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Nuclear waste: Veolia and EDF pool their expertise

EDF and Veolia have entered into a partnership to co-develop innovative solutions for nuclear power plant decommissioning and radioactive waste treatment

Issue

Handling the many nuclear power plants reaching the end of their useful lives worldwide.

Goal

Decommission a nuclear plant without risk to personnel or the environment and optimize the management of the resulting hazardous waste.

Veolia's response

In partnership with EDF, standardize two Veolia solutions: GeoMelt® waste treatment technology and Dexter robotic arm technology.

In June 2018, France’s leading energy supplier EDF and Veolia entered into an unprecedented partnership to develop technologies to improve the treatment and management of waste from nuclear power plant decommissioning. The partnership subsequently launched a first joint venture in summer 2019.


GeoMelt®

GeoMelt®

has treated nuclear and hazardous waste since the 1990s and has produced over 26,000 metric tons of glass for storage.


Nuclear waste

Nuclear waste

A shared industrial culture

A pioneer in treating the most difficult pollution, Veolia believes that a paradigm shift can now be made in managing and treating radioactive waste. One way to achieve this is to use existing, proven industrial technologies and adapt them to nuclear applications.

This approach has won over EDF, which has waste feedstock for which these technological developments could be of use, research capabilities, and recognized nuclear expertise that could accelerate Veolia’s approach.

“With EDF’s nuclear engineering and Veolia’s expertise, we both wished to look at how we could use our complementarities to jointly create value in decommissioning or radioactive waste treatment,” explains Sylvain Granger, Deconstruction and Waste Projects Department Director at EDF.

As such, the two companies decided to study a possible convergence in two areas: decommissioning graphite gas reactors using robotic techniques and treating radioactive waste from nuclear activity using the GeoMelt® vitrification process.

The continually surprising potential of vitrification

“We do not destroy radioactivity,” explains Jean- Christophe Piroux, Director of Technologies and Innovation at Veolia Nuclear Solutions in Continental Europe, in charge of the GeoMelt® project. “The challenge of waste treatment is therefore to package it in a stable and safe vitreous matrix, which has exceptional confinement properties, while Dexter is a robotic arm, developed internally by Veolia, which replicates the movements of a human arm in real time. The arm’s remote control by the human operator, via a secure Internet connection, provides access to environments inaccessible to humans, such as reactor cores being decommissioned. It is the only system of its kind that has more than 15,000 hours’ operation under real-life conditions. The operator views the place to inspect, which can be several kilometers away, on their screen. To effectively deal with the unexpected in an inaccessible environment, more than 2,000 tools have been adapted for Dexter. Both robust and easy to handle, it can manipulate objects from 10 kg (for an arm) to 100 kg (two arms attached to a crane) and pick up objects as small as a pencil. Its incredible sensitivity allows it to “feel” a strip of adhesive on a flat surface. Under the EDF and Veolia partnership, Dexter could be used to sort, identify, and package radioactive waste from graphite stack decommissioning. The remote operation platform will therefore be much more technologically sophisticated than the various existing robotic systems currently used in many operations. reducing the initial volume of the waste, thereby maintaining storage capacities compared to commonly used processes such as cementing, which increase the volume of packaged waste.”

“The choice of glass is crucial,” continues Jean-Christophe Piroux. Glass has excellent longterm behavior with respect to the release of radionuclides into the environment. It takes shortlived low- and medium-level waste about 300 years before its radioactivity declines below the natural background.

“Our GeoMelt® technique also offers a solution for special waste for which there is currently no treatment process,” concludes Jean-Christophe Piroux. There is no treatment or storage process to treat certain waste from the deconstruction of nuclear power stations, for example.

GeoMelt® is an interesting solution, both in terms of performance and cost. This technology has already been tried and tested: The UK Atomic Energy Authority and the US Department of Energy used it to treat nuclear waste. 200 metric tons of glass was produced on the Hanford site in the USA using this technique.

Dexter: a remote handling system

Dexter is a robotic arm, developed internally by Veolia, which replicates the movements of a human arm in real time. The arm’s remote control by the human operator, via a secure Internet connection, provides access to environments inaccessible to humans, such as reactor cores being decommissioned. It is the only system of its kind that has more than 15,000 hours’ operation under real-life conditions.

The operator views the place to inspect, which can be several kilometers away, on their screen. To effectively deal with the unexpected in an inaccessible environment, more than 2,000 tools have been adapted for Dexter. Both robust and easy to handle, it can manipulate objects from 10 kg (for an arm) to 100 kg (two arms attached to a crane) and pick up objects as small as a pencil. Its incredible sensitivity allows it to “feel” a strip of adhesive on a flat surface.

Under the EDF and Veolia partnership, Dexter could be used to sort, identify, and package radioactive waste from graphite stack decommissioning. The remote operation platform will therefore be much more technologically sophisticated than the various existing robotic systems currently used in many operations.

Robots in the decommissioning arena

“The current challenge of decommissioning nuclear power plants is optimizing and standardizing processes to prepare for scaling up,” says Sylvain Granger.

This may concern UNGG (graphite gas) reactors, already shut down in France and Great Britain, as well as PWRs (pressurized water reactors) in the future.

“Decommissioning graphite reactor cores is exceptional in every respect,” explains Sylvain Granger. “The equipment is encased in a very thick concrete structure that is extremely dense and very complex to access. Overall, the mass of material to be decommissioned is about twenty times greater than the mass of equivalent equipment for a light water reactor. In addition, we need to handle, cut, and package a very specific material — graphite, while in more conventional operations, the material concerned is essentially metal and concrete.”

EDF and Veolia have joined forces and pooled their skills to meet this challenge. Remote operation solutions incorporating all these constraints will be studied under this partnership. The studies are expected to take about twenty years.

The Dexter remote handling system (see boxed text), among other solutions developed by Veolia, has the specificity of allowing great dexterity and instant force feedback* for the operator.

With remote decommissioning and vitrification, the Veolia and EDF joint teams are gradually overcoming the technical obstacles they face. “Through the creation of joint ventures, we aim to go beyond the technical discussion stage. These partnerships should allow the emergence of innovative industrial models for the most complex projects,” concludes François Parot, Head of Continental Europe at Veolia Nuclear Solutions.

* Force feedback: the remotecontrolled robotic tool exerts a force on contact with an item that it picks up and then handles. This force is fed back to the operator. Force feedback mechanisms are computer operated to reproduce the force feedback that would be felt if the operator were using their own hands.

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