Wuhan Aiwei focuses on the production and manufacturing of security equipment, and is a private enterprise engaged in international trade, technical consulting, sales, and leasing. It provides entrance and exit security hardware equipment, software, services, and solutions for security service providers and large government agencies around the world.


Radiation safety and protection

1. Principles of zoning and regional division

Our unit provides a guidance plan for zoning management and division of the inspection site for the inspection system, and refers to the relevant provisions of the Radiation Protection Requirements for Goods/Vehicle Radiation Inspection Systems (GBZ143-2015) for radiation workplaces. For the inspection system of freight vehicles driven by drivers, the radiation source room and the effective wiring harness area on both sides should be designated as a control area, with a dose equivalent rate greater than 2.5 in the surrounding area outside the control area μ The Sv/h area is designated as a supervision area, Determine the zoning of the inspection site for this project: Manage the inspection site by dividing it into control and supervision areas, and set corresponding signs.
(1) Control area: the detection area between the radiation source and detector, as well as the detection channel area within a range of 0.5m on both sides. The radiation dose rate at the boundary of the control area is controlled to not exceed 10 μ Gy • h-1. No personnel are allowed to enter the control area while checking the working status of the system.
(2) Supervision area: Check any area within the 3m lane range on both sides of the gantry, except for the control area. The radiation dose rate at the boundary of the supervision area should be controlled to not exceed 2.5 μ Gy • h-1. No personnel other than the driver of the inspected vehicle and radiation workers are allowed to enter the supervision area during the inspection of the system's working status. Unless necessary for testing, staff should stay outside the supervision area.
 
2. Workplace radiation protection shielding design

(1) The relevant radiation protection shielding design of the X-ray source room is as follows:
Cabinet size: 3700 x 1100 x 1900mm; Cabinet inner wall: 1-2mm lead equivalent; Collimator: 30mm thick lead drum with a 2mm wide uniform gap in the center; Shutter: 20mm thick L-shaped lead shielded shutter.
(2) Design of radiation protection shielding for detector subsystems
The detector subsystem receives radiation that passes through the inspected object, including the column and beam sections. The back of the detector is shielded with a J-shaped lead plate, with a width of approximately 655mm. The back of the detector column is protected with a 30mm lead plate, and the protection on both sides of the column is shielded with a 10mm lead plate. The lead plates are interlocked with each other; The crossbeam protection adopts 5mm lead plates, which are interlocked with each other. Ray fan-shaped beam angle: 600, the ray beam is perpendicular to the shielding body of the cabinet. The width of the door arch is 1000mm, and it can effectively shield the fan-shaped beam.
 
3. Radiation safety measures

1. System self-test
Only when the vehicle enters the detection area, the safety shutter automatically opens, and a fan-shaped beam of radiation is emitted. The truck moves within the fan-shaped beam, and the beam scans the entire vehicle body.
2. Shielded compartment
Check the system design of the shielded compartment and install safety doors on it.
3. Automatic training machine settings
Check that the continuous X-ray beam output time of the system design cannot exceed 10 seconds, and enter the training machine state at a fixed time. The system needs to be restarted to continue working.



4. Other inherent safety performance

When the system is damaged by accidental impact, the X-ray emitting device automatically stops working; When the system automatically detects lane parking or damaged vehicles, the X-ray emitting device automatically stops working.

5. Safety interlocking device

1. Automatic interlocking

The control panel is equipped with a key switch interlock, and the X-ray machine can only emit X-rays when the key is inserted and in the "working" position. The system design can effectively prevent personnel from entering the safety interlocking facilities of the control area under detection status. When personnel enter the control area by mistake, the high-voltage power supply will be automatically cut off and the beam output will be automatically stopped. The system is designed with an automatic interlocking device, which automatically cuts off the high voltage and stops the X-ray beam when a malfunction occurs, effectively avoiding additional exposure to workers or the public. When the ground sensing system does not detect the passage of vehicles, the equipment cannot be started normally and the specific situation of the fault is displayed on the terminal.

2. Emergency stop switch

There are safety switches installed on the cabinets of the security inspection system equipment for large track moving vehicles, and multiple emergency stop switches are installed on the cabinets and distribution boxes. High voltage power supplies, oil coolers, radiation detectors, and other equipment have fault alarm signals. There is an emergency stop button on the main interface of the operation software, which is connected to the hardware. Any abnormality will cut off the power supply of the high voltage power supply and stop the X-ray beam. The main controller will monitor all these abnormal alarm signals and display the reason for the alarm on the operation software. The emergency stop switch can cut off the impact of X-rays on the environment in emergency situations.

3. Video surveillance device

The system is designed with a license plate automatic recognition system, including video surveillance devices, embedded and integrated structure, lighting, image capture, and recognition algorithm integration. The stop recognition system can effectively recognize and record information such as license plates and personnel activities. Install an anti-theft alarm system in the system and implement 24-hour monitoring of the inspection system.
Check the installation of surveillance cameras in the radiation workplace to observe the presence of personnel and the operational status of equipment in the radiation workplace.
The above safety interlocking system can effectively prevent accidental radiation exposure.

4. Safety warning signs

At the entrance of the inspection system inspection lane, prominent ionizing radiation warning signs should be installed on the surface of the radiation source box to warn surrounding personnel not to approach.

5. Warning system

Install a set of green, red, and yellow warning lights and bells on the inspection system door frame. When the system is powered on, the green alarm light comes on; When the X-ray machine is ready to beam out, the yellow alarm light is on and the alarm light is on; When the X-ray machine emits the beam, the red alarm light lights up and the alarm bell rings.