Any area where radiation levels could allow a major portion of the body to receive a dose in excess of 5 millirems in one hour is defined as:

A radiation area is specifically defined based on the potential exposure to radiation. The definition stipulates that any location where radiation levels could permit a significant portion of the body—meaning any critical organs or large areas—to receive a dose exceeding 5 millirems in one hour is categorized as such. This definition is crucial as it helps determine the necessary safety protocols and protective measures that must be in place to guard individuals from harmful radiation exposure.

The classification as a radiation area highlights the need for monitoring and potentially limiting access to ensure safety and compliance with regulatory standards. It serves as an important part of radiation safety practices, guiding personnel on where additional precautions are required to mitigate exposure risks. Other designations, like restricted areas or controlled areas, relate to different exposure parameters or access controls but do not specifically address the same threshold of radiation dose in this context.