Pressurized and Boiling Water Reactors
The security of pressurized and boiling water reactors (PWRs and BWRs) in nuclear power plants has gained a lot of significance since the incident in Fukoshima. Moreover, it will remain an important topic after the nuclear power phase-out in Germany. So, critical decisions should be promptly supported by computer simulations in the case of a conversion or even of an incident. In the last years the software COCOSYS has been developed by the Gesellschaft für Reaktorsicherheit (GRS).
Temperature Stratification in Water
The spatial area at the containment of PWRs and BWRs contains large hydraulic seals (condensation chamber at BWRs), which can also arise at an incidence (sump and reactor cavity at PWRs, control rod drive room at BWRs). These hydraulic seals have a distinct three-dimensional geometry, in which temperature stratification can occur in the water.
The global model of COCOSYS can only handle an averaged water temperature so far. Hence, hydrodynamic and thermal simulations are not sufficiently detailed in some cases.
Development of Compatible Softare CoPool
The aim of the BMWi project CoPool (1501369) is the development of a compatible software “CoPool”, which allows for a more precise simulation of flow and heat exchange without increasing the computational costs.
Therefore, we have to find a compromise solution between
- accuracy of the models
- discretization of equations
- the geometry
- the necessary simulation time