Key Protection Points:

1. Entrance: For general X-rays, when the source strength (tube voltage) > 400 kV, a detour (maze) should be provided at the entrance. Detours are also required for gamma-ray, neutron, and accelerator particle areas.

2. Walls: Thickness should be determined by calculation. For masonry walls, the mortar should be dense and no post-filling holes should be left. For cast-in-place concrete walls, compaction must be ensured to be uniform and the density must meet design requirements, especially preventing material slippage and "sinking." Large-volume concrete should be reinforced with temperature-controlled reinforcement to prevent shrinkage cracking. When using lead plates, lead-containing or boron-containing plastic plates, the overlap width should be > 10 mm, and the nails fixing the plates should be covered with lead plates.

3. Protective Doors: Thickness should be determined by calculation. The overlap width between the door and the wall should be ≥ 100 mm, and double doors should not have a through gap in the middle.

4. Observation Windows and Pass-through Windows: Determined according to process operation needs. The windowsill height should be determined according to practical requirements, the height and orientation of the radiation source device, and the specific situation of personnel stationed outdoors.

5. Ventilation: Forced ventilation systems should be installed in all rooms, with air changes per hour meeting radiation protection regulations. Ventilation facilities should incorporate measures to prevent radiation leakage (special attention should be paid to neutron and accelerator rooms).

6. Ductwork: Ductwork should avoid passing through protective walls or panels. If passage through these walls is unavoidable, a zigzag route should be used, and measures should be taken to prevent radiation leakage from weak points.

7. Electrical: Indoor busbars should be installed at least 3 meters above the ground, and high-voltage components of equipment should be grounded. Grounding devices must be located away from underground conduits. Radiation source rooms should be equipped with alarm devices that are integrated with door interlocking systems.