The Proliferation Resistance and Physical Protection Evaluation Methodology Working Group of the Generation IV International Forum produced a full-system case study on the Example Sodium Fast Reactor Nuclear Energy System (ESFR-NES). The ESFR-NES is a hypothetical fuel cycle complex consisting of four sodium-cooled fast reactors of medium size collocated with an on-site dry-fuel storage facility and a spent-fuel reprocessing facility based on electrochemical recycling technology. The complex recycles irradiated fuels from two feed streams, oxide fuel from off-site light water reactors and metal fuel from the on-site sodium-cooled fast reactors. Both of these streams are recycled on-site; uranium and transuranics are sent to the electrochemical reprocessing fuel cycle facility. The two streams combine and the fuel cycle facility creates new ESFR-NES metal fuel for the four on-site sodium-cooled fast reactors. The major safeguards concepts driving the safeguards analysis were timeliness goals and material quantity goals. Specifically, the recycled fuel, the in-process material in the fuel reprocessing facility, the off-site light water reactor spent fuel received at the ESFR-NES, and spent fuel from the on-site fast reactors will contain plutonium. The International Atomic Energy Agency defines the material within the ESFR-NES as "direct-use material" with a stringent timeliness goal of 3 months and a material quantity goal of 8 kg of plutonium. Furthermore, the ESFR-NES may have some intrinsic safeguards features if the plutonium and uranium are not separated during reprocessing. This facility would require major modifications to separate the plutonium from other transuranic elements in the reprocessed fuel. The technical difficulty in diverting material from the ESFR-NES is at least as strongly impacted by the adversaries' overall technical capabilities as it is by the effort required to overcome those barriers intrinsic to the nuclear fuel cycle. The intrinsic proliferation resistance of the ESFR-NES can affect how extrinsic measures in the safeguards approach for the complex will provide overall proliferation resistance.