Purpose: Patients receiving high doses of radioactive isotopes for thyroid cancer treatment often require hospitalization due to high external radiation exposure. Meals are provided, leading to food waste generation, which is sometimes managed using food waste disposers. Given that shredded food waste is classified as radioactive liquid waste along with water, it is necessary to discuss measures to reduce its volume. This study aims to investigate the difference in the generation of radioactive liquid waste when using a food waste dryer compared to a food waste disposer. Materials and Methods: (1) The amount of water used per cycle with a food waste disposer was measured ten times to determine the average. (2) The changes in tank levels during the period of food waste dryer usage (June to December 2023, 61 patients) and food waste disposer usage (June to December 2021, June to December 2022, 101 patients) were observed to measure and compare the generation of radioactive liquid waste. Results: (1) It was found that an average of 1.58 liters of water was used when processing food waste with a food waste disposer. (2) Comparing the generation of radioactive liquid waste during the periods of food waste dryer and food waste disposer usage revealed an approximate reduction of 8.96 liters per patient when using the food waste dryer. Conclusion: Using a food waste dryer instead of a food waste disposer results in a reduction of radioactive liquid waste. Through this reduction, it is believed that it will be possible to alleviate the burden of expanding storage tanks in medical facilities, reduce the amount of radioactive solid waste, prevent bad odors and pests caused by food waste left around disposers, improve hygiene, and increase patient satisfaction. Therefore, the use of food waste dryer is recommended.