A system and method for detecting radiation from a source in a container
is disclosed. A continuous optical fiber path is disposed in a medium
which is part of or associated with a container and which encloses the
volumetric space of the container. The optical fiber path provides a
volumetric mass of optical fiber which is reactive to radiation from a
radiation source in the container to cause an irreversible change in the
light carrying capacity or other characteristic of the optical fiber. A
light source is coupled to one end of the optical fiber path for
introducing light having a predetermined characteristic. A light detector
is coupled to the other end of the optical path for receiving light from
the optical path. A circuit is coupled to the light detector and is
operative to detect a total loss of light or a change in the
predetermined characteristic of the light and to provide an alarm
indication thereof. The alarm indication can be transmitted to one or
more receiving sites via communications paths which can include existing
communications networks.