Final answer:
The maximum radiation level in an uncontrolled area per year must be 1 mSv to ensure public safety.
Step-by-step explanation:
The maximum radiation level that must be ensured in an uncontrolled area per year is 1 mSv (millisievert). This level is set to ensure the safety of individuals who may be exposed to radiation but are not occupationally involved with radioactive materials or radiation-producing devices. In controlled areas, where personnel are professionally engaged in activities involving radiation, higher limits are applicable but still regulated to ensure safety based on the current standards provided by regulatory authorities such as the International Commission on Radiological Protection (ICRP) or respective national authorities.