What should the activity level on surfaces be reduced to when decontaminating areas where radioactive materials were used?

When decontaminating areas where radioactive materials were used, it is essential to reduce the activity level on surfaces to at or near background levels. This standard is established to minimize any potential risk associated with residual radioactivity. Achieving levels that are comparable to background radiation ensures that any remaining radioactive materials are not significant enough to pose a health hazard to individuals working in or visiting the space.

Background levels are defined as the natural radiation that is always present in the environment from various sources, including cosmic rays and terrestrial materials. By reducing radioactive contamination to at or near these background levels, facilities can safely allow routine operations to resume without posing an increased risk of exposure to radiation.

It's important to clarify that while minimizing radioactive contamination is critical, aiming for a zero level may not be practical or necessary since certain low levels are natural and unavoidable in most environments. Additionally, the idea that contamination will simply decay over time can be misleading, as it does not take into account the necessity for intervention to manage safety effectively. Therefore, establishing a target of at or near background level is a sound practice in radiation safety protocols.