An electric induction gas-sealed tunnel furnace (10, 30 or 40) in combination with a process gas leak handling system, the electric induction gas-sealed tunnel furnace (10, 30 or 40) comprising: a furnace enclosure forming a closed tunnel region for containing the process gas along the longitudinal length of the furnace enclosure through which a workpiece passes through for induced heating, the closed tunnel region of the furnace enclosure having a workpiece entry end and a workpiece exit end; a furnace enclosure entry end flange (12a or 12b) located at the workpiece entry end and a furnace enclosure exit end flange (12a or 12b) located at the workpiece exit end; an induction coil disposed around the longitudinal length of the closed tunnel region of the furnace enclosure; the improvement comprising: the process gas leak handling system comprising: a barrier material (22, 32 or 42) forming a gas-tight barrier chamber (20, 34 or 44) around the exterior of the longitudinal length of the furnace enclosure, the barrier material having a sealed entry end interface with the furnace enclosure entry end flange and a sealed exit end interface with the furnace enclosure exit end flange; a barrier gas regulator to regulate a flow of a barrier gas to the gas-tight barrier chamber; a pressure sensor to sense a barrier gas pressure in the gas-tight barrier chamber or a differential pressure between the barrier gas pressure and a process gas pressure of the pressure gas; and a pressure controller comparing the barrier gas pressure or the differential pressure and outputting a fault signal if the barrier gas pressure or the differential pressure exceed a set pressure band. a furnace enclosure forming a closed tunnel region for containing the process gas along the longitudinal length of the furnace enclosure through which a workpiece passes through for induced heating, the closed tunnel region of the furnace enclosure having a workpiece entry end and a workpiece exit end; a furnace enclosure entry end flange (12a or 12b) located at the workpiece entry end and a furnace enclosure exit end flange (12a or 12b) located at the workpiece exit end; an induction coil disposed around the longitudinal length of the closed tunnel region of the furnace enclosure; the process gas leak handling system comprising: a barrier material (22, 32 or 42) forming a gas-tight barrier chamber (20, 34 or 44) around the exterior of the longitudinal length of the furnace enclosure, the barrier material having a sealed entry end interface with the furnace enclosure entry end flange and a sealed exit end interface with the furnace enclosure exit end flange; a barrier gas regulator to regulate a flow of a barrier gas to the gas-tight barrier chamber; a pressure sensor to sense a barrier gas pressure in the gas-tight barrier chamber or a differential pressure between the barrier gas pressure and a process gas pressure of the pressure gas; and a pressure controller comparing the barrier gas pressure or the differential pressure and outputting a fault signal if the barrier gas pressure or the differential pressure exceed a set pressure band. a barrier material (22, 32 or 42) forming a gas-tight barrier chamber (20, 34 or 44) around the exterior of the longitudinal length of the furnace enclosure, the barrier material having a sealed entry end interface with the furnace enclosure entry end flange and a sealed exit end interface with the furnace enclosure exit end flange; a barrier gas regulator to regulate a flow of a barrier gas to the gas-tight barrier chamber; a pressure sensor to sense a barrier gas pressure in the gas-tight barrier chamber or a differential pressure between the barrier gas pressure and a process gas pressure of the pressure gas; and a pressure controller comparing the barrier gas pressure or the differential pressure and outputting a fault signal if the barrier gas pressure or the differential pressure exceed a set pressure band.