MANCINTAP: Time and Space Dependent Neutron Activation Tool Algorithm Improvement and Analysis of a PWR Nozzle Gallery

摘要

Mancintap [1], a fully automated tool for determining the activation patterns in complex 4D scenarios and evaluating the distribution of the ensuing radiation fields, has been improved. The constraint of forcing the user to define a single global mesh in order to approximate the whole problem, a limitation which prevented an accurate description of detail-rich geometries, has been overcome. The algorithm was improved and many limitations were relaxed. MANCINTAP is now capable of handling many different geometry elements in a given area at once, even if they have very different geometries and characteristic dimensions, thus allowing a vastly more complete and detailed analysis. Different meshes can be superimposed to the 3D geometry, allowing for an appropriate, dedicated treatment of all the relevant features of the problem, and the results are automatically combined in order to provide a global perspective. These new capabilities were accurately tested by applying the tool to the study of time-dependent radiation levels during shutdown in the upper reactor cavity and nozzle gallery regions of a 2-loop PWR reactor.