Six factor formula

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The six-factor formula is used in nuclear engineering to determine the multiplication of a nuclear chain reaction in a non-infinite medium.

Contents

Six-factor formula: [1]
SymbolNameMeaningFormulaTypical thermal reactor value
Thermal fission factor (eta)neutrons produced from fission/absorption in fuel isotope1.65
Thermal utilization factorneutrons absorbed by the fuel isotope/neutrons absorbed anywhere0.71
Resonance escape probability fission neutrons slowed to thermal energies without absorption/total fission neutrons0.87
Fast fission factor (epsilon)total number of fission neutrons/number of fission neutrons from just thermal fissions1.02
Fast non-leakage probabilitynumber of fast neutrons that do not leak from reactor/number of fast neutrons produced by all fissions0.97
Thermal non-leakage probabilitynumber of thermal neutrons that do not leak from reactor/number of thermal neutrons produced by all fissions0.99

The symbols are defined as: [2]

Multiplication

The multiplication factor, k, is defined as (see nuclear chain reaction):

k = number of neutrons in one generation/number of neutrons in preceding generation

See also

References

  1. Duderstadt, James; Hamilton, Louis (1976). Nuclear Reactor Analysis. John Wiley & Sons, Inc. ISBN   0-471-22363-8.
  2. Adams, Marvin L. (2009). Introduction to Nuclear Reactor Theory. Texas A&M University.