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The conceptual design of a 1200 MW thermal, 500 MW electrical, Traveling Wave Reactor (TWR) Plant has been completed with the objective of completing construction and startup by 2020. The reactor is a pool-type, sodium-cooled fast reactor and has been named TerraPower - 1 (TP-1). The TP-1 core will operate for over 40 years without refueling, but provisions have been made to insert highly instrumented test fuel and materials assemblies and to remove them for post irradiation examination and testing. These test assemblies will provide the bases for validating fuel design for future generations of TWRs. The fuel design is supported by an extensive materials and fuel development program. TP-1 uses proven technologies for most of the plant with a few notable exceptions. The fuel pins are designed to vent fission product gases to the primary sodium coolant in a controlled manner. Venting the fuel pins enables deep burnups required to sustain the core for over 40 years and greatly reduces the probability of cladding failures. Detailed studies have shown that the only significant impacts on the primary coolant and reactor operation are the fission product noble gases and Cs137. The noble gases decay, except for Kr85m, which is collected on carbon beds and stored in shielded vessels. Cs137 is removed from the primary coolant by reticulated carbon traps at a rate that prevents build up and keeps the primary coolant activity levels similar to fast reactors with unvented fuel. The intermediate heat exchanger is another area of innovation using printed circuit, plate-type modules that form a compact, robust safety barrier between the primary and intermediate coolants, while maintaining very high thermal-hydraulic efficiency. Thermal efficiency is also enhanced by the use of compact helical coil steam generators that yield a gross electrical conversion efficiency of 42%. The seismically qualified active decay heat removal system is backed up by an independent, passive system using natural convection of ambient air to ensure decay heat removal even under station blackout conditions. Preliminary safety studies have confirmed satisfactory decay heat removal and acceptable reactivity coefficients. Initial identification of design basis and beyond design basis events has been completed. A level 1 Probabilistic Risk Assessment (PRA) is underway such that designers are informed of probability sequences that can benefit from design changes. An extensive external review of the TP-1 Plant conceptual design has been completed and the initial Technical Baseline of the TP-1 Plant is being established. It is anticipated that preliminary and final design can be completed in about three years which would enable licensing efforts to progress to the point that a construction decision could be made. A successful 2020 startup and demonstration of TWR technology will give energy planners a sustainable nuclear power option that does not require reprocessing, reduces proliferation risk and opens the door for further longer term innovation.