JET work effort data collection for ITER ORE optimization

• Published in: Fusion engineering and design 2019-09, Vol.146, p.69-73
• Main Authors: Campling, Darryl, Macheta, Peter, Moran, James, Porfiri, Maria Teresa
• Format: Article
• Language: English
• Subjects: ALARA; Data acquisition; ITER; JET; Joint European Torus; Maintenance; Nuclear power plants; Occupational radiation exposure; Optimization; Radiation effects; Remote handling; Shutdowns; Tokamak devices; Work effort
• ISSN: 0920-3796; 1873-7196
• DOI: 10.1016/j.fusengdes.2018.11.032

Occupational radiation exposure (ORE) assessment is one important topic of the licensing process for ITER, the first experimental fusion machine, which is under construction in Cadarache, (France). Since this machine is the first of a kind, the maintenance activities for component replacement and repair are foreseen to be frequent and complex. In this context, remote handling (RH) will play a major role due to the high radiation fields inside the tokamak building. In any case, the hands on maintenance will be required, at least to prepare the work areas in which the RH will be used. Knowledge of the work effort (WE), that is, the time necessary to perform a task multiplied by the number of workers engaged in the task, is the first step to build an ORE assessment. The collection of WE data during JET maintenance shutdowns has been planned and performed in the last several years in the framework of the Eurofusion WPJET3 program to build a validated WE data base (WE-DB). The WE-DB is essential for ITER ORE analyses. The WE-DB ver.1.0 dates back to the ORE studies for ITER-FEAT, but at that time they included several data values based on engineering judgement that now need to be confirmed and validated by the WE data gathered in the fieldwork. The methodology of the WE collection is described in this work along with the updating of the WE-DB on the base of the monitored activities at JET. In addition, comparison with the WE data used in the previous ITER ORE assessments will allow not only the ability to correctly tune the WE for the evaluated tasks, but also to apply the ALARA process by means of a fast and simple tool.