NONLINEAR RELATIVE STABILITY ANALYSIS OF SOME NIGERIAN GEOLOGICAL FORMATIONS AS RADIOACTIVE WASTES REPOSITORY
Keywords:
radionuclides activity, infiltration rate, relative stability, fixed points, geological formationAbstract
This work determines the relative capabilities of some geological formations in Nigeria as radioactive wastes repository. Reaction term of the advection-diffusion-reaction transport in porous media was reworked to address nonlinear radioactive decay and sorption. Lyapunov’s indirect method identified three critical points. A stable attractor at the origin, flanked by two symetric saddles. Phase Potraits show that Caesium and Strontium are well stabilized in sandstone, consolidated clay and limestone. In shale, the focus at the origin indicates weak stability for the two radionuclides. However, for Plutonium, the origin is consisitently a weak node. Hence, its dynamics/disappearance rate is very slow. At half-lifes, breakthrough curves in 200cm radius of host soils show that Strontium and Caesium are best contained in sandstone and consolidated clay. However, they deeply infilterate limestone. Similarly, a fifth of Plutonium’s reposed concentration completely infiltrated the simulation aperture. Hence, Plutonium should not be reposed in natural formations.
Downloads
Published
How to Cite
Issue
Section
License
The contents of the articles are the sole opinion of the author(s) and not of NIJOTECH.
NIJOTECH allows open access for distribution of the published articles in any media so long as whole (not part) of articles are distributed.
A copyright and statement of originality documents will need to be filled out clearly and signed prior to publication of an accepted article. The Copyright form can be downloaded from http://nijotech.com/downloads/COPYRIGHT%20FORM.pdf while the Statement of Originality is in http://nijotech.com/downloads/Statement%20of%20Originality.pdf
For articles that were developed from funded research, a clear acknowledgement of such support should be mentioned in the article with relevant references. Authors are expected to provide complete information on the sponsorship and intellectual property rights of the article together with all exceptions.
It is forbidden to publish the same research report in more than one journal.