Abstract: A biological protection for closing an opening in a wall delimiting a radiation zone, this protection comprising at least one iris diaphragm with a base in the form of a flat disk carrying petals formed by plates having a triangular contour and made of a material protecting against ionising radiation. These petals are movable parallel to the base between an open state in which the petals delimit together a central aperture and a closed state in which the petals are closely joined to form together a continuous closed wall.

Abstract: A head for housing an instrument comprises a first part and a second part which is movable relative to the first part. The first part is configured to be rigidly connected to a support mast. The second part comprises an opening which leads outside of the head and into a housing for the instrument. The housing is located inside the head.

Abstract: A method for modeling an environment with a risk of nuclear contamination comprising steps of: acquiring, using a detector (10) and through a 3-dimensional displacement of the detector in the environment, information related to the topography of the environment and radiological measurement data of the environment, and then via a computer processing unit (20), associating the radiological measurement data with location data in the environment, the location data having been deduced from path data of the detector, incrementially creating, using the information and via the computer processing unit: at least one matrix in which topographic data of the environment and the radiological data associated with the location data are compiled, and a 3-dimensional mapping representing the environment in which the topographic data and the radiological data are jointly represented.