Speaker
Anton Travleev
(INR-NK)
Description
Nuclear heating of the vacuum vessel (VV) is an important issue for the design and the safe operation of ITER. The heating distribution must be known with high accuracy to identify hot spots which may be crucial for the reliable operation. The VV is heated by neutrons passing through the blanket shield modules and gaps, and photons generated in the VV structure. The heating distribution is thus strongly affected by materials and geometry of in-vessel components. An accurate representation of these components is therefore a key prerequisite for reliable results of the nuclear heating distribution in the VV.
To satisfy such requirements, C-lite, the reference model of ITER for neutron transport simulations with the Monte Carlo code MCNP, was updated with a semi-detailed representation of the in-vessel components (IVC) as currently designed for blanket rows 7 to 12. Semi-detailed IVC models in blanket rows 1 - 6 and 13 - 18 were already available, although corresponding to an earlier design stage. The engineering CAD models for blanket rows 7 to 12 were processed according to the needs of neutronics simulations, converted into MCNP geometry representation and then integrated into C-lite, together with the available models of blanket rows 1-6 and 13-18.
The updated C-lite model was applied to compute distributions of the nuclear heating in the VV with the MCNP6 Monte Carlo code using mesh tallies with a resolution of 2 cm. The calculations were performed on the HELIOS supercomputer located in Rokkasho, Japan.
The paper describes the updating of C-lite in detail and presents the results of heating calculations using both analogue Monte Carlo and various variance reduction techniques. The new results confirm the VV hot spots obtained previously for C-lite with a simplified IVC representation but give less conservative results for VV regions behind the updated IVCs.
Co-authors
Albrecht Kyrieleis
(Clean Energy – Europe, Amec Foster Wheeler, 305 Bridgewater Place, Warrington, WA3 6XF, United Kingdom)
Alex Martin
(ITER Organisation, Route de Vinon sur Verdon, 13115 Saint Paul Lez Durance, France)
Andrew Turner
(Culham Science Centre, Abingdon, Oxon, OX14 3DB, United Kingdom)
Anton Travleev
(INR-NK, Karlsruhe Institute of Technology, Eggenstein-Leopoldshafen, Germany)
Eduard Polunovskiy
(ITER Organisation, Route de Vinon sur Verdon, 13115 Saint Paul Lez Durance, France)
Fabio Moro
(UTFUS-TECN, ENEA, Via E. Fermi 45, 00044 Frascati (Rome), Italy)
Lei Lu
(INR-NK, Karlsruhe Institute of Technology, Eggenstein-Leopoldshafen, Germany)
Raul Pampin
(Fusion for Energy, Josep Pla 2, Torres Diagonal Litoral B3, 08019 Barcelona, Spain)
Rosaria Villari
(UTFUS-TECN, ENEA, Via E. Fermi 45, 00044 Frascati (Rome), Italy)
Ulrich Fischer
(INR-NK, Karlsruhe Institute of Technology, Eggenstein-Leopoldshafen, Germany)
