Development of a new two-dimensional Cartesian geometry nodal multigroup discrete-ordinates method

Technical Report · Thu Jul 01 04:00:00 EDT 1982

DOI:https://doi.org/10.2172/5261627· OSTI ID:5261627

Pevey, R E

The purpose of this work is the development and testing of a new family of methods for calculating the spatial dependence of the neutron density in nuclear systems described in two-dimensional Cartesian geometry. The energy and angular dependence of the neutron density is approximated using the multigroup and discrete ordinates techniques, respectively. The resulting FORTRAN computer code is designed to handle an arbitrary number of spatial, energy, and angle subdivisions. Any degree of scattering anisotropy can be handled by the code for either external source or fission systems. The basic approach is to (1) approximate the spatial variation of the neutron source across each spatial subdivision as an expansion in terms of a user-supplied set of exponential basis functions; (2) solve analytically for the resulting neutron density inside each region; and (3) approximate this density in the basis function space in order to calculate the next iteration flux-dependent source terms. In the general case the calculation is iterative due to neutron sources which depend on the neutron density itself, such as scattering interactions.

• Research Organization: Oak Ridge National Lab., TN (USA); Tennessee Univ., Knoxville (USA). Dept. of Nuclear Engineering
• DOE Contract Number: W-7405-ENG-26
• OSTI ID: 5261627
• Report Number(s): ORNL/CSD/TM-182; ON: DE82018570
• Country of Publication: United States
• Language: English

Related Subjects

654003* -- Radiation & Shielding Physics-- Neutron Interactions with Matter
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
COMPUTER CALCULATIONS
COMPUTER CODES
D CODES
ENERGY DEPENDENCE
FORTRAN
ITERATIVE METHODS
MULTIGROUP THEORY
NEUTRON DENSITY
NEUTRON LEAKAGE
NEUTRON TRANSPORT THEORY
PROGRAMMING LANGUAGES
REACTORS
SPACE DEPENDENCE
TRANSPORT THEORY
TWO-DIMENSIONAL CALCULATIONS