US Patent 7676015 Boundary condition adjustment methods and systems

Methods and systems for reactor lattice depletion are disclosed. One exemplary method, among others, comprises the steps of defining a reactor eigenvalue, the reactor eigenvalue being a specified ratio of actual neutron production to loss in the reactor; producing a lattice eigenvalue, the lattice eigenvalue being an estimated ratio of neutron production to loss in the lattice; and adjusting a boundary condition of the lattice to cause convergence of the lattice eigenvalue and the reactor eigenvalue in order to produce at least one physics parameter.