The materials requirements for net

Abstract

Type 316L austenitic and 1.4914 martensitic steels have been selected as alternative first wall and breeder structural component materials for NET. The constitutions and structures of these steels are surveyed and the effects of neutron irradiation on their bulk properties and behaviour (void swelling, creep and rupture, fatigue, fracture toughness and hydrogen embrittlement) are discussed in terms of the proposed NET operating conditions. The investigations which are being undertaken to provide the additional data required to enable the optimum material to be chosen prior to starting the detailed design of NET are indicated. Surface damage of the first wall may also result from the bombardment by ions and energetic neutral atoms from the plasma and from plasma disruption, run-away electron and arcing effects. Various potential solutions for protecting the first wall from plasma disruptions are considered.