Nuclear reactor protective system

Abstract

A nuclear reactor protective system includes a cylindrical concrete wall surrounding the reactor's pressure vessel in radially spaced relation with respect to the latter, the space between the two being large enough to permit the insertion of a device for monitoring the pressure vessel's wall condition. To protect the concrete wall against thermal radiation from the reactor pressure vessel's wall, a plurality of metal plates are positioned in this space, each in the form of a cylindrical segment, the pressure vessel's wall being cylindrical. These plates partially overlap each other normally to form a circumferentially continuous multi-layer arrangement of the metal plates which are slightly radially interspaced by thermally non-conductive members to provide dead air-space thermal insulation between the pressure vessel's wall and the concrete wall. These overlapping plates are positioned in the space between the two walls so that at least some of the plates adjacent to the pressure vessel's wall may be circumferentially displaced to more completely overlap and open the space to provide room for the insertion of the device adjacent to the pressure vessel's wall to monitor the condition of the latter, these plates being replaced to their original positions after the monitoring. Other features are included.

Dependencies are inferred from the claim text.