EDF did not say what the budget impact would be of redrafting its design after four years of work, nor whether it would delay the rollout of its SMRs, which had been advertised as being ready for market in the 2030s.
A source at Nuward, EDF's subsidiary designing the SMRs, told Reuters the decision to go back to the drawing board came after talks with prospective clients such as Vattenfall, CEZ and Fortum, who are examining investments in both third-generation full-size nuclear plants and the yet-to-be-built small-scale reactors.
Those potential buyers need security that promised costs won't balloon and delivery deadlines will be met — and are more willing to invest in a product based on proven technologies to ensure the levelised cost of electricity for the SMRs would be in the range of 70 to 100 euros per megawatt-hour, the source said.
EDF said in an emailed statement that its SMR design subsidiary Nuward had reached the basic design phase, in which the engineering teams were able to study the complete model of the plant in more detail, and that at this point EDF had decided to "evolve the design".
"The reorientation consists of developing a design built exclusively from proven technological bricks. It will offer better conditions for success by facilitating technical feasibility," an EDF spokesperson said via email.
SMRs are smaller-sized nuclear reactors, billed as cheaper and quicker to roll out than full-size models, which can take decades to build.
They are primarily aimed at replacing coal-fired plants or providing localized electricity for small industrial sites or remote municipalities.
A new plan of action on design choice should come in several months, the Nuward source said.
EDF's public statement comes after French investigative outlet L'Informé reported, citing company sources, that the internal SMR design was being scrapped after encountering engineering difficulties, and that EDF would have to partner with other companies or use off-the-shelf technologies to avoid delays or budget overruns.
Nuward had received innovation-related state subsidies to develop its technology.
EDF has also signed agreements with companies across Europe to develop SMRs alongside conventional large reactors.
