Abstract: A neutron activation analysis installation comprises a neutron generator whose target chamber communicates through a transport means with a test sample receiving and loading assembly which, in its turn, communicates with a test sample impurity concentration measuring unit. The receiving and loading assembly is in communication with the impurity concentration measuring unit over a channel having a through lateral port communicating on one side with the input of an irradiated sample surface layer removal unit, an irradiated sample distribution assembly being arranged on the other side of the port. The irradiated sample distribution assembly represents an air cylinder with a hollow rod having a bar arranged along the axis thereof and mounting on its end a sample receiver. The bar is disposed in a manner allowing its rotation about the longitudinal axis thereof and reciprocating motion through the port in the channel.