EDF ramps up nuclear decommissioning efficiency with eyes on Europe

As France's EDF expands into new decommissioning markets, learnings at the group's first pressurized water reactor dismantling is informing new cutting, tooling and waste strategies.

EDF Cyclife will soon apply dismantling learnings to the Fessenheim plant in Alsace. It is also forming new decommissioning partnerships outside France. (Image credit Florival Fr).

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A new partnership agreement between EDF's decommissioning subsidiary Cyclife and Finland's Fortum highlights EDF's aim to become a leader in the European nuclear decommissioning space. Cyclife Sweden and Fortum announced May 30 they will jointly develop services in nuclear decommissioning and waste management, focusing on the Nordic region.

European nuclear decommissioning activity is on the rise as ageing fleets and energy policy shifts combine with stubbornly-low wholesale power prices. By 2020, some 150 European reactors will have reached a 40-year lifespan.

Cyclife pursues a "waste-lead approach" to decommissioning, leveraging knowledge from EDF’s large French nuclear fleet and decommissioning facilities in France, Germany, UK and Sweden.

EDF operates 58 commercial pressurized water reactors (PWRs) at 19 sites in France, as well as 14 advanced gas cooled reactors in the UK. The group is currently decommissioning nine reactors in France across four different reactor technologies. These projects include the Chooz A pressurized water reactor (PWR), six natural uranium graphite gas reactors (UNGG) at the St Laurent, Chinon and Bugey sites, the Brenillis heavy water reactor (HWR) and the Super Phoenix fast breeder reactor (FBR).

     France's operational nuclear plant sites

Source: World Nuclear Association (WNA).

Chooz A is a key project for EDF as this is the first of 58 PWR reactors to be decommissioned in France in the coming decades. France currently plans to reduce the share of nuclear power from 75% of generation to 50% by around 2030-2035. The dismantling of the Chooz A reactor is being led by Westinghouse.

Scheduled for completion by 2022, the Chooz A project has enabled EDF to create an optimization plan for the rest of the French nuclear fleet, Guilhelm Le Roy, Chief Technology Officer at Cyclife, told the Ninth Annual Nuclear Decommissioning Conference Europe on May 24.

Efficiency savings will be implemented in areas such as nuclear steam supply systems (NSSS), large component management and waste transportation, Le Roy said.

Chooz A has also helped EDF set out a tooling strategy, demonstrating the cost benefits of developing new tools versus procuring existing tools, he said.

The latest learnings will soon be put to the test at Fessenheim in northeast France, where two operational PWRs are set to close in 2019.

EDF aims to complete the decommissioning of the two Fessenheim reactors within 15 years, Le Roy said.

"This is a new challenge given by the top management of EDF," he said.

Fleet gains

EDF has estimated the cost of decommissioning its nuclear fleet at 350 million euros per reactor, far lower than cost estimates by other European operators which range between 900 million and 1.3 billion euros per reactor, according to a French Parliamentary report published in 2017. Higher cost estimates by UK, German and U.S. operators that are further along the decommissioning process might be assumed to be closer to actual spending requirements, the committee warned.

In a response statement, EDF said its cost estimates are based upon learnings from nine ongoing decommissioning projects in France. Chooz A decommissioning work was "continuing in accordance with the timetable and the budget," it noted.

A Westinghouse-led team has begun underwater cutting operations of the Chooz A upper reactor internals, ahead of vessel segmentation, Le Roy told the conference on May 24.

"In the next weeks we will attack the lower internals and in the two next years, the vessel cutting operation," he said.

As engineer-architect of its nuclear plants, EDF can access expertise from the design, construction, operation and decommissioning phases.

In one example, a steam generator replacement program across the operational PWR fleet provided EDF with data that will help to optimize decommissioning tasks, Frederic Magloire, EDF’s Chief Technical Officer of the Chooz A project, said in 2016.

Productivity of steam generator replacements rose by up to 40% between the first of kind implementation and the fleet-wide series roll-out, Magloire said.

"We think these kind of large operations are very close to [Reactor Pressure Vessel] dismantling, because you use the same tools, you use very [similar] techniques- there is very little difference from one site to another," he said.

Graphite reactors

Decommissioning work is at various stages across EDF's six graphite reactor projects in France. EDF has switched its approach from underwater decommissioning to ‘dry’ decommissioning and the company hopes to apply its latest learnings to the future decommissioning of its UK AGR plants.

The decommissioning of three reactors at Chinon represents the "pilot" project for EDF's graphite reactor plans, Le Roy said.

Cyclife plans to build an industrial-sized demonstrator near Chinon which will test and qualify decommissioning tools and different project scenarios, he said. Digital modelling will be used with the demonstrator to optimize decommissioning strategies for other reactors.

The Chinon, St Laurent, and Bugey projects have already produced a number of key learnings, including best practice for working with alpha-contaminated waste and in asbestos conditions, Le Roy said.

"The safety authorities in France are very focused on these two issues," he noted.

                         Nuclear waste inventory on EU territory

Table refers to very low-level waste (VLLW), low-level waste (LLW), intermediate-level waste (ILW) and high-level waste (HLW).

Source: Euratom, May 2018.

Cyclife has also performed the treatment of large and heavy components and it plans to ship these large components to Cyclife facilities in the UK and Sweden for cutting, melting and sorting activities, Le Roy said.

"We don't have right now an opening route, but we are working on it," he said.

Nuclear Energy Insider