What is the maximum allowable surface reading for returned containers to ensure they pose no removable contamination?

The maximum allowable surface reading for returned containers to ensure they pose no removable contamination is established based on regulatory guidelines that define acceptable levels of radiation exposure. A surface reading of 0.5 mr/hr is consistent with safety standards that aim to protect workers and the public from excess radiation exposure.

This threshold indicates that at this level of radiation, containers are deemed safe for handling and transport, ensuring that any potential contamination is within a manageable limit. Adhering to this standard helps minimize the risk of radiation exposure while ensuring that operations involving radioactive materials can be conducted safely.

In the context of the other options, levels either below or above this threshold would not satisfy the safety criteria. A reading below 0.5 mr/hr could suggest an overly conservative measure, while readings significantly above this limit would pose increased risks, thereby disqualifying those options from being allowable surface readings for ensuring safety against removable contamination.