Nuclear Binding, Stability and Decay in Quantum-Geometry Dynamics: Short-Distance p-Gravity, the Minimum-Volume Threshold, and the Nuclear Stability Equation

Quantum-Geometry Dynamics (QGD) recognizes only the two forces derived from its axioms—p-gravity between preons(+) and n-gravity between preons(−)—and no separate strong, weak or electromagnetic interaction. This paper sets out the QGD account of the atomic nucleus. At nuclear separations the repulsive n-gravity term is negligible and the gravitational coupling reduces to the distance-independent attraction k⋅ma⋅mbk \cdot m_a \cdot m_bk⋅ma⋅mb, which binds nucleons without gluons or colour charge. Electromagnetic repulsion between protons is nullified below a minimum separation because the space between them cannot contain a free-preon(+) field; the repulsion is restored as the nucleus grows. A nucleus is stable when the summed electromagnetic repulsion equals the summed gravitational attraction on each proton (the Nuclear Stability Equation). Neutrons raise the attraction without adding repulsion and therefore act as gravitational ballast. The size limit of the nuclear chart and radioactive decay are the deterministic restoration of equilibrium when this balance is breached; fission releases the intrinsic momentum of liberated preons(+), E=mc~E = m \tilde{c}E=mc~. This paper is a supplementary restatement and organisation of material developed in P11 Chapters 10–11. It separates structural accounts from testable predictions and states plainly what remains open: the quantitative scale of the repulsion, the neutron-rich decay branch, nuclear saturation and shell structure, and the weak-interaction phenomenology. The paper is not a numbered entry in the QGD/MPDT P-series. It introduces no new axioms, forces, or theorems beyond those already present in the monograph.