**4. Conclusion**

EBR-II was arguably the most significant, meaningful, and successful sodium cooled fast reactor power plant demonstration in the history of nuclear power. It must be emphatically stated that the success of EBR-II was the result of actual demonstration rather than simulation and modeling or claims of future success based on short-lived small past experiments. Over a 30-year operating lifetime, the reactor demonstrated all aspects necessary for using a sodium cooled fast reactor for power production. Numerous technological advancements were made using EBR-II. Foremost among the advancements were 1) the demonstration of a pool type primary coolant arrangement with all primary piping and pumps located within the pool, 2) the ability to conduct fuel handling activities in opaque molten sodium, 3) the ability to transfer fuel into and out of the primary sodium pool while the reactor was operating at full power, 4) the ability to safely operate a system where heat is transferred from molten sodium to water, 5) the development of metallic fuel, 6) the demonstration of tremendous fuel burnup, and 7) the demonstration of compact on-site fuel reprocessing. The most significant accomplishment of EBR-II was the demonstration of the inherent safety associated with the overall reactor design and material properties that allowed the reactor to survive the most severe accident scenarios, loss of flow without SCRAM and loss of heat sink without SCRAM, with no fuel damage.

It is hoped that the success of EBR-II will not only influence the design of future sodium cooled fast reactors, but that it will be identified as an example of the true feasibility of such designs. This chapter is dedicated to the memory of Len Koch who was present for the startup of EBR-I and served as one of the principal EBR-II designers.
