  EDFA, as part of the Power Plant Physics and Technology programme, has been
working on the pre-conceptual design of a Demonstration Power Plant (DEMO). As
part of this programme, a review of the remote maintenance strategy considered
maintenance solutions compatible with expected environmental conditions, whilst
showing potential for meeting the plant availability targets. A key finding was
that, for practical purposes, the expected radiation levels prohibit the use of
complex remote handling operations to replace the first wall. In 2012/13, these
remote maintenance activities were further extended, providing an insight into
the requirements, constraints and challenges. In particular, the assessment of
blanket and divertor maintenance, in light of the expected radiation conditions
and availability, has elaborated the need for a very different approach from
that of ITER. This activity has produced some very informative virtual reality
simulations of the blanket segments and pipe removal that are exceptionally
valuable in communicating the complexity and scale of the required operations.
Through these simulations, estimates of the maintenance task durations have
been possible demonstrating that a full replacement of the blankets within 6
months could be achieved. The design of the first wall, including the need to
use sacrificial limiters must still be investigated. In support of the
maintenance operations, a first indication of the requirements of an Active
Maintenance Facility (AMF) has been elaborated.
