美国标准是对环境中人产生的每年的核辐射总量。
The NRC requires that the release of radioactive material from a nuclear power plant must not result in a radiation dose of greater than 3 millirem to any individual in an unrestricted area.
This limit applies to every civilian facility that uses radioactive material.
The U.S. Environmental Protection Agency (EPA) has established a Maximum Contaminant Level (MCL) of 4 millirem per year for beta particle and photon radioactivity from man-made radionuclides in drinking water.
