Optimizing the use of gadolinium as burnable poison in nuclear fuel: towards a boron free PWR
type: Dataset
description: Reactivity excess in Nuclear Power Plants is controlled by reactor's active systems: boric acid dilution and control rods. Alternatively, negative reactivity insertion can be made in a passive way using burnable poisons, i.e. neutron absorbers, this is the case of gadolinium (Gd). In the industrial framework of U²³⁵ enrichment increase and boric acid restraint, the goal of this thesis is to optimize the distribution of gadolinium in UO₂ ceramics to obtain a high-performance provision of negative reactivity in Pressurized Water Reactors. In this sense, the work is focus on new gadolinium-rich materials. Thus, U-Gd-O phase diagram was explored in the field of high Gd contents. Two cubic phases were found and characterized: the C1 and C2 phases. With the aim of an industrial application, C1 phase was selected as candidate for Gd addition into UO₂ pellets. The optimal distribution of C1 phase within a nuclear fuel assembly was studied using APOLLO 2.8 neutron transport code. Parametrical calculations were performed. These neutronic studies have ended in a successful "concept of poisoned pellet". Finally, some prototype pellets following this concept were made in laboratory to proof it feasibility. All the obtained results shows that the proposed concept of a neutrophage C1-phase coating on UO₂ pellets is a convenient way to reduce reactivity excess within the frame-work of long irradiation cycles. This concept could be potentially applied in industrial scale. Consequently a patent application process was initiated.
landing page: https://theses.hal.science/tel-00951801
keyword: acide-borique
keyword: antireactivite
keyword: barbotine
keyword: bore
keyword: boric-acid
keyword: boron
keyword: brevet
keyword: burnable-poison
keyword: c1
keyword: c2
keyword: centrale-nucleaire
keyword: ceramic-slip
keyword: coating
keyword: couples-dinterdiffusion
keyword: diagramme-de-phase-u-gd-o
keyword: diffusion
keyword: diffusion-couples
keyword: drx
keyword: eds
keyword: enrobage
keyword: epr
keyword: epr-pressurized-water-reactor
keyword: epr-rep
keyword: exces-de-reactivite
keyword: frittage
keyword: gadolinium
keyword: gd
keyword: gdo
keyword: gduo
keyword: infoeu-reposemanticsdoctoralthesis
keyword: meb
keyword: negative-reactivity
keyword: nuclear-power-plant
keyword: nuclear-reactor
keyword: patent-application
keyword: phase-diagram
keyword: physphysphys-atom-phphysics-physicsphysics-physicsatomic-physics-physicsatom-ph
keyword: poison-consommable
keyword: pressurized-water-reactor
keyword: pwr
keyword: reacteur-a-eau-sous-pression
keyword: reacteur-nucleaire
keyword: reactivity-excess
keyword: rep
keyword: sem
keyword: sintering
keyword: spimatengineering-sciences-physicsmaterials
keyword: theses
keyword: u-gd-o
keyword: uo
keyword: xrd
issued: 2026-05-06T06:06:03.395246
modified: 2026-05-06T06:06:03.395251
language: fr
contact point: Organization
  fn: CCSD

test_moissonnage_selune
type: Agent

Optimizing the use of gadolinium as burnable poison in nuclear fuel: towards a boron free PWR
type: Distribution
format: HTML
access URL: https://theses.hal.science/tel-00951801
issued: 2026-05-06T06:06:03.399531
modified: 2026-05-06T06:06:03.301365