On January 1, 2005 a major step was taken in the complete reorganization of the former Interfaculty Reactor Institute, aimed at boosting scientific quality. On that date, both the Reactor Institute Delft (RID) and the department Radiation, Radionuclides & Reactors (R3) started as new organizational entities within the faculty of Applied Sciences. In September 2012, the name of the deperment was changed into Radiation Science and Technology (RST).

RID is the Dutch national centre for multidisciplinary research and education involving its scientific nuclear reactor, nuclear radiation and radionuclides. Its infrastructure is being used by the research department Radiation Science and Technology and by scientists from other universities. RID and RST together form the national focal point of expertise in the fields of reactor physics, neutron and positron radiation, radiation detection and detection systems as well as radiochemistry. Besides reorganization of the main research focal points within the RST department, the RST organization has actively taken up increased educational responsibilities within the Faculty of Applied Sciences.

The cooperation with the other departments of the Faculty of Applied Sciences has increased significantly since RST is part of the Faculty. These contacts and links will be even tighter when the new housing of the departments BT, ChemE and BN has been realised in a new building that is connected to the RID premises. As a consequence of the new research focus, a complete new structure in five sections (research programmes) was defined. The new focus on health is visible in the sections RIH and RD&M. Explicit emphasis was put on neutron and positron instrument development (resulting in the section NPM2). PNR is a natural evolution of the former section Reactor Physics, with a broader scope than neutronic issues. FAME combines the material research themes of the two former IRI-sections using positrons and neutrons, with a major focus on materials for sustainable energy.