firing circuit and ebw or efi function cooperatively to provide a substantial safety advantage an unusually high voltage surge is required to detonate the ebw detonator or efi and the capacitive firing cartridge delivers the high voltage surge in a precisely controlled manner the system is relatively impervious to static discharges stray electrical fields and radio frequency emissions since the ebw and efi detonation systems are functionally the same hereafter and in the attached invention claims reference to an ebw detonator is intended to include and encompass an efi the lower end of the outer housing tube 12 is operatively opened and closed by a nose plug 40 the nose plug 40 comprises a plug base 42 having an o ring fitting within the lower end of the outer housing bore 14 the plug base 42 may be secured to the outer housing tube 12 by shear pins or screws 44 to accommodate a straight push assembly projecting from the interior end of the plug base is a guide tube boss 46 having an axial throughbore 48 and a receptacle socket 50 for a detonator cap 66 projecting from the exterior end of the plug base 42 is a heavy wall nose tube 52 having a nose cap 54 the nose cap 54 may be disassembled from the nose tube 52 for manual access into the interior bore 56 of the nose tube 52 detonation signal conductor leads 58 are routed from the firing cartridge 26 through the upper detonator housing and along the wall of housing bore 14 a conductor channel 60 routes the leads 58 through the nose plug base 42 into the nose tube interior 56 this nose tube interior provides environmental protection for electrical connections 62 with conductor.