how should I cite the website:http://www.world-nuclear.org/info/Nuclear-Fuel-Cycle/Nuclear-Wastes/Radioactive-Waste-Management/ using the SoE
This source should be cited as an electronic source. It does not look as if it is in print anywhere as the site shows that this resource is kept up to date online. Take a look at the SoE style guide. The only thing that will throw you off is the author, use the organization's name.
-SoE citation guideline -- http://lgdata.s3-website-us-east-1.amazonaws.com/docs/620/1378237/SoE_Citation_Style.pdf