Ignitor and enclosure structure

Abstract

Hydrogen ignitor and housing structure having high-strength and lightweight characteristics for surface mounting within a nuclear reactor containment vessel are disclosed. A unitary main body is formed from stainless steel sheet metal free of internal or external structural bracing to provide an open-ended enclosure for placement and interconnection of electrical transformer equipment for the hydrogen ignitor. The open end of the main body enclosure is hermetically sealed with a unitary stainless steel sheet metal cover plate which interlocks with the main body sidewall so that forces, due e.g. to changes of pressure, tending to distort the configuration of the sidewall or cover plate, are absorbed by both through such interlocking. Hermetic sealing of the enclosure is maintained while providing limited access for external placement of an ignitor glow probe and for line voltage power supply internally of the enclosure. A single opening in the cover plate for a glow plug having an ignitor glow probe is sealed by coaction between portions of a glow plug housing and a glow plug structure which provide coacting metal-to-metal sealing surfaces. A single opening in the sidewall provides for access of line voltage electrical conductors through a conduit which is sealed to the sidewall about its external surface and is sealed along its interior by a metal disk joined to the conduit internally of the enclosure and by hardenable sealant occupying the interior of the conduit. An aperture in the metal disk permits entry of electrical conductors with change of pressure forces at any remaining area of such aperture being distributed over the larger transverse area of the conduit occupied by sealant.