Fusion Science and Technology / Volume 61 / Number 4 / May 2012 / Pages 321-331
There is a strong indication that the dual-cooled LiPb blanket is the preferred concept for many fusion power plants being designed around the world. The ability of the blanket to provide tritium self-sufficiency is among the important issues that we investigated in detail for ARIES-ACT to pinpoint the design elements that degrade the breeding the most, using state-of-the-art neutronics codes. A novel stepwise approach was developed to identify the exact cause of the degradation in the tritium breeding ratio (TBR), initially 1.8 for an ideal system, reaching 1.05 for a practical design. More broadly, this paper gives many insights into the impact that internal components of the blanket as well as essential parts of a tokamak can have on the TBR and the more damaging or enhancing conditions or changes to the breeding. To overcome the challenges of dealing with all tritium-related uncertainties in several subsystems, we suggest adjusting the Li enrichment online during operation to mitigate concerns about the danger of placing the plant at risk due to tritium shortage as well as the problem of handling and safeguarding any surplus of tritium.