What level of radiation exposure defines a High Radiation Area?

The correct choice identifies a High Radiation Area as defined by regulatory standards, particularly in the context of radiation protection and safety within nuclear medicine and other radiological practices. A High Radiation Area is designated when the level of radiation exposure is 100 mRem/hr or greater.

The significance of this threshold is rooted in the need to protect workers and the public from potentially harmful levels of radiation exposure. The Department of Energy and other regulatory bodies use this measure to determine when additional safety protocols, signage, and protective measures are necessary to minimize exposure.

To contextualize, the other options represent lower levels of radiation and do not meet the criteria for classification as a High Radiation Area. For example, 500 rads/hr is an extremely high and hazardous level but is not the defined threshold for a High Radiation Area; it indicates a serious incident requiring immediate attention. Similarly, 5 mR/hr and 1 mSv/hr do not reach the levels set for high radiation exposure, which is specifically noted as being 100 mRem/hr. Understanding these distinctions is important for professionals working in PET and radiologic technologies, ensuring adequate safety measures are in place according to established guidelines.