Abstract
The planned in situ maintenance tasks in the ITER port interspace are fundamental to ensure the operation of equipment to control, evaluate and optimize the plasma performance during the entire facility lifetime. They are subject to a limit of shutdown dose rates (SDDR) of 100 μSv h-1 after 106 s of cooling time, which is nowadays a design driver for the port plugs as well as the application of ALARA. Three conceptual shielding proposals outside the ITER ports are studied in this work to support the achievement of this objective. Considered one by one, they offer reductions ranging from 25% to 50%, which are rather significant. This paper shows that, by combining these shields, the SDDR as low as 57Δ μSv h-1 can be achieved with a local approach considering only radiation from one port (no cross-talk form neighboring ports). The locally evaluated SDDR are well below the limit which is an essential pre-requisite for achieving 100μSv h-1 in a global analysis including all contributions. Further studies will have to deal with a realistic port plug design and the cross-talks from neighbour ports.
Original language | English |
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Article number | 076018 |
Journal | Nuclear Fusion |
Volume | 58 |
Issue number | 7 |
DOIs | |
State | Published - Jun 1 2018 |
Externally published | Yes |
Funding
We appreciate the support given by MINECO under funding for Juan de la Cierva-formación program 2016 & I + D + I-Retos PRG. ENE2015-70733-R; Comunidad de Madrid PRG. TechnoFusion(II)-CM, S2013/MAE-2745; and ETS Ingenieros Industriales-UNED 2017 programme. It has been also supported by the Spanish MINECO and
Funders | Funder number |
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Ministerio de Economía y Competitividad |
Keywords
- ITER
- direct-one step method
- shutdown dose rate