I don't speak German so I can't check how the article got his maps, but I don't think the winds in France are mostly West-East. Also I think it's more than just sending the fallout on the other side of the border in the location of the nuclear power plants:

-close to a water source with the Rhine basin -close to where the electricity will be used (Paris and its suburbs on the West side, Germany to sell on the East side, major cities all around) -close to where heavy industry exists (both for use and production of the construction pieces) -Outside of the areas of seismic risk