Radiation safety criteria are the radiation dose limits for NPP personnel and the population at the NPP site during normal operation and in the design basis and beyond design basis accidents.

The following dose limits are established for the population and for NPP personnel:

— The effective individual radiation dose for the population during normal operation should not exceed 20 qSv per year;

— The effective individual radiation dose for the population at the boundary of the buffer area during design basis and beyond design basis accidents should not exceed 5 mSv for the entire body during the first year after the accident. In this case, special protection measures for the population are not required;

— For NPP personnel working directly with radiation sources, the effective individual dose during normal operation should not exceed 20 mSv per year on average during any successive five years, with the absolute maximum being 50 mSv per year.

When designing the power unit — its structures and means of radiation protection and isolation (localization) — measures are taken to reduce radiation dose rates in NPP rooms, radionuclide releases to the environment, and radiation doses to personnel, and to keep these radiation parameters as low as possible in line with the ALARA concept.

Radiation safety criteria are met when the design limits for the following parameters are not exceeded:

— Level of primary coolant activity defined by fission products;

— Releases of radioactive substance into the atmosphere through the exhaust pipe;

— Radiation levels in NPP rooms.

Radiation safety criteria are fulfilled owing to consistent implementation of the defence in depth concept, which is based on application of several barriers to the release of ionizing and radioactive substances into the environment, and owing to application of technical and administrative measures to protect and maintain the effectiveness of these barriers.