A 30 cm by 38 cm, brass, plaque whose inscription reads: “Nuclear Power Demonstration (Prototype CANDU Reactor). For demonstrating the concept of the distinct-design, horizontal, pressure-tube, natural-uranium fueled, heavy water moderated and cooled CANDU reactor with on-power fueling. Designated as a Nuclear Historic landmark, November 2002 by the American Nuclear Society.” The back of the plaque contains some details of the construction and an instruction that “No Diamond Shield”, presumably a polish, should be used to buff the surface.