Vitrification of noble metals containing NCAW simulant with an engineering scale melter (ESM): Campaign report

ESM has been designed as a 10th-scale model of the DWPF-type melter, currently the reference melter for nitrification of Hanford double shell tankwaste. ESM and related equipment have been integrated to the existing mockup vitrification plant VA-WAK at KfK. On June 2-July 10, 1992, a shakedown test using 2.61 m{sup 3} of NCAW (neutralized current acid waste) simulant without noble metals was performed. On July 11-Aug. 30, 1992, 14.23 m{sup 3} of the same simulant with nominal concentrations of Ru, Rh, and Pd were vitrified. Objective was to investigate the behavior of such a melter with respect to discharge of noble metals with routine glass pouring via glass overflow. Results indicate an accumulation of noble metals in the bottom area of the flat-bottomed ESM. About 65 wt% of the noble metals fed to the melter could be drained out, whereas 35 wt% accumulated in the melter, based on analysis of glass samples from glass pouring stream in to the canisters. After the melter was drained at the end of the campaign through a bottom drain valve, glass samples were taken from the residual bottom layer. The samples had significantly increased noble metals content (factor of 20-45 to target loading). They showed also a significant decrease of the specific electric resistance compared to bulk glass (factor of 10). A decrease of 10- 15% of the resistance between he power electrodes could be seen at the run end, but the total amount of noble metals accumulated was not yet sufficient enough to disturb the Joule heating of the glass tank severely

Plans and Speculated Actions

In the last decades, much design research around “future-focused thinking” has come to prominence in relation to changes in human behaviour, at different scales, from the Quantified Self, to visions of smart cities, to Transition Design. The design of products, services, environments and systems plays an important role in affecting what people do, now and in the future: what has become known in recent years as design for behaviour change. Our Conversation is motivated by three, interlinked questions: on designers’ agency; on sense-making; and on complexity. We will collectively explore considerations of people, and people’s behaviour, in design, particularly in the ways visions of futures are drafted

Science goals and new mission concepts for future exploration of Titan’s atmosphere, geology and habitability: titan POlar scout/orbitEr and in situ lake lander and DrONe explorer (POSEIDON)

In response to ESA’s “Voyage 2050” announcement of opportunity, we propose an ambitious L-class mission to explore one of the most exciting bodies in the Solar System, Saturn’s largest moon Titan. Titan, a “world with two oceans”, is an organic-rich body with interior-surface-atmosphere interactions that are comparable in complexity to the Earth. Titan is also one of the few places in the Solar System with habitability potential. Titan’s remarkable nature was only partly revealed by the Cassini-Huygens mission and still holds mysteries requiring a complete exploration using a variety of vehicles and instruments. The proposed mission concept POSEIDON (Titan POlar Scout/orbitEr and In situ lake lander DrONe explorer) would perform joint orbital and in situ investigations of Titan. It is designed to build on and exceed the scope and scientific/technological accomplishments of Cassini-Huygens, exploring Titan in ways that were not previously possible, in particular through full close-up and in situ coverage over long periods of time. In the proposed mission architecture, POSEIDON consists of two major elements: a spacecraft with a large set of instruments that would orbit Titan, preferably in a low-eccentricity polar orbit, and a suite of in situ investigation components, i.e. a lake lander, a “heavy” drone (possibly amphibious) and/or a fleet of mini-drones, dedicated to the exploration of the polar regions. The ideal arrival time at Titan would be slightly before the next northern Spring equinox (2039), as equinoxes are the most active periods to monitor still largely unknown atmospheric and surface seasonal changes. The exploration of Titan’s northern latitudes with an orbiter and in situ element(s) would be highly complementary in terms of timing (with possible mission timing overlap), locations, and science goals with the upcoming NASA New Frontiers Dragonfly mission that will provide in situ exploration of Titan’s equatorial regions, in the mid-2030s

Explorer of Enceladus and Titan (E2T): Investigating Ocean Worlds' Evolution and Habitability in the Saturn System

The NASA-ESA-ASI Cassini-Huygens mission has revealed Titan and Enceladus to be two of the most enigmatic worlds in the Solar System. Titan, with its organically rich and dynamic atmosphere and geology, and Enceladus, with its active plume of water vapor and ice including trace amounts of organics, salts, and silica nano-particles, both harboring subsurface oceans, are prime environments to investigate the conditions for the emergence of life and the habitability potential of ocean worlds, as well as the origin and evolution of complex planetary systems. The Explorer of Enceladus and Titan (E2T) is a space mission concept dedicated to investigating the evolution and habitability of these Saturnian satellites and is proposed in response to ESA's M5 Cosmic Vision Call, as a medium-class mission led by ESA in collaboration with NASA. E2T has a focused state-of-the-art payload that will provide in-situ chemical analysis, and high-resolution imaging from multiple flybys of Enceladus and Titan using a solar-electric powered spacecraft in orbit around Saturn. With significant improvements in mass range and resolution, as compared with Cassini instrumentation, the Ion and Neutral Gas Mass Spectrometer (INMS) and the Enceladus Icy Jet Analyzer (ENIJA) time-of-flight mass spectrometers will provide the data needed to decipher the subtle details of the aqueous environment of Enceladus from plume sampling and of the complex pre-biotic chemistry occurring in Titan's atmosphere. The Titan Imaging and Geology, Enceladus Reconnaissance (TIGER) mid-wave infrared camera will map thermal emission from Enceladus' tiger stripes at meter scales and investigate Titan's geology and compositional variability at decameter scales