A fascinating interactive LEGO model of CROCUS, a zero-power, uranium-fueled, water-moderated fission reactor used for teaching and research purposes at Switzerland’s École Polytechnique Fédérale de Lausanne (EPFL), has been created by Vincent Lamirand, a scientist at EPFL’s Laboratory of Reactor Physics and Systems Behaviour. Lamirand, who teaches courses on reactor experiments and radiation detection and leads the experimental research with CROCUS, is using the model to teach his students about the reactor. He is hoping that the LEGO company will eventually produce his model for the public to purchase.