A nuclear radiation monitoring apparatus comprising: communication circuitry configured to receive nuclear radiation data generated by a nuclear radiation detector, the nuclear radiation data being indicative of nuclear radiation emitted from each of a plurality of portions of an object and detected by the nuclear radiation detector; classification circuitry configured to classify the detected nuclear radiation using the nuclear radiation data; intensity determination circuitry configured to determine a value of an intensity parameter indicative of an intensity of the classified nuclear radiation for each portion of the object using the nuclear radiation data; visualisation data generation circuitry configured to generate visualisation data indicative of the classification of the classified nuclear radiation and, for each portion of the object, visualisation data indicative of the portion of the object and the determined intensity parameter value of the portion of the object; and display output circuitry configured to output the generated visualisation data for display.