Stiffness confinement method for solving nuclear reactor kinetics equations

Thesis/Dissertation · Tue Jan 01 04:00:00 EST 1985

OSTI ID:6224978

Attard, A C

The point kinetics equations are stiff, coupled differential equations. This stiffness problem in reactor kinetics is overcome by the stiffness confinement method (SCM) for solving the kinetic equations. The idea is based on the observation that the stiffness characteristic is present only in the time response of the prompt neutron density, but not in that of the delayed neutron precursors. A method is, therefore, devised to have the stiffness decoupled from the differential equations for the precursors and confined to the one for the prompt neutrons, which can be analytically solved. Numerical examples of applying the method to a variety of problems confirm that the step size of time increment can be greatly increased and the computing time much saved as compared to other conventional methods. The effects of including temperature feedback into the formulism of (SCM), and extending (SCM) from the point kinetics model to space-time kinetics, are qualitatively examined. The theory is of general validity and involves no approximation other than the discretization of the time variable.

• Research Organization: Carnegie-Mellon Univ., Pittsburgh, PA (USA)
• OSTI ID: 6224978
• Country of Publication: United States
• Language: English

Related Subjects

22 GENERAL STUDIES OF NUCLEAR REACTORS
220100* -- Nuclear Reactor Technology-- Theory & Calculation
BARYONS
DELAYED NEUTRONS
ELEMENTARY PARTICLES
EQUATIONS
FERMIONS
FISSION NEUTRONS
HADRONS
NEUTRON DENSITY
NEUTRONS
NUCLEONS
NUMERICAL SOLUTION
PROMPT NEUTRONS
REACTOR KINETICS EQUATIONS
TEMPERATURE EFFECTS