Journal
PROGRESS IN NUCLEAR ENERGY
Volume 83, Issue -, Pages 59-72Publisher
PERGAMON-ELSEVIER SCIENCE LTD
DOI: 10.1016/j.pnucene.2015.03.002
Keywords
Neutron fractional diffusion equation; Anomalous diffusion; Non-local gradient; Flux limited diffusion coefficient
Categories
Ask authors/readers for more resources
Normal diffusion process is quite valid for media without production and absorption. In these media particles move by scattering reaction and mean square displacement of particles is linear function of time (< r(t)(2)> similar to t). In the nuclear reactors both production and absorption are present and consequently normal diffusion fails to describe neutrons behavior. In this circumstance sub or super diffusion (also called anomalous diffusion) phenomena are occurred. We have developed a new scheme of diffusion equation which is established on the spatial-fractional derivatives, neutron fractional diffusion equation (NFDE). The NFDE uses an arbitrary order of differential operators and it can model anomalous diffusion in the more accurate manner. The second drawback of diffusion equation is related to high absorption (or production) regions where a steep spatial gradient is existent. Based on the Fick's law, if gradient of flux is very large the neutron current will exceed the scalar flux (vertical bar(J) over bar vertical bar > phi). In order to dump this effect, the flux limited diffusion theory is used to calculate diffusion coefficient. The proposed model is validated against experimental measurements of DIMPLE reactor. (C) 2015 Elsevier Ltd. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available