This document discusses principles of radiation protection including justification, optimization, and dose limits. It describes how justification requires that the benefits of any radiation exposure outweigh the risks, and optimization aims to keep radiation exposure as low as reasonably achievable. Various personnel protective devices are described such as lead aprons, gloves, glasses and gonad shields that can reduce radiation exposure. The document emphasizes applying principles of time, distance and shielding to minimize dose and ensuring radiation practices are justified.