Speaker
Description
Occupational radiation exposure (ORE) assessments are initiated from the earliest stages of nuclear facility design in order to identify high-dose operations, support dose optimization, and guide the selection of appropriate design solutions. Maintenance activities on plant systems may contribute significantly to both individual and collective doses to personnel. Consequently, ORE evaluations for maintenance activities are an essential element of the iterative application of the ALARA principle, as they can inform design modifications and optimization strategies aimed at reducing occupational exposure.
This work presents the methodology developed for the assessment of ORE associated with maintenance activities in DEMO, with particular focus on the operational radiological exposure analysis of maintenance activities for the DEMO Electron Cyclotron Resonance Heating (ECRH) system. The analysis is based on radiation field characterization, estimated dose rates, maintenance procedures, intervention frequency, the use of personnel protective equipment and associated work effort to estimate collective dose to workers, taking into account contributions from both external and internal exposure pathways.
Although the current level of design maturity does not yet allow for highly detailed ORE assessments, the present estimations give an envelope evaluation of collective dose to personnel due to preventive ECRH maintenance operations, concluding that Remote Handling Tools are required in order to perform the maintenance of the ECRH system. These results are provided to system designers to support the optimization and integration of plant systems and components from a radiological protection perspective.
The outcomes of this work provide input to the DEMO Generic Site Safety Report Volume 4 (GSSR-4), which addresses the occupational radiological hazards anticipated in DEMO and defines the measures required for worker protection [1]. The study therefore contributes to the development and safety-oriented design optimization of future fusion facilities, such as the EU Fusion Pilot Plant (FPP) and subsequent First-Of-A-Kind (FOAK) fusion plant.
- This work has been carried out within the framework of the EUROfusion Consortium, funded by the European Union via the Euratom Research and Training Programme (Grant Agreement No 101052200 — EUROfusion). Views and opinions expressed are however those of the author(s) only and do not necessarily reflect those of the European Union or the European Commission. Neither the European Union nor the European Commission can be held responsible for them.
[1] DEMO Generic Site Safety Report, Volume 4 v.3.1, Occupational Safety, EFDA_D_2PMKPL_v.3.1, 2024