Currently, borosilicate glasses are utilised to immobilise highly radioactive waste. They are durable materials; however, they corrode in aqueous solutions, resulting in silica-rich alteration layers. This study employed the nuclear waste leaching tests (MCC-1, MCC-3) on International Simple Glass (ISG) samples. The corrosion rate in pure water and saturated water with respect to ISG corrosion products was investigated at an initial pH of 6.3 and a reaction temperature of 90 °C. For 3, 7, 14, 28, 90, and 180 days, batch experimental models with extremely high and very low glass surface area to volume (S/V) ratios were examined. The results showed that early saturation in the higher S/V system resulted in a ten order magnitude reduced corrosion rate compared to the lower S/V system. This emphasises the significance of saturation in achieving a reduced corrosion rate. This research proved the significant influence of the solution’s chemistry on the glass corrosion rate via pH and other chemical parameters.