Development of advanced nodal diffusion methods for modern computer architectures

Thesis/Dissertation · Fri Jan 01 00:00:00 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
• Resource Relation: Other Information: Thesis (Ph. D.)
• Country of Publication: United States
• Language: English

Related Subjects

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