The new PALLAS-reactor will help even more patients with cancer treatments
Did you know that nearly 30,000 patients worldwide depend on the production of medical isotopes every day? These radioactive products are indispensable for the diagnosis and treatment of cancer. The challenge we face is to ensure the production of these life-saving isotopes for the future. This is where the new PALLAS-reactor comes into the picture, a project in Petten in the province of Noord-Holland (The Netherlands), that will secure the future continuation of medical isotope production.
But why is the PALLAS-reactor so important? The current High Flux Reactor (HFR), which has been in operation in Petten since 1961, is approaching the end of its technical life. In addition, the 63-year-old reactor is increasingly in need of intensive maintenance and cannot meet the growing demand for medical isotopes. “The HFR was originally intended as a research reactor for testing materials and was only later adapted for isotope production. The PALLAS-reactor, on the other hand, has been specifically designed for large-scale production”, explains Jan van der Marel, project director at PALLAS.
When completed, the new PALLAS-reactor will take the production of medical isotopes to a higher level, enabling the Netherlands to continue helping millions of people for the next 50 years. Jan van der Marel: “The new reactor will enable us not only to meet the demand in the Netherlands but also to make a significant contribution to the supply of medical isotopes throughout Europe and even the world.” Although the basis of the design is inspired by the OPAL reactor in Australia, PALLAS is far from being a mere copy. While the OPAL reactor mainly focuses on research and produces medical isotopes to a limited extent, PALLAS is the exact opposite. This reactor has been designed to focus on medical isotope production capacity, with room for research activities. PALLAS is, therefore, a unique reactor specifically designed to meet the growing demand for medical isotopes, representing a major step in advancing the production and availability of these life-saving resources.
But how exactly does the reactor work? Imagine a large reactor pool filled with water, about four metres wide and fifteen metres deep. The reactor core is located at the bottom of the pool. Special nuclear with enriched uranium are used in the reactor. These elements are positioned in a reflector vessel where they emit neutrons. The reactor pool also contains special ‘targets’. These targets are materials that have been designed to capture the neutrons. When the neutrons come into contact with the targets, they are converted into isotopes. Isotopes are a special type of atoms that are radioactive, meaning they emit radiation. In medicine, they are used to detect and treat diseases such as cancer. Thanks to this radioactivity, doctors can see what is happening in the body, and isotopes are used to treat cancer.
ICHOS, a collaboration between Argentina’s INVAP and subcontractors such as Iv for engineering, plays a key role in the development of the new PALLAS-reactor. José Louis Molina, project director at ICHOS, explains: “Our main task is to deliver a radioisotope production facility that meets PALLAS’ high performance standards.” ICHOS has been involved since the early design phase and is working closely with Iv to ensure all aspects of the facility meet the required quality standards.
Iv is working with a team of around 100 people on the realisation of the new reactor. “We are responsible for the engineering and support of the conventional systems that enable the reactor to operate”, says André van Es, senior project manager at Iv. These include nuclear and conventional HVAC systems, tap water, waste and rainwater systems, building management systems, radioactive liquid waste systems, demineralised water systems, compressed air systems, industrial gas systems and secondary cooling systems. “Without these systems, the process would not be possible. In this way, we ensure that everything around the reactor works properly, enabling the reliable and safe production of medical isotopes.”
In addition to these systems, Iv is also responsible for all the instrumentation, such as temperature and pressure gauges, necessary to operate the systems and communicate with other systems – a vital and complex task due to the many interfaces and connections that need to be appropriately coordinated.
“In a nuclear reactor, it is important to create different ‘zones’ for managing air to ensure that radiation is kept within safe limits”, says André. “No air can be allowed to flow from the inner zone, where the radiation is strongest, to the surrounding zones around the reactor. So we have to make sure that air can only flow from the surrounding zones to the inner zone to prevent any release of radioactivity by air. We achieve this by regulating the air pressure between the different zones. Any exposure or release of radioactivity will remain within the dedicated zones. The air within these inner zones is filtered through special filters and safely released into the environment.”
According to André, Iv’s experience with similar technologies in the pharmaceutical industry is very useful in this project. For example, zoning principles are also used in vaccine manufacturing plants to prevent the escape of viruses. In addition to the technical challenges of zoning, the logistics around the reactor are also crucial. “In a production environment like this, everything has to run quickly, safely and efficiently”, explains André. “The isotopes are handled and packaged in ‘hot cells’. These cells must be safely shielded to prevent operators from being exposed to too much radiation. The products must be safely transferred from the reactor via the hot cells to the logistics areas for transport without the risk of radiation contamination.” André: “Imagine that there are six hot cells for handling isotopes. For each cell, the correct pressure cascade must be ensured between each of them as well as in relation to the surrounding logistics areas, so the air flows in the right direction and the risk of radiation contamination remains within the limitations of the applicable standards. Such complexity makes it imperative that our systems are well designed, function properly and are reliable.”
The design of the PALLAS-reactor must meet strict requirements to guarantee safety. The most important aspect is that everything must be designed in accordance with the Nuclear Energy Act and the ‘Dutch Safety Regulations for Nuclear Power Plants’ (DSR). These regulations ensure the reactor remains safe in various emergencies, such as earthquakes, floods and aircraft accidents. André explains: “The reactor design must be able to withstand extreme conditions. So this means that the systems themselves must remain reliable and continue functioning, even in the event of an emergency. For example, in the event of a flood, the power supply systems for critical equipment, such as diesel generators and control systems, must continue to operate to prevent the situation from becoming unmanageable.” Radiation in the immediate vicinity of the reactor also presents a challenge in terms of material use. The new reactor needs to last at least 60 years. Radiation affects the materials inside the reactor. Constant exposure to radiation can cause materials to age or be damaged more quickly. Therefore, all materials in the reactor must be resistant to this radiation and designed to last for decades. Furthermore, systems such as piping and ducting must be designed to allow for regular cleaning and maintenance.
“What excites me about this project is the enormous challenge of systems engineering, including verification and validation (V-model), and information management”, says André. “It’s not only about the technical complexity of the installations but also the coordination of all models and data. For example, we have to make all 3D models available centrally every two weeks in a so-called ‘Common Data Environment’ and ensure full coordination. This means that during the engineering phase, we have to make sure that all information relating to, for example, pressure, temperature and the materials used is immediately available and linked.”
André adds: “I don’t think any other project in the Netherlands is coordinating and making information available in this way.” According to him, working with different (international) parties and tooling systems that do not always integrate seamlessly makes it even more complex. Ensuring all the information is brought together correctly and everyone is working with the correct data is a huge challenge.
José adds: “When all 500 systems finally work together, and everything operates as it should during commissioning, it feels like scoring a goal in the World Cup final. We have a crucial moment in the process called ‘criticality’. This means we have brought the reactor to capacity and maintained stability. It’s a big moment for us, comparable to winning the World Cup. It confirms that the reactor works.” But José is quick to point out that criticality is only the beginning. “After criticality, we still have to demonstrate the system’s performance. There is still a lot of work to be done to ensure that everything complies with the requirements. But you can already see that the project is successful at that point. Then comes the fine-tuning phase.”
The PALLAS-reactor represents a major step in the production of medical isotopes and is also a possible blueprint for future reactor projects. José Louis explains: “We are building a virtual model (digital twin) of the reactor to train operators and simulate operations as realistically as possible. Such a model involves a lot of work, but it helps us to manage the reactor safely without having to use the actual installation, which has to last at least 60 years.”
The demand for medical isotopes continues to grow. The PALLAS project not only solves the current problems but also demonstrates how we can build other reactors in the future. The current PALLAS-reactor has been in the pipeline for decades as a replacement for the HFR. Jan van der Marel has been involved in this project since 2016. “From the very beginning, we have had to overcome many obstacles in terms of obtaining the necessary permits. So, even at the start of the project, we didn’t know if it would be successful. However, now it is clear that we have successfully overcome the last hurdle: approval from the Ministry of Health. From now on, all the challenges ahead are in our own hands.”
The transition from the old HFR reactor to the new PALLAS-reactor is a process that will take place over the coming years. For a period of around two years, both reactors will continue to operate to ensure uninterrupted production of medical isotopes. Once the PALLAS-reactor has reached full capacity, the HFR will be decommissioned. Construction of the new medical isotope reactor in Petten will commence next year. If everything goes according to plan, the PALLAS-reactor will be ready around 2030.
Ralf, managing director Industry, would be delighted to discuss this with you! Get in touch via +31 88 943 3700 or send a message.
