Engineering research reduces radioactive waste at Sellafield

The spent nuclear fuel storage ponds at Sellafield are amongst the oldest and largest in the world. Some are amongst the most hazardous legacies in Europe, housing thousands of forms of radioactive waste. Unlike more recent facilities, some ponds were not lined and radioactivity has pervaded their structures, severely complicating the ease with which they can be dismantled.

Collaborative projects with engineers at Lancaster led to a revised definition of the ‘safe state to reach’ and a revised strategy for removal of the water. This reduced decommissioning costs and the level of risk to site workers.
Led by Professor Malcolm Joyce, research into the depth of radioactive contamination in concrete led Sellafield Ltd to revise their definition of the safe state to be reached at their Pile Fuel Storage Pond (PFSP) facility. In partnership with industry partners, a new strategy was formulated by which to remove its contaminated surface to advance dismantling of the pond structure.
The previous strategy was not deemed to be the lowest-risk option. The team developed the D:EEP technology that provided crucial information on the depth of wall material to be removed and will permit the water level to be reduced in stages, until such time that the structure can be demolished. Members of the original research team now hold new roles in partnering institutions continuing to ensure that the pathway to impact is fully realised for other structures in addition to PFSP.

• Sellafield Ltd revised the process by which they will decommission PFSP reducing risk to workers, realising a 99.5% decrease in the volume of radioactive waste arisings (from 2,800 m3 to 14 m3) and a related waste disposal cost saving of £140 million.
• The Nuclear Decommissioning Authority revised their definition of the safe state to be reached, prior to demolition, of PFSP.
• Collaborators REACT Engineering Ltd were able to spin out a new business (Createc Ltd) to implement these changes. A KTP Associate on the project is now Nuclear Instruments Chief Scientist at REACT and former researcher is now Senior Radiometric Specialist with Sellafield Ltd
• The D:EEP technology was highly commended in the NDA Group Supply Chain Awards collaboration category and achieved a Sellafield Business Excellence Gold Award. The team were awarded the James Watt medal for best paper in 2014 by the Institution of Civil Engineers for the key underpinning research paper.