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Mol, Belgium

Filliatre P.,CEA Cadarache Center | Filliatre P.,French Atomic Energy Commission | Vermeeren L.,SCK | Vermeeren L.,French Atomic Energy Commission | And 6 more authors.
Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment | Year: 2011

The fission chambers that provide in-core measurements of the neutron flux in nuclear reactors are also sensitive to the γ-ray flux. According to experimental data, this contribution can be dominant in current mode. We present a calculation route, relying on a description of the physical phenomena, that compute the γ-ray signal in a fission chamber, coming directly from the γ-ray flux, and indirectly from the neutron flux and activated structures. We use it in a working example for which we show that the main contribution of the γ-ray flux to the signal comes from the interaction of the γ-rays with the electrodes. The relative contribution of gammas created by neutron interactions in the detector is small. The comparison of this example with experimental results yields a good qualitative agreement: the γ-ray signal may dominate in current mode, but is effectively suppressed in fluctuation mode. This calculation route will be useful for the design of fission chambers to be operated under high neutron and γ-ray flux. © 2011 Elsevier B.V. All rights reserved.

Vandeplassche D.,SCK | Biarrotte J.-L.,Institute Of Physique Nucleaire | Klein H.,Institute For Angewandte Physik | Podlech H.,Institute For Angewandte Physik
IPAC 2011 - 2nd International Particle Accelerator Conference | Year: 2011

Accelerator Driven Systems (ADS) are promising tools for the efficient transmutation of nuclear waste products in dedicated industrial installations, called transmuters. The Myrrha project at Mol, Belgium, placed itself on the path towards these applications with a multipurpose and versatile system based on a liquid Pb-Bi (LBE) cooled fast reactor (70 MWth) which may be operated in both critical and subcritical modes. In the latter case the core is fed by spallation neutrons obtained from a 600 MeV proton beam hitting the LBE coolant/target. The accelerator providing this beam is a high intensity CW superconducting linac which is laid out for the highest achievable reliability. The combination of a parallel redundant and of a fault tolerant scheme should allow obtaining an MTBF value in excess of 250 hours that is required for optimal integrity and successful operation of the ADS. Myrrha is expected to be operational in 2023. The forthcoming 4-year period is fully dedicated to R&D activities, and in the field of the accelerator they are strongly focused on the reliability aspects and on the proper shaping of the beam trip spectrum. Copyright © 2011 by IPAC'11/EPS-AG.

Pheron X.,Andra Inc | Pheron X.,CNRS Hubert Curien Laboratory | Girard S.,CEA DAM Ile-de-France | Boukenter A.,CNRS Hubert Curien Laboratory | And 4 more authors.
Optics Express | Year: 2012

The use of distributed strain and temperature in optical fiber sensors based on Brillouin scattering for the monitoring of nuclear waste repository requires investigation of their performance changes under irradiation. For this purpose, we irradiated various fiber types at high gamma doses which represented the harsh environment constraints associated with the considered application. Radiation leads to two phenomena impacting the Brillouin scattering: 1) decreasing in the fiber linear transmission through the radiation-induced attenuation (RIA) phenomenon which impacts distance range and 2) modifying the Brillouin scattering properties, both intrinsic frequency position of Brillouin loss and its dependence on strain and temperature. We then examined the dose dependence of these radiation-induced changes in the 1 to 10 MGy dose range, showing that the responses strongly depend on the fiber composition. We characterized the radiation effects on strain and temperature coefficients, dependencies of the Brillouin frequency, providing evidence for a strong robustness of these intrinsic properties against radiations. From our results, Fluorine-doped fibers appear to be very promising candidates for temperature and strain sensing through Brillouin-based sensors in high gamma-ray dose radiative environments. © 2012 Optical Society of America.

Vermote S.,Ghent University | Wagemans C.,Ghent University | Serot O.,CEA Cadarache Center | Heyse J.,SCK | And 8 more authors.
Nuclear Physics A | Year: 2010

The emission probabilities and the energy distributions of tritons, α and 6He particles emitted in the spontaneous ternary fission (zero excitation energy) of 250Cf and 252Cf and in the cold neutron induced fission (excitation energy ≈6.5 MeV) of 249Cf and 251Cf are determined. The particle identification was done with suited ΔE-E telescope detectors, at the IRMM (Geel, Belgium) for the spontaneous fission and at the ILL (Grenoble, France) for the neutron induced fission measurements. Hence particle emission characteristics of the fissioning systems 250Cf and 252Cf are obtained at zero and at about 6.5 MeV excitation energies. While the triton emission probability is hardly influenced by the excitation energy, the 4He and 6He emission probability in spontaneous fission is higher than for neutron induced fission. This can be explained by the strong influence of the cluster preformation probability on the ternary particle emission probability. © 2010 Elsevier B.V.

News Article
Site: www.materialstoday.com

Dear authors, reviewers, readers of The Journal of Nuclear Materials In January 2016, the Journal of Nuclear Materials will go through a very important editorial transition. Dr Louis Mansur, who has been an editor and then the Chairman of the Editors for over 25 years will be stepping down. For the past eighteen month, I have been working to prepare for this transition. I want to take this opportunity to thanks the current editorial team again for their service to the journal and the nuclear materials community: Drs Louis Mansur (ORNL, USA), Roger Stoller(ORNL, USA), Takeo Muroga (NIFS, Japan), Toru Ogawa (Nagaoka University of Technology, Japan), Malcolm Griffiths (CNL, Canada) and Stephane Gin (CEA, France). It is my pleasure to announce that Prof. Gary Was from the University of Michigan will be assuming the role of Editor-in-Chief. He will lead a core team of Senior Editors along side Prof. Steve Zinkle, UT/ORNL Governor's Chair at the University of Tennessee, Prof. Shigeharu Ukai from Hokkaido University and Dr. David Petti from Idaho National Laboratory. Each of the Senior Editors will be supported by a team of 2–3 Associate Editors. The current list of Associate editor is K. Fukuya (Institute of Nuclear Engineering, Fukui, Japan), Q. Huang (Institute of Nuclear Energy Safety Technology, CAS, China), M. Preuss (University of Manchester, UK), N. Dacheux (Université de Montpellier / CEA, France), L. Snead (Massachusetts Institute of Technology, USA),Y. Dai (Paul Scherrer Institute, Switzerland), Jean-Paul Crocombette (CEA France), Lorenzo Malerba (SCK-CEN, Belgium), with C. Stanek (LANL, USA) expected to join very soon. The overall editorial team should comprise 12 members as of 1st January 2016, with an expectation that it will grow to 13 in the first months of 2016. The team therefore encompassed a broad expertise on the various topics of interest to the journal. This extended editorial team will allow us to develop a strategy to better serve the nuclear materials community. We expect that most of the editors will be present at the forthcoming NuMAT 16 conference in Montpellier in November 2016, and please make your way to the conference if you wish to meet and exchange your views with them.

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