Abstract: Control clusters, each of which comprises a plurality of neutron-absorbing rods, are operable by means of electromagnetic mechanisms whose coils are powered by power bridges driven from a control desk (11). The control system includes a controlling hard-wired logic circuit (12) serving the desk and supervising a plurality of hard-wired logic interfaces each of which serves a subgroup (10) of electromagnetic mechanisms for a determined number of clusters. The static power assemblies (9) each including a hard-wired logic interface and the power bridges of the subgroup(s) (10) served thereby are successively and independently replaced by at least one electronic power assembly (23) constituted by a computer and the power bridges of a subgroup served thereby.

Abstract: Installation for electric connection of devices placed inside the containment of a PWR, comprising a first cable associated with each electric device, extending from the device and connected to a fixed connector installed above the cover of the reactor vessel. A second cable is connected to the connector and to a connector fixed to a plate remote from the reactor vessel. Each second cable is formed from several sections including a first section for connection to the fixed connector above the cover and to a lead-in connector at the end of a leak tight conduit installed horizontally above the cover and a second section inside the conduit. A third section is adapted for connection to a lead-out connector from the conduit and to the connector fixed to the plate at a distance from the reactor.