AN ALTERNATE METHOD OF COMPUTING RESONANCE ABSORPTION AND RESONANCE ESCAPE PROBABILITY IN INTERMEDIATE REACTORS

Technical Report · Thu Feb 25 04:00:00 EST 1960

OSTI ID:4808115

Fischer, P G

An approximate method for treating the energy se1fshielding, and consequent reduction in resonance absorption. which occurs in strong isolated resonances is outlined which enables a reasonably gross energy lattice to be retained for multigroup reactor analysis calculations. The procedure makes use of an approximate expression for the neutron flux within a resonance based on the Wigner (Coveyou-Macauley) slowing down model to obtain the resonance absorption integral directly. Since a multigroup calculation must preserve only such integrals, the precomputed resonance absorption may be used directly in the calculation. The proposed procedure is a straightiorward adaptation of a procedure used in the MUFT codes. Although less accurate than a detailed slowing- down calculation in which the resonance cross-section structure is preserved, ft provides an alternate and presumably satisfactory representation since the predominate physical effect in neutron slowimg-down, neutron flux depression in the resonances, is ineluded. One limitation on the method is the necessity for representing each resonance in terms of single-level Breit-Wigner parameters. Extension of the resonance integral calculation to automatically include Doppler broadening is discussed. (auth)

• Research Organization: General Electric Co. Aircraft Nuclear Propulsion Dept., Cincinnati
• DOE Contract Number: AT(11-1)-171
• NSA Number: NSA-16-011146
• OSTI ID: 4808115
• Report Number(s): DC-60-2-295
• Country of Publication: United States
• Language: English

Related Subjects

ABSORPTION
AIRCRAFT
BREIT-WIGNER FORMULA
CAPTURE
COMPOUND NUCLEI
COMPUTERS
CONFIGURATION
COOLANT LOOPS
CROSS SECTIONS
ENERGY
EQUATIONS
ERRORS
FUEL ELEMENTS
FUELS
GAS COOLANT
GROUP THEORY
HEAT TRANSFER
HIGH TEMPERATURE
MATERIALS TESTING
MECHANICAL PROPERTIES
MECHANICAL STRUCTURES
MODERATORS
MUFT-CODE
MULTIPLICATION FACTORS
NEUTRON FLUX
NUCLEAR REACTIONS
NUMERICALS
PLANNING
PRESSURE
PROGRAMMING
PROPULSION
REACTOR TECHNOLOGY
REACTORS
RESONANCE
RESONANCE ESCAPE PROBABILITY
SLOWDOWN
SPECTRAL SHIFT
TEMPERATURE
THERMAL STRESSES