Innovative LWR Simulation Tool for the Nuclear Renaissance in the UK

The government of the United Kingdom has signed the contracts for the construction of Hinkley Point C, the first nuclear power plant since 20 years as a first step for the Nuclear Renaissance in the UK. In a BBC article, the major points for the construction have been given as Hinkley C will deliver 7% of our electricity when most other nuclear power stations will be closed down. The huge project will provide an economic stimulus.
As a consequence of this decision, the nuclear industry in the UK is facing significant challenges in all engineering disciplines around the new build program as well as the following operation of a fleet of light water reactors (LWRs) instead of the well-known gas cooled reactors of the past. This means the UK has to educate a body of competence for operation, regulation, and consultancy for the construction and the operation of this reactor type. When the reactors are put into operation a part of the reactor core has to be renewed every year while the other part of the core has to be rearranged to make the optimal, economic use of the fuel assemblies. Within this process the operator has to proof each time that the new core configuration is in the envelope of the regulation and the operation will be safe. This proof is mastered by extensive computer simulations. Within these simulations, it has to be proven that the safety limits for each fuel pin in the reactor can be maintained.
At present, the industrial simulation for the fuel management is based on the first generation simulation tools which are now almost 20 years in operation and the evolutionary development of these tools. This scheme is robust, but it lacks in representing the coupling between the different physical phenomena which influence each other. The uncertainty of the results caused by the current limitations has been taken into account by increasing the safety margin to the operational limits which can result in reduced economic performance. The nowadays available computational resources open the possibility for significantly improved solutions. New methods are under development in several other countries. However, many of this high performance 'brute force' solutions are time-consuming and pose requests to the computational environment. This makes these simulation schemes highly interesting from the scientific point of view, but the solutions are not ideal for the industrial application due to the time as well as the computational demand but also due to the high complexity for the user. In contrast to these brute force solutions, I propose a smart approach, which on the one hand can overcome the limitations of the brute force simulation but on the other hand, will deliver a comparable quality of the result in the zones of high interest. The idea is to couple different scientific state-of-the-art tools of the second generation to create a simulation tool which can provide a locally detailed resolution of the reactor fuel structure inside the fuel assembly. This tool will be linked to specific codes for the simulation of the behaviour of the fuel pin inside the fuel assembly. The computational efficiency can be achieved by the focusing the efforts to the zones of interest where the fuel rods are closest to the safety limits.
This approach using different spatial resolutions and coupling different physical simulations for different spatial resolutions has the potential to improve the accuracy of the prediction of the fuel rod like it is required to improve the industrial simulation for nuclear reactors of the nuclear renaissance. It will help to reduce unnecessary high safety margins by improved covering of the underlying physics of the simulations. This will lead to improved economic performance as well as improved safety of the operation and thus reduce the cost of electricity production.

WHO MIGHT BENEFIT FROM THIS RESEARCH?
Simulation of the nuclear reactor's core is the high priority task on all the stages of the nuclear facilities' life-cycle, starting from the design over the operational management to finally the decommissioning. Therefore the accurate modelling of the physical processes in the nuclear power plants is the vital necessity. The quality, as well as performance of the calculations, influence not only on the safety of the nuclear power plant but also on its economic efficiency.
The main beneficiaries of the proposed project are groups in academic as well as in industrial organisations and regulatory bodies performing safety and economical estimations of the nuclear power plants. Another possible community which can gain the benefit from this research project is technical support organisations. Finally, in the case of industrial application of the proposed ideas, the benefit from this research will approach the broad public in the form of lower electricity prices and higher shareholder values of the production companies.
The project is, on the one hand, a way to create new IP for the UK. On the other hand, it supports the UK in being an interesting market for investment and being attractive for students from abroad. Thus attracting bright minds to move to the UK to support the development of an innovative nuclear industry.

HOW MIGHT THEY BENEFIT FROM THIS RESEARCH?
Bringing this proposal for a future innovative core simulation into operation will help to develop an advanced tool essential for the specialists in the field of nuclear operation and safety, for nuclear power plants operators and for other specialists in the field of nuclear engineering. They can benefit from this project through using more advanced and reliable computational methods for prediction of the NPP's behaviour. The project will lead to more robust calculation schemes which are more user-friendly than the highly scientific high fidelity methods. Since the advanced calculations are performed for only one or a few assemblies, it is possible to obtain results of the calculations with acceptable effort (in time as well as in computational demand). From the practical point of view, computation should be possible on a desktop computer without the massive use of supercomputers or computer clusters. It is important for industrial application of the codes. Application of the developed program complex on the different stages of the NPP's life cycle will increase its nuclear safety and economic efficiency. Thus, the final consumers of the electricity can benefit from this project through increased safety and economic efficiency of the nuclear power plants which can lead to reduced electricity prices or increased shareholder values of the operating companies. Both will be achieved by reducing unnecessary safety margins which lead to improved economic of the nuclear electricity production.