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Published on 15 December 2023

Objectives: Determine how well high-power EPR-type reactors can respond to the needs of France's nuclear plants and estimate the potential worldwide market for these reactors. Complete an economic analysis of a 100% MOx EPR.


Large reactors have to be able to compete economically with other low-carbon energy generation assets. The impacts of a variety of constantly-evolving inputs—the series effect, changing project financing, the EU Green taxonomy, construction efficiencies, supply chain improvements, and integration of nuclear into a grid with more and more renewables—makes monitoring economic competitiveness over time especially important. 

Beyond the intrinsic cost-competitiveness of any given technology, the very definition of cost-competitiveness will change in relationship to shifting markets. For example, French utility EDF, historically positioned on electricity, is beginning to look at opportunities in heat and cold. 

Business models will also change. Currently, electric utilities make their money by selling electricity. However, emerging revenue streams on the capacity and flexibility markets, for instance, will continue to gain traction.

​Another key topic is policy. Regulations and financial incentives and their impacts on reactor economics also merit in-depth analysis. 

The end goal is to predict, as accurately as possible, what the specifications for tomorrow's large nuclear reactors will be and to what extent these reactors will be able to compete with new market entrants, be they renewables or SMRs. 

Our energy landscape is about to undergo some profound changes, both technically and economically. At I-Tésé, we want to make sure that high-power nuclear can still play its role in a Net Zero future in this rapidly-evolving landscape before additional investments are made in this technology. 

The majority of our research has focused on flexibility until now. But we will soon be turning our attention to system costs and the economics of solutions like a 100% MOx EPR. 

As renewable energy penetration rates increase, the conventional metric, LCOE (levelized cost of energy), is no longer the best way to assess the economic competitiveness of a power plant. System cost must be gradually integrated into the equation. Economists agree that this is the way forward. However, regulatory mechanisms are still doing things the old way and perceived complexity is standing in the way of change. It does remain a fundamental issue, though, and one that will shape tomorrow's economy. I-Tésé will be keeping a close eye on developments at the NEA and the IEA in this area and orienting our research accordingly

Gen IV

Only a small amount of natural uranium can be used for generation II and III reactors. To make sure this natural resource is used as efficiently as possible and is available for thousands of years to come, new types of reactors will have to be developed. The Generation IV International Forum was created to promote research and development in this field. These reactors are currently much more expensive than LWRs. The issue of cost is central to the development of FNRs. But to address cost, a number of other questions must be answered first. Can some types of reactors be improved? If so, how?

​For SFRs, beyond direct improvements to reactor designs, it is also important to factor in the value of the plutonium produced in breeder mode. For example, the advantages of symbiotic combinations of 100% MOx FNR and LWR plants (EPR or even EPR adapted for cost optimization) could be calculated. We plan to do an economic analysis of a 100% MOx EPR to determine whether the technology is worth pursuing. 

Technical and economic analyses of alternative scenarios such as increased nuclear flexibility and the construction of Gen IV SMRs would also be useful.​


Gen III and Gen IV nuclear flexibility

Gen III flexibility​

At I-Tésé we base our flexibility studies on scenarios developed by RTE, France's electricity grid infrastructure operator. RTE's scenarios model nuclear demand depending on what other generation assets are available on the grid (scheduled vs. variable production, supply from other countries). 

Antares-Simulator, an open-source software application, is used by RTE to produce two key pieces of information: technical (power variations) and economic (marginal cost per kWh). 

This second piece of information tells us whether a nuclear plant is cost-competitive or not. Some new challenges around this kind of analysis have emerged. The conventional metric, LCOE (levelized cost of energy), is no longer considered by economists to be the best way to assess the economic competitiveness of a power plant. This raises the question of how to address what is known as “system costs." We use Antares-Simulator for this purpose. 

The software allows us to determine whether or not a given electricity mix is viable. If it is deemed viable, the software will then calculate the flexibility needs that nuclear plants will have to respond to. 

This factual technical information is fundamental to understanding the broader issues. Antares-Simulator is a valuable tool that allows the CEA to make recommendations on how to best adapt our energy system to the challenges of the energy transition.

Gen IV flexibility

For Gen IV reactors, flexibility is a less-immediate, but still major issue. Gen IV reactors are not affected by stability issues due to Xe oscillation like thermal-neutron reactors are. This does not mean that flexibility won't present some new technical challenges for these kinds of reactors. The emergence of new reactors will also raise some economic questions, like whether or not it is beneficial to reduce the load factor of plants that are more expensive than LWRs or, on the contrary, to leverage these plants' flexibility (or other characteristics) to provide new services.​

 Contact : Jérôme CANEL