Abstract: Claimed embodiments of the integral nuclear reactor relate to nuclear technology and can be used in reactors with different types of heat transfer fluids with a high boiling point, such as, for example, liquid metals, molten salts, etc. Design features of the invention embodiments claimed which have a coil heat exchanger sectioned along the secondary heat carrier circuit provides for an improvement in technical and economic features due to a decrease in metal consumption of the reactor; efficient use of the internal volume of the reactor; improved safety in case of the heat exchanger tube leaks; enabling the removal of residual heat during the time after removal of the protective plug before fuel discharge operations.