April 23, 2024

Nuclear Decommissioning Services: Ensuring Safe Closure of Nuclear Facilities

As aging nuclear power plants around the world approach the end of their operational lifespans, the need for specialized nuclear decommissioning services is growing. Properly decommissioning nuclear reactors and safely closing nuclear sites is a complex process that requires extensive planning, experienced project management, and strict adherence to regulatory safety standards.

Planning for End of Life

The first and most important step in any nuclear decommissioning project is thorough planning. Comprehensive decommissioning plans must be developed well in advance of final reactor shutdown to determine project schedules, budgets, regulatory approvals needed, and resource requirements. These plans involve characterizing the radioactive inventory within plant systems, structures and components to identify risks and challenges. Detailed studies are also conducted to evaluate the safest and most cost-effective decontamination and dismantling methods based on plant design and radiation levels. Leading nuclear decommissioning services firms employ teams of engineers, health physicists and planners to develop robust decommissioning plans meeting all regulatory guidelines.

Radiological Surveys and Characterization

Before major decontamination and dismantling activities can begin, radiological surveys are performed throughout nuclear facilities to map radiation fields and pinpoint radioactive hot spots. Specialized services providers utilize a variety of radiation detection instruments like Geiger counters, scintillation detectors and gamma cameras to perform these surveys. Radiation measurements are recorded to characterize residual radioactive materials and guide subsequent decontamination efforts. Facilities may also undergo radiochemical analyses to identify specific radionuclides present. This critical data forms the basis for development of worker job exposures and dosage estimates over the lifetime of the decommissioning project.

Decontamination of Systems and Components

Perhaps the most complex aspect of nuclear decommissioning involves decontamination of radioactive plant systems, structures and porous materials like concrete that have absorbed radiation over decades of operation. Leading specialists in nuclear decontamination services utilize a range of proven techniques including chemical decontamination, grit blasting, high-pressure water jetting and abrasive removal methods. Remote systems may also be deployed for hard to access areas or components with high dose rates. Decontamination is performed within controlled areas with appropriate shielding, ventilation, personnel protective equipment and waste handling protocols. Strict clearance surveys and package inspection verify materials are safely reduced to “clean” status for recycle or disposal.

Dismantling and Segmentation

After thorough decontamination, the physical dismantling and size reduction of deactivated plant components and systems can commence. Nuclear components like reactor vessels, steam generators and large piping runs require precise cutting and segmentation methods in a controlled manner while containing radioactive dust and particles. Specialized remote and robotic equipment along with fixings, rigging and lifting tools are utilized by top dismantling contractors with experience segmenting complex nuclear hardware in the most radiologically protective manner. Resulting waste fragments or packages are surveyed to ensure compliance with shipping and disposal criteria before being packaged and transported offsite.

Radioactive Waste Management

A key service supporting nuclear decommissioning projects involves the handling, processing, storage and shipping of the large volumes of radioactive waste that are generated. Principal categories of radioactive waste from decommissioning activities include activated and contaminated metals, filters, spent resins, personal protective equipment and soils. Services firms provide specialized waste processing facilities to segregate, volume reduce and immobilize different waste streams into stable forms suitable for shallow land burial or interim storage prior to disposal. Transportation, packaging and inspection services are also leveraged to ship categorized radioactive waste offsite to licensed disposal or storage facilities in compliance with stringent regulations.

Regulatory Guidance and Oversight Compliance

Given the inherent safety risks, nuclear decommissioning projects are tightly regulated under guidelines established by bodies like the US Nuclear Regulatory Commission or equivalent international entities. Expert regulatory consulting services ensure safety documentation, plans and work practices fulfilling these regulatory expectations are developed and properly implemented. Independent third-party radiological surveying verifies compliance with required dose and contamination limits throughout project execution. Leading firms also manage detailed record keeping, audits and reporting necessary to maintain licensed authority for performing nuclear decommissioning activities at each site or facility.

Site Remediation and Release

Even after the final removal of all radiological hazards, nuclear sites undergoing decommissioning must still undergo comprehensive remediation and environmental restoration services prior to being released for other future use. This may involve remediation of any soil or groundwater contamination as well as demolition of residual non-radiological site structures and utilities if required. Final status surveys verified by independent parties are required to demonstrate applicable site criteria have been attained and regulatory bodies will authorize unrestricted site release with no radiological controls or institutional controls needed. At this point the property can be repurposed or redeveloped free of any nuclear legacy.

Transition to Safe Store or Entombment

In some cases full radiological dismantlement and removal of hazards may not be immediately feasible or the preferred decommissioning strategy. Here nuclear decommissioning projects transition facilities into a state of “safe enclosure” with structural and systems engineering services applied toward entombing radioactive components in structurally stable concrete or metal cocoons. Professional decommissioning management then enacts long-term surveillance, maintenance and monitoring programs to allow the radioactive material within to naturally decay to innocuous levels over decades, at which point final site cleanup can eventually be completed.

With over 100 commercial nuclear reactors worldwide having already undergone decommissioning, and many more aging plants soon to follow, specialized nuclear decommissioning services will remain an important industry ensuring safe closure of nuclear facilities. Strict regulation and adherence to safety dictate these complex projects can only be accomplished through proven expertise and processes developed over years of experience. Leading firms are committed to advancing strategies and technologies to complete nuclear legacy management in a manner that protects workers, public health and the environment.

1. Source: Coherent Market Insights, Public sources, Desk research
2. We have leveraged AI tools to mine information and compile it