An overview of the EU breeding blanket design strategy as an integral part of the DEMO design effort.

Highlights • The performance and reliability of the breeding blanket are foremost considerations in the development and deployment of fusion power. • No breeding blanket has ever been built or tested. Hence, its integrated functions and reliability represent a very challenging development. • This paper provides an overview of the revised design and development strategy for the DEMO breeding blanket in Europe. • It includes a proposal to change the EU TBM options to be tested in ITER, in particular to replace a HCLL concept with a WCLL concept. • This is needed to obtain important information from the two current breeders (solid and liquid) and coolants (helium and water) being considered for DEMO. Abstract This paper provides an overview of the newly revised design and development strategy for the DEMO breeding blanket in Europe. This has been defined to take into account the input from the DEMO pre-conceptual design activities, the findings and recommendations of a thorough technical and programmatic assessment of the breeding blanket and the EU ITER Test Blanket Module (TBM) programs, conducted in 2017 by an independent expert panel. This work has led to the identification of (i) the most mature and technically sound breeding blanket concepts to be used as "driver" and "advanced" breeding blankets in DEMO, the latter to be installed and tested in a limited number of properly designed segments, potentially being more attractive for future fusion power plants; (ii) the remaining technical gaps and R&D priorities. A number of urgent steps that are required to better align and strengthen the EU TBM and DEMO Breeding Blanket Program as a whole and to aim at an efficient implementation of the work are described in this paper. These include a proposal to change the EU TBM options to be tested in ITER in order to obtain important and useful information from the two current breeders (solid and liquid) and coolants (helium and water) considered for DEMO. [ABSTRACT FROM AUTHOR]