EU DEMO safety and balance of plant design and operating requirements. Issues and possible solutions

Abstract The EU DEMO preliminary safety and operating design requirements are being defined aiming at obtaining the nuclear license. The DEMO design approach is being organized, by taking into account the Nuclear Power Plant, ITER and Generation IV lessons learnt. Outstanding challenges remain in areas exhibiting large gaps beyond ITER. Those require a pragmatic approach, especially to evaluate and improve the readiness of technical solutions through dedicated physics and technology RD (ii) radioactive inventory minimization and control; (iii) energy inventory control and mitigation; (iv) power conversion system challenges and possible simplification; (v) huge and complex electrical loads; (vi) layout of the tokamak building versus plant and safety criteria. Any effort to reduce the complexity of a Fusion Power Reactor through simplification and rationalization of the design of the main systems translates into a more robust plant configuration enlarging safety margins and operational thresholds.