Cooling device for base portion of reactor pressure vessel supporting skirt

A lower end of a skirt for supporting a reactor pressure vessel is mounted on a concrete foundation by way of a sole plate and a base plate. A large number of heat releasing fins made of brass are protruded outwardly and upwardly from the outer circumferential surface of the sole plate. Blowers for supplying air to the heat releasing fins are disposed to a portion above the heat releasing fins each at a predetermined space in the circumferential direction. Heat generated from the reactor pressure vessel during operation transfers from the support skirt to the sole plate and to the foundation by way of the sole plate and the base plate. The heat transfers also to the heat releasing fins and dissipated rapidly. In addition, since air is blown from the blowers, heat is dissipated efficiently from the heat releasing fins. (I.N.)