The imaging power of X and γ rays is an invaluable tool for defense and security. High power radiation allows inspection of whole cargo vessels with the ability to detect steel objects and organic matter, guns or people.
This has led to widespread implementation on border checkpoints to increase throughput and detection ability. Similarly, similar lower power systems are used in airports for bag screening to provide quick and thorough analysis of what is being brought onto the plane.
Both measures provide safety, and require shielding to keep people safe and eliminate exposure to harmful radiation. With proper shielding, these processes can continue day-to-day with no accumulated dosage on the personnel responsible for their operation.