Enabling Safe Decommissioning Strategy for the JET Fusion Reactor
Context
UK Atomic Energy Authority (UKAEA) is responsible for the decommissioning of the Joint European Torus (JET)—the UK’s flagship experimental nuclear fusion reactor. Following the end of its operational life, the reactor required decommissioning in a way that maintained containment of radioactive materials while enabling safe dismantling of complex internal structures. A proposed approach involved the use of laser cutting technology deployed from within the reactor, allowing dismantling to be carried out from the inside out while preserving the integrity of the external containment structure.
At the time of engagement, the project was at concept and feasibility stage, representing a world-first decommissioning challenge with no established precedent.
Problem
The decommissioning of the JET reactor presented a unique and highly complex challenge. As a first-of-a-kind project, there was no established methodology for fusion reactor decommissioning, particularly using advanced techniques such as internal laser cutting.
The project needed to satisfy:
Strict nuclear regulatory requirements, including Ionising Radiations Regulations 2017
Assurance of containment to prevent environmental contamination
Demonstration of safety and feasibility for novel decommissioning methods
This was further complicated by:
The technical complexity of the reactor, a legacy asset with fragmented and varied historical records
A multi-stakeholder environment, including government, regulators, and international scrutiny
An organisation balancing academic research objectives with practical delivery requirements
Budget constraints within a publicly funded programme
While the technical capability was strong, the approach was heavily engineering-led, with a focus on innovation and optimisation. This created a critical risk:
Solutions could become technically sophisticated but operationally high-risk
The project required a risk-led, delivery-focused perspective to ensure that proposed approaches were practical, proportionate, and aligned with nuclear safety priorities.
Approach
Moongate Consultancy provided independent expert advisory support to the JET decommissioning programme.
The engagement involved detailed review of technical and strategic documentation, providing critical oversight of proposed methodologies and assumptions.
Drawing on experience from advanced decommissioning programmes within the Sellafield Limited environment, Moongate introduced a practical, risk-based perspective grounded in real-world delivery.
Key contributions included:
Challenging engineering-led assumptions and reframing the problem around risk and safety
Advising on the application of design risk assessment principles to guide decision-making
Translating lessons learned from fission decommissioning into a fusion context
Highlighting likely challenges associated with deploying innovative technologies in regulated environments
Providing input on programme timelines, feasibility, and implementation risks
A key aspect of the role was navigating a highly experienced and academically strong stakeholder group, where proposed solutions were technically advanced but required alignment with practical delivery realities.
Moongate contributed throughout the project lifecycle, supporting:
Strategy development
Option evaluation
Risk identification and prioritisation
This ensured that the programme incorporated practical insight alongside technical innovation.
Result
Moongate’s involvement introduced a more structured, risk-led perspective into the decommissioning strategy.
Key outcomes included:
Improved clarity around key technical and safety risks
Greater emphasis on design risk assessment as a driver for decision-making
Identification of challenges associated with implementing advanced technologies in a nuclear context
More informed and balanced evaluation of potential decommissioning approaches
The project progressed with a stronger understanding of the relationship between innovation, risk, and deliverability, supporting more robust and defensible strategic planning.
Impact
This engagement provided critical real-world grounding to a first-of-a-kind nuclear decommissioning challenge.
Moongate Consultancy enabled:
Better-informed decision-making, balancing innovation with safety and practicality
Reduced risk of pursuing overly complex or high-risk solutions
Integration of operational experience into a research-led environment
A more robust and credible decommissioning strategy
Without this input, the programme risked:
Over-emphasising technical optimisation at the expense of safety and deliverability
Underestimating practical challenges associated with novel approaches
Repeating issues already encountered in comparable nuclear decommissioning programmes
This case demonstrates Moongate Consultancy’s ability to:
Support first-of-a-kind nuclear challenges
Translate practical experience into strategic insight
Provide independent, risk-focused guidance in complex, uncertain environments