The diagrams follows the process through which uranium is used for the production of nuclear power.
There are five stages represented here, in the order that they are performed in. The procedure is not circular, however steps 3 to 5 may form a cycle. The images are clear and concise, and so is their sequencing. This helps the viewer identify some of the upsides and downsides of the approach, These are, in order, the fact that fuel can be reused, and that eventually the waste will have to be stored underground, inconveniently so.
The process begins with obtaining the uranium. It is a natural material that is extracted from the earth. It can be used in generators to produce electricity, but only after it has been treated. This involves the conversion end enrichment of the crude mineral to obtain U-235 pellets. These pellets are what power the nuclear plants, and will last up to four years, after which they become spent. This is where the diagram indicates two possible routes, depending on the state of the used material. One will either attempt to re-process and re-use some of the fuel, or have to dispose of it. Disposal is achieved by storing the depleted U-235 in containers that will be buried. Here is where the process inevitably comes to an end.
Thus, the diagram helps the reader better comprehend how uranium can be used for generating electricity, all the while introducing the advantages and disadvantages of the given method.