Transmutation of isotopes - Ecological and energy production aspects

This paper describes principles of Accelerator-Driven Transmutation of Nucl ear Wastes (ATW) and gives some flavour of the most important topics which are today under investigations in many countries. Pin assessment of the pot ential impact of ATW on a future of nuclear energy is also given. Nuclear r eactors based on self-sustained fission reactions - after spectacular devel opment in fifties and sixties, that resulted in deployment of over 400 powe r reactors - are wrestling today more with public acceptance than with irre solvable technological problems. In a whole spectrum of reasons which resul ted in today's opposition against nuclear power few of them are very releva nt for the nuclear physics community and they arose from the fact that deve lopment of nuclear power had been handed over to the nuclear engineers and technicians with some generically unresolved problems, which should have be en solved properly by nuclear scientists. In a certain degree of simplifica tion one can say, that most of the problems originate from very specific fe atures of a fission phenomenon: self-sustained chain reaction in fissile ma terials and very strong radioactivity of fission products and very long hal f-life of some of the fission and activation products. And just this enormo us concentration of radioactive fission products in the reactor core is the main problem of managing nuclear reactors: it requires unconditional guara ntee for the reactor core integrity in order to avoid radioactive contamina tion of the environment; it creates problems to handle decay heat in the re actor core and finally it makes handling and/or disposal of spent fuel almo st a philosophical issue, due to unimaginable long time scales of radioacti ve decay of some isotopes. A lot can be done to improve the design of conve ntional nuclear reactors (like Light Water Reactors); new, better reactors can be designed but it seems today very improbable to expect any radical ch ange in the public perception of conventional nuclear power. In this contex t a lot of hopes and expectations have been expressed for novel systems cal led Accelerator-Driven Systems, Accelerator-Driven Transmutation of Waste o r just Hybrid Reactors. All these names are used for description of the sam e nuclear system combining a powerful particle accelerator with a subcritic al reactor. A careful analysis of possible environmental impact of ATW toge ther with limitation of this technology is presented also in this paper.