Status of EU DEMO heat transport and power conversion systems.

Highlights • EU- DEMO shall be strongly Balance of Plant oriented. • Two BOP options are considered for both WCLL BB and HCPB BB BoP with the aim to minimize technological risks. • Preliminary design of HCPB/WCLL BB PHTS, IHTS, ESS and conceptual design of PCS have been perfomed. • BB PHTS, IHTS, ESS and PCS are considered to be feasible, but further investigations need before drawing any firm conclusions. • The direct coupling of the BB PHTS to PCS is under analysis with the help of the Industry. Abstract DEMO in Europe is considered to be the nearest-term reactor design to follow ITER and capable of demonstrating production of electricity, operating with a closed fuel-cycle and to be a facilitating machine between ITER and a commercial reactor. The aim of this paper is to show the design progress of the complex system's "chain" devoted to the extraction of the plasma generated pulsed thermal power and its conversion into electricity delivered to the grid, including the Primary Heat Transport System (PHTS), the Power Conversion System (PCS) and the Intermediate Heat Transport System (IHTS) – provided by an Energy Storage System (ESS) – in between PHTS and PCS, which is introduced for the scope of smoothing the generated pulsed plasma power removed by PHTS transmitted to PCS for a more continuous conversion/production of electricity and to guaranty plant lifetime. This will be done with reference to two breeding blanket concepts: the Helium Cooled Pebble Bed (HCPB) Breeding Blanket (BB) and the Water Cooled Lithium Lead (WCLL) BB. The PHTS design criteria and the system design finalization through a descriptive 3D CAD model which shows the system inside the tokamak building are presented. The design and operational challenges as well as the on-going development plans to investigate possible design simplifications (e.g. the direct coupling of Breading Blanket PHTS to PCS) and improved technology readiness actions potentially leading to better plant reliability and cost minimisation are briefly described. [ABSTRACT FROM AUTHOR]