A vision for the nuclear fuel cycle was put in place about 5 decades ago. It was based on the assumption of rapid growth in the use of nuclear energy that might become limited by uranium resources. Thus, a transition from the utilization of about 1% of the uranium energy in LWR reactors to fuel multi-recycling in fast reactors, which would be able to fully utilize the energy from uranium Breeding in thermal reactors like the LWRs was envisioned to need thorium as a base fertile fuel. A more recent systematic examination of the options for future reactors was conducted in the 2008 to 2011 framework, which revealed the availability of vast amounts of uranium ore, such that breeding of fuel in reactors might not be needed before the later part of the 21st century. The study also revealed that having reactors with a breeding ratio of slightly above one is as good as having those of higher breeding ratio (practically limited to 1.25). Thus, recycling in reactors other than the metal cooled reactor would be effective from the resource extension point of view. These insights were obtained using a specially developed fuel cycle analysis tool, CAFCA, which was the first such tool with a built in optimization function based on genetic algorithms.