This Safety Guide provides recommendations for ensuring radiation protection in the design of new nuclear power plants, design modifications to operating plants, and checking the adequacy of the radiation protection aspects of design at different stages in the lifetime of operating plants. It also provides recommendations for measures to be taken in the design for the protection of site personnel, the public and the environment, and outlines the methodologies used to calculate on-site and off-site radiological conditions and to verify that the design provides an adequate level of radiation protection during operating lifetime and decommissioning. The guide is intended primarily for land-based, stationary nuclear power plants with water cooled reactors designed for electricity generation or for other heat generating applications. This publication is intended for organizations responsible for designing, manufacturing, and constructing nuclear power plants, operating organizations and contractors, including plant operators who are involved in planning, managing and implementing the design and design modification of nuclear power plants, and regulatory bodies and technical support organizations.