MATERIALS EFFECTS AND DESIGN IMPLICATIONS OF DISRUPTIONS AND OFF-NORMAL EVENTS IN ITER

Damage to plasma-facing components (PFCs) and structural materials dur ing abnormal plasma behavior such as hard disruptions, edge-localized modes (ELMs), and vertical displacement events (VDEs) is considered a serious life-limiting concern for these components. The PFCs in the In ternational Thermonuclear Experimental Reactor (ITER), such as the div ertor, limiter and parts of the first wall, will be subjected to high energy deposition during these plasma instabilities. High erosion loss es on material surfaces, high temperature rise in structural materials (particularly at the bonding interface), and high heat flux levels an d possible burnout of the coolant tubes are critical constraints that severely limit component lifetime and therefore degrade reactor perfor mance, safety and economics. Recently developed computer models and si mulation experiments are being used to evaluate various damage to PFCs during the abnormal events. The design implications of plasma-facing and nearby components are discussed, and recommendations are made to m itigate the effects of these events. (C) 1998 Elsevier Science S.A. Al l rights reserved.