The minimum energy required to disassemble a system of particles into separated parts is called Binding energy.
Nuclear binding energy is the energy required to split a nucleus of an atom into its component parts: protons and neutrons, or, collectively, the nucleons. ie., it is the energy required to separate the nucleons in a nucleus to infinity. This is equal to the energy released if the nucleons are brought together from infinity to form the nucleus. The binding energy of nuclei is always a positive number, since all nuclei require net energy to separate them into individual protons and neutrons.