LABORATORI NAZIONALI DI LEGNARO
One of the core activities of the Nuclear Safety, Security and Safeguards Unit is the determination of cross section data for neutron induced reactions. Therefore, two neutron production facilities are operated at the EC-JRC-IRMM. The time-of-flight facility GELINA, producing a pulsed white neutron source with neutron energies ranging from thermal energy up to 20 MeV, and a 7 MV Van de Graaff accelerator where high intensity quasi mono-energetic neutron beams are produced to study neutron induced reactions in the continuum. In this lecture the time-of-flight facility GELINA will be presented. This facility has been developed to study resonance structures of neutron induced reactions in support to nuclear energy applications. These resonance structures are the basis of two analytical methods which have been developed at the EC-JRC-IRMM for the characterization of materials and objects: Neutron-Resonance-Capture-Analysis (NRCA) and Neutron-Resonance-Transmission-Analysis (NRTA). NRTA and NRCA are non-destructive methods which are applicable to almost all stable elements and isotopes; determine the bulk elemental composition; do not require any sample taking or surface cleaning and result in a negligible residual radioactivity. They have been already been applied to determine the elemental composition of an archaeological objects and to characterize nuclear reference materials. The JRC-IRMM has also been involved in the extension of the methods for imaging applications by using position sensitive detectors at the ISIS facility of the Rutherford Appleton Laboratory in the UK. Due to the expertise with NRTA and NRCA, the JRC-IRMM has been invited by the JAEA (Japan Atomic Energy Agency) to assist them in the development of a non-destructive method “Neutron Resonance Densitometry (NRD)”. This method has been proposed as an NDA technique to quantify nuclear material in particle-like debris of melted fuel that is formed in severe nuclear accidents such as the one occurred at the Fukushima Daiichi nuclear power plants.

DATA: 15-01-2013