THE MARKET FOR NUCLEAR DECOMMISSIONING and radioactive waste management looks set for decades of growth. Today, there are 451 reactors in operation in 30 countries and at least half of them are approaching the end of their 30- to 40-year original design life. While life extensions are possible, stringent post-Fukushima requirements and economic factors mean that some 200 reactors, in particular smaller units are likely to shut down in the next two decades, according to Patrick O’Sulllivan, decommissioning specialist at the International Atomic Energy Agency in Vienna. In the past few years, reactors have been retired in Germany, Sweden, USA and the UK. However, of the 166 units that have been permanently shut down, only about 20 have been decommissioned.

There are two options for decommissioning: immediate dismantling; or deferred dismantling, where a nuclear facility is maintained and monitored in a condition that allows the radioactivity to decay; afterwards (often decades later) the plant is dismantled and the property decontaminated.

The current trend is towards immediate dismantling. This is driven by a combination of environmental, political and economic factors. “Share price and enterprise value are now associated with sustainable decision-making, and the nuclear sector is one of the cleanest as all wastes are accounted for,” says Bill Roberts, director of UK-based consultancy Decommology.com.

“A decommissioning industry adds considerable value to its host economy, creating innovation, competitive advantages and benefit for adjacent sectors as well as for the environment and future generations,” Roberts adds.

Proceeding with immediate dismantling also has practical benefits. It allows use of first-hand knowledge of the condition of the plant from people who have worked there. However, it also increases the risks involved with handling of radioactive wastes, and finding a solution for storage of nuclear waste and spent nuclear fuel.

Technology

Key technologies for decommissioning are those that assist in understanding the levels of radioactivity within the facility, says O’Sullivan. The facility needs to be characterised effectively in order to plan dismantling.

“New technological developments in recent years such as compact gamma cameras and drones, may make the process of characterisation much more efficient,” O’Sullivan adds. “Once the measurements have been made, an electronic representation of the facility may be created on which dose levels are superimposed, and to plan, using IT systems similar to those used in video gaming, how to undertake the dismantling.”

Virtual reality can help with planning, so rather than physically building a model to test dismantling options, computer-aided modelling systems can be used.

Robotics can also be used for some of the decommissioning work in situations where the level of radiation is too high for human entry. At the Sellafield site in the UK, a range of robots have been developed and deployed for cleaning up the legacy ponds and silos. Robots have been used for characterisation work at the damaged Fukushima Daiichi reactors in Japan, and elsewhere.

Beyond this, new technologies including 3D printing, new welding/casting processes and modular construction, have the potential to reduce costs. One area that could benefit is the manufacturing of radioactive waste containers.

Collaboration

Collaboration is playing an increasingly important role in nuclear decommissioning. There are many international networks, facilitated by the IAEA, the OECD Nuclear Energy Agency and others through which experts involved in decommissioning activities can come together and share their experiences, lessons learned and so on.

Decommissioning costing is one area of close international collaboration, according to O’Sullivan. “We have collaborated closely in developing a standardised approach to presenting decommissioning cost estimates to facilitate comparison – the International Structure for Decommissioning Costing (ISDC),” he says.

The IAEA has also established the DAROD project, a collaborative project concerned with exchanging good practices on the decommissioning and remediation of accident-damaged nuclear sites, and it has launched a decommissioning peer review service, known as ARTEMIS.

There is scope for collaboration across industries. In the UK, the Nuclear Decommissioning Authority (NDA) has recently stepped up collaboration with the oil and gas sector, thanks perhaps to its current chairman David Peattie. Peattie joined the NDA in 2017, after 35 years in oil and gas.

“Technologies developed for use on the NDA’s sites, such as snake-arm robotics, are now being used to solve challenges in the oil and gas sector,” Peattie said during the TotalDECOM Conference in Manchester in April 2018.

“In return, remotely operated vehicles first used in oil and gas are now being used to clean up hazardous nuclear facilities, such as the legacy ponds at Sellafield.” 

Collaboration is also possible with other high-tech sectors, including automotive and aerospace.

Nuclear Engineering International has published a special edition for distribution at this year¹s World Nuclear Exhibition.

The focus of the special edition is on how digital solutions, virtual reality, robotics and other emerging technologies have the potential to secure the future of nuclear power.

With existing reactors facing increasing market pressures, digitalisation and automation offer opportunities to improve efficiency and reduce costs.

Robotics, data analytics and new simulation capabilities can aid cleanup of legacy facilities. New technology is also revolutionising the workplace, and can help the nuclear industry to attract a new generation of talent to replace its ageing workforce.

Looking ahead to the next decades, innovative technologies from small modular reactors to Generation IV designs and new fusion concepts, promise to make the next generation of nuclear energy more competitive with other energy sources.

Read your World Nuclear Exhibition Special Edition – New technology encouraging excellence in nuclear energy