The decommissioning of nuclear, defence, and energy infrastructure is a highly complex and carefully regulated process. While many associate commissioning with the start-up of new facilities, it is equally critical when shutting them down safely. At MissionCX, we apply our commissioning expertise to ensure that decommissioning projects are carried out securely, efficiently, and in full compliance with industry regulations.
Why Does Decommissioning Require Commissioning?
Commissioning skills are directly transferable to decommissioning projects, and ensure safety, environmental protection, and regulatory compliance. Before a nuclear plant, defence facility, or energy infrastructure can be decommissioned, its systems must be tested, verified, and prepared for deactivation. This process requires the same rigorous validation of that required to commission new build nuclear projects.
Key reasons commissioning is essential in decommissioning:
- Verifying System Readiness for Deactivation – Just as we test systems before operation, we must ensure they are functioning as expected before being deactivated to avoid hazards.
- Safe Removal of Hazardous Materials – Cooling systems, radiation shielding, and waste containment structures must be tested and verified before controlled shutdown and dismantling.
- Preventing Environmental & Safety Risks – Any residual energy, radiation, or hazardous substances must be carefully managed, requiring the same expertise used in commissioning.
- Regulatory & Compliance Requirements – The Office for Nuclear Regulation (ONR), Environment Agency, and International Atomic Energy Agency (IAEA) require commissioning processes to validate decommissioning safety.
- Ensuring Long-Term Site Stability – Post-decommissioning monitoring systems must be commissioned to ensure ongoing safety and environmental integrity.
MissionCX’s Role in Nuclear Decommissioning
At MissionCX, we provide specialist commissioning services that support the entire decommissioning lifecycle, ensuring safe transitions from operational facilities to dismantled sites.
- System Readiness Testing – Assessing plant conditions and verifying shutdown readiness.
- Decontamination & Waste Handling – Ensuring safe material disposal and radiation containment.
- Shutdown Verification & Validation – Ensuring all systems are correctly deactivated, depressurised, and de-energised.
- Environmental & Safety Compliance – Meeting UK and international nuclear safety regulations.
- Long-Term Monitoring Commissioning – Setting up systems for safe site maintenance post-decommissioning.
The UK’s Decommissioning Landscape: What’s Happening Now?
With an increasing focus on clean energy transitions, the UK is leading major nuclear decommissioning projects. Key sites include:
- Sellafield (Cumbria) – The UK’s most complex nuclear decommissioning site, home to legacy fuel storage, reprocessing plants, and decommissioned reactors.
- Dounreay (Scotland) – Formerly the UK’s fast breeder reactor test site, now undergoing full-scale decommissioning.
- Magnox Reactors (Across the UK) – Early-generation nuclear power stations undergoing controlled defueling and dismantling.
- Submarine Dismantling Programme (Rosyth & Devonport) – The UK’s nuclear submarine fleet is being carefully dismantled under strict regulatory control.
Commissioning in decommissioning ensures these projects meet stringent safety and environmental standards while keeping costs and risks under control.
10 Key Facts About Nuclear Decommissioning
1️⃣ The UK’s nuclear decommissioning programme costs £3 billion per year (NDA, 2023).
2️⃣ Sellafield will take over 100 years to fully decommission, making it one of the most complex sites in the world (NDA, 2023).
3️⃣ The first stage of decommissioning can take 10–20 years, involving reactor cooling, defueling, and waste management.
4️⃣ The UK’s Magnox reactor sites will take until at least 2100 to be fully cleared (NDA, 2023).
5️⃣ The UK has 27 decommissioning sites, including power stations, defence sites, and nuclear research facilities (NDA, 2023).
6️⃣ Decommissioning is one of the biggest growth areas in the nuclear sector, with new technologies being developed to improve efficiency and safety.
7️⃣ The cost of decommissioning the UK’s early nuclear sites is estimated at over £132 billion (UK Government, 2022).
8️⃣ Robotic and AI-assisted technologies are being introduced to improve safety and efficiency in dismantling radioactive structures.
9️⃣ Fusion energy plants, like the STEP programme, will require a completely different decommissioning approach due to the low-waste, low-radiation nature of fusion.
🔟 Commissioning ensures that the decommissioning process is safe, controlled, and meets strict regulatory standards.
Future of Decommissioning & Why MissionCX is the Right Partner
The demand for specialist commissioning expertise in decommissioning is growing rapidly. With aging nuclear infrastructure, evolving safety regulations, and complex technical challenges, our expertise is critical in ensuring projects are delivered safely, efficiently, and cost-effectively.
At MissionCX, we bring:
- Deep expertise in nuclear decommissioning and commissioning integration.
- Proven track record of supporting UK decommissioning programmes.
- Commitment to safety, regulatory excellence, and innovation.
As the nuclear sector continues to evolve, MissionCX remains at the forefront of ensuring safe and sustainable decommissioning practices that protect people, the environment, and future generations.
📌 For more information on nuclear decommissioning projects in the UK, visit:
- Nuclear Decommissioning Authority (NDA) – www.gov.uk/nda
- Sellafield Ltd Decommissioning Programme – www.sellafieldsites.com
- Office for Nuclear Regulation (ONR) – www.onr.org.uk
📢 Sources:
This article is based on insights from UK Government decommissioning reports, the Nuclear Decommissioning Authority (NDA), the Office for Nuclear Regulation (ONR), and key industry research on nuclear site remediation and waste management best practices.