Throughout the lifetime of nuclear facilities, radiological inspections are of vital importance, as controlling the radiological state of these facilities is necessary to ensure that their operations remain safe. These inspections are equally important during dismantling and decommissioning (D&D). Inspections of facilities that have contained radionuclides, particularly high activity cells, and very high activity cells are the first step when planning to carry out maintenance and D&D operations. Therefore, the development of investigation robots for hostile environments is a strategic approach in the nuclear field in order to meet these needs. The CEA and CYBERIA have worked together to develop the RICA robot (Robot d'Inspection pour Cellules Aveugles, or blind cell inspection robot), which can locate and measure the activity of radioactive sources. Since 2007, RICA is one of the strategic apparatuses that the CEA has been using for dismantling operations in its nuclear facilities. This small tracked robot was developed to offer a good level of modularity in terms of the onboard equipment able to carry out inspection and sampling missions in extremely hostile environments. To be able to do this, it can be operated either with a complete unit of radiological measurement tools or with a remote‐handling arm. The measurement unit consists of a gamma camera, a gamma spectrometer, and a dose rate detector. This innovative radiological measurement unit enables in situ activity quantification and the collection of all the information necessary to interpret the radiological spectra. On the other hand, when equipped with a remote‐handling arm, the unit can be used to carry out samplings, which will then be analyzed in a laboratory. This paper first presents the RICA robot, giving its main technical features. The innovative radiological measurement unit is described, explaining each of its bricks. The gamma irradiator tests that qualified the robot's functioning under irradiation are described, and the dose resistance results are analyzed. Lastly, examples of tasks in which RICA has been used in CEA nuclear facilities illustrate the robot's modularity.