DESIGN AND SAFETY FEATURES OF DAPHNE

Heavy water moderated and enriched uranium-fueled Daphne, a zero energy reactor, consists of an aluminum reactor vessel into which lattice plates, fuel, and thimbles can be loaded to mock-up either a Dido or a Pluto core arrangement. Provision is made to measure the effect on reactivity of rigs, loops, and samples destined for the high flux reactors. Daphne also provides a convenient test facility for new designs of control and safety mechanisms and fuel elements. Daphne can also be used for fundamental studies of reactor physics of high neutron leakage heavy water systems and for experiments on reactor kinetics. Improved methods of flux measurement and neutron spectrometry will also be tried out in Daphne. The power level will be restricted to a maximum of 100 w. A fast shut-down system consists of four independent safety rods acting inside four of the fuel elements. Schematic dlagrams are presented of heavy water flow system, heavy water dump valve, reactor core set up for a Pluto test, fuel element, reactor top plate, and the reactor. Characteristics of nucleonic and physical instruments are given. The operational program is outlined. (N.W.R.)