System Design and Operational Strategy for Radiopharmaceutical Waste Decay Tanks Using Patient Load Profiling in a Hospital Nuclear Medicine Facility
Year: 2026
Type: article
Abstract: Background: Radiopharmaceutical liquid waste requires radionuclide-specific retention, whereas decay tanks are often sized based on average wastewater flow. Objective: To develop a patient-load-based decay tank design and operating strategy for the planned nuclear medicine facility at Bali International Hospital. Methods: An engineering design approach integrated planned weekly patient loads, administered activities, surveyed water use, and radioactive accumulation and decay modeling. The adopted aqueous discharge criterion was 0.01 MBq/L, derived from the iodine-131 (I-131) clearance level of 10 Bq/g. Results: The planned service profile comprised 58 diagnostic and 42 therapeutic patients per week, generating 7,750 L and 3,900 L of wastewater, respectively. Following a 10-week filling period, therapeutic effluent was modeled to have an activity concentration of 4.43 MBq/L and required 11 weeks of isolated decay. Diagnostic effluent required approximately 39.6 hours to reach the criterion; a 3-day retention period was therefore adopted. The proposed segregated configuration comprises three 40,000-L therapeutic tanks and three 10,000-L diagnostic tanks. Segregation avoids approximately 85,000 L of additional storage compared with retaining diagnostic effluent for the therapeutic decay period. Conclusion: Patient-load profiling supports distinct capacity and rotation strategies for diagnostic and therapeutic radioactive waste. Model-predicted compliance with the discharge criterion does not, by itself, authorize discharge without activity measurement, input reconciliation, and regulatory verification.
Institution: Binus University
Language: English
Subfield: Safety, Risk, Reliability and Quality
Field: Engineering
Domain: Physical Sciences
Open Access status: diamond
Funder: Binus University
OpenAlex ID: W7225577950