Simulation codes for application in reactor safety

The research and development work of GRS mainly concentrates on the fields of core behaviour, core meltdown processes, transients and leakage events in the cooling circuit, accident behaviour, containment system and structural-mechanical behaviour of components. The development of methods is an important task in this respect. One focus here is the development and validation of simulation codes that deal with reactor safety.

These methods are not only applied by GRS in its statements, expert opinions and analyses on the occurrence probability of failures. More than 50 organisations in Germany (e.g. the TÜV) and abroad benefit from these developments and make use of GRS codes. As examples, the main deterministic and probabilistic codes of GRS are listed here, which can be used to simulate accidents and severe accidents, but also ageing and detailed phenomena.

GRS's main customer in the field of reactor safety research is the Federal Ministry for Economic Affairs and Energy. Based on the results from research and development, the respective application-oriented work is included in the interdisciplinary analyses for the scientific expert advice of the federal supervisory authority.

Structural mechanics simulation codes

Codes for the simulation of structural mechanics deal with the safety and lifetime of components in nuclear power plants, e.g. containment structures, pipelines, containers and fuel rod cladding tubes. GRS codes for structural mechanics analyses are WinLeck, PROST and TESPA-ROD.

Codes for the simulation of thermal hydraulics and severe accident sequences

GRS develops computer codes that simulate the fuel rod and core behaviour and severe accident sequences. These include, among others, COCOSYS, ATHLET and ATHLET-CD. Together, the three simulation codes form the GRS code system AC2. In addition, AC2 includes the visualisation tool ATLAS and the optional Numerical Toolkit (NuT) interface to external numerical libraries.

Reactor physics simulation codes

GRS simulation codes dealing with phenomena related to nuclear fission are QUABOX-CUBBOX, TORT-TD, KMACS and KENOREST.

Simulation codes for uncertainty analyses

Codes for analysing the reliability of computational results (e.g. SUSA) examine and evaluate uncertainty sources – parameters, model assumptions, algorithms - in these computer codes to quantify the effect of inaccurate input values in computer codes.

ATLAS analysis simulator

The analysis simulator ATLAS provides a simulation environment used for the visualisation of data and the interactive control of dynamic processes in nuclear power plants. ATLAS is therefore used, for example, for the training of nuclear power plant personnel.

AnTeS - Analysis and test system for digital instrumentation and control (I&C) systems

With AnTeS, GRS operates a platform for analysing and testing digital I&C systems, such as those used in nuclear power plants and research reactors. Within AnTeS, researchers can combine virtual and real systems to analyse digital I&C systems and develop methods for their evaluation.

FaSTPro analysis tool for source term prognosis

The analysis tool FaSTPro (Fast Source Term Prognosis) enables the prediction of possible radioactive releases in the event of potential accidents in nuclear power plants. It uses the commercial software Netica ™ of the Norsys Software Corp. to calculate the associated release probabilities.

Overview Simulation Codes for Accidents