Extension of nTRACER high fidelity transport code for boiling water reactor simulations and general geometry modeling

Jacob S Hader, Purdue University

Abstract

One of the current limitations of high fidelity deterministic codes for performing light water reactor analyses is modeling the detailed and realistic geometry and material distributions within the reactor core. Additionally, as the computational environment continues to evolve, it is expected that these high fidelity codes will become integral to the reactor design process. As a way to facilitate the continued development of nTRACER, a high-fidelity method of characteristics based neutron transport solver, work has been performed to extend both its geometry modeling and simulation capabilities. In this work, a procedure for generalizing the geometry modeling in nTRACER was developed and an automated process for modeling arbitrary boiling water reactor geometry was created. Additionally, a one-dimensional drift-flux model was implemented into the existing nTRACER framework to account for two-phase flow and its effects on the coolant density change within the core. To verify the accuracy of the extended geometry module, the eigenvalues and spatial flux distributions of the 2-D/3-D C5G7 MOX benchmark problems were compared against the pre-existing, built-in nTRACER geometry module. Finally, verification of the boiling water reactor simulations was done by comparing results for a series of 2-D pin cells and 2-D assemblies between nTRACER and MCNP6.

Degree

M.S.

Advisors

Yang, Purdue University.

Subject Area

Nuclear engineering

COinS