What signifies a surface radiation measurement of a Type B package?

In the context of Type B packages, which are designed for transporting radioactive materials, the measurement of surface radiation is crucial for ensuring safety and compliance with regulations. The correct answer indicates that a surface radiation measurement of more than 50 mR/hr is a significant threshold for Type B packages.

Type B packages are constructed to safely contain high levels of radioactive materials, and as such, they allow for higher radiation levels at the surface compared to other package types (like Type A packages). The specification of more than 50 mR/hr serves as a regulatory limit that helps ensure the packages are adequately shielded. This level indicates that the package is capable of containing highly radioactive materials but is still designed to protect personnel from the potential hazards associated with these levels of radiation.

Measurements less than 2 mR/hr or less than 10 mR/hr would typically apply to Type A packages, which are used for materials of lower radioactivity and are designed with stricter limits for radiation exposure at the surface to minimize risk. On the other hand, measurements more than 500 mR/hr would typically indicate unsafe radiation levels that exceed the operational limits for safe handling, implying that a package would require special consideration and precautions, possibly indicating an unsafe condition if observed in practice