Accelerator-driven subcritical nuclear energy systems open a new, seemingly cost-effective means for nuclear power without the production of long-term high-level waste stream. With the use of accelerator a very intense source of spallation neutrons is created which can be used for energy generation, transmutation of some long-lived nuclear waste into stable or short-lived products and for weapons plutonium reduction. Many advantages of the accelerator-driven transmutation of waste make this method technologically possible and attractive. Since the accelerator-driven systems should never achiewe critically their main advantage is minimisation of the respective concern, which is quite serious for conventional nuclear reactors. It is also important that such a system has the possibility of safer plutonium burning. Fission products, which are mostly stable or short-lived nuclides, can be left to decay naturally. Only such isotopes as ⁹³Zr, ⁹⁹Tc, ¹⁰⁷Pd, ¹²⁹I, ¹³⁵Cs need special attention and can be candidates for transmutation. Non-fissile actinides can be transmuted into fissile nuclides by neutron bombardment and then fissioned.