Status of art of reaction models for projectiles far from stability

This talk will review the status of art of nuclear and Coulomb breakup theories and their relation to optical models of elastic scattering of exotic projectiles. The effect of the final state interactions between the breakup particle and the core and target nuclei will be clarified and some typical numerical calculations for the relevant observables will be presented and compared to experimental data. Finally new results will be shown to demonstrate the feasibility of a novel type of experiment involving heavy projectiles far from stability on heavy targets.Comment: 10 pages, 4 figures. Proceedings of NN2007, Rio de Janeir

The GUINEVERE Project for Accelerator Driven System Physics

paper 9414International audienceThe GUINEVERE project is part of the EUROTRANS Integrated Project of the 6th EURATOM Framework Programme. It is mainly devoted to ADS on-line reactivity monitoring validation, sub-criticality determination and operational procedures (loading, start-up, shut-down, ...) as a follow-up of the MUSE experiments. The project consists in coupling a fast lead core, set-up in the VENUS reactor at SCK*CEN Mol (B), with a GENEPI neutron source under construction by CNRS. To accommodate the accelerator in a vertical coupling configuration, the VENUS building is being heightened. The fast core will be loaded with enriched Uranium and will be moderated and reflected with solid lead (zero power experiment). For the purpose of the experimental programme, the neutron source has to be operated not only in pulsed mode but also in continuous mode to investigate the current-to-flux reactivity indicator in representative conditions of a powerful ADS. In this latter mode it is also required to make short beam interruptions to have access to the neutron population decrease as a function of time: from this spectrum it will be possible to apply different analysis techniques such as "prompt decay" fitting techniques and "source jerk" techniques. Beam interruptions will be repeated at a programmable frequency to improve time spectra statistics. Different sub-criticality levels (keff=0.99, 0.97, 0.95, ...) will be investigated in order to obtain a full set of data points for the final overall validation of the methodology. This paper describes the status of the experimental facility assembling, and the foreseen experimental programme to be started

Reactivity monitoring of the accelerator driven VENUS-F subcritical reactor with the “current-to-flux” method

International audienceIn this article, we evaluate the quality and robustness of a method envisaged for the on-line monitoring of the subcriticality of an ADS, called the ‘‘current-to flux” (CTF) method. For this evaluation, we performed a dedicated experiment at the GUINEVERE facility. It is hosted at the SCK-CEN and consists of the subcritical VENUS-F reactor coupled to a continuous external neutron source provided by the GENEPI-3C accelerator. During this experiment, the reactor control rods were moved in various patterns, and the subsequent dynamical evolutions of the reactor reactivity were monitored using nine fission chambers (FCs). The space-energy effects that bias the reactivity values are corrected using a procedure based on simulations computed with the Monte Carlo neutron transport code MCNP. We investigate the precision of this correction procedure by comparison with a reactivity value extracted with the beam interruption technique and we demonstrate its insensitivity to the simplifications made on the VENUS-F reactor modeling and to a simulation key parameter such as the boron carbide density filling the control rods

An Alternative Source Jerk Method Implementation for the Subcriticality Estimation of the VENUS-F Subcritical Core in the FREYA Project

International audienceAs a prolongation of the FP-6 GUINEVERE (Generation of Uninterrupted Intense NEutron pulses at the lead VEnus REactor)project at the VENUS-F facility at SCK• CEN, the FP-7 FREYA (Fast Reactor Experiments for hYbrid Applications) project was launched in2011. The FREYA project aims at validating the methodology for subcriticality monitoring of a subcritical core as proposed in the MUSEexperiments conclusions. This is needed for the reactivity monitoring of a powerful ADS (Accelerator Driven System) like MYRRHA.Experiments are also needed for sub-critical and critical ADS and LFR (Lead Fast Reactor) core characterisation for benchmarking andlicensing purposes. Several levels of sub-criticality of the first subcritical core were measured applying the integral Source Jerk methodand compared to the reference results obtained with the MSM (Modified Source Multiplication) method

Analysis of prompt decay experiments for ADS reactivity monitoring at VENUS-F GUINEVERE facility

International audienc

Effective delayed neutron fraction measurement in the critical VENUS-F reactor using noise techniques

International audienceThis paper present the measurements of VENUS-F kinetic parameters using the Rossi-Alpha methods. The VENUS-F reactor is a zero-power reactor based in Mol, Belgium at SCK-CEN [1]: its fuel is made of metallic enriched uranium with pure lead in order to simulate the behavior of a lead fast reactor. The reactor can be operated in a sub-critical state when it is coupled with the GENEPI-3C neutron source [2]. At the beginning of 2014, a measurement campaign was performed in the critical state in order to estimate the kinetic parameters of the reactor. In this paper, two measurements are analyzed at two different powers (approximately 2W and 30W) with 7 different fission chambers (with a 235-U deposit that varies from 1g to 10mg). All the correlation functions needed for the Rossi-Alpha method have been built for each possible set of two detectors for the two power levels and values of the effective delayed neutron fraction obtained are then compared. Experimental results show the importance to operate at a very low power. The final value for the effective delayed neutron fraction is finally estimated to be (730 ±11) pcm and the prompt neutron generation time is estimated to be equal to (0.41 ± 0.04) μsec

Reactivity Measurements at GUINEVERE Facility Using the Integral kp Method

International audienceIn the framework of the GUINEVERE (EUROTRANS-IP FP6) and FREYA (FP7) projects, a two-level procedure is developed to measurethe time variations of an ADS reactivity ρ(t). First, the time variations of the reactor power and neutron source intensity are monitored online,allowing to extract the fast fluctuations of ρ(t) around a reference value. Then, absolute measurements of ρ are periodically performed toreadjust the relative measurements. These calibration measurements require the analysis of the decay of the neutron population triggeredby programmed beam interruptions. In this paper, we describe an innovative method developed to measure the prompt multiplicationfactor, kp, of a subcritical reactor (and therefore its absolute ρ). Unlike conventional methods used for reactivity measurements, ourapproach only relies on the prompt decay of the neutron population, therefore enabling the use of shorter beam interruptions (< 50 μs) thanusual (~ 1 ms). After a review of the method’s mechanics, we apply it to measurements performed at the GUINEVERE facility, with theVENUS-F reactor, a zero power lead subcritical fast reactor. During these measurements, the neutron source was operated in pulsemode. Our results, promising, are compared with reference reactivity values provided by a MSM analysis

Reactivity Measurements at GUINEVERE Facility Using the Integral kp Method

International audienceIn the framework of the GUINEVERE (EUROTRANS-IP FP6) and FREYA (FP7) projects, a two-level procedure is developed to measurethe time variations of an ADS reactivity ρ(t). First, the time variations of the reactor power and neutron source intensity are monitored online,allowing to extract the fast fluctuations of ρ(t) around a reference value. Then, absolute measurements of ρ are periodically performed toreadjust the relative measurements. These calibration measurements require the analysis of the decay of the neutron population triggeredby programmed beam interruptions. In this paper, we describe an innovative method developed to measure the prompt multiplicationfactor, kp, of a subcritical reactor (and therefore its absolute ρ). Unlike conventional methods used for reactivity measurements, ourapproach only relies on the prompt decay of the neutron population, therefore enabling the use of shorter beam interruptions (< 50 μs) thanusual (~ 1 ms). After a review of the method’s mechanics, we apply it to measurements performed at the GUINEVERE facility, with theVENUS-F reactor, a zero power lead subcritical fast reactor. During these measurements, the neutron source was operated in pulsemode. Our results, promising, are compared with reference reactivity values provided by a MSM analysis

An Alternative Source Jerk Method Implementation for the Subcriticality Estimation of the VENUS-F Subcritical Core in the FREYA Project

International audienceAs a prolongation of the FP-6 GUINEVERE (Generation of Uninterrupted Intense NEutron pulses at the lead VEnus REactor)project at the VENUS-F facility at SCK• CEN, the FP-7 FREYA (Fast Reactor Experiments for hYbrid Applications) project was launched in2011. The FREYA project aims at validating the methodology for subcriticality monitoring of a subcritical core as proposed in the MUSEexperiments conclusions. This is needed for the reactivity monitoring of a powerful ADS (Accelerator Driven System) like MYRRHA.Experiments are also needed for sub-critical and critical ADS and LFR (Lead Fast Reactor) core characterisation for benchmarking andlicensing purposes. Several levels of sub-criticality of the first subcritical core were measured applying the integral Source Jerk methodand compared to the reference results obtained with the MSM (Modified Source Multiplication) method

The GUINEVERE Experiment: first PNS measurements in a lead moderated sub-critical fast core

Item ID: 700368 / ISBN: 978-0-89448-091-1International audienc