Glossary

Term used to include the measures established to prevent failure to comply with a law or agreement that bans the use of nuclear materials or facilities with non-peaceful aims. It is usually used in the plural.

A set of components, systems or administrative regulations used at nuclear or radioactive sites to prevent accidents. At a nuclear power plant there are usually three 3 safety barriers: the fuel rod cladding, the reactor vessel (the primary circuit) and the reactor containment. The fuel pellet itself is sometimes added as a first barrier, since under normal operating conditions its treatment enables it to retain a large part of the generated fission products.

Emergency room of the Spanish Nuclear Safety Council.

1. Fluorescent screen: Surface covered with a fluorescent substance that emits light when it receives an ionising radiation. 2. Reinforcement screen: Sheet which under the action of X-rays emits a secondary radiation that contributes to the printing of the plate. 3. Radiation-absorbing device that blocks its path in order to intercept radiation totally or partially.

Time interval needed for the number of atoms in a radioactive nuclide to be reduced by half through spontaneous decay.

Thickness of a given substance that reduces by half the intensity of a certain type of radiation, when it is interposed in its path.

Material placed between a source of radiation and personnel in order to minimise the number of particles and radiation, and protect personnel from the effects of such radiation.

Correction factor owing to radiation attenuation.

Unit of equivalent and effective radiation dose in the International System of Units: 1 Sv = 1 J/kg. The old unit is the REM. 1Sv = 100 REM.

Brief external exposure or internal exposure resulting from radionuclide intake during a short period of time.

Device or substance capable of emitting ionising radiation.

In reactor technology, synonymous with shutdown. When following a nuclear reactor's stop the coolant temperature remains high, this is known as a hot shutdown. If the coolant temperature falls, the term used is "cold shutdown".

Person authorised by the Spanish Nuclear Safety Council and in charge of directing the operation of a nuclear or radioactive facility and the work of the operators and, where applicable, of replacing the operators.