Delayed neutron
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SOURCES 4C : a code for calculating ([alpha],n), spontaneous fission, and delayed neutron sources and spectra. Open
SOURCES 4C is a computer code that determines neutron production rates and spectra from ({alpha},n) reactions, spontaneous fission, and delayed neutron emission due to radionuclide decay. The code is capable of calculating ({alpha},n) sour…
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Evidence for X-Ray Emission in Excess to the Jet-afterglow Decay 3.5 yr after the Binary Neutron Star Merger GW 170817: A New Emission Component Open
For the first ∼3 yrs after the binary neutron star merger event GW 170817, the radio and X-ray radiation has been dominated by emission from a structured relativistic off-axis jet propagating into a low-density medium with n 900 days after…
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<sup>235</sup>U(n, f) Independent fission product yield and isomeric ratio calculated with the statistical Hauser–Feshbach theory Open
In this work, we have developed a Hauser–Feshbach fission fragment decay model, HF3D, which can be applied to the statistical decay of more than 500 primary fission fragment pairs (1,000 nuclides) produced by the neutron induced fission of…
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The characterization of radioactive waste: a critical review of techniques implemented or under development at CEA, France Open
This review paper describes the destructive and non-destructive measurements implemented or under development at CEA, in view to perform the most complete radioactive waste characterization. First, high-energy photon imaging (radiography, …
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Observation of New Neutron-rich Isotopes among Fission Fragments from In-flight Fission of 345 MeV/nucleon <sup>238</sup>U: Search for New Isotopes Conducted Concurrently with Decay Measurement Campaigns Open
International audience
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Improved measurement of the reactor antineutrino flux at Daya Bay Open
This work reports a precise measurement of the reactor antineutrino flux using 2.2 million inverse beta decay (IBD) events collected with the Daya Bay near detectors in 1230 days. The dominant uncertainty on the neutron detection efficienc…
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Angular momentum effects in fission Open
Background: The role of angular momentum in fission has long been discussed\nbut the observable effects are difficult to quantify. Purpose: We discuss a\nvariety of effects associated with angular momentum in fission and present\nquantitat…
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Extension of the Hauser-Feshbach fission fragment decay model to multichance fission Open
The Hauser-Feshbach fission fragment decay model, $\\mathtt{HF^3D}$, which\ncalculates the statistical decay of fission fragments, has been expanded to\ninclude multi-chance fission, up to neutron incident energies of 20 MeV. The\ndetermin…
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14 MeV calibration of JET neutron detectors—phase 2: in-vessel calibration Open
A new DT campaign (DTE2) is planned at JET in 2020 to minimize the risks of ITER operations. In view of DT operations, a calibration of the JET neutron monitors at 14 MeV neutron energy has been performed using a well calibrated 14 MeV neu…
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Neutronic and Thermal-Hydraulic Safety Analysis for the Optimization of the Uranium Foil Target in the RSG-GAS Reactor Open
The G. A. Siwabessy Multipurpose Reactor (Reaktor Serba Guna G.A. Siwabessy, RSG-GAS) has an average thermal neutron flux of 2×1014 neutron/(cm2 sec) at the nominal power of 30 MW. With such a high thermal neutron flux, the reactor is suit…
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Evaluations of Energy Spectra of Neutrons Emitted Promptly in Neutron-induced Fission of 235 U and 239 Pu Open
The energy spectra of neutrons emitted promptly in the neutron-induced fission reactions of 235U and 239Pu were re-evaluated for ENDF/B-VIII.0. The evaluations presented here are based on a careful modeling of all relevant physics processe…
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Dynamic Monte Carlo transient analysis for the Organization for Economic Co-operation and Development Nuclear Energy Agency (OECD/NEA) C5G7-TD benchmark Open
With ever-advancing computer technology, the Monte Carlo (MC) neutron transport calculation is expanding its application area to nuclear reactor transient analysis. Dynamic MC (DMC) neutron tracking for transient analysis requires efficien…
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Nuclear data sensitivity and uncertainty analysis of effective neutron multiplication factor in various MYRRHA core configurations Open
A sensitivity and uncertainty analysis was carried out to estimate the uncertainty in the neutron multiplication factor keff and to identify the most important nuclear data for neutron induced reactions for criticality calculations of the …
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A Review of Molten Salt Reactor Kinetics Models Open
Interest in circulating fuel reactors (CFRs), particularly molten salt reactors (MSRs) of the fluid fuel type, has been growing in the last two decades. Starting with a resurgence of interest in Europe, there have been a growing number of …
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Simultaneous Determination of Neutron-Induced Fission and Radiative Capture Cross Sections from Decay Probabilities Obtained with a Surrogate Reaction Open
Reliable neutron-induced-reaction cross sections of unstable nuclei are essential for nuclear astrophysics and applications but their direct measurement is often impossible. The surrogate-reaction method is one of the most promising altern…
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Comprehensive Second-Order Adjoint Sensitivity Analysis Methodology (2nd-ASAM) Applied to a Subcritical Experimental Reactor Physics Benchmark: III. Effects of Imprecisely Known Microscopic Fission Cross Sections and Average Number of Neutrons per Fission Open
The Second-Order Adjoint Sensitivity Analysis Methodology (2nd-ASAM) is applied to compute the first-order and second-order sensitivities of the leakage response of a polyethylene-reflected plutonium (PERP) experimental system with respect…
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Towards saturation of the electron-capture delayed fission probability: The new isotopes 240 Es and 236 Bk Open
The new neutron-deficient nuclei ²⁴⁰Es and ²³⁶Bk were synthesised at the gas-filled recoil separator RITU. They were identified by their radioactive decay chains starting from ²⁴⁰Es produced in the fusion–evaporation reaction ²⁰⁹Bi(³⁴S,3n)…
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Neutronics and Transient Analyses of a Supercritical CO2-cooled Micro Modular Reactor (MMR) Open
This paper presents the neutronics and transient studies of a supercritical CO2-cooled micro modular reactor (MMR). The suggested MMR is an extremely compact, integrated, and truck-transportable reactor with 36.2 MWth power and a 20-year l…
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Impact of fission neutron energies on reactor antineutrino spectra Open
Recent measurements of reactor-produced antineutrino fluxes and energy\nspectra are inconsistent with models based on measured thermal fission beta\nspectra. In this paper, we examine the dependence of antineutrino production on\nfission n…
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Design Study of 200MWth Gas Cooled Fast Reactor with Nitride (UN-PuN) Fuel Long Life without Refueling Open
\nDesign study of 200 MWth Gas Cooled Fast Reactor with UN-PuN fuel long life without refueling has been done. GFR is one type reactor in Generation IV reactor system. It uses helium coolant and fast neutron spectrum. Helium is chemical in…
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Genetic algorithm for nuclear data evaluation applied to subcritical neutron multiplication inference benchmark experiments Open
An optimization algorithm has been developed for the first time for application to International Criticality Safety Benchmark Evaluation Project (ICSBEP) subcritical neutron multiplication inference benchmark experiments. The optimization …
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Evaluation of fission product yields and associated covariance matrices Open
The independent and cumulative fission product yields (FPYs) and their covariance matrices were newly evaluated for thermal- and fast-neutron induced fission and spontaneous fission. We principally evaluated the independent isobaric charge…
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Unexpected high-energy γ emission from decaying exotic nuclei Open
Publication in the conference proceedings of EUSIPCO, Viena, Austria, 2004
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Modified Point-Kinetics Model for Neutron Precursors and Fission Product Behavior for Fluid-Fueled Molten Salt Reactors Open
Fluid-fueled nuclear reactors, such as molten salt reactors (MSRs), have recently gained significant interest. These advanced reactors represent a potential revolutionary shift in the implementation of nuclear power, and as a broad class o…
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A novel fractional technique for the modified point kinetics equations Open
A fractional model for the modified point kinetics equations is derived and analyzed. An analytical method is used to solve the fractional model for the modified point kinetics equations. This methodical technique is based on the represent…
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Numerical modelling of modular high-temperature gas-cooled reactors with thorium fuel Open
The volumetric homogenization method for the simplified modelling of modular high-temperature gas-cooled reactor core with thorium-uranium fuel is presented in the paper. The method significantly reduces the complexity of the 3D numerical …
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Current Mode Neutron Noise Measurements in the Zero Power Reactor CROCUS Open
The present article is an overview of developments and results regarding neutron noise measurements in current mode at the CROCUS zero power facility. Neutron noise measurements offer a non-invasive method to determine kinetic reactor para…
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Results of Three Neutron Diagnosed Subcritical Experiments Open
Neutron diagnosed subcritical experiments (NDSEs) aim to measure the fission chain decay of subcritical test objects initiated by neutrons from an external source. The ultimate goal of future NDSEs is to make such measurements on dynamic s…
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Derivation of the Two-Exponential Probability Density Function for Rossi-Alpha Measurements of Reflected Assemblies and Validation for the Special Case of Shielded Measurements Open
Rossi-alpha measurements of fissionable assemblies are used to estimate the prompt neutron decay constant α. Reactivity can be inferred from α if the values of the neutron generation time and effective delayed neutron fraction are assumed.…
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Power calibration methodology at the CROCUS reactor Open
In the present article, we detail the method used to experimentally determine the power of the CROCUS zero-power reactor, and to subsequently calibrate its ex-core monitor fission chambers. Knowledge of the reactor power is a mandatory qua…