External supply of nuclear fuel is unreliable
Iran has been let down before by external suppliers of nuclear fuel (including the US and German / French companies), making Iran sceptical of relying on the analogous proposal of offshore nuclear fuel supply from Russia.
"Before the revolution Iran had a contract with the USA for the supply of fuel for a reactor. They gave the reactor but refused to give the fuel …. Siemens, the German Company, was to construct a power plant but they cancelled the contract. We have a share in Eurodif of France, 10 % but they didn’t give us one gram of fuel. . . I think if a country has just a little brain it would not depend on the fuel from another country”
Interview with Ali Larijani, USA Today, 6 February 2006.