The future of nuclear power: monitoring, modelling and managing risk

Research highlights

• Aided post-disaster clean-up and repopulation efforts in Fukushima. 
• Developed advanced climate modelling tools to predict long-term impacts on nuclear waste storage. 
• Provided critical insights that have shaped international nuclear safety policies. 

Nuclear power is set to play a crucial role in the global transition to low-carbon energy, already contributing around 10% of the world’s electricity.

However the expansion of nuclear energy hinges on the ability to manage risks effectively.

Researchers at the University of Bristol have responded to this challenge by pioneering innovative approaches to strengthen the public and environmental safety of nuclear energy and improve contamination monitoring. 

Pioneering contamination mapping technologies 

On 11 March 2011, a devastating earthquake and tsunami struck Japan, critically damaging the Fukushima Daiichi Nuclear Power Plant and triggering radiation leaks.

The disaster displaced thousands of residents and raised urgent questions about public safety. 

In response, a team from Bristol’s Schools of Geographical Sciences and Physics led by Professors David Richards, Tom Scott and Dr Peter Martin collaborated with Kyoto University to transform the effectiveness and accuracy of radiation monitoring.

Traditional methods relied on either high-altitude manned aircraft, which lacked spatial precision, or on-foot surveys with handheld detectors that put operators at risk.

To address these limitations, the Bristol team developed low-altitude unmanned aerial vehicles (UAVs) equipped with lightweight gamma-ray spectrometers. 

The solution provide to be highly effective at autonomously mapping radiation intensity at the metre scale and charting the movement of radionuclides through the environment, providing unprecedented spatial resolution.

Using data from soil and moss samples, the team also employed high-resolution mass spectrometry and nanoscale imaging to assess contamination levels of uranium, plutonium and caesium.  

Influence on post-disaster recovery  

Just months after the leak, this mapping activity and analysis found a very low abundance of radioactive elements at most evacuated sites.

This effectively indicated safe regions around the plant - data which local authorities used to support repopulation.  

A key factor was that Bristol’s contamination analyses moved beyond proof-of-principle to offer practical advice to decision makers.

The entire population of nearby Minamisoma City, some 54,000 people, were displaced following the accident.

The city’s Senator declared that Bristol researchers had “provided independent evidence that helped us consider the safety of our district, before and after clean-up”.  

Bristol’s imaging techniques also helped to identify radiation leaks at sites storing some of the millions of bags of radioactive waste collected after the accident.

The leaks were fixed as a result, with routine monitoring implemented to prevent further contamination.  

Advancing climate modelling for nuclear waste management 

Managing nuclear waste, which remains hazardous for millennia, poses another major challenge.

Geological repositories, designed to store high-level radioactive material hundreds of metres underground, must withstand environmental changes over tens of thousands of years.

In another strand of Bristol’s efforts to improve nuclear safety, Professor Dan Lunt and his team have developed groundbreaking tools to address this issue. 

Using Bristol’s advanced supercomputing facilities, the team has created a statistical emulator capable of projecting Earth’s climate far beyond the typical 80-90 year horizon.

Factoring in shifts in Earth’s orbit and axial tilt, the emulator simulates climate evolution, ice sheet dynamics and groundwater fluctuations over timescales of tens to hundreds of thousands of years.

These insights help assess the long-term safety of nuclear repositories by predicting potential risks such as erosion and water table changes. 

Studies using the emulator were developed and facilitated through the International Atomic Energy Agency (IAEA), who suggested that the results could be applied to any nuclear safety assessment programme worldwide.  

To date, the work has informed regulatory assessments by the Swedish and Finnish nuclear waste authorities (SKB and Posiva, respectively). Posiva, in the Safety Case for their long-term geological disposal facility, stated that “without this report and the work underpinning it, we would not be able to submit a complete case.”  

Looking ahead 

The University of Bristol continues to refine its technologies and methodologies. Current projects include exploring autonomous radiation mapping and enhanced climate models to further safeguard nuclear sites.

With this continued innovation, Bristol is helping to shape a safer, more sustainable nuclear future.