Classification of Workplaces and Monitoring in Nuclear Medicine Facilities

1. Controlled Areas

Controlled areas require specific protective measures to ensure radiation exposure is minimized and controlled. These areas are characterized by:

• Unpredictable or variable doses to workers.
• Higher radiation levels requiring strict controls and monitoring.
• Designated boundaries, often using structural elements planned during facility design.

Examples in a nuclear medicine facility:

• Preparation rooms for radiopharmaceuticals.
• Storage areas for radioactive materials and waste.
• Injection rooms where radiopharmaceuticals are administered.
• Imaging rooms and waiting areas for injected patients, due to contamination risks.
• Areas for patients receiving therapeutic radionuclides.

In certain cases, areas handling pure beta emitters like 90Y, 89Sr, or 32P may not need controlled area designation since these radionuclides are not excreted from the body.

2. Supervised Areas

Supervised areas have predictable and stable exposure conditions and typically do not require additional protective measures beyond standard monitoring. These areas:

• Are kept under regular review to ensure safety.
• Require no specific controls for occupational exposure.

3. Workplace Monitoring

Workplace monitoring ensures the safety and integrity of controlled and supervised areas through regular checks for radiation levels or contamination.

3.1 Exposure Monitoring

Purpose: Measure radiation levels in microsieverts per hour.

Tools: Survey meters or exposure meters.

Application: Conducted at various points to identify radiation risks.

3.2 Contamination Monitoring

Purpose: Detect radioactive material on surfaces.

Method: Routine checks in predefined areas to prevent contamination spread.

4. Routine Monitoring Procedures

• Responsibility: A designated and trained staff member performs monitoring.
• Predefined Locations: Measurements are conducted in areas outlined by the Radiation Protection Officer (RPO).
• Record Keeping: Results are recorded and analyzed against predefined investigation levels.
• Follow-up Actions: Any exceedance of these levels requires immediate investigation and corrective measures.