Research visits

Here you can find updates from research and collaborative visits relevant to the Geological Disposal Facility. 

Highlights and any visit opportunities can be found each month in the NWS RSO newsletter.

The Studsvik Report

In mid-March, NWSers Luke Townsend (Spent Fuel Research Manager) and Keiran Hughes (Project Manager) journeyed to the Swedish countryside for an exciting trip to see some NWS science in action.

The opportunity to travel to Nyköping arose as part of an ongoing research project in the Spent Fuel team (part of the Site Characterisation & Research and Development Team within the Technical Directorate) with our Swedish collaborators Studsvik. The project forms an integral part of the Spent Fuel Research Programme which aims to provide fundamental underpinning data for the safety case. The safety case will support the safe disposal of spent fuel in a UK Geological Disposal Facility (GDF). But why do we care about spent nuclear fuel? And why are we doing experiments on it in Sweden? This short story about our trip will provide all the answers! 

Left – A beautiful but cold (feels like temperature of -7 °C) evening on the Nyköpingsån in Nyköping; Right – Keiran and Luke braving the cold on Studsvik pier after a successful visit to the Studsvik nuclear site.

Spent nuclear fuel is a particular type of radioactive waste due for disposal in a UK GDF. It is produced when nuclear fuel reaches the end of its useful life in a nuclear reactor and is removed, cooled, and stored while awaiting final disposal. The UK has a significant legacy inventory of spent nuclear fuel, with this waste constituting around 90% of the total radioactivity that is due for disposal in a GDF. As NWS plans to dispose of spent fuel over tens to hundreds of thousands of years in the GDF, it’s important to understand how the waste will behave if it comes into contact with groundwater in the distant future.

To explore this further, NWS have recently started a set of experiments at the laboratories in Studsvik to understand how a UK-specific type of spent fuel (known as Advanced Gas-cooled Reactor (AGR) fuel) behaves when it is in contact with water for a prolonged period of time (~1 year). Because spent fuel is highly radioactive, only a small number of highly specialised facilities in the world have the capabilities to perform these challenging experiments which is what led Keiran and Luke to brave a trip to snowy Sweden.

As part of the visit to the nuclear site, NWS were shown around the Hot Cell Laboratory (HCL) where the current NWS AGR experiment is taking place inside a highly specialised facility known as a ‘Cave’ (see image below). The HCL contained an impressive array of equipment and capabilities, with eight caves available for all types of highly radioactive work. All caves were manufactured with significant amounts of radiation shielding, including lead-lined walls and radiation-shielding glass (hence the orange window to the cave), and their use requires highly skilled teams to operate robotic arms inside the cave.

Left – The ongoing NWS experiment on real spent fuel. The experiment will be running in this cave at Studsvik until March 2026; Right – Keiran and Luke stand in front of the cave where the NWS experiment is taking place with clean examples of the flasks that are being used to study the spent fuel.

A labelled example of the type of flask used in the AGR leaching study.

In addition to visiting the HCL, NWS were invited to view the other facilities available at Studsvik, which included a large hall containing many corrosion experiments (including experiments looking at how nuclear power plant steel behaves under high pressure conditions), and the InDrum facility (a newly developed technology that aims to compact complex and mixed radioactive wastes for more efficient disposal; read more here: https://www.studsvik.com/key-offerings/waste-management-technology/treatment-technologies/indrum-our-own-facility/).

Overall, the trip to Studsvik was invaluable for NWS to understand how international nuclear sites operate and what capabilities they have to offer the UK GDF programme. Seeing the recently started AGR experiment in action was also a hugely important part of the ongoing research for safe disposal of spent fuel in the UK. When the experiment concludes in Spring 2026, the data from this experiment will play a key role in underpinning the safe disposal of a significant proportion of the UK’s spent fuel inventory.