Methods and Models for the Coupled Neutronics and Thermal-Hydraulics Analysis of the CROCUS Reactor at EFPL

Abstract

In order to analyze the steady state and transient behavior of the CROCUS reactor, several methods and models need to be developed in the areas of reactor physics, thermal-hydraulics, and multiphysics coupling. The long-term objectives of this project are to work towards the development of a modern method for the safety analysis of research reactors and to update the Final Safety Analysis Report of the CROCUS reactor. A first part of the paper deals with generation of a core simulator nuclear data library for the CROCUS reactor using the Serpent 2 Monte Carlo code and also with reactor core modeling using the PARCS code. PARCS eigenvalue, radial power distribution, and control rod reactivity worth results were benchmarked against Serpent 2 full-core model results. Using the Serpent 2 model as reference, PARCS eigenvalue predictions were within 240 pcm, radial power was within 3% in the central region of the core, and control rod reactivity worth was within 2%. A second part reviews the current methodology used for the safety analysis of the CROCUS reactor and presents the envisioned approach for the multiphysics modeling of the reactor.

Ten springs of experiments in CROCUS

“…Thanks to a cut in the superior grid, essentially consisting of two half-grids, and appropriate motors and controls, the TRAX device can move the fission chamber axially and radially along the mid-cross section of the core. Precise axial but especially radial relative neutron flux profiles were measured and compared to Monte Carlo simulations, with the interesting observation of the transition between the two core lattices [62]. In addition, using a preliminary version of the POLLEN linear oscillator, the axial extraction of a Cd sample was measured locally with the fission chamber [60].…”

The COLIBRI experimental program in the CROCUS reactor: characterization of the fuel rods oscillator

“…A. The CROCUS reactor [6 ], [7] , [16] - [24] , [8]- [15] CROCUS at the École Polytechnique Fédérale de Lausanne (EPFL) is an experimental zero-power reactor, uranium-fueled and water-moderated, dedicated to teaching radiation and reactor physics, and to research [6]- [24]. A complete description of the reference core can be found in the International Reactor Physics Experiments Handbook (IRPhE) [25], [26].…”

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].…”