France is planning to introduce commercial fast neutron nuclear reactors (FNRs) in 2040 and to phase out its operational Generation II light water reactors (LWRs) by 2050, a conference has heard.
Christophe Béhar, head of the nuclear energy division at the French Commissariat à l’énergie atomique et aux énergies alternatives (CEA), told the European Nuclear Congress in Marseille, France, that France is looking to “intensify its efforts” to develop FNRs with a closed fuel cycle.
He said challenges involved in the development of FNRs are related to mastering the plutonium stockpile created as a by-product of the existing LWR fleet, discovering a way to use the total energy potential of natural uranium, and minimising the volume of radiotoxic nuclear waste.
The Astrid FNR research project will provide one way of demonstrating fast neutron technology, Mr Béhar said.
Astrid will be built at CEA’s Marcoule nuclear site. CEA is leading the Astrid project and will design the reactor core and fuel.
However, Astrid, a sodium-cooled fast-neutron reactor, will be different from France’s early generation FNRs, Phénix and Superphénix. Phénix, a prototype, was shut down in 2009 and electricity production at Superphénix, a liquid sodium FNR, ended in 1996.
Based on experience gained from Phénix and Superphénix, Astrid will use advanced safety design features such as a loss-of-coolant-safe core design and nitrogen gas instead of water for the turbine-cooling loop.
Mr Béhar said “a new concept of fast neutron reactors” is necessary to strengthen and demonstrate the safety of sodium-cooled FNRs.
Construction of Astrid is expected to begin in 2020 with fuel loading in 2025, depending on the licensing of the technology by the French nuclear regulator (Autorité de Sûreté Nucléaire, ASN). Mr Béhar said discussions with ASN about licensing are “positive”.
As a second option, Mr Béhar said France will also develop a gas-cooled FNR through the Allegro project, where the CEA supports the V4G4 consortium consisting of the four Visegrad countries – the Czech Republic, Hungary, Poland and Slovakia.
The Allegro project needs to address specific safety issues related to using gas as a coolant for the nuclear reactor as well as the development of a new, specific type of fuel for this type of reactor, Mr Béhar said.
Mr Béhar said France is also planning to develop a closed nuclear fuel cycle for its LWR fleet through the expanded use of mixed-oxide fuel (MOX), which it uses in 22 of its 57 LWRs.
The use of MOX fuel is a step towards closing the fuel cycle by recovering the plutonium produced as a by-product by reactors that use regular uranium-oxide fuel (UOX). The plutonium is reprocessed and blended with natural, reprocessed or depleted uranium before being re-introduced into the reactor as fresh fuel.
Mr Béhar said waste products from the use of MOX fuel can be re-processed and used as fuel for FNRs, further developing the closed fuel cycle.
There are six designs for FNRs being developed around the world. They are: the gas-cooled fast reactor (GFR); the lead-cooled fast reactor (LFR); the molten-salt reactor (MSR); the sodium-cooled fast reactor (SFR); the supercritical water-cooled reactor (SCWR); and the very high-temperature reactor (VHTR).
About 20 FNRs have operated since the 1950s and 22 countries are developing these so-called Generation IV nuclear reactor technologies.