SCK•CEN is working on the design of MYRRHA, a multi-purpose irradiation installation. MYRRHA is part of the research into and development of a reactor technology that allows the transmutation of long-lived and highly radiotoxic isotopes from highly radioactive waste of the current generation of commercial nuclear production plants to shorter-lived and less radiotoxic isotopes. MYRRHA is a flexible fast spectrum research reactor that is driven by an Accelerator Driven System (ADS). It consists of a 600 MeV proton linear accelerator, a spallation target and a multiplication core with fissile material cooled with liquid lead-bismuth.
SCK•CEN aims to obtain a permit for the construction of MYRRHA in 2028. In order to obtain this permit, a thorough safety demonstration of the installation must be provided. This function is part of the safety analysis of the MYRRHA reactor.
The expert group "Nuclear Systems Physics" or NSP is responsible for the safety analysis of the MYRRHA installation and is also largely responsible for the safety design of this installation.
NSP is made up of Engineers and Physicists who draw up models that allow the real behaviour of the installation to be reliably predicted in circumstances involving accidents. The studies using these models make it possible to demonstrate that the installation is capable of dealing with postulated accidents in a safe manner or must indicate which modifications to the design of the installation are necessary to cope with these accidents.
At present, the NSP team consists of about 12 people who primarily have thermohydraulic and reactor physics expertise. This team will be considerably strengthened in order to obtain a building permit by 2028.
As a "Nuclear Safety Analyst", you are responsible for drawing up the appropriate models for simulating accident situations and for performing calculations using these models. This function specifically concerns thermohydraulic models of accident situations for which the usual one-dimensional thermohydraulic codes are not applicable or may be unreliable and for which CFD calculations are therefore required in order to make a reliable prediction. This relates to the choice to design the primary circuit as a 'pool' system, which has important advantages for safety but also makes the safety analysis more complex.
Accidents that necessitate the use of CFD include, for example, fractures of the reactor vessel and of pressurised structures in the reactor.
The development of reliable models for these accident situations requires a highly in-depth understanding of the theoretical background of thermohydraulics and how thermohydraulic problems can be correctly modelled and solved with existing CFD packages such as ANSYSFluent and OpenFOAM.
In many cases, the safety analyses require models and solutions that are innovative and scientific in nature and which can be published in the relevant professional literature.
• Master's degree in engineering sciences, preferably with a specialisation in thermohydraulics;
• Experience in solving complex thermohydraulic problems.
• Experience in drawing up CFD models for thermohydraulic problems.
• A PhD in a thermohydraulic subject would be a plus.
• Good knowledge of English.
• Knowledge of Dutch and/or French would be an advantage.
• A thorough and careful approach to work in terms of quality.