Hydraulic Characterization of the Full Scale Mock-Up of the DEMO Divertor Outer Vertical Target

In the frame of the pre-conceptual design activities of the DEMO work package DIV-1 “Divertor Cassette Design and Integration” of the EUROfusion program, a mock-up of the divertor outer vertical target (OVT) was built, mainly in order to: (i) demonstrate the technical feasibility of manufacturing procedures; (ii) verify the hydraulic design and its capability to ensure a uniform and proper cooling for the plasma facing units (PFUs) with an acceptable pressure drop; and (iii) experimentally validate the computational fluid-dynamic (CFD) model developed by the University of Palermo. In this context, a research campaign was jointly carried out by the University of Palermo and ENEA to experimentally and theoretically assess the hydraulic performances of the OVT mock-up, paying particular attention to the coolant distribution among the PFUs and the total pressure drop across the inlet and outlet sections of the mock-up. The paper presents the results of the steady-state hydraulic experimental test campaign performed at ENEA Brasimone Research Center as well as the relevant numerical analyses performed at the Department of Engineering at the University of Palermo. The test facility, the experimental apparatus, the test matrix and the experimental results, as well as the theoretical model, its assumptions, and the analyses outcomes are herewith reported and critically discussed.

Assessment and modeling of sewer network development utilizing Arc GIS and SewerGEMS in Kabul city of Afghanistan

The absence of a wastewater collection, management, and disposal scheme is one of Kabul’s most serious environmental issues. This has resulted in both health and ecological problems. This research used Arc GIS and SewerGEMS tools to assess the viability of a decentralized sewerage collection model in the research area. The research area was chosen as the city’s 5th district. Land-use and land-cover, Digital Elevation Model (DEM), and Satellite data were used to construct the network’s geometry in the Arc map environment. SewerGEMS software was used to perform hydraulic simulation and modeling. The variables were regulated based on the results of the study using conventional wastewater topology guidelines. Based on the outputs of hydraulic analysis, it is concluded that the decentralized wastewater collection system would be the best option for the area. It can be deduced from hydraulic design findings that the hydraulic model was successfully developed and built. The methodology can be applied for the development of future wastewater master plans of the city.

Physical parameters for the estimation of the return coefficient in the sewer of the La Chivera watershed

Estimating the amount of flow carried by the sanitary sewer system in a locality is essential for the design of new facilities. Having a record of the flow rates allows the adequate hydraulic design of a drainage system. The objective of this work is to determine the physical parameters for the estimation of the return coefficient that allows estimating the flow rates for the sanitary sewer of the La Chivera watershed, San José de Cúcuta, Colombia. In this sense, dry weather monitoring of the wastewater in the study area was carried out. The data collected in the field were used to construct the hourly flow variation curve or inflow hydrograph in the drainage system. The average hourly flow parameters were estimated with a value of 205.7 m3/h, a value recorded at the 11th hour of the day. Similarly, the average daily flow was determined with a value of 180.3 m3/h, while the maximum peak factor was 1.14. Finally, through the physical parameters of the sanitary sewer, the return coefficient was determined, which is 0.72, a value that represents the conditions of the study area.

Preliminary Study on HTR-10 Operating in Higher Outlet Temperature

High Temperature Gas-cooled Reactor (HTGR), which has well-known safety features and high temperature heat supply capability, is expected to be widely used for heat supply and technology heat utilization including the hydrogen production, and so contributing to the reduction of carbon dioxide emissions in various sectors. The 10 MW High Temperature gas-cooled test Reactor (HTR-10) had been constructed and operated in China as a pilot plant to demonstrate the inherent safety features of the modular HTGR. The first criticality of HTR-10 at air condition was realized on December 1, 2000, and the full power operation for 72 h on January 29, 2003. Supported by Chinese National S&T Major Project, HTGR for hydrogen production are now being studied. The physical and thermal hydraulic design to raise the outlet helium temperature of the HTR-10 reactor core from 700 °C to 850~1000 °C is carried out. In this paper, the preliminary thermal hydraulic design of the HTR- 10 with the outlet helium temperature of 950 °C (HTR-10H) is introduced. The power density distribution, the fuel temperature distribution and the reactor pressure vessel (RPV) temperature are studied to identify what need to be focused on next. Besides, the typical DLOFC accident has been studied to evaluate the safety feature of the HTR-10 operating under higher core temperature and outlet temperature. The preliminary results show that, operated at the higher outlet helium temperature, the original acceptance criteria for HTR-10 will be challenged. In the future, the design optimization, as well as the possible modification of these acceptance criteria, which were set more than two decades ago, should be studied based on the current knowledge of the fuel element properties and structure material properties.