Status of the Development of an Embedded Transport Treatment of Control Rods and of Radial Flux Expansion in Cylindrical Nodal Diffusion Codes

Technical Report · Tue Sep 01 04:00:00 EDT 2009

DOI:https://doi.org/10.2172/971363· OSTI ID:971363

Gleicher, II, Frederick N; Ougouag, Abderrafi M

A new diffusion-transport hybrid nodal method in R-Z is presented that can effectively treat non-multiplying zones in pebble bed reactors. The new method seamlessly combines the analytic coarse mesh finite difference (CMFD) diffusion formulation and a transport theory based response matrix formulation while retaining the properties and structure of the CMFD diffusion solver. The resulting combined formulation is utilized in selected non-multiplying nodes to capture angular effects on the flux. Test results indicate that the method has been implemented correctly into the CYNOD reactor kinetics code. This document also presents a status report on the development of a better source approximation for the Green’s function nodal solution in the radial direction of cylindrical geometry. The basic theory has been developed, including obtaining polynomials that are orthonormal over the domain of integration and the derivation of approximately half of the required matrix elements (single and double integrals in the source expansions).

• Research Organization: Idaho National Laboratory (INL)
• Sponsoring Organization: DOE - NE
• DOE Contract Number: AC07-05ID14517
• OSTI ID: 971363
• Report Number(s): INL/EXT-09-16788
• Country of Publication: United States
• Language: English

Related Subjects

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS
APPROXIMATIONS
CONTROL ELEMENTS
DIFFUSION
Embedded Transport
GEOMETRY
MATRIX ELEMENTS
NGNP
Nodal Diffusion
PEBBLE BED REACTORS
POLYNOMIALS
REACTOR KINETICS
TRANSPORT
TRANSPORT THEORY