MYRRHA design enters final phase
European nuclear players co-draft
Four leading nuclear players will help complete the design of the innovative research reactor MYRRHA. By concluding a framework agreement with them, the nuclear research centre SCK CEN is bringing extra knowledge and manpower on board. In doing so, SCK CEN is once again making a significant leap towards the implementation of MYRRHA.
SCK CEN is currently working hard on the construction of MYRRHA, the world’s first particle accelerator-powered research reactor. The construction of MYRRHA is taking place in several phases. In phase 1, the nuclear research centre is building MINERVA, the particle accelerator with energy of up to 100 megaelectron volts (MeV). In phase 2, the energy level will be raised to 600 MeV, and in phase 3 the construction work on the reactor itself begins. With the MYRRHA reactor, the nuclear research centre will demonstrate the economic and technical feasibility of transmutation. “A prerequisite for starting construction is a final design. This design is entering its final phase,” explains Rafaël Fernandez, an engineering manager at SCK CEN. In 2020, the engineering team gave themselves a well-deserved pat on the back. After extensive analysis and adjustment, they had completed the design of the primary system for the MYRRHA research reactor.
“It was not an easy task. After all, MYRRHA is a global one-of-a-kind. This means we can’t rely on third-party knowledge for that part. To test each design aspect in practice, we have established an extensive R&D programme ourselves,” Fernandez said. This programme covers a wide range of topics: from safety to economic feasibility and even logistics.
Now that this puzzle has been solved, tin 2021 the engineers began the next design phase: linking the MYRRHA reactor’s primary system to secondary systems and auxiliary systems. “The further you move away from the reactor core, the more generic the components become. We are therefore entering areas where there is already a great deal of knowledge and experience available on the market. So the cards are different: at this stage, other nuclear players can make a substantial difference to us,” says fellow engineer Graham Kennedy. In order to attract those players, the nuclear research centre launched a public tender. In the end, they brought four leading nuclear players on board. “The framework agreement is synonymous with additional knowledge, experience and manpower – all of which brings the implementation of MYRRHA closer once more.”
The implementation of MYRRHA is following a tight schedule. Thanks to the relevant experience that the specialists bring to the project, the nuclear research centre can stick to the current schedule. “The aim is to complete an initial integrated design by the end of 2022,” clarifies Graham Kennedy. This design will already be quite mature by that point. “This isn’t their first time for the nuclear players we’ve selected. They have designed nuclear facilities and successfully transformed them into reality before. Thanks to those projects, they can already anticipate potential points of improvement.” This includes the areas for improvement that comprehensive safety studies may point out. Such studies expose the design to specific scenarios.
“What if a plane hits the reactor building, an earthquake hits the region, or there is a fire inside the facility? Even in unexpected situations, can the built-in mechanisms continue to ensure safety? The safety studies will identify areas of improvement that we’ll take to the drawing board. At the end of the road, we have to be sure that the design can meet all the strict safety requirements,” says Rafaël Fernandez. And the end of the journey is 2024. By then, the nuclear research centre must demonstrate that the preliminary design can enter the final design phase: where an external consortium will make the final adjustments to the design in order to submit a licence application.
Experience is an asset
The development of the MYRRHA research reactor involves many domains. “These include conventional nuclear techniques such as civil engineering, ventilation and remote manipulation on the one hand, and specific nuclear techniques for fast reactors on the other. For this reason, we divided the call for public tender into two lots: one lot covering all the conventional systems and components and one lot focusing specifically on components for fast reactors. By dividing the contract into two lots, we were able to choose parties with distinct added value for each lot,” concludes Raphael Fernandez. So experience is an asset. During the course of the project, the chosen parties will be presented with specific assignments , for which they can submit a bid.
Transmutation in a nutshell
Nuclear waste is generated in the production of nuclear energy. That nuclear waste contains long-lived, highly radiotoxic residues, known as minor actinides (mainly neptunium, americium and curium). Those residues remain highly radioactive for hundreds of thousands of years. Bombarding them with fast neutrons causes those heavy nuclei to split. The minor actinides will be converted from highly radiotoxic waste into a waste that is no longer toxic, gives off less heat, and a much lower radioactivity lifespan. The process is called transmutation and thus reduces the requirements for geological disposal. With MYRRHA, the nuclear research centre is aiming to demonstrate the process on a semi-industrial scale. That makes MYRRHA the stepping stone to industrial nuclear waste incinerators.