Chapter 5 - Radiation Safety

Abstract

It is essential that activities involving radiation exposure, such as the production and use of radiation sources and radioactive materials, and the operation of nuclear installations and management of the radioactive waste they produce, be subject to certain standards of safety in order to protect persons exposed to radiation. Ionising radiation and radioactive substances are natural and permanent features of the environment, and thus the risks associated with radiation in all its forms can only be restricted, not eliminated entirely. Deterministic effects due to radiation exposure are the result of different processes, mainly cell killing and delayed cell division, which can, if extensive enough, impair the function of the exposed tissue. The severity of a particular deterministic effect in an exposed individual increases with the dose above the threshold for the occurrence of the effect. Internal exposure results from intake of an unsealed radioactive material to the human body. Protection against internal exposure, therefore, can be achieved by preventing a radioactive material from being taken into the body. To control the radiation exposure of workers, medical patients and the public, many countries have developed laws, which are supported by administrative measures and enforced by inspectors. Equally important is to have internationally agreed standards. As the use of radioactivity in industry, medicine and power generation increases, there is a general need for dosimetric systems that can be applied to continuous monitoring and accident situations. Personnel dosimetry is a proper and most effective means of assuring compliance with regulations governing the use of radioactive materials and ionising radiation with the requirement to keep radiation exposure “as low as reasonably achievable”.