Device for thermal insulation of a vessel wall

A device for thermal insulation of a vessel and especially of the internal wall of the primary vessel of a liquid metal cooled fast reactor, within an annular space delimited between the primary vessel and an inner vessel which is enclosed by said primary vessel and has a free extremity, wherein said device comprises a plurality of superposed resilient heat-insulating elements, said elements being such as to extend circumferentially around the common axis of the two vessels, the primary vessel and the inner vessel having a common vertical axis, the primary vessel being suspended from a horizontal vault roof which delimits with the level of liquid metal within the inner vessel a space filled with an insulating layer of inert gas charged with liquid metal aerosols, the free end of the inner vessel being protected from the insulating gas layer by a cylindrical baffle-plate mounted beneath the vault roof and coaxial with the inner vessel, said baffle-plate being immersed in the liquid metal.