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CEA research on...

The current nuclear fleet

Published on 4 January 2017

​The CEA devotes a great deal of energy to research programmes to meet the needs of its industrial partners. This research focuses on reactors in the French fleet and covers issues such as service life, performance, availability and nuclear safety. Optimising the fuel cycle facilities is also an area of concern.

​Research on
2nd and 3rd generation reactors

Research is carried out in two areas:

  • Behaviour of structural materials over time and under the extreme conditions existing in a nuclear reactor core
  • Management of reactor operations, such as fuel reloading times, service life, dismantling, etc.

By identifying the limits of the current nuclear systems, researchers are able to develop new materials and tools designed to extend the service life of nuclear power plants, while improving their energy efficiency and economic profitability.

VideoResearch for the current fleet of reactors (subtitled)

Research on
the nuclear fuel cycle

The purpose of such research is to improve fuel performance in Generation II and III reactors, as well as to develop innovative fuels for Generation IV. Each phase of the nuclear fuel cycle is analysed with the objective of extracting the maximum efficiency from uranium, while keeping the environmental impact to a strict minimum. This involves studying the different physical and chemical processes that the fuel undergoes:

  • Front-end of the fuel cycle: improving the processes used to extract uranium from its ore and to enrich it (research on new extractants and development of innovative technologies)
  • Back-end of the fuel cycle: adapting current spent fuel treatment techniques to market changes, studying waste treatment within the scope of the Act dated 28 June 2006, including the separation of fission products, transmutation, vitrification and conditioning.

Research on nuclear safety

Researchers at the CEA have developed a range of tools so they can model and/or experimentally reproduce hazardous situations on a small-scale, as well as identify their precise consequences on nuclear facilities. There are different kinds of situations and causes:

  • Internal: studying the behaviour of structural materials and fuels subjected to extreme conditions (runaway reactions, malfunctions, etc.)
  • External: studying the effects of natural disasters (e.g. earthquakes) and hazards.

Research on safety issues requires investigating the mechanisms and measures that can halt the progression of a severe accident, as well as analysing the hydrogen risk, estimating the radioactivity that may result from any releases outside the reactor vessel, and understanding earthquake risks and resistance.
Operating experience collected from past events is used to better identify and predict potential hazardous phenomena for nuclear facilities.

Processes developed
and means invested at the CEA

The CEA employs two approaches in parallel to carry out research on the current reactor fleet:

  • Conducting experiments using test reactors, shaking tables, and hot laboratories
  • Performing numerical simulations using models integrated into super-computers.

These two complementary approaches are essential: the information collected during experiments is used as input data for the simulations, whereas the simulations help design the mock-ups and experimental facilities.

Research tools
developed by the CEA
to optimise the current fleet

Experimental reactors:
  • Osiris (material testing)
  • Éole and Minerve (neutronic studies)
  • JHR (Jules Horowitz reactor which will replace Osiris with added functionalities)

Hot laboratories:
  • Atalante (treatment and conditioning of spent fuel)
  • LECA-STAR and LECI (analysis of fuels and irradiated materials)
  • Verdon facility in the LECA-STAR (nuclear safety and fission product releases)
  • LEFCA (fuel fabrication)

Technology platforms:
  • Tamaris (nuclear safety, earthquake resistance)
  • JANNuS (front-end studies on materials)
  • Plinius (Platform for Improvements in Nuclear
  • Industry and Utility Safety – severe accident studies)
  • Thermohydraulic loops (Hermès, OMEGA, etc.)
  • Mistra (safety with respect to hydrogen)

Chooz nuclear power plant
Chooz nuclear power plant © F. Rhodes/CEA

Reactor pool
The decay of radioactive nuclei in a reactor pool leads to the release of charged particles that travel through the water at a greater speed than that of light, producing a bluish light known as the Cherenkov effect. © G.Lesénéchal/CEA

Pliers holding a clad pellet
LECA-STAR - Remotely controlled gripper holding a clad pellet © G.Lesénéchal/CEA

Earthquake-resistance tests
Earthquake-resistance tests on a 1/4 scale mock-up of a nuclear building using the Azalée shaking table on the Tamaris experimental platform. © P.Stroppa/CEA

Eole experimental reactor
EOLE experimental reactor © P.Stroppa / CEA