Mary Cruse is the science communicator at the Diamond Light Source, the UK’s national synchrotron science facility at Harwell Science and Innovation Campus. The facility is used by more than 3,000 academic and industrial researchers across a wide range of disciplines including structural biology, energy, engineering, nanoscience and environmental sciences. Read Mary’s next column on October 14

Research is taking place in Oxford to help find safe solutions to this problem currently faced by governments around the world.

With certain types of waste, the associated radioactivity can take a million years to decay to safe levels, so we need to find ways of securely storing it for a huge amount of time, long after we’re gone.

It seems like a daunting task, but scientists are on the case, helping the UK to plan for a storage facility capable of outlasting humanity itself.

Much of the UK’s radioactive waste – produced as a result of the nuclear, medical, research, manufacturing, and defence industries – is already safely disposed of, but not all of this waste is the same, and small amounts of more highly radioactive material need to be dealt with differently.

This type of waste is currently stored temporarily in special facilities that are engineered to last about 100 years, but we’ll soon require a permanent disposal solution.

And so, in 2006, the UK government decided on building a geological disposal facility (GDF) to house the nation’s waste in rock deep underground.

The planned GDF will be composed of multiple protective barriers of cement and clay buffers, housed deep inside natural rock.

Once stored underground, the waste can safely decay without dangerous radiation ever reaching the surface.

Because the radioactivity associated with this waste takes so long to decay, GDFs around the world will need to be some of the longest lasting structures ever built by humankind.

To build something like this requires a lot of research.

We need to understand how the materials behave at the smallest scale and under different conditions. Thus scientists are turning to technical facilities like Diamond to investigate the design, materials, and environment best suited for the task.

Using X-ray techniques, scientists can scrutinise minute structural changes to materials which will be present in and around the GDF.

They can explore substances like clay and cement in atomic detail, learning more about how they are likely to behave as part of the structure.

But as well as thoroughly understanding these materials, we also need to know how they could change over time.

Once in the ground, radionuclides from the waste will interact with environmental materials on an atomic scale; scientists therefore need to know how this interaction could affect the GDF over hundreds of thousands of years.

In regular laboratories, scientists can study samples over a period of seconds, hours, or weeks. But using long-duration experimental facilities at the UK’s synchrotron in Oxfordshire, it’s possible to measure reactions and interactions in samples over a period of two years.

By scrutinising the behaviour of cement in the initial period when evolution is more rapid, it is possible to create mathematical models and extrapolate the impact over a much longer amount of time. This means scientists can predict minute atomic changes that may occur to the GDF far into the future.

Thanks to Oxfordshire-based science facilities, we’re able to better anticipate what will happen on an atomic scale many thousands of years from now. We’re making choices that will have an impact far into the future, and thanks to science we can ensure we get it right.