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Reaching 2,100 Degrees: Steps to Melter Heatup
Heatup of a melter in the Low-Activity Waste Facility consists of a series of activities to prepare for and establish a molten pool of glass inside the melter. It takes approximately two months to heat up one melter (approximately 22 days for the initial heatup, followed by several days of testing, followed by about 30 days of checkout).
Initial Heatup: Once the empty melter is heated to temperature using temporarily installed startup heaters, quantities of ground glass – called frit – are added until enough melted glass is present to cover the melter’s electrical heating electrodes.
Energizing the Melter: The normal melter power supplies are energized, flowing electricity through the glass pool to generate heat, like a toaster heating element, and the temporary heaters are removed.
Bubblers are Installed: Next, bubblers are installed to introduce air into the bottom of the melter glass pool to mix the glass.
More Glass Frit is Added: More glass frit is added to raise the pool to the normal operating level, and then the melter is ready to start receiving tank waste feed materials (non-hazardous simulant will be used during testing).
Minimizing Risk: The first melter will be heated up, commissioned and verified operational before the second melter is heated and tuned. This two-phase process reduces risk and enables lessons learned from the first melter heatup to be incorporated into plans for heating up the second melter.
Offgas Tuning and Testing: Upon heatup of the second melter, the melter and associated exhaust, known as offgas, and support systems will concurrently be verified operational.
Timing of Heatup: The melters are heated up during the commissioning phase to ensure all testing of systems feeding into and out of the melter, and the melters themselves, are verified ready to start. It also allows for the melters, which have a design life of about five years, to maximize the time expended in operations treating tank waste.
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