Formulations of the principal physical processes active during the formation of nuclear debris are described, with an emphasis on first principles approaches and moderate computational costs. The discretization of these models for implementation into numerical codes is also discussed. * For the rest of this report we will use the term particle to refer both to liquid and solid particles.

Fraction of the total mass in the condensed phase as a function of time for each species (left), and volume fraction of the condensed phase normalized for its value at time 10 seconds (right). These curves are indistinguishable for case 1 and case 2 . . . . . . . . . . . . 13 Vapor curves for the three species considered (left), and cooling curve of the system (right). .