Development of advanced nodal diffusion methods for modern computer architectures

Thesis/Dissertation · Fri Jan 01 04:00:00 EST 1988

OSTI ID:7261825

Rajic, H L

A family of highly efficient multidimensional multigroup advanced neutron-diffusion nodal methods, ILLICO, were implemented on sequential, vector, and vector-concurrent computers. Three-dimensional realistic benchmark problems can be solved in vectorized mode in less than 0.73 s (33.86 Mflops) on a Cray X-MP/48. Vector-concurrent implementations yield speedups as high as 9.19 on an Alliant FX/8. These results show that the ILLICO method preserves essentially all of its speed advantage over finite-difference methods. A self-consistent higher-order nodal diffusion method was developed and implemented. Nodal methods for global nuclear reactor multigroup diffusion calculations which account explicitly for heterogeneities in the assembly nuclear properties were developed and evaluated. A systematic analysis of the zero-order variable cross section nodal method was conducted. Analyzing the KWU PWR depletion benchmark problem, it is shown that when burnup heterogeneities arise, ordinary nodal methods, which do not explicitly treat the heterogeneities, suffer a significant systematic error that accumulates. A nodal method that treats explicitly the space dependence of diffusion coefficients was developed and implemented. A consistent burnup-correction method for nodal microscopic depletion analysis was developed.

• Research Organization: Illinois Univ., Urbana, IL (USA)
• OSTI ID: 7261825
• Country of Publication: United States
• Language: English

Related Subjects

22 GENERAL STUDIES OF NUCLEAR REACTORS
220100* -- Nuclear Reactor Technology-- Theory & Calculation
99 GENERAL AND MISCELLANEOUS
990200 -- Mathematics & Computers
BURNUP
COMPUTER ARCHITECTURE
COMPUTER CALCULATIONS
DIFFERENTIAL EQUATIONS
EQUATIONS
MULTIGROUP THEORY
NEUTRAL-PARTICLE TRANSPORT
NEUTRON DIFFUSION EQUATION
NEUTRON TRANSPORT
NEUTRON TRANSPORT THEORY
PROGRAMMING
PWR TYPE REACTORS
RADIATION TRANSPORT
REACTORS
TRANSPORT THEORY
VECTOR PROCESSING
WATER COOLED REACTORS
WATER MODERATED REACTORS