Moment integral method for rectangular and hexagonal nodal kinetics

Journal Article · Sat Dec 31 04:00:00 EST 1994 · Transactions of the American Nuclear Society

OSTI ID:89275

Fitzpatrick, W E; Ougouag, A M

Modern nodal methods have been extended to the treatment of kinetic problems via finite differencing of the time variable or via quasi-static methods. More analytic approaches include the stiffness confinement method and the linear leakage time integration method. A semianalytical time-integration techniques coupled to a one-dimensional version of the ILLICO spatial nodal algorithms was also recently developed. In this paper the new technique is modified to allow for piecewise exponential time behavior and to conform more closely to the original formulation of the ILLICO spatial algorithm. The modified treatment is then extended to two-dimensional rectangular and hexagonaI geometries. The newer method employs an analytical solution of the flux over each time interval once a shape for the time dependence of the effective source has been assumed. Thus, the reformulated kinetic method introduces only a slight modification to the steady-state nodal formalism and is readily incorporated into a multidimensional kinetic routine. The method has been implemented and tested on two-dimensional transient problems in rectangular and hexagonal geometry.

• OSTI ID: 89275
• Report Number(s): CONF-941102--
• Journal Information: Transactions of the American Nuclear Society, Journal Name: Transactions of the American Nuclear Society Vol. 71; ISSN TANSAO; ISSN 0003-018X
• Country of Publication: United States
• Language: English

Related Subjects

22 GENERAL STUDIES OF NUCLEAR REACTORS
66 PHYSICS
HEXAGONAL CONFIGURATION
NEUTRON DIFFUSION EQUATION
NEUTRON FLUX
NODAL EXPANSION METHOD
REACTOR CORES
REACTOR PHYSICS