcess Simulation environment. basis for the this RELAP5/MOD3.3 Engineering Handbook, updated to 26th cycle and also includes upflow conversion modification. A detailed nodalisation created each system every separately validated. current covers primary circuit with core kinetics model, secondary their contr...