Report of Contributions
Total Page:16
File Type:pdf, Size:1020Kb
SOFT 2018 Report of Contributions https://agenda.enea.it/e/soft2018 SOFT 2018 / Report of Contributions Path planning and space occupatio … Contribution ID: 1 Type: not specified Path planning and space occupation for remote maintenance operations of transportation in DEMO Monday, 17 September 2018 11:00 (2 hours) The ex-vessel Remote Maintenance Systems in the DEMOnstration Power Station (DEMO)are responsible for the replacement and transportation of the plasma facing components. The ex-vessel operations of transportation are performed by overhead systems or ground vehicles. The time duration of the transportation operations has to be taken into account for the reactor shutdown. The space required to perform these operations has also an impact in the economics ofthepower plant. A total of 87 trajectories of transportation were evaluated, with a total length of approximately 3 km. The total occupancy volume is, comparatively, between 21 and 45 Olympic swimming pools, depending mainly to the type of transportation adopted in the upper level of the reactor building. Taking into account the recovery and rescue operations in case of failure, the volume may increase up to, between 43 and 64 Olympic swimming pools. The estimation of the total time duration of all expected transportation missions in the reactor building are between 166 hours (7 days) and 388 hours (16 days). This time estimation does not include docking, accelerations or other opera- tions that are not transportation. The travel speed is assumed constant with a maximum value of 20cm/s (the same value assumed for Cask and Plug Remote handling System in the International Thermonuclear Experimental Reactor - ITER). The results achieved in this preliminary assessment will help the design process to optimize the time duration of the reactor shutdown and the layout of the DEMO power plant. This work has been carried out within the framework of the EUROfusion Consortium and hasre- ceived funding from the Euratom research and training programme 2014-2018 under grant agree- ment No 633053. The views and opinions expressed herein do not necessarily reflect those ofthe European Commission. Co-authors: Dr VALE, Alberto (Instituto de Plasmas e Fusao Nuclear, Instituto Superior Técnico); Dr DIAS, Jose (Instituto de Plasmas e Fusao Nuclear, Instituto Superior Técnico) Presenter: Dr VALE, Alberto (Instituto de Plasmas e Fusao Nuclear, Instituto Superior Técnico) Session Classification: P1 Track Classification: Vessel/In-Vessel Engineering and Remote Handling October 9, 2021 Page 1 SOFT 2018 / Report of Contributions ECART analysis of the STARDUST … Contribution ID: 2 Type: not specified ECART analysis of the STARDUST dust resuspension tests with an obstacle presence Monday, 17 September 2018 11:00 (2 hours) The activated/toxic dust resuspension inside the vacuum vessel of future fusion devices asITER or DEMO is a safety issue of main concern. In case of a LOVA or a LOCA, dusts produced during the normal and off-normal conditions can be released inside the tokamak building or towards the external environment. These accidents are not expected during the whole lifetime of the ITER machine, though in the past they were considered in the ITER Generic Site Safety Report with a conservative assumption for the lack of reliable resuspension models in the employed safety codes. To relax this strong assumption and validate resuspension models in fusion like conditions, differ- ent experimental campaigns in the STARDUST facility were performed at the ENEA laboratories in Frascati (Rome). In the first experimental campaign (2004), the resuspension of Tungsten (W), Carbon (C) and Stainless Steel (SS) dusts was investigated in an “empty tank” configuration, while the resuspension of the same dust types in presence of an internal obstacle was studied in the second campaign (2005). The obtained experimental results stressed that only a minor fraction of dusts is effectively resuspended. In the present work, focalized on the ECART code validation for the safety analysis of future fusion installations, a further step in the assessment of the semi- empirical “force balance” resuspension model implemented in the ECART code against the data obtained during the second experimental campaign (tank with an inner obstacle) is performed. The code predictions are quite in agreement with these STARDUST experimental data, andthree charts (one for each dust type) were elaborated to predict the resuspension magnitude basing on the flow velocity on the structure where the dusts are initially collected. Co-authors: Dr PACI, Sandro (Pisa University); Dr BRUNO, Gonfiotti (Pisa University); Dr PORFIRI, Maria Teresa (ENEA) Presenter: Dr PACI, Sandro (Pisa University) Session Classification: P1 Track Classification: Power Plants Safety and Environment, Socio-Economics and Technol- ogy Transfer October 9, 2021 Page 2 SOFT 2018 / Report of Contributions Experimental investigation on the … Contribution ID: 3 Type: not specified Experimental investigation on the interruption performance of a switch based on artificial current zero Monday, 17 September 2018 11:00 (2 hours) The quench protection switch (QPS) is indispensable to protect the magnet coils from thedamage of a quench in a superconducting Tokamak. In this paper, a QPS based on the artificial current zero is involved. The vacuum circuit breaker (VCB), which is driven by a high-speed electromagnetic re- pulsion mechanism, is used as the main circuit breaker (MCB). Two kinds of commercial vacuum interrupters (VIs), which have electrodes generating axial magnetic field (AMF) and transverse magnetic field (TMF), respectively, are applied. Meanwhile, the breaking current with amplitude of 15-25kA is generated by a LC oscillating circuit. The countercurrent with frequency in range of 500~5000Hz is provided by a commutation branch. The interruption performance of the two VIs under different breaking current and frequencies of countercurrents is investigated. Theex- periment results indicate that the differences of interruption performance under the two types of magnet fields are enlarging with the increasing of the frequencies of countercurrents. Co-authors: Dr LI, Sheng (Xi’an Jiaotong University); Dr ZHAO, Linyan (Xi’an Jiaotong Univer- sity); Dr SHI, Zongqian (Xi’an Jiaotong University); Dr DING, Dongdong (Xi’an Jiaotong Univer- sity); Dr LIU, Yuhan (Xi’an Jiaotong University); Dr JIA, Shenli (Xi’an Jiaotong University); Dr WANG, Lijun (Xi’an Jiaotong University) Presenter: Dr LI, Sheng (Xi’an Jiaotong University) Session Classification: P1 Track Classification: Magnets and Power Supplies October 9, 2021 Page 3 SOFT 2018 / Report of Contributions Hydrogen isotopes distribution m … Contribution ID: 4 Type: not specified Hydrogen isotopes distribution modeling by ”FC-FNS” code in fuel systems of fusion neutron source DEMO-FNS Monday, 17 September 2018 11:00 (2 hours) Tokamak-based fusion neutron source (FNS) [Kuteev B.V. et al 2010 Plasma Phys. Rep. 36 281, Kuteev B.V.et al Nucl. Fusion 55 (2015) 073035] is the centerpiece of the fusion-fission hybrid reactor (combining nuclear and thermonuclear technologies). In Russia, for the demonstration of stationary and hybrid technologies, the DEMO-FNS project has been developed, which should operate at least 5000 hours per year. The plasma operation in a tokamak requires the continuous injection of the fuel mixture containing hydrogen isotopes (deuterium and tritium) into the vacuum chamber, as well as its subsequent pumping out and processing. Calculation of the distribution of tritium (as well as deuterium and protium) in fuel systems is important for assessing safety features of the facility and for designing these systems. To simulate hydrogen isotope flows and inventories in the fuel systems of FNS, computer code FC-FNS [Ananyev S.S. et al Fusion Eng. Des. (2016), Volumes 109–111, Part A, pp 57–60] has been created that continues to be developed. This report describes capabilities of the code. The results of calculations are presented forthe conceptual design of DEMO-FNS. The balance of three hydrogen isotopes is taken into account, the performance of deprotiation systems is calculated to maintain the required level of protium in the plasma tokamak and detritiation (for the variant of the neutral injection system - NBI). Three alternative scenarios for supplying gas to NBI system are simulated. It is shown that the proposed approach to NBI fueling allows reducing the total amount of tritium in FS up to 1.5 times, that leads to the initial loading for DEMO-FNS of 460 g. The time for tritium breeding up to the amount sufficient for starting a new similar device will be 2.5 - 4 years (for different scenarios forFSNBI). Co-author: Dr ANANYEV, Sergey (NRC Kurchatov institute) Presenter: Dr ANANYEV, Sergey (NRC Kurchatov institute) Session Classification: P1 Track Classification: Fuel Cycle and Breeding Blankets October 9, 2021 Page 4 SOFT 2018 / Report of Contributions Hydraulic characterization of twin … Contribution ID: 6 Type: not specified Hydraulic characterization of twin box joints for ITER magnets Monday, 17 September 2018 11:00 (2 hours) The ITER magnet system will be the largest superconducting magnet system ever built. Thesys- tem, all inside a cryostat, is mainly composed by a central solenoid (CS) split in 6 modules, a set of 18 toroidal field (TF) D-shaped coils and 6 poloidal field (PF) coils. Each of these coils usevariable type of cable-in-conduit-conductors (CICC) actively cooled by supercritical helium