Development of a Connection-method Calculation Utility for the DORT-TORT Code

A code package has been developed to utilise connection-method calculation for both 2-D and 3-D SN codes, DORT-TORT, extending further the capabilities of DORSET/TORSET. It also includes support utilities to make input preparation easier. Potential uses of the method are, for example, to allow the coupling of one problem to the end of another by transforming output fluxes of the former into an external source term for the latter. For evaluating the code's applicability in a more specific way, the coupling calculation has been performed using a two-leg duct-streaming problem with a 14 MeV neutron source. The RZ-RZ (DORT) result shows good overall agreement with the reference MCNP4B result. However, it is also found that the result is influenced by the dimension of the calculation region and that some transformation error has occurred. For evaluating the 3-D transformation, full preparation of first collision source is required for TORT.