Research reactors furnish elevated fluxes of neutrons for use in basic and applied research. The inventory of these reactors is large, although there are two main types.

--heavy water reactors that furnish strong fluxes of neutrons in the form of beams, essentially used in basic research;

--light water reactors, better adapted to materials tests, with two subtypes:

1.) pool reactors with open cores, cooled and moderated by light water, generally multi-purpose and simple to use and access;

2.) and light water reactors with closed, pressurized vessels, able to operate at powers greater than those of the pool reactors, but more difficult to use because of the closed vessels [Techin B 3030].

Research reactors are located at present at the Institut Laue-Langevin in Grenoble and in several CEA centers: Cadarache, Grenoble, Saclay, Valduc, and, if one counts Phénix, Valhro--Marcoule. Fontenay also housed research reactors.