Search results for " reactor"

High precision measurement of the radiative capture cross section of 238U at the n_TOF CERN facility

2016

The importance of improving the accuracy on the capture cross-section of 238U has been addressed by the Nuclear Energy Agency, since its uncertainty significantly affects the uncertainties of key design parameters for both fast and thermal nuclear reactors. Within the 7th framework programme ANDES of the European Commission three different measurements have been carried out with the aim of providing the 238U(n,γ) cross-section with an accuracy which varies from 1 to 5%, depending on the energy range. Hereby the final results of the measurement performed at the n-TOF CERN facility in a wide energy range from 1 eV to 700 keV will be presented. © The Authors, published by EDP Sciences, 2017.

New measurement of the 242Pu(n,γ) cross section at n-TOF-EAR1 for MOX fuels: Preliminary results in the RRR

2016

The spent fuel of current nuclear reactors contains fissile plutonium isotopes that can be combined with 238U to make mixed oxide (MOX) fuel. In this way the Pu from spent fuel is used in a new reactor cycle, contributing to the long-term sustainability of nuclear energy. The use of MOX fuels in thermal and fast reactors requires accurate capture and fission cross sections. For the particular case of 242Pu, the previous neutron capture cross section measurements were made in the 70’s, providing an uncertainty of about 35% in the keV region. In this context, the Nuclear Energy Agency recommends in its “High Priority Request List” and its report WPEC-26 that the capture cross section of 242Pu…

Fukushima, or the Black Swan of Nuclear Energy

2012

By its own merits, the great earthquake that hit Japan on 11 March 2011 would have qualified as one of the worse disasters of recent times. With a magnitude of 9.0 MW, it was the most powerful known earthquake ever to have hit Japan, and one of the most powerful in history. It released a surface energy 2 × 1017 Joule. Enough, if harnessed, to power a city the size of Los Angeles for an entire year.

Electrochemical treatment of organic pollutants in macro and micro reactors

2011

Abatement of 3-methylbutanal and trimethylamine with combined plasma and photocatalysis in a continuous planar reactor

2014

International audience; This paper deals with the 3-methylbutanal ((CH3)2CHCH2COH) removal with the help of a nonthermal surface plasma discharge coupled with photocatalysis. The capability of this process for gas treatment was studied. A planar reactor system was developed in order to perform the effect of adding photocatalytic material in plasma surface discharge barrier dielectric (SDBD) zone on (i) 3-methylbutanal removal, (ii) selectivity of CO2 and CO, (iii) byproducts formation such ozone formation. It was found that the influence of the UV light generated by SDBD reactor was very low. The activation of the photocatalyst media could be negligible. Whereas, the introduction of externa…

The Six Flux Model for the modelling of radiant fields in heterogeneous photoreactors

2002

MODELING OF A TiO2-COATED QUARTZ -WOOL PACKED-BED PHOTOCATALYTIC REACTOR

2010

A fixed-bed, photocatalytic laboratory reactor aimed to degrade pollutants from water streams was designed and built. Quartz wool coated with a thin film of TiO2 was employed as the reactor filling. The photocatalyst was placed in the reactor forming a loose packing to guarantee the intimate contact among reactants, photons, and the photocatalytic surface. This reactor was employed to study the photocatalytic decomposition of a model pollutant (formic acid). A reactor–radiation–reaction model was developed, which was comprised of the reactor mass balance, radiation model, and kinetic model for the degradation of formic acid. The local superficial rate of photon absorption, which was necessa…

Radiation model of a TiO2-coated, quartz wool, packed-bed photocatalytic reactor

2010

The radiation field of a packed-bed photocatalytic reactor filled with quartz wool coated with titanium dioxide was modeled using the Monte Carlo technique and the following information: the radiation flux emitted by the lamps, the diameter size distribution of the quartz fiber cloth, the mass of quartz fibers and of TiO2 that was immobilized on the fiber surface as well as the refractive index and the spectral absorption coefficient of the materials of the system. Modeling predictions were validated with radiometer measurements of the transmitted radiation through the reactor, the root mean square error being < 9.7%. Finally, by means of a parametric study, the validated model was used to …

Development of a Higee bioreactor (HBR) for production of polyhydroxyalkanoate: Hydrodynamics, gas–liquid mass transfer and fermentation studies

2010

Abstract This study addresses the hydrodynamics and mass transfer characterisation of a Higee bioreactor (HBR) for application to polyhydroxyalkanoate (PHA) production from Pseudomonas putida KT2442 fermentation. The motivation for this work is to address the potential oxygen transfer limitations which can severely impede the progress of this aerobic fermentation process and reduce PHA productivity in conventional bioreactors. It is shown that a maximum of 2.5 transfer units can be achieved in an oxygen-stripping operation where the presence of packing, higher rotor speeds, higher air flowrates and lower liquid flowrates all have a positive influence on the number of transfer units (NTU). W…

Neutrino Physics with JUNO

2016

The Jiangmen Underground Neutrino Observatory (JUNO), a 20 kton multi-purpose underground liquid scintillator detector, was proposed with the determination of the neutrino mass hierarchy as a primary physics goal. It is also capable of observing neutrinos from terrestrial and extra-terrestrial sources, including supernova burst neutrinos, diffuse supernova neutrino background, geoneutrinos, atmospheric neutrinos, solar neutrinos, as well as exotic searches such as nucleon decays, dark matter, sterile neutrinos, etc. We present the physics motivations and the anticipated performance of the JUNO detector for various proposed measurements. By detecting reactor antineutrinos from two power plan…