Abstract: A head equipment support structure system (HESS) (10) particularly adapted to be cooperatively associated with a nuclear reactor vessel (12) for purposes of effecting a separation of the electrical cables (30) that are utilized in the head area of such a vessel (12), as well as for purposes of providing support for these cables (30). The subject HESS (10) which is in the form of an integral structure that is removably supported relative to the vessel (12) combines the features of cable support structure, missile shield, and cooling ductwork support structure. The HESS (10) embodies horizontally disposed multiple decks (14) to which the cables (30) are vertically routed from the reactor vessel head. The decks (14), which are located in vertically spaced relation directly above the reactor vessel head, support and separate the cables (30).