Design of Separated Element Reflector Experiments in CROCUS: PETALE

Abstract

The present article describes the preliminary design studies for PETALE (Programme d’Etude en Transmission de l’Acier Lourd et ses Eléments), an oncoming experimental program in the CROCUS reactor. Within the framework of the Venus-Eole-Proteus collaboration, PETALE continues the nuclear data validation efforts required for modeling GEN-III pressurized water reactors with heavy steel reflectors. The inelastic scattering cross sections at around 1 MeV of iron-56, as well as nickel and chromium isotopes, will be studied separately. The water reflector will be replaced successively by sheets of stainless steel alloy and pure metals—iron, nickel, and chromium. Data will be extracted from two sources: the measured neutron flux attenuation using adequate dosimetry and possibly fission chambers in the metal reflector and from the criticality effects of these reflectors. PETALE will also be used with nuclear data adjustment methods because, as a separated and elemental integral experiment, it allows the limiting of compensation effects in the nuclear data adjustments. A parametric study has been carried out with MCNPX for assessing the optimal configuration and the feasibility of the experiments. This study is the first step toward optimizing the global sensitivity of the experiments to the reactions in the energy range of interest, thus assessing the measurements’ target uncertainties and preparing further use of the program results.

Uncertainty propagation for the design study of the PETALE experimental programme in the CROCUS reactor

“…A zoom on the interface between CROCUS and the metal reflector shows the first foil with a width multiplied by 10 in order to be visible (1 g of indium for the first foil instead of 0.1 g). A first parametric study [2] performed with the MCNP code [10] has shown that the dimension of the plates can be limited to 30 × 30 cm 2 with acceptable border effects. In order to obtain precise data for the different isotopes composing a heavy reflector, the measurements will be repeated for different plate compositions: Fe, Ni, Cr, and steel.…”

“…Such experiments can be employed to validate the present nuclear data libraries and numerical codes, or can be used to improve the nuclear data libraries via assimilation techniques. In this frame, the present work is related to the PETALE experimental programme [1,2] during its design phase. This programme aims at providing better constraints on the neutron cross sections in heavy reflectors for water reactors such as the European Pressurized Reactor (EPR) [3,4].…”

An Experimental Programme optimized with Uncertainty Propagation: PETALE in the CROCUS Reactor

“…CROCUS is an experimental zero-power reactor, uranium-fuelled and water-moderated, dedicated to education in radiation and reactor physics, and to research [6][7][8][9][10][11][12][13][14][15][16][17]. A complete description of the core can be found in the International Reactor Physics Experiments Handbook (IRPhE) [18].…”

Power calibration methodology at the CROCUS reactor

“…HE CROCUS reactor is a two-zone, uranium-fuelled light water moderated facility operated by the Laboratory for Reactor Physics and Systems Behaviour (LRS) at the Swiss Federal Institute of Technology Lausanne (EPFL). With a maximum power of 100 W, it is a zero-power reactor used for teaching and research purposes, most recently for studies on intrinsic and induced neutron noise, highly-localized measurements, and nuclear data [1]- [19]. Knowledge of the reactor power is a mandatory quantity for a safe operation.…”