[en] Purpose: To reduce the thermal stresses and improve the reliability of dip plates in LMFBR type reactors by constituting the dip plates with a plurality of segments and a plurality of auxiliary members while leaving them set free. Constitution: Arc-shaped segments are suspended by way of cylindrical supports respectively from the lower surface of a shielding plug disposed in the upper portion of a reactor container and dipped below the level of coolants. Each of the segments is supported approximately at its center of gravity by one support from the lower surface of the shielding plug. The support has a sufficient regidity to horizontal shock waves in the segment and is bonded to the plate by welding. The segment is formed so thin that thermal stresses due to the temperature slope along the plate thickness may be decreased and it is movable radially so that it can avoid severe thermal bendings when displaced radially due to heat expansion. (Moriyama, K.)