Testing was performed to identify a candidate glass to demonstrate the vitrification process with Idaho National Engineering and Environmental Laboratory (INEEL) high-activity waste (HAW). The specific HAW composition used in glass development was a best estimate of the product of separating the HAW fraction from zirconia calcine (called Zr-HAW). This waste stream contains roughly 93 massO/OZr02 on a dried, nonvolatile oxide basis. Therefore, the volubility of Zr02 in a low-temperature borosilicate glass was expected to dictate the loading of Zr-HAW.