Results of first safety assessment of the concept of a lead-cooled Energy Amplifer

In 1995, a group headed by Professor C. Rubbia presented the concept of an energy amplifier, a combination of a subcritical fissile assembly and a pro ton accelerator used to produce spallation neutrons. The concept has been p lanned for use not only as a transmutation store for radioactive waste, but also for continuous operation as a power plant. The coolant used is liquid lead. A first assessment of the technical safety of the concept revealed that the energy amplifier is feasible from the point of view of reactor physics, wh ile the behavior of materials still needs to be clarified in mon detail. It s advantages include the passive safety concept, the good properties of lea d as a coolant compared to the sodium used in fast breeders, and the high l evel of inherent safety. Its drawbacks include the large structural height required because of natural circulation; the Large volume of lead; the haza rd of "lead solidification" due to the small margin between the operating t emperature and the melting temperature of lead; and the possibility of supe rprompt criticality arising in case of a loss of the core geometry.