This question is brief and simple. As a layman, it is my understanding that QCD (Quantum Chromodynamics) explains the nuclear force as a "residual" force, mediated by pions (mesons), which pinch off as "virtual" pairs of quarks from the protons and neutrons. In terms of pions being responsible for the residual nuclear force, how does one fit nuclear fission into the picture? Is the energy from the splitting of, say, a uranium isotope coming from the release of pions or something? When "binding energy", generated by pion exchange, is released, what is happening on the quark level, or on the level of QCD? Any info or reference is appreciated.
EDIT: This question has been resolved, because I've found Nuclear effective field theory: Status and perspectives. I never heard of nuclear EFT or "ab initio nuclear physics," it is not something you come across in standard reading, but this is precisely what I was looking for. Also, Microscopic Theory of Nuclear Fission (PDF).