Preliminary study on limited impact criterion for design extension conditions not practically eliminated

The 12th five-year plan of nuclear safety, prevention and control of radioactive pollution and the vision in 2020 'requires that new nuclear power plants constructed in the thirteen five-year and after that should practically eliminate the possibility of large radioactive release as far as possible in the design for the vision in 2020. Safety of Nuclear Power Plants: Design (SSR-2/1) requires 'For design extension conditions that cannot be practically eliminated, only protective measures that are of limited scope in terms of area and time shall be necessary for protection of the public, and sufficient time shall be made available to implement these measures.' Typical limited impact criterion are analyzed and suggestions on determination of limited impact criterion are given. (authors)