Introduction to Decay Tanks in Hospital Nuclear Medicine Departments and Advantages of Yuanhang Environmental Protection

I. Overview of Decay Tanks in Hospital Nuclear Medicine Departments

In hospital nuclear medicine departments, decay tanks are critical facilities for treating radioactive wastewater. During nuclear medicine diagnosis and treatment, radionuclides such as iodine-131 and technetium-99m are used. The wastewater generated after these procedures, if discharged directly, can severely impact the environment and public health. Based on the half-life principle of radioactive materials, decay tanks collect, store, and monitor wastewater to allow sufficient decay of radioactive substances, reducing radioactivity levels until discharge standards are met.

Decay tanks are typically constructed from corrosion-resistant and aging-resistant stainless steel to ensure long-term stable operation. Their structure includes decay tank bodies, control systems, and monitoring systems. The decay tank bodies hold the wastewater, withstand pressure and radiation, and are manufactured to strict standards to prevent leaks. The control system regulates parameters such as temperature, pressure, and flow rate, enabling remote monitoring and operation to improve efficiency and safety. The monitoring system uses highly sensitive detectors to track the concentration and decay of radioactive substances in real time, providing data support for treatment.
Common types of decay tanks in hospitals include push-flow and intermittent systems. Push-flow systems allow wastewater to flow sequentially through multiple connected tanks; they are simple in structure and low in cost, but variations in water level and solid sedimentation can affect treatment effectiveness, potentially leading to non-compliant discharge. Intermittent systems fill one decay tank before sealing it and moving to the next, cycling through the process. As long as the actual wastewater volume does not exceed the design estimate, discharge standards can be met, and pressure drainage can remove sediments.

II. Advantages of Yuanhang Environmental Protection in the Field of Decay Tanks

(I) Technological Innovation Advantages
Multi-Tank Graded Treatment Technology: Yuanhang Environmental Protection designs parallel dual-tank or multi-tank systems tailored to radionuclides with different half-lives. For example, the 4-stage stainless steel decay tank at North China University of Science and Technology Affiliated Hospital uses a parallel graded treatment process. For wastewater containing iodine-131, scientific planning of storage levels across tanks reduces the decay cycle to 60% of that of traditional single-tank systems. A 125m3 system achieves efficient daily treatment of 50m3 of wastewater.
Dynamic Adjustment of Storage Time: Strictly based on radionuclide half-lives, such as ≥180 days for iodine-131 and ≥30 days for technetium-99m, ensuring radioactive activity decays steadily below safe limits.

Efficient Pretreatment Technology: Equipped with a cutter pump crushing device to quickly pulverize solid residues in wastewater, combined with gravity sedimentation in settling tanks, multi-layer filtration, and activated carbon adsorption, improving subsequent decay efficiency. In one research institution, this pretreatment increased decay efficiency by approximately 20%.

(II) Advantages in Intelligent Monitoring and Control

Precise Monitoring: Integrated γ-ray detectors, water quality sensors, and temperature and humidity monitoring devices provide real-time tracking of key parameters such as radioactive activity, pH, conductivity, and environmental temperature and humidity. In a project at China Medical University, the system automatically adjusted drainage cycles based on iodine-131 decay curves, improving efficiency by 70% compared to manual operation and reducing annual operational costs by 30%.

Advanced Control: Utilizes PLC programmable control systems and intelligent human-machine interfaces, enabling remote monitoring and automatic wastewater discharge, reducing manual intervention. Equipped with leak detection, gamma camera positioning, and sump pits to handle leaks. For example, in a project at a hospital in Henan, during a sudden power outage, the UPS power supply automatically switched over, with an interruption time of less than 30 seconds, preventing leakage risks.

(III) Safety and Reliability Advantages

Material and Corrosion Resistance: Decay tank bodies are constructed from corrosion-resistant stainless steel, with epoxy resin anti-corrosion treatment on inner walls, providing radiation resistance and corrosion protection, with a service life exceeding 20 years.
Multiple Protective Measures: Equipped with water seals or check valves to prevent wastewater backflow. The rooms housing decay tanks are lined with lead plates (≥3mm), controlling radiation dose rates below 2.5μSv/h, and feature negative pressure exhaust systems to eliminate harmful gases. For example, in a project at Qingdao West Coast New Area People's Hospital, external walls used double-layer concrete block walls (120cm) with barium protective mortar, and ceilings were coated with 120cm thick barium mortar, ensuring radiation isolation.

(IV) Flexible Design and Expansion Advantages

Innovative Structural Design: Utilizes modular stainless steel tank designs with standardized interfaces between modules, enabling easy installation and rapid assembly into decay tanks of various sizes to meet diverse hospital needs. A customized mobile decay tank unit for a nuclear physics research institute at the Chinese Academy of Sciences used lightweight stainless steel and quick-connect interfaces to meet temporary storage and decay needs for high-activity waste liquids.
Rational Layout Planning: Employs parallel layouts that separate storage for long and short half-life radionuclides, improving tank utilization and allowing different radionuclides to decay in suitable environments.

(V) Environmental Compliance and Management Advantages

Strict Regulatory Compliance: Designs and constructs decay tanks in strict accordance with national environmental regulations and standards, ensuring legal compliance and達標(biāo) discharge of wastewater.
Transparent Management: The system automatically generates檢測 reports covering key treatment data and can integrate with hospital and environmental department systems, enabling transparent and traceable management of the entire treatment process. For example, in a project at Guangzhou First People's Hospital Nansha Branch, an IoT cloud platform實時采集 data, issues alerts for abnormalities, and coordinates emergency responses, ensuring discharge complies with GB 18466-2005 standards.

In summary, Yuanhang Environmental Protection offers multi-dimensional advantages in the field of decay tanks for hospital nuclear medicine departments, providing safe, efficient, and intelligent solutions for radioactive wastewater treatment, supporting the safe operation of hospital nuclear medicine departments, and safeguarding the environment and public health.