Abstract:
A radio-pharmaceutical pig (900) for transporting a syringe containing a radio-pharmaceutical includes a first cylindrical member (910) having a first tungsten body (912) defining a first cavity (916) therein. A second cylindrical member (930) has a second tungsten body (932) defining a second cavity (936) therethrough and is capable of engagement with the first cylindrical member (910) so that the first cavity (916) is in substantial alignment with the second cavity (936). A third cylindrical member (950) includes a third tungsten body (952) defining a third cavity (956) and is capable of engagement with the second cylindrical member (930) so that the third cavity (956) is in substantial alignment with the second cavity (936). The first cavity (916), the second cavity (936) and the third cavity (956) are shaped so as to be complimentary in shape of the syringe (10).
Abstract:
An advanced gray rod control assembly (GRCA) is for a nuclear reactor. The reactor has a plurality of fuel assemblies each including numerous elongated fuel rods supported in an organized array by substantially transverse support grids, and a plurality of guide thimbles disposed through the support grids and along the fuel rods. The GRCA includes a spider assembly structured to provide controlled insertion of gray rod assemblies within the thimbles of the fuel assembly, thereby controlling the rate of power produced by the reactor. Each gray rod assembly includes an elongated tubular member, a first end plug, a second end plug, a substantially pure silver neutron-absorber disposed within the tubular member, and a support tube surrounding the neutron-absorber within the tubular member to resist silver-swelling. Delta-power of the reactor is improved by minimizing the exposed surface area of the absorber and distributing it among all of the rods of the GRCA.
Abstract:
A multi-layered ceramic tube having an inner layer of high purity beta phase stoichiometric silicon carbide, a central composite layer of continuous beta phase stoichiometric silicon carbide fibers, and an outer layer of fine-grained silicon carbide. The ceramic tube is particularly suited for use as cladding for a fuel rod used in a power plant or reactor. The ceramic tube has a desirable combination of high initial crack resistance, stiffness, ultimate strength, and impact and thermal shock resistance.
Abstract:
This invention relates to a method of preparing a nuclear fuel including the step of depositing a coating including silicon nitride bonded silicon carbide on a nuclear fuel surface. The invention extends to a nuclear fuel element (10) and to a nuclear fuel particle (30).
Abstract:
This invention relates to a method of preparing a nuclear fuel including the steps of depositing silicon carbide on a nuclear fuel surface and at least partly reducing the silicon carbide to diamond. The invention extends to a nuclear fuel element (10) and to a nuclear fuel particle (30).
Abstract:
L'adaptateur (12) et le carter des mécanismes (13) sont réalisés en une seule pièce, sous la forme d'un carter intégré qui est fixé par l'intermédiaire du tube adaptateur (12) dans une ouverture (9a, 9b) de traversée du couvercle de cuve (10). La gaine tubulaire (14) comporte une partie filetée (14a) qui est engagée par vissage dans une partie taraudée (13c) à l'extrémité du carter intégré (15), dans une disposition parfaitement coaxiale. On réalise une soudure d'étanchéité (18) entre deux lèvres d'étanchéité respectives du carter intégré (15) et de la gaine tubulaire (14). Le joint de soudure (18) est réalisé par fusion d'un métal d'apport entre deux parties d'extrémité de jonction des lèvres d'étanchéité par un procédé de soudage orbital automatique. L'étape de montage et de soudage de la gaine tubulaire (14) sur le carter intégré (15) peut être effectuée sur le site du réacteur nucléaire avec une réalisation du joint soudé (18) sans défaut.
Abstract:
La présente invention a pour objet :- un procédé d'élaboration d'un conteneur fermé, dont la fermeture est étanche et résistance mécaniquement, par solidarisation de deux éléments métalliques du type corps (1) et couvercle (2);- ledit conteneur fermé, dont la structure comprend, solidarisés l'un à l'autre, les deux éléments métalliques identifiés ci-dessus;- les éléments constitutifs dudit conteneur, considérés indépendamment et conjointement, avant leur solidarisation : a) ledit corps (1) et b) ledit couvercle (2); la structure interne de l'un desdits deux éléments (1 ou 2) comportant un guide d'accostage (3 ; 30 ; 300), ainsi que c) ledit guide d'accostage (3; 30 ; 300), per se, lorsqu'il intervient à titre de pièce rapportée.
Abstract:
An improved nuclear shielding material based on a resistant organic matrix that is flexible or resilient after room temperature polymerization, and sufficiently fluid before polymerization so as to effectively fill voids in radiation containment structures. The material can be formulated to undergo pyrolysis and transform into a strong ceramic material. Along with the organic matrix the material contains a primary radiation shielding component such as tungsten carbide powder. Additional optional components include: a neutron absorbing/gamma blocking compound such as boron carbide powder, a heat conducting material such as diamond powder, a high temperature resistant compound such as silicon dioxide powder, a second neutron blocking compound which also imparts electrical conductivity, namely barium sulfate powder, and a hydrogen gas surpassing component which readily absorbs hydrogen such as sponge palladium- Refractory materials and rare earth oxides can be included to favor effective ceramic transition.
Abstract:
A neutron reflector bolting structure capable of firmly retaining a neutron reflector in a core tank even if a relaxation of tie rods occurs by the radiation of neutrons, comprising a neutron reflector (20) positioned inside the core tank (12) in a reactor vessel and formed by combining a plurality of divided step parts with each other, a plurality of tie rods for fixing the neutron reflector (20) to the core tank (12), and a plurality of bolts (1) for fixing only the lowermost step part (20A) of the plurality of step parts of the neutron reflector (20) to the core tank (12).