American Nuclear Society
Home

Home / Store / Journals / Electronic Articles / Nuclear Science and Engineering / Volume 92 / Number 2 / Pages 261-266

A Generalization of the Livolant-Jeanpierre Theory for Resonance Absorption Calculation

P. Reuss

Nuclear Science and Engineering / Volume 92 / Number 2 / Pages 261-266

February 1986

Format:

Price:$30.00
Member Price:$27.00
Member Savings:$3.00

Because of the large number of heavy nuclide resonances, a detailed neutron flux calculation in the epithermal range cannot be made by standard nuclear reactor codes: It would need several tens of thousands of energy points. However, by using precalculated effective reaction rates, only a few tens of groups are sufficient for accurate spectrum and reaction rate calculations, if a consistent formalism is used. Such a formalism was elaborated in the 1970s by M. Livolant, F. Jeanpierre for the “one resonant nuclide-one resonant zone” problem, and was implemented in the APOLLO code. In practical cases there are several resonant nuclides and often resonant zones of different characteristics, e.g., a lattice constituted with different kinds of pins, a lattice with irregular “water holes,” a fuel element with temperature (therefore Doppler effect) gradients, and so on. Since these problems cannot be correctly treated by APOLLO, a generalization of the formalism was derived. The basic principles were retained, and an algorithm was constructed that would not require too expensive calculations. The Livolant-Jeanpierre theory is briefly summarized, equations for the most general case are presented, some approximations for practical calculations are proposed, and numerical tests on significant examples are discussed.

 
 
 
Questions or comments about the site? Contact the ANS Webmaster.
advertisement