The reactor of the future is not fixed in place, locked to a single purpose, or built for the world as it was. DARWIN is a new kind of nuclear energy platform: mobile, reconfigurable, and designed for the challenges that the 21st century is already bringing.

The world’s energy needs are changing faster than its energy systems. Climate disasters, water scarcity, failing infrastructure, and the rapid growth of renewable energy are all demanding something that conventional nuclear power plants, and even today’s Small Modular Reactors, were never designed to provide: flexibility. DARWIN is our answer to that challenge. A research initiative led by the Jožef Stefan Institute in Ljubljana, Slovenia, DARWIN is designing the scientific and engineering foundations of a reactor that can do what no reactor has done before: adapt.

Nuclear power plants today produce one thing: electricity, delivered to a grid, from a fixed location, for a hundred years. They are remarkable machines, but they were designed for a world that is rapidly changing. DARWIN proposes something different. A Small Modular Reactor whose core components can be reconfigured within days. A platform that can generate electricity, pump floodwater, desalinate seawater, produce clean hydrogen, supply industrial heat, or manufacture medical isotopes, all from the same underlying system, switched between functions as the need arises. It is not a reactor built for one era. It is a reactor built to evolve.

In August 2023, two-thirds of Slovenia flooded in a single day. The damage cost an estimated 7 billion euros. Cities in Asia and the Middle East are regularly recording temperatures above 50 degrees Celsius. Freshwater supplies are failing across three continents. Critical infrastructure including power grids, water systems, and transport networks is being tested by extreme weather events that are growing in frequency and severity. These are not distant future scenarios. They are happening now, and they are accelerating. The energy systems we will need to respond to them do not yet exist. DARWIN is the first step toward building them.

DARWIN is a three-year research programme at the conceptual design stage, the essential first step in a much longer journey. Our team of reactor physicists, nuclear engineers, and computational scientists at the Jožef Stefan Institute is working to understand the fundamental scientific and engineering challenges of building a fast-reconfigurable, multi-purpose reactor platform. We are mapping the use cases that future nuclear energy must serve. We are designing and simulating reactor module concepts. We are developing the advanced computational tools, including Monte Carlo particle transport, machine learning, and computational fluid dynamics, that will be needed to optimise a reactor unlike any that exists today. We are also building an open roadmap that invites the global research and engineering community to engage, contribute, and build on what we discover. This is not a closed project. It is the beginning of an open international initiative, with Slovenia at its centre.