Fusion Engineering and Design 88 (2013) 2621–2626 Contents lists available at ScienceDirect Fusion Engineering and Design journal h om epa ge: www.elsevier.com/locat e/fusengdes Maintenance inside IFMIF Test Facility—(Technical) logistics M. Mittwollen a,* , M. Kubaschewski a , V. Madzharov a , D. Eilert a , K. Tian b , F. Arbeiter b , V. Heinzel b a Karlsruhe Institute of Technology, Institute for Conveying Technology and Logistics, Karlsruhe, Germany b Karlsruhe Institute of Technology, Institute for Nuclear Research and Safety, Karlsruhe, Germany a r t i c l e i n f o Article history: Received 14 September 2012 Received in revised form 28 May 2013 Accepted 29 May 2013 Available online 24 June 2013 Keywords: Fusion Logistics Handling Simulation Process IFMIF a b s t r a c t The International Fusion Material Irradiation Facility (IFMIF) is designed to study and qualify structural and functional materials which shall be used in future fusion nuclear power plants. The Test Cell is the area of convergence of primary IFMIF sub-systems, and physically accommodates the lithium target and the test modules. The Test Cell will be opened once a year for maintenance and replacing the highly stressed test modules and other components like the lithium target. Scores of different parts and components with extremely different sizes, shapes, and weights must be dismantled and moved remotely. Down time of IFMIF interrupts irradiation of specimen and is very expensive. Thus it must be as short as possible enabled e.g. by optimized technical logistics. With structured description of processes, alternatives can be identified. Considering specific properties of tools performing the tasks, e.g. operation times can be calculated by simulation. Analyzing the results of a simulation, partial processes may be identified for improvement and as basis to get an optimum solution. Shown on the example of the HFTM dismantling process, the method can as well be applied on all other sub-systems. © 2013 Elsevier B.V. All rights reserved. 1. Introduction IFMIF is designed to test, study, and qualify materials that may be utilized in future fusion reactors by exposing the materials in high irradiation environments [1]. IFMIF will apply two par- allel accelerators (40 MeV, 125 mA each) to produce high energy deuteron beams impacting at a liquid lithium target to generate high energy neutron flux (main peak at 14 MeV) that can produce high irradiation damage rates of up to 50 dpa (displacements per atom) per full power year [2,3]. Inside IFMIF Test Facility, there is a cavity called Test Cell (TC) which is physically accommodating the lithium target and the test modules which are exposed to the neutron flux [4]. The Test Cell is placed underneath the Access Cell (AC), through which the TC inventory is transferred to different hot cells for operation on the Modules resp. the Target (see Fig. 1). Layout and arrangement of hot cells was discussed in [5]. Due to simulation results about behavior of materials under intense irradiation of fast neutrons, it is planned to have a period of about 11 months of irradiation followed by a maintenance period of about 1 month for replacement of the test modules, the lithium target, and for maintain and repair of all related sub systems. * Corresponding author. Tel.: +49 721 60848605. E-mail address: martin.mittwollen@kit.edu (M. Mittwollen). Down time of IFMIF is very expensive (several 100 kD per day), and therefore all maintenance processes should be as short respec- tively fast as possible. To meet these requirements, a model of the maintenance process is established and evaluated in this study. 2. Description of processes The decentralized development of IFMIF may lead to misun- derstandings of processes and unclear definitions of interfaces – connected processes may be incompatible. Therefore it is neces- sary to get a common comprehension of the processes especially regarding the flow of materials, staff and information. Even though looking quite chaotic, a pure phenomenological description made on a blackboard is very suitable to make up one’s mind and get a first image of the processes to be performed (see Fig. 2). Then the major functions may be listed in a functional perfor- mance specification (see Fig. 3). After that a huge work package is waiting as one should fill in all major and minor steps of maintenance in the right sequence. What comes naturally – mixing up different levels of detailing – could be avoided by prior thinking and defining of segmented levels (see Fig. 4). The different levels have the following meaning: Levels 0 and 1: The first two levels give an overview on the replace- ment procedure during maintenance period. They should be 0920-3796/$ – see front matter © 2013 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.fusengdes.2013.05.109