In 1994, 580 kg of highly enriched reactor fuel for the Alfa class submarine was found in a room at Ulba Metallurgical Facility in Kazakhstan by an American engineer visiting from Oak Ridge National Laboratory. Shortly after the finding, it was discovered that an Iranian delegation had visited the facility seeking to purchase reactor fuel (it's unclear on if it was before or after the discovery). The CIA launched Project Sapphire, which was able to successfully recover and secure the stockpile. The Ulba stockpile is the largest known stockpile of unsecured weapons grade fissile material from the fall of the Soviet Union. How plausible would it have been for the material to have found its way to a rogue state, or perhaps even a terrorist group? Could a state or group with sufficient resources have covertly assembled nuclear weapons using the material? Would 1990s technology have allowed for more advanced fission or even boosted fission designs to have been built without testing, as in The Sum of All Fears?