Lead-Lined Radiation-Proof Automatic Doors Installed at a Multi-Modality Imaging Center in the Middle East

Project Background

A purpose-built multi-modality diagnostic imaging center in the Middle East required radiation shielding doors for its CT scan, conventional X-ray, and nuclear medicine departments. The facility operates under the regulatory oversight of the national nuclear regulatory authority, which mandates all doorways in radiation-controlled areas to meet specific shielding equivalency requirements expressed in millimeter-lead equivalency (mmPb). The center's radiation safety officer specified that all doors must be custom-engineered with verifiable shielding performance and must also function as automatic sliding doors to support high patient throughput workflows.

Challenges & Requirements

Radiation-proof doors present a unique set of engineering challenges distinct from conventional automatic doors:

• High door weight: lead-lined panels significantly increase leaf weight (300–900 kg per door), requiring heavy-duty motor and track systems
• Precise shielding specification: CT room doors required 8 mmPb equivalency; X-ray rooms required 3 mmPb; nuclear medicine suite required 12 mmPb
• Continuous overlap sealing: radiation can scatter through gaps; door edges required overlapping lead-lined jambs with no direct line-of-sight
• Smooth patient-facing operation: despite the heavy structure, doors must open and close smoothly and quietly
• Interlock compatibility: CT and nuclear medicine rooms required two-door interlock systems to prevent simultaneous opening

Oredy's Solution

Oredy's engineering team conducted a site survey and prepared custom shielding calculations verified by the client's radiation physicist. Twelve sets of lead plate automatic sliding doors were manufactured across three shielding specifications. The door panels were constructed with a cold-rolled steel skin bonded to high-purity lead plate cores, then finished with a durable powder-coated surface. The track and drive system was upgraded to Oredy's heavy-duty HDS series, rated for door leaf weights up to 900 kg, with a variable-frequency drive (VFD) motor providing smooth, controlled acceleration and deceleration regardless of load. Overlapping lead-lined edge frames were installed at all door jamb positions to eliminate any direct radiation path. For the CT and nuclear medicine rooms, interlocked door pair controllers were configured to prevent simultaneous opening of both doors in each vestibule.

Results & Client Feedback

Pre-occupancy radiation surveys conducted by an independent physicist confirmed that all 12 door installations met or exceeded the specified mmPb shielding equivalency. The facility's medical director noted that the automatic operation of these heavy doors — which had been a point of concern during the planning stage — was smooth and silent, with no negative impact on patient experience. The interlock system functioned precisely as designed, preventing any inadvertent double-door opening events. The imaging center passed its regulatory inspection without requirements for remedial shielding work, allowing it to open on schedule.

Key Technical Specifications

• Door Type: Single-panel and bi-parting heavy-duty automatic sliding
• Lead Core: High-purity lead plate (3 mmPb / 8 mmPb / 12 mmPb options)
• Outer Skin: Cold-rolled steel, powder-coated finish
• Max Door Leaf Weight: 900 kg per panel
• Drive System: Oredy HDS heavy-duty series, VFD motor
• Edge Sealing: Overlapping lead-lined jamb frames, zero line-of-sight
• Interlock Function: Two-door interlock controller, configurable logic
• Certifications: CE, ISO 9001; shielding calculations per IAEA standards