Applicability of abrasive waterjet cutting to irradiated graphite decommissioning

Characterization, dismantling and pre-disposal management of irradiated graphite (i-graphite) have an important role in safe decommissioning of several nuclear facilities which used this material as moderator and reflector. In addition to common radiation protection issues, easily volatizing long-lived radionuclides and stored Wigner energy could be released during imprudent retrieval and processing of i-graphite. With this regard, among all cutting technologies, abrasive waterjet (AWJ) can successfully achieve all of the thermo-mechanical and radiation protection objectives. In this work, factorial experiments were designed and systematically conducted to characterize the AWJ processing parameters and the machining capability. Moreover, the limitation of dust production and secondary waste generation has been addressed since they are important aspects for radiation protection and radioactive waste management. The promising results obtained on non-irradiated nuclear graphite blocks demonstrate the applicability of AWJ as a valid technology for optimizing the retrieval, storage, and disposal of such radioactive waste. These activities would benefit from the points of view of safety, management, and costs

Modulation of the postural effects of cognitive load by hypnotizability

Aim of the experiment was to study whether cognitive load aVects postural control more in low (Lows) than in highly hypnotizable (Highs) subjects due to the latter\u27s greater attentional abilities. Standing Highs and Lows underwent an experimental session (closed eyes) consisting of a basal condition and of mental computation in an easy (stable support) and a diYcult (unstable support) postural condition. Variability [standard deviation (SD)] and complexity [sample entropy (SampEn)] of the movement of the centre of pressure (CoP), its mean velocity (Velocity), the area swept by the CoP (Area) and the ratio between the CoP trajectory length and area [length for surface (LFS)] were measured. Few hypnotizability-related diVerences were detected (reduction in the Highs\u27 SD and increases in the Lows\u27 LFS in the diYcult postural condition). Thus, the hypnotizability-related postural diVerences observed in previous studies during sensory alteration could not be accounted mainly by attentional abilities

thermodynamic properties of pb3u11o36

Abstract In order to progress in the development of Lead-cooled Fast Reactors, from the safety point of view it is essential to understand the chemical compatibility between liquid lead and uranium oxide. In the present work, entropy and heat capacity of Pb3U11O36, a possible ternary compound coming from fuel-coolant chemical interaction, were determined for the first time. Entropy at 298.15 K was obtained from low temperature heat capacity measurements using the Physical Property Measurement System (PPMS) in the temperature range 2–300 K, while the high temperature heat capacity has been measured by a drop calorimeter from 373 K to 1200 K. The experimental thermodynamic properties were compared with the values computed by means of DFT-GGA simulations, obtaining a very good agreement

Thermal stability and high-temperature behavior of the natural borate colemanite: An aggregate in radiation-shielding concretes

Colemanite is a natural borate that can be used as an aggregate in neutron-radiation shielding concretes. In this study, we report its thermal behavior, up to 500 degrees C, by describing: 1) its dehydration mechanisms and 2) its thermo-elastic parameters. The thermal expansion of colemanite is significantly anisotropic. The refined volume thermal expansion coefficient at ambient conditions is: alpha(V0) = 4.50(10).10(-5) K-1. The loss of structural H2O occurs at least from similar to 240 degrees C, and at T > 325 degrees C an irreversible amorphization occurs, followed by a complete dehydration. The potential implications on the use of colemanite as concrete-aggregate are discussed. (C) 2019 Elsevier Ltd. All rights reserved

Cutting-edge R&D activities of CIRTEN in support of the Technology Park annexed to the Italian National Repository of radioactive waste

R&D activities taking place at the institutions belonging to Consorzio Interuniversitario per la Ricerca TEcnologica Nucleare are here presented and discussed. A special focus is on Technology Park annexed to the Italian National Repository of radioactive waste

Politiques marginales : l'art au-delà du binarisme barbarie ou civilité

A abordagem clássica do Estado para com os sujeitos que orbitam as esferas desprestigiadas do capital vem lançando mão de concei-tos como o de exclusão social e sujeitos em vulnerabilidade. Subjaz a estes conceitos a oposição: bárbaros x civilizados, fazendo recair apenas sobre os primeiros a pecha de violentos. Neste ensaio, dis-cutimos as estratégias de conduzir as condutas daqueles tomados pelas Políticas de Estado como sujeitos a corrigir. Contrapomos a tais práticas as operações estéticas realizadas por dois artistas bra-sileiros: o artista plástico Helio Oiticica e o poeta Waly Salomão. Em suas experimentações estes criadores nos legaram importantes operações éticas que, ao produzirem híbridos paradoxais entre civi-lidade e barbárie, permitem a passagem de uma Política do Estado para uma Política do Comum.The classical approach of the State to the subjects that orbit the dis-credited spheres of capital has been using concepts such as social exclusion and subjects in vulnerability. Underlying these concepts are the opposition: barbarians x civilized, imposing only on the first the stereotype of violent. In this essay, we discuss the strategies em-ployed to conduct the conduct of those taken by State Policies as subjects to be corrected. We oppose to such practices some aesthetic operations performed by two Brazilian artists: the plastic artist Helio Oiticica and the poet Waly Salomão. In their experiments these creators have bequeathed us important ethical operations that, by producing paradoxical hy-brids between civility and barbarism, allow the transition from a State Policy to a Politics of the Common.El abordaje clásico del Estado hacia los sujetos que orbitan las esferas desprestigiadas del capital utiliza conceptos como el de exclusión social y sujetos en vulnerabilidad. Subyace a estos conceptos la oposición: bárbaros x civilizados, haciendo con que solo los primeros sean dichos violentos. En este ensayo discutimos las estrategias de conducir las conductas de aquellos pillados por las Políti-cas de Estado como sujetos a corregir. Contraponemos a estas prácticas las operaciones estéticas realizadas por dos artistas brasileños: el artista plástico Hélio Oiticica y el poeta Waly Salomão. En sus experimentaciones estos creadores nos han legado importantes operaciones éticas que, en cuanto producen híbridos paradoxales entre civilidad y barbarie, permite un pasaje desde una Política del Estado hacia una Política del Común.L'approche classique de l'État envers les sujets qui gravitent autour des sphères discréditées du capital a utilisé des concepts tels que l'exclusion sociale et les sujets vulnérables. Sous-jacents à ces concepts se trouvent l'opposition: barbares x civilisés, les faisant tomber seulement sur les premiers le stéréotype de violents. Dans cet essai, nous discutons comment les stratégies employées pour conduire les conduits de ceux pris par les politiques de l'Etat comme sujets à corriger. Nous nous opposons aux ces pratiques l'es opérations esthétiques des deux artistes brésiliens: l'artiste plasticien Helio Oiticica et le poète Waly Salomão. Dans leurs expériences ces créateurs nous ont légué d'importantes opérations éthiques qui, en produisant des hybrides paradoxaux entre civilité et barbarie, permettent le passage d'une politique d'Etat à une politique du commun

Pyroprocess Experiments at ENEA Laboratories

A new facility, known as Pyrel III, has been installed at ENEA laboratories for pyrochemical process studies under inactive conditions. It is a pilot plant which allows electrorening and electroreduction experiments to be conducted on simulated fuel. The main component of the plant is a zirconia crucible. The crucible is heated by a furnace which is supported in an externally water-cooled well under the oor of a steel glove-box, where an argon atmosphere is maintained by a continual purge of about 10 L·min-1. The vessel is loaded with LiCl-KCl eutectic salt (59-41 mol%) and is currently operated at 460 °C. Several improvements on Pyrel II (the previous operating plant) have been introduced into Pyrel III. They are described in detail, together with the results from the rst experimental campaign which used lanthanum metal.Moreover, studies about the treatment of chloride salt wastes from pyroprocesses have been conducted in parallel. They follow two main routes: on one hand, a matrix termed sodalite, a naturally occurring mineral containing chlorine, has been synthesized from a mix of nepheline, simulated exhausted salts and glass frit; on the other hand, a novel method proposed by Korea Atomic Energy Research Institute (KAERI) is under assessment. The nal waste forms have been fully characterized with the support of the Politechnique of Milan, by means of density measurements, thermal analysis, and stereomicroscopy observations, FTIR, XRD, and RAMAN spectra, as well as leach tests under static condition