EP0055679A2 - Container for under water storage of irradiated fuel assemblies, and method to realize such a container - Google Patents
Container for under water storage of irradiated fuel assemblies, and method to realize such a container Download PDFInfo
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- EP0055679A2 EP0055679A2 EP81402101A EP81402101A EP0055679A2 EP 0055679 A2 EP0055679 A2 EP 0055679A2 EP 81402101 A EP81402101 A EP 81402101A EP 81402101 A EP81402101 A EP 81402101A EP 0055679 A2 EP0055679 A2 EP 0055679A2
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- Prior art keywords
- nickel
- boron carbide
- coating
- particles
- layer
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- G—PHYSICS
- G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
- G21F—PROTECTION AGAINST X-RADIATION, GAMMA RADIATION, CORPUSCULAR RADIATION OR PARTICLE BOMBARDMENT; TREATING RADIOACTIVELY CONTAMINATED MATERIAL; DECONTAMINATION ARRANGEMENTS THEREFOR
- G21F9/00—Treating radioactively contaminated material; Decontamination arrangements therefor
- G21F9/28—Treating solids
- G21F9/34—Disposal of solid waste
- G21F9/36—Disposal of solid waste by packaging; by baling
Definitions
- the invention relates to a case for the storage under water of irradiated fuel assemblies and to a method for producing such a case.
- boxes for storing irradiated fuel assemblies in the fuel pool comprising walls made of a material having good neutron absorption capacity, in order to limit the radioactivity in the fuel pool and to its neighborhood.
- these housings are generally constituted by a parallelepipedic envelope of stainless steel with square section of sufficient dimensions to receive a fuel assembly, open at one of its ends and externally coated with a neutron absorbing material .
- these boxes rest by their lower base on supports common to a set of boxes where they are arranged side by side so that the fuel assemblies can be stored under water, vertically, inside the pool of the combustible.
- the square section fuel assemblies used in nuclear reactors have a very large height compared to their transverse dimensions, so that the assemblies storage boxes themselves have a very elongated shape.
- the neutron absorbing coatings deposited on the external faces of the cases must contain a quantity of boron carbide per unit area of the case sufficient to ensure efficient absorption of the neutrons emitted by the irradiated assemblies.
- boron 10 which is the absorbent element contained in boron carbide, on a cm 2 of surface , which represents approximately 0.146 g of boron carbide for the same surface.
- boxes for the storage of irradiated fuels constituted by a metal casing coated with debore carbide particles coated in a metallic material such as nickel.
- Such a coating can be obtained by spraying at a high temperature a mixture of nickel powder and boron carbide, on the external surface of the housing, using a plasma torch.
- Boron steel absorbent plates are also known but the thickness necessary to obtain a sufficient absorbent effect is of the order of 8 to 9 mm.
- the boxes currently known therefore have relatively large wall thicknesses, which significantly increase their mass and size in the transverse directions.
- the object of the invention is therefore to propose a case for the storage under water of irradiated fuel assemblies with a square section constituted by a metallic parallelepipedic envelope with a square section of sufficient dimensions to receive a fuel assembly, open to at least one with its two ends and externally coated with a neutron absorbing material constituted by particles of boron carbide coated in a metallic binder constituted by nickel, this casing having to have a rigidity and an adequate capacity for absorbing neutrons, while being a reduced mass and transverse size.
- the thickness of the metallic envelope is between 1.5 and 2.5 mm and the thickness of the neutron absorbing coating is at most equal to 2 mm; the mass of boron carbide per cm2 of surface of the housing being greater than 0.146 g over the entire external surface thereof, with the exception of the areas adjacent to the edges.
- Example 1 A tubular envelope of stainless steel was made with a length slightly greater than 4 meters and a diameter of 28 cm, from a sheet of thickness 2 mm.
- a deposit of boron carbide particles coated with nickel is then carried out on this tubular casing provided with its covers using a plasma torch ammented by coated powders.
- a plasma torch with a power of 40 KW is used. ensuring the projection of a powder formed of particles of boron carbide coated with nickel.
- Boron carbide is used in the form of a powder whose grains have a size of between 60 and 100 microns for the preparation of a coated powder with which the plasma torch will be fed.
- an initiation layer of palladium is deposited on the calibrated boron carbide grains by immersing the powder in a solution containing a few grams of sodium nitrite per liter, a few ppm of palladium per liter and a few drops of wetting agent. After immersion, the powder is drained and then dried for two hours at 110 °.
- the boron carbide grains then have a very thin surface layer of absorbed palladium which is a practically monoatomic layer.
- This powder is then introduced comprising the initiation layer into coating tubes closed at each of their ends by wire cloths making it possible to retain the powder inside the tube.
- the coating tubes are then moved continuously in a chemical nickel plating bath of the Kanigen type.
- the powder of boron carbide is covered with a layer of nickel which thickens over time.
- the treatment was extended to obtain grains of boron carbide coated with nickel, in which the mass of the boron carbide relative to the weight of nickel represents from 20 to 50%.
- the coating tubes are rinsed and the nickel-coated carbide powder is collected and dried in an oven for 2 hours at 120 °.
- the powder is then ready to be used for projection in the plasma torch.
- a coating with a thickness of 1 mm was made on the surface lateral side of the tubular casing which, taking into account the concentration of boron carbide in the powder, provides the desired density of neutron absorbing elements per cm 2 of the surface of the casing, with the exception of the areas masked by the caches.
- the tubular casing is rotated about its axis at constant speed and the torch moves in a direction parallel to the axis of the tubular casing.
- the torch moves in a direction parallel to the axis of the tubular casing.
- Several torches can also be used, each moving over a portion of the length of the tubular casing, to reduce the duration corresponding to the coating.
- the tubular envelope Prior to the plasma torch deposition operation, the tubular envelope can be preheated to a temperature allowing better adhesion of the particles at the time of their projection.
- Each of the particles of boron carbide coated with high density nickel is projected onto the substrate at high speed with high kinetic energy and is welded onto it at the time of impact by temperature rise and by mechanical effect.
- the softening of the surface layer of nickel and its heating in fact allow very effective attachment to the substrate or the coating layer itself at the time of impact.
- the thickness of the nickel layer deposited on the grains of boron carbide has a thickness of between 2 and 10 microns for 80% of the particles which have been tested. We were able to make sure Check with these controls that the boron carbide grains are completely coated with a layer of nickel at the end of the treatment which has been described.
- tubular casing After coating, the tubular casing is cooled to room temperature and then put into the form of a parallelepiped with a square section of 22 cm side, by cold deformation.
- the folding of the tubular envelope for the realization of the parallelepiped edges is done according to the generatrices located under the covers along which no coating deposition has been made. This prevents bursting of the coating during the final mechanical shaping of the parallelepiped.
- the dimensions and the precise geometry of the casing envelope are obtained after coating, so that the possible deformations of the tubular envelope at the time of its preheating and at the time of the plasma deposition have no effect on the shape and the final dimensional accuracy of the case.
- the method described therefore made it possible to obtain a thin-walled housing comprising an effective absorbent layer but of small thickness.
- the coating process can be completed using a plasma torch, by supplying the torch with nickel or stainless steel powder so as to produce a layer with a thickness close to 200 microns above the coating layer comprising boron carbide, which eliminates the roughness of the coating due to B4C.
- the extremely smooth and continuous nickel or stainless steel surface layer plays a role protective for the coating layer.
- Example 2 A stainless steel box of parallelepiped shape was produced.
- the unit which has undergone chemical degreasing and then electrolytic degreasing is subjected to a chemical depassivation treatment in hydrochloric or fluonitric bath.
- the box is then placed in a large electrolysis tank filled with a bath containing NiCl2 at the rate of 250 g per liter and hydrochloric acid at the rate of 130 g per liter. Then performs processing of R electrolytic assivation in two stages on the outer surface of the housing. During the first phase, or anode phase, lasting 15 seconds, the box constitutes the anode and the electrolysis current density is 1 to 2 amperes per dm2.
- the box constitutes the cathode and the electrolysis current is 3 amperes per dm2.
- the four faces of the case are then pre-nickeled, inside the electrolysis tank containing a working bath comprising NiS04 at the rate of 280 g per liter of NiCl2 at the rate of 45 g per liter, H3B03 at a rate of 45 g per liter, as well as a few milliliters of a wetting agent.
- the duration of this treatment is half an hour and the current density is 4 amperes per dm2.
- a set of operations aimed at obtaining an absorbent coating, by rotating the box a quarter of a turn .between each deposition of boron carbide powder, after fixing the last deposited layer.
- These operations successively include the constitution of a regular layer of particles of boron carbide B4C on one face of the housing, the electrolytic deposition of nickel through the layer of powder of B4C until the particles are perfectly attached to the substrate and joined together, then the deposition of a new layer of B4C particles followed by the deposition of electrolytic nickel for the attachment of these particles, the number of successive layers required being determined by the quantity of boron carbide to be deposited per unit of surface of the case.
- the entire housing is placed in the electrolysis tank so that the nickel layers grow at the same time on all four sides sides of the case.
- a powder was used consisting of B4C particles with a maximum dimension of 200 microns and each of the layers of boron carbide deposited by gravity on the faces of the housing had a thickness identical to the maximum dimension of the particles, ie say 200 microns. In this way, unwanted overlaps of the particles are avoided and the regularity / thickness / neutron efficiency of the coating is improved and improved.
- the coating therefore consists of a superposition of monolayers, that is to say of layers of powder constituted by grains arranged side by side with a minimum of superposition of several grains, these monolayers being linked together by the deposition of nickel.
- the nickel deposits between the boron carbide particles are obtained using an electrolysis bath identical to that used for pre-nickel plating and a current density of 2 amperes per dm2. Each of the successive electrolysis operations is continued for half an hour.
- the coating operation is terminated by an electrolysis of 2 hours with a current density of 2 amperes per dm2 in order to
- the box is then removed from the rinsed and dried electrolysis tank.
- the various layers of particles of B4C trapped in the nickel matrix deposited one above the other are practically continuous insofar as one carries out a regular distribution of these particles to constitute the successive layers.
- particles of a smaller size for example 60 microns in admixture with particles of 200 microns.
- the particles of smaller size are interposed between the particles of 200 microns to produce a continuous layer of boron carbide.
- the superimposition of several monolayers makes it possible to avoid the presence of coating zones containing a very small amount of B4C.
- the repair tition of the particles is therefore extremely homogeneous and on the other hand the proportion of B4C particles relative to the nickel matrix is large, if we compare it with what was obtained by the previously known methods. This proportion is for example, in the case which has just been described, 50% by mass.
- a coating is therefore obtained easily by the process according to the invention comprising the desired quantity of boron carbide and therefore of boron 10 per cm 2 of substrate, while having a coating layer with a total thickness of less than 2 mm.
- Example 3 Operations similar to those which have been described in connection with Example 2 are carried out on a stainless steel casing of parallelepiped shape and using a chemical bath instead of an electrolytic bath.
- the operations carried out are identical, namely a pre-nickel plating of the substrate, then a gravitational deposition of a first layer of boron carbide particles, then a chemical nickel plating allowing the particles to be bonded, followed by a new deposition of a monolayer.
- boron carbide particles which are then bonded together by chemical deposition of a nickel layer, these successive operations continuing until the coating comprises a sufficient quantity of boron carbide per cm2.
- the neutron absorbing coating can be produced on the housing by a method different from those which have been described above, that this deposition can be carried out both on the housing having its final shape and on a blank which is then shaped and that the metal envelope may be made of a metallic material other than stainless steel, for example aluminum.
- the thickness of the metal casing can be different from 2 mm, but however in the case of boxes for the storage of fuel assemblies under water, it is necessary that this thickness is between 1.5 and 2.5 mm, for reconcile both the requirements concerning the mechanical strength of the box and the heat exchanges between the fuel assembly contained in the box and the pool water.
- the invention applies not only to the storage of fuel assemblies for a water nuclear reactor but it also applies to the transport of irradiated materials using boxes according to the invention as transport containers.
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Abstract
Description
L'invention concerne un boitier pour le stockage sous eau d'assemblages combustibles irradiés et un procédé de réalisation d'un tel boitier.The invention relates to a case for the storage under water of irradiated fuel assemblies and to a method for producing such a case.
.Dans le domaine de l'exploitation des réacteurs nucléaires, en particulier les réacteurs nucléaires à eau, il est nécessaire de stocker ou de transporter des matériaux radio-actifs, tels que des assemblages combustibles irradiés sortant du coeur du réacteur et pour améliorer les conditions de stockage ou de transport de ces matériaux, il est nécessaire de disposer de boitiers dont les parois absorbent les neutrons émis par ces matières.In the field of the operation of nuclear reactors, in particular water nuclear reactors, it is necessary to store or transport radioactive materials, such as irradiated fuel assemblies leaving the reactor core and to improve conditions storage or transport of these materials, it is necessary to have boxes whose walls absorb the neutrons emitted by these materials.
En particulier il est souhaitable de disposer de boitiers de stockage des assemblages combustibles irradiés dans la piscine du combustible, comportant des parois en un matériau ayant une bonne capacité d'absorption des neutrons, pour limiter la radio-activité dans la piscine du combustible et à son voisinage.In particular, it is desirable to have boxes for storing irradiated fuel assemblies in the fuel pool, comprising walls made of a material having good neutron absorption capacity, in order to limit the radioactivity in the fuel pool and to its neighborhood.
Dans le cas des réacteurs nucléaires à eau, ces boitiers sont généralement constitués par une enveloppe parallélépipédique en acier inxoydable à section carrée de dimensions suffisantes pour recevoir un assemblage combustible, ouverte à l'une de ses extrémités et revêtue extérieurement par une matière absorbant les neutrons.In the case of nuclear water reactors, these housings are generally constituted by a parallelepipedic envelope of stainless steel with square section of sufficient dimensions to receive a fuel assembly, open at one of its ends and externally coated with a neutron absorbing material .
Dans la piscine du combustible, ces boitiers reposent par leurbase inférieure sur des supports communs à un ensemble de boitiers où ils sont disposés côté à côte de façon que les assemblages combustibles puissent être stockés sous eau, verticalement, à l'intérieur de la piscine du combustible.In the fuel pool, these boxes rest by their lower base on supports common to a set of boxes where they are arranged side by side so that the fuel assemblies can be stored under water, vertically, inside the pool of the combustible.
Les assemblages combustibles à section carrée ptilisés dans les réacteurs nucléaires ont une hauteur très importante par rapport à leurs dimensions transversales, si bien que les boitiers de stockage des assemblages ont eux-mêmes une forme très allongée.The square section fuel assemblies used in nuclear reactors have a very large height compared to their transverse dimensions, so that the assemblies storage boxes themselves have a very elongated shape.
Il est nécessaire de maintenir entre les boitiers constituant un rate- lier ou rack de stockage, un espace suffisant pour assurer un contact thermique adéquat entre l'eau de la piscine du réacteur et le boitier et pour assurer un effet modérateur suffisant. Pour assurer qu'une lame d'eau suffisante existe entre les faces des boitiers, il faut que ceux-ci présentent des dimensions et une géométrie parfaitement contrôlées. On prévoit donc généralement des boitiers d'nne grande rigidité permettant d'assurer une tenue mécanique suffisante et un maintien des écarts entre les faces des boitiers à l'intérieur du rack de stockage. L'enveloppe métallique de ces boitiers est donc d'une épaisseur relativement importante, par exemple de l'ordre de 3 à 4 mm.It is necessary to maintain sufficient space between the boxes constituting a storage area or rack for ensuring adequate thermal contact between the water in the reactor pool and the box and for ensuring a sufficient moderating effect. To ensure that a sufficient sheet of water exists between the faces of the boxes, they must have perfectly controlled dimensions and geometry. Provisions are therefore generally made for boxes with high rigidity, making it possible to ensure sufficient mechanical strength and maintaining the gaps between the faces of the boxes. inside the storage rack. The metal envelope of these boxes is therefore of relatively large thickness, for example of the order of 3 to 4 mm.
D'autre part, les revêtements absorbant les neutrons déposés sur les faces externes des boitiers doivent contenir une quantité de carbure de bore par unité de surface du boitier suffisante pour assurer une absorption efficace des neutrons émis par les assemblages irradiés.On the other hand, the neutron absorbing coatings deposited on the external faces of the cases must contain a quantity of boron carbide per unit area of the case sufficient to ensure efficient absorption of the neutrons emitted by the irradiated assemblies.
Pour obtenir une absorption efficace des neutrons par un revêtement déposé sur la surface externe latérale du boitier, il est nécessaire d'avoir au moins 20 mg de bore 10 qui est l'élément absorbant contenu dans le carbure de bore, sur un cm2 de surface, ce qui représente environ 0,146 g de carbure de bore pour la même surface.To obtain effective absorption of neutrons by a coating deposited on the lateral external surface of the housing, it is necessary to have at least 20 mg of boron 10 which is the absorbent element contained in boron carbide, on a cm 2 of surface , which represents approximately 0.146 g of boron carbide for the same surface.
On connaît des boitiers de stockage d'assemblages combustibles irradiés dont le revêtement externe absorbant les neutrons est constitué par des particules de carbure de bore fixées sur la paroi à revêtir par un liant organique tel qu'une résine polymère. Pour des durées de stockage importantes en piscine du combustible, il est impossible d'utiliser des boitiers comportant un tel revêtement sur leur surface externe car les résines polymères risquent d'être détruites lors d'un séjour prolongé dans l'eau de la piscine du combustible. D'autre part, de telles résines polymères enrobant le carbure de bore constituent un isolant thermique entre l'assemblage contenu à l'intérieur du boitier et l'eau de la piscine du combustible.There are known boxes for storing irradiated fuel assemblies whose external neutron absorbing coating consists of boron carbide particles fixed to the wall to be coated with an organic binder such as a polymer resin. For long storage periods in the fuel pool, it is impossible to use boxes having such a coating on their external surface because the polymer resins risk being destroyed during a prolonged stay in the pool water. combustible. On the other hand, such polymer resins coating boron carbide constitute a thermal insulator between the assembly contained inside the case and the water of the fuel pool.
On connaît également des boitiers pour le stockage de combustibles irradiés constitués par une enveloppe métallique revêtue de particules de carbure debore enrobées dans un matériau métallique tel que le nickel.Also known are boxes for the storage of irradiated fuels constituted by a metal casing coated with debore carbide particles coated in a metallic material such as nickel.
Un tel revêtement peut être obtenu par projection à haute température d'un mélange de poudre de nickel et de carbure de bore, sur la surface externe du boitier, à l'aide d'un chalumeau à plasma.Such a coating can be obtained by spraying at a high temperature a mixture of nickel powder and boron carbide, on the external surface of the housing, using a plasma torch.
Cependant, pour obtenir une densité suffisante de matériau absorbant sur la surface du boitier, il est nécessaire de déposer des couches relativement épaisses de revêtement, par exemple d'une épaisseur de 3 à 6 mm. Il est en effet nécessaire d'utiliser une proportion de poudre de nickel dans le mélange de poudre relativement importante, pour assurer une bonne adhésion du revêtement sur le substrat.However, to obtain a sufficient density of absorbent material on the surface of the housing, it is necessary to deposit relatively thick layers of coating, for example with a thickness of 3 to 6 mm. It is indeed necessary to use a relatively large proportion of nickel powder in the powder mixture, to ensure good adhesion of the coating to the substrate.
Si on utilise des épaisseurs plus faibles de revêtement, celui-ci ne possède plus de propriétés absorbantes suffisantes.If smaller thicknesses of the coating are used, the latter no longer has sufficient absorbent properties.
On connaît également des plaques absorbantes en acier au bore mais l'épaisseur nécessaire pour obtenir Un effet absorbant suffisant est de l'ordre de 8 à 9 mm.Boron steel absorbent plates are also known but the thickness necessary to obtain a sufficient absorbent effect is of the order of 8 to 9 mm.
Les boitiers connus actuellement ont donc des épaisseurs de parois relativement importantes, qui augmentent sensiblement leur masse et leur encombrement dans les directions transversales.The boxes currently known therefore have relatively large wall thicknesses, which significantly increase their mass and size in the transverse directions.
Le but de l'invention est donc de proposer un boitier pour le stockage sous eau d'assemblages combustibles irradiés à section carrée constitué par une enveloppe parallélépipédique métallique à section carrée de dimensions suffisantes pour recevoir un assemblage combustible, ouverte à l'une au moins de ses deux extrémités et revêtue extérieurement par une matière absorbant les neutrons constituée par des particules de carbure de bore enrobées dans un liant métallique constitué par du nickel, ce boitier devant avoir une rigidité et une capacité d'absorption des neutrons suffisantes, tout en étant d'une masse et d'un encombrement transversal réduits.The object of the invention is therefore to propose a case for the storage under water of irradiated fuel assemblies with a square section constituted by a metallic parallelepipedic envelope with a square section of sufficient dimensions to receive a fuel assembly, open to at least one with its two ends and externally coated with a neutron absorbing material constituted by particles of boron carbide coated in a metallic binder constituted by nickel, this casing having to have a rigidity and an adequate capacity for absorbing neutrons, while being a reduced mass and transverse size.
Dans ce but, l'épaisseur de l'enveloppe métallique est comprise entre 1,5 et 2, 5mm et l'épaisseur du revêtement absorbant les neutrons est au plus égale à 2 mm; la masse de carbure de bore par cm2 de surface du boitier étant supérieure à 0,146 g sur toute la surface externe de celui-ci, à l'exception des zones voisines des arêtes.For this purpose, the thickness of the metallic envelope is between 1.5 and 2.5 mm and the thickness of the neutron absorbing coating is at most equal to 2 mm; the mass of boron carbide per cm2 of surface of the housing being greater than 0.146 g over the entire external surface thereof, with the exception of the areas adjacent to the edges.
Afin de bien faire comprendre l'invention, on va décrire à titre d'exemple non limitatif, plusieurs exemples de réalisation d'un boitier pour le stockage d'assemblages combustibles irradiés dans la piscine du combustible d'un réacteur nucléaire à eau.In order to clearly understand the invention, there will be described by way of nonlimiting example, several embodiments of a case for the storage of irradiated fuel assemblies in the fuel pool of a nuclear water reactor.
Exemple 1 : On a réalisé une enveloppe tubulaire en acier inoxydable d'une longueur un peu supérieure à 4 mètres et d'un diamètre de 28cm, à partir d'une tôle d'épaisseur 2 mm.Example 1: A tubular envelope of stainless steel was made with a length slightly greater than 4 meters and a diameter of 28 cm, from a sheet of thickness 2 mm.
On a placé le long de 4 génératrices de cette enveloppe tubulaire disposées pour deux d'entre elles dans un premier plan passant par l'axe de l'enveloppe tubulaire et pour les deux autres pans le plan perpendiculaire au premier plan passant par l'axe de lienveloppe tubulaire, des caches permettant de masquer chacun une zone d'une largeur d'environ 20 mm sur la surface latérale de l'enveloppe tubulaire.Was placed along 4 generatrices of this tubular envelope arranged for two of them in a first plane passing through the axis of the tubular envelope and for the other two sections the plane perpendicular to the first plane passing through the axis of tubular envelope, covers making it possible to mask each an area with a width of approximately 20 mm on the lateral surface of the tubular envelope.
On effectue ensuite un dépôt de particules de carbure de bore enrobées de nickel sur cette enveloppe tubulaire munie de ses caches en utilisant un chalumeau au plasma ammenté par des poudres enrobées.A deposit of boron carbide particles coated with nickel is then carried out on this tubular casing provided with its covers using a plasma torch ammented by coated powders.
Pour la réalisation de cette couche de revêtement absorbant les neutrons, on utilise un chalumeau à plasma d'une puissance de 40 KW assurant la projection d'une poudre formée de particules de carbure de bore revêtues de nickel.To produce this neutron absorbing coating layer, a plasma torch with a power of 40 KW is used. ensuring the projection of a powder formed of particles of boron carbide coated with nickel.
On utilise du carbure de bore sous forme d'une poudre dont les grains ont une taille comprise entre 60 et 100 microns pour l'élaboration d'une poudre enrobée avec laquelle on alimentera la torche à plasma. Pour la fabrication de la poudre enrobée, on procède au dépôt d'une couche d'initiation de palladium sur les grains de carbure de bore calibrés en immergeant la poudre dans une solution contenant quelques grammes de nitrite de sodium par litre, quelques ppm de palladium par litre et quelques gouttes de mouillant. Après immersion, on égoutte la poudre puis on la sèche pendant deux heures à 110°.Boron carbide is used in the form of a powder whose grains have a size of between 60 and 100 microns for the preparation of a coated powder with which the plasma torch will be fed. For the production of the coated powder, an initiation layer of palladium is deposited on the calibrated boron carbide grains by immersing the powder in a solution containing a few grams of sodium nitrite per liter, a few ppm of palladium per liter and a few drops of wetting agent. After immersion, the powder is drained and then dried for two hours at 110 °.
Les grains de carbure de bore présentent alors une très fine couche superficielle de palladium absorbé qui est une couche pratiquement monoatomique.The boron carbide grains then have a very thin surface layer of absorbed palladium which is a practically monoatomic layer.
On introduit alors cette poudre comportant la couche d'initiation dans des tubes d'enrobage fermés à chacune de leurs extrémités par des toiles métalliques permettant de retenir la poudre à l'intérieur du tube.This powder is then introduced comprising the initiation layer into coating tubes closed at each of their ends by wire cloths making it possible to retain the powder inside the tube.
Les tubes d'enrobage sont alors déplacés de façon continue dans un bain de nickelage chimique du type Kanigen.The coating tubes are then moved continuously in a chemical nickel plating bath of the Kanigen type.
Pendant son agitation dans le bain de nickelage, la poudre de carbure de bore se recouvre d'une couche de nickel qui s'épaissit au cours du temps. Au cours de différents essais, on a prolongé le traitement pour obtenir des grains de carbure de bore enrobés de nickel, dans lesquels la masse du carbure de bore par rapport au poids de nickel représente de 20 à 50 %.During its stirring in the nickel-plating bath, the powder of boron carbide is covered with a layer of nickel which thickens over time. During various tests, the treatment was extended to obtain grains of boron carbide coated with nickel, in which the mass of the boron carbide relative to the weight of nickel represents from 20 to 50%.
En fin d'opération, les tubes d'enrobage sont rinçés et la poudre de carbure enrobée de nickel est récupérée et séchée à l'étuve pendant 2 heures à 120°.At the end of the operation, the coating tubes are rinsed and the nickel-coated carbide powder is collected and dried in an oven for 2 hours at 120 °.
La poudre est alors prête pour servir à la projection dans la torche à plasma.The powder is then ready to be used for projection in the plasma torch.
On a utilisé une poudre comportant en masse, un tiers de.carbure de bore et deux tiers de nickel, pour alimenter la torche à plasma qui fonctionne dans les conditions suivantes :
- - courant d'alimentation : 700 ampères sous 30 volts
- - débit d'argon : 30 m3 par heure
- - débit de poudre : environ 2 kg par heure.
- - supply current: 700 amperes at 30 volts
- - argon flow: 30 m3 per hour
- - powder flow: approximately 2 kg per hour.
On a réalisé un revêtement d'une épaisseur de 1 mm sur la surface latérale externe de l'enveloppe tubulaire qui, compte tenu de la concentration du carbure de bore dans la poudre, fournit la densité voulue d'éléments absorbant les neutrons par cm2 de la surface de l'enveloppe, à l'exception des zones masquées par les caches.A coating with a thickness of 1 mm was made on the surface lateral side of the tubular casing which, taking into account the concentration of boron carbide in the powder, provides the desired density of neutron absorbing elements per cm 2 of the surface of the casing, with the exception of the areas masked by the caches.
Pendant toute l'opération de revêtement, l'enveloppe tubulaire est en rotation autour de son axe à vitesse constante et le chalumeau se déplace dans une direction parallèle à l'axe de l'enveloppe tubulaire. On peut également utiliser plusieurs chalumeaux se déplaçant chacun sur une portion-de la longueur de l'enveloppe tubulaire, pour diminuer la durée correspondant au revêtement.During the entire coating operation, the tubular casing is rotated about its axis at constant speed and the torch moves in a direction parallel to the axis of the tubular casing. Several torches can also be used, each moving over a portion of the length of the tubular casing, to reduce the duration corresponding to the coating.
Préalablement à l'opération de dépôt au chalumeau au plasma, l'enveloppe tubulaire peut être préchauffée à une température permettant une meilleure adhésion des particules au moment de leur projection.Prior to the plasma torch deposition operation, the tubular envelope can be preheated to a temperature allowing better adhesion of the particles at the time of their projection.
-Par rapport aux techniques antérieures où l'on utilisait un mélange de poudre de carbure de bore et de nickel, les grains de carbure de bore entièrement revêtus de nickel ne subissent aucune oxydation à haute température à la sortie du chalumeau à plasma et le dépôt obtenu a une composition très homogène.-Compared to previous techniques where a mixture of boron carbide powder and nickel was used, the grains of boron carbide entirely coated with nickel undergo no oxidation at high temperature at the outlet of the plasma torch and the deposition obtained has a very homogeneous composition.
De cette façon, il est possible de déposer une couche homogène et très adhésive d'un revêtement comportant une très forte proportion de carbure de bore. On peut donc limiter l'épaisseur du revêtement à une valeur faible, par exemple 1 mm.In this way, it is possible to deposit a homogeneous and highly adhesive layer of a coating comprising a very high proportion of boron carbide. It is therefore possible to limit the thickness of the coating to a low value, for example 1 mm.
Chacune des particules de carbure de bore enrobées de nickel de grande densité est projetée sur le substrat à grande vitesse avec une grande énergie cinétique et se soude sur celui-ci au moment du choc par élévation de température et par effet mécanique. Le ramollissement de la couche superficielle de nickel et son échauffement permettent en effet un accrochage très efficace sur le substrat ou la couche de revêtement elle-même au moment du choc.Each of the particles of boron carbide coated with high density nickel is projected onto the substrate at high speed with high kinetic energy and is welded onto it at the time of impact by temperature rise and by mechanical effect. The softening of the surface layer of nickel and its heating in fact allow very effective attachment to the substrate or the coating layer itself at the time of impact.
On s'est rendu compte également qu'un dépôt chimique de nickel sur les particules de carbure de bore conduisait à un meilleur accrochage des particules, lors de la formation du revêtement qu'un dépôt électrolytique de nickel , du fait du point de fusion plus bas du dépôt chimique.It has also been realized that a chemical deposition of nickel on the particles of boron carbide leads to better adhesion of the particles, during the formation of the coating than an electrolytic deposition of nickel, due to the melting point more bottom of the chemical deposit.
Un autre avantage de l'utilisation de grains de carbure de bore enrobés est qu'on peut stocker et manipuler la poudre sans craindre la séparation de ses éléments constitutifs. L'épaisseur de la couche de nickel déposée sur les grains de carbure de bore a une épaisseur comprise entre 2 et 10 microns pour 80 % des particules qui ont été testées. On a pu s'assurer par ces contrôles que les grains de carbure de bore sont entièrement revêtus d'une couche de nickel à l'issue du traitement qui a été décrit.Another advantage of using coated boron carbide grains is that the powder can be stored and handled without fear of the separation of its constituent elements. The thickness of the nickel layer deposited on the grains of boron carbide has a thickness of between 2 and 10 microns for 80% of the particles which have been tested. We were able to make sure Check with these controls that the boron carbide grains are completely coated with a layer of nickel at the end of the treatment which has been described.
Le procédé de revêtement qui vient d'être décrit permet d'obtenir un revêtement extrêmement homogène, chacun des grains de la poudre amenés au chalumeau ayant pratiquement la composition en carbure de bore et en nickel du dépôt à réaliser sur le boitier.The coating process which has just been described makes it possible to obtain an extremely homogeneous coating, each of the grains of the powder brought to the torch having practically the composition of boron carbide and nickel of the deposit to be produced on the casing.
Après revêtement, l'enveloppe tubulaire est refroidie jusqu'à la température ambiante puis mise sous la forme d'un parallélépipède à section carrée de 22 cm de c$té, par déformation à froid.After coating, the tubular casing is cooled to room temperature and then put into the form of a parallelepiped with a square section of 22 cm side, by cold deformation.
Le pliage de l'enveloppe tubulaire pour la réalisation des arêtes du parallélépipède se fait suivant les génératrices situées sous les caches le long desquelles on n'a pas réalisé de dépôt de revêtement. On évite ainsi l'éclatement du revêtement lors de la mise en forme mécanique finale du parallélépipède.The folding of the tubular envelope for the realization of the parallelepiped edges is done according to the generatrices located under the covers along which no coating deposition has been made. This prevents bursting of the coating during the final mechanical shaping of the parallelepiped.
Les dimensions et la géométrie précise de l'enveloppe du boifier sont obtenues après revêtement, si bien que les déformations-éventuelles de l'enveloppe tubulaire au moment de son préchauffage et au moment du dépôt plasma n'ont aucune incidence sur la forme-et la précision dimensionnelle finale du boitier.The dimensions and the precise geometry of the casing envelope are obtained after coating, so that the possible deformations of the tubular envelope at the time of its preheating and at the time of the plasma deposition have no effect on the shape and the final dimensional accuracy of the case.
Si le dépôt avait été réalisé directement sur une enveloppe métallique de forme parallélépipèdique, on n'aurait pas pu garantir l'obtention, avec une épaisseur de paroi de 2 mm, d'une géométrie et de dimensions précises du boitier, à cause des déformations d'origine thermique.If the deposit had been made directly on a metal envelope of parallelepiped shape, we could not have guaranteed obtaining, with a wall thickness of 2 mm, a precise geometry and dimensions of the case, because of the deformations of thermal origin.
Le procédé décrit a donc permis d'obtenir un boitier à paroi mince comportant une couche absorbante efficace mais de faible épaisseur.The method described therefore made it possible to obtain a thin-walled housing comprising an effective absorbent layer but of small thickness.
Le fait que la zone voisine des arêtes du boitier ne soit pas recouverte de revêtement n'a pratiquement pas d'incidence sur la capacité d'absorption des neutrons de celui-ci. De toute façon, l'augmentation de l'épaisseurde la lame d'eau rendue possible grâce à la faible épaisseur du bditier compense largement cette faible diminution de la capacité d'absorption neutronique du boitier.The fact that the area near the edges of the case is not covered with a coating has practically no effect on the neutron absorption capacity of the latter. In any case, the increase in the thickness of the water layer made possible by the small thickness of the housing more than compensates for this small reduction in the neutron absorption capacity of the housing.
Pour améliorer la tenue à l'usure et à la corrosion des boitiers, on peut terminer l'opération de dépôt de revêtement au chalumeau plasma, en alimentant le chalumeau par de la poudre de nickel, ou d'acier inoxydable de façon à réaliser une couche d'une épaisseur voisine de 200 microns au-dessus de la couche de revêtement comportant le carbure de bore, ce qui élimine les aspérités du revêtement dues au B4C. La couche superficielle de nickel ou d'acier inoxydable extrêmement lisse et continue joue un rôle protecteur pour la couche de revêtement.To improve the wear and corrosion resistance of the housings, the coating process can be completed using a plasma torch, by supplying the torch with nickel or stainless steel powder so as to produce a layer with a thickness close to 200 microns above the coating layer comprising boron carbide, which eliminates the roughness of the coating due to B4C. The extremely smooth and continuous nickel or stainless steel surface layer plays a role protective for the coating layer.
Exemple 2 : On a réalisé un boitier en acier inoxydable de forme parallélépipédique.Example 2: A stainless steel box of parallelepiped shape was produced.
Le boitier qui a subi un dégraissage chimique puis un dégraissage électrolytique est soumis à un traitement chimique de dépassivation en bain chlorhydrique ou fluonitrique. On place alors le boitier dans une cuved'électrolyse de grandes dimensions remplie d'un bain renfermant du NiCl2 à raison de 250 g par litre et de l'acide chlrhydrique à raison de 130 g par litre. On réalise alors un traitement de déRassivation électrolytique en deux phases sur la surface externe du boitier. Au cours de la première phase, ou phase anodique, d'une durée de 15 secondes, le boitier constitue l'anode et la densité de courant d'électrolyse est de 1 à 2 ampères par dm2.The unit which has undergone chemical degreasing and then electrolytic degreasing is subjected to a chemical depassivation treatment in hydrochloric or fluonitric bath. The box is then placed in a large electrolysis tank filled with a bath containing NiCl2 at the rate of 250 g per liter and hydrochloric acid at the rate of 130 g per liter. Then performs processing of R electrolytic assivation in two stages on the outer surface of the housing. During the first phase, or anode phase, lasting 15 seconds, the box constitutes the anode and the electrolysis current density is 1 to 2 amperes per dm2.
Au.cours de la seconde phase ou phase cathodique, d'une durée de 2 mn, le boitier constitue la cathode et le courant de l'électrolyse est de 3 ampères par dm2. During the second phase or cathodic phase, lasting 2 minutes, the box constitutes the cathode and the electrolysis current is 3 amperes per dm2.
On réalise alors un pré-nickelage des quatre faces du boitier, à l'intérieur de la cuve d'électrolyse contenant un bain de travail comportant du NiS04 à raison de 280 g par litre du NiCl2 à raison de 45 g par litre, du H3B03 à raison de 45 g par litre, ainsi que quelques millilitres d'un mouillant. La durée de ce traitement est d'une demi-heure et la densité de courant est de 4 ampères par dm2. On effectue ensuite, successivement sur chacune des faces externes du boitier placée en position horizontale dans la cuve d'électrolyse, un ensemble d'opérations visant à l'obtention d'un revêtement absorbant, en faisant tourner le boitier d'un quart de tour.entre chaque dépôt de poudre de carbure de bore, après fixation de la dernière couche déposée.The four faces of the case are then pre-nickeled, inside the electrolysis tank containing a working bath comprising NiS04 at the rate of 280 g per liter of NiCl2 at the rate of 45 g per liter, H3B03 at a rate of 45 g per liter, as well as a few milliliters of a wetting agent. The duration of this treatment is half an hour and the current density is 4 amperes per dm2. Then carried out, successively on each of the external faces of the box placed in a horizontal position in the electrolysis tank, a set of operations aimed at obtaining an absorbent coating, by rotating the box a quarter of a turn .between each deposition of boron carbide powder, after fixing the last deposited layer.
Ces opérations comportent successivement la constitution d'une couche régulière de particules de carbure de bore B4C sur une face du boitier, le dépôt électrolytique de nickel à travers la couche de poudre de B4C jusqu'au moment où les particules sont parfaitement accrochées au substrat et solidarisées entre elles, puis le dépôt d'une nouvelle couche de particules de B4C suivie par le dépôt de nickel électrolytique pour l'accrochage de ces particules, le nombre de couches successives nécessaires étant déterminé par la quantité de carbure de bore à déposer par unité de surface du boitier.These operations successively include the constitution of a regular layer of particles of boron carbide B4C on one face of the housing, the electrolytic deposition of nickel through the layer of powder of B4C until the particles are perfectly attached to the substrate and joined together, then the deposition of a new layer of B4C particles followed by the deposition of electrolytic nickel for the attachment of these particles, the number of successive layers required being determined by the quantity of boron carbide to be deposited per unit of surface of the case.
La totalité du boitier est placée dans la cuve d'électrolyse si bien que les couches de nickel croissent en même temps sur les quatre faces faces du boitier.The entire housing is placed in the electrolysis tank so that the nickel layers grow at the same time on all four sides sides of the case.
On a utilisé une poudre constituée par des particules de B4C d'une dimension maximum de 200 microns et chacune des couches de carbure de bore déposée par gravité sur les faces du boitier avait une épaisseur identique à la dimension maximum des particules, c'est à dire 200 microns. De cette façon, on évite des chevauchements indésirables des particules et l'on amé-et liore la régularité d'épaisseur/d'efficacité neutronique du revêtement. Le revêtement est donc constitué par une superposition de monocouches, c'est à dire de couches de poudre constituées par des grains disposés côte à côte avec un minimum de superposition de plusieurs grains, ces monocouches étant liées entre elles par le dépôt de nickel.A powder was used consisting of B4C particles with a maximum dimension of 200 microns and each of the layers of boron carbide deposited by gravity on the faces of the housing had a thickness identical to the maximum dimension of the particles, ie say 200 microns. In this way, unwanted overlaps of the particles are avoided and the regularity / thickness / neutron efficiency of the coating is improved and improved. The coating therefore consists of a superposition of monolayers, that is to say of layers of powder constituted by grains arranged side by side with a minimum of superposition of several grains, these monolayers being linked together by the deposition of nickel.
On détermine facilement la quantité de poudre nécessaire pour la réalisation d'une monocouche sur une surface déterminée et correspondant à l'aire de chacune des faces du boitier.It is easy to determine the quantity of powder necessary for the production of a monolayer on a determined surface and corresponding to the area of each of the faces of the housing.
Les dépôts de nickel entre les particules de carbure de bore sont obtenus en utilisant un bain d'électrolyse identique à celui utilisé pour le prénickelage et une densité de courant de 2 ampères par dm2. Chacune des opérations d'électrolyse successives est poursuivie pendant une demi-heure.The nickel deposits between the boron carbide particles are obtained using an electrolysis bath identical to that used for pre-nickel plating and a current density of 2 amperes per dm2. Each of the successive electrolysis operations is continued for half an hour.
Lorsque la densité de carbure de bore déposé par cm2 de face du boitier est supérieure à 0,146 g, on termine l'opération de revêtement par une électrolyse de 2 heures avec une densité de courant de 2 ampères par dm2 afinWhen the density of boron carbide deposited per cm2 of face of the housing is greater than 0.146 g, the coating operation is terminated by an electrolysis of 2 hours with a current density of 2 amperes per dm2 in order to
de fixer définitivement les particules de revêtement et de réaliser une couche continue de nickel au-dessus des couches de particules de carbure de bore enrobées par le nickel.to permanently fix the coating particles and to produce a continuous layer of nickel on top of the layers of boron carbide particles coated with nickel.
Le boitier est alors sorti du bac d'électrolyse rincé puis séché.The box is then removed from the rinsed and dried electrolysis tank.
Dans tous les cas, on a pu obtenir une densité de carbure de bore, c'est à dire une efficacité du boitier en ce qui concerne l'absargtion des neutrons, suffisante, avec un dépôt d'une épaisseur totale inférieure\à 2 mm.In all cases, it was possible to obtain a density of boron carbide, that is to say an efficiency of the case with regard to the absorption of neutrons, sufficient, with a deposit of a total thickness less than 2 mm .
Les différentes couches de particules de B4C emprisonnées dans la matrice de nickel déposées les unes au-dessus des autres sont pratiquement continues dans la mesure où l'on effectue une répartition régulière de ces particules pour constituer les couches successives. Cependant, il est possible d'utiliser des particules d'une taille inférieure, par exemple 60 microns en mélange avec les particules de 200 microns. Les particules de taille plus faible viennent s'intercaler entre les particules de 200 microns pour réaliser une couche continue de carbure de bore.The various layers of particles of B4C trapped in the nickel matrix deposited one above the other are practically continuous insofar as one carries out a regular distribution of these particles to constitute the successive layers. However, it is possible to use particles of a smaller size, for example 60 microns in admixture with particles of 200 microns. The particles of smaller size are interposed between the particles of 200 microns to produce a continuous layer of boron carbide.
La superposition de plusieurs monocouches permet d'éviter la présence de zones de revêtement renfermant une très faible quantité de B4C. La répartition des particules est donc extrêmement homogène et d'autre part la proportion de particules de B4C par rapport à la matrice de nickel est importante, si on la compare à ce qui était obtenu par les procédés connus antérieurement. Cette proportion est par exemple, dans le cas qui vient d'être décrit de 50 % en masse. On obtient.donc facilement par le procédé suivant l'invention un revêtement comportant la quantité voulue de carbure de bore et donc de bore 10 par cm2 de substrat, tout en ayant une couche de revêtement d'une épaisseur totale inférieure à 2 mm.The superimposition of several monolayers makes it possible to avoid the presence of coating zones containing a very small amount of B4C. The repair tition of the particles is therefore extremely homogeneous and on the other hand the proportion of B4C particles relative to the nickel matrix is large, if we compare it with what was obtained by the previously known methods. This proportion is for example, in the case which has just been described, 50% by mass. A coating is therefore obtained easily by the process according to the invention comprising the desired quantity of boron carbide and therefore of boron 10 per cm 2 of substrate, while having a coating layer with a total thickness of less than 2 mm.
Exemple 3 : On réalise des opérations semblables à celles qui ont été décrites à propos de l'exemple 2, sur une enveloppe en acier inoxydable de forme parallélépipédique et en utilisant un bain chimique au lieu d'un bain électrolytique. Les opérations réalisées sont identiques, à savoir un prénickelage du substrat, puis un dépôt gravitaire d'une première couche de particules de carbure de bore, puis un nickelage chimique permettant la liaison des particules, suivi.d'un nouveau dépôt d'une monocouche de particules de carbure de bore qui sont ensuite liées entre elles par dépôt chimique d'une couche de nickel, ces opérations successives se poursuivant jusqu'au moment où le revêtement comporte une quantité suffisante de carbure de bore par cm2.Example 3: Operations similar to those which have been described in connection with Example 2 are carried out on a stainless steel casing of parallelepiped shape and using a chemical bath instead of an electrolytic bath. The operations carried out are identical, namely a pre-nickel plating of the substrate, then a gravitational deposition of a first layer of boron carbide particles, then a chemical nickel plating allowing the particles to be bonded, followed by a new deposition of a monolayer. boron carbide particles which are then bonded together by chemical deposition of a nickel layer, these successive operations continuing until the coating comprises a sufficient quantity of boron carbide per cm2.
L'invention ne se limite pas aux modes de réalisation qui viennent d'être décrits, elle en comporte au contraire toutes les variantes.The invention is not limited to the embodiments which have just been described, on the contrary it includes all variants thereof.
C'est ainsi qu'on peut réaliser le revêtement absorbant les neutrons sur le boitier par une méthode différente de celles qui ont été décrites ci-dessus, qu'on peut réaliser ce dépôt aussi bien sur le boitier ayant sa forme définitive que sur une ébauche qui est ensuite mise en forme et que l'enveloppe métallique peut être constituée par un autre matériau métallique que l'acier inoxydable, par exemple de l'aluminium.Thus, the neutron absorbing coating can be produced on the housing by a method different from those which have been described above, that this deposition can be carried out both on the housing having its final shape and on a blank which is then shaped and that the metal envelope may be made of a metallic material other than stainless steel, for example aluminum.
L'épaisseur de l'enveloppe métallique peut être différente de 2 mm, mais cependant dans le cas des boitiers pour le stockage des assemblages combustibles sous eau, il est nécessaire que cette épaisseur soit comprise entre 1,5 et 2,5 mm, pour concilier à la fois les impératifs concernant la tenue mécanique du boitier et les échanges thermiques entre l'assemblage combustible contenu dans le boitier et l'eau de la piscine.The thickness of the metal casing can be different from 2 mm, but however in the case of boxes for the storage of fuel assemblies under water, it is necessary that this thickness is between 1.5 and 2.5 mm, for reconcile both the requirements concerning the mechanical strength of the box and the heat exchanges between the fuel assembly contained in the box and the pool water.
L'invention s'applique non seulement au stockage des assemblages combustibles pour réacteur nucléaire à eau mais elle s'applique également au transport de matériaux irradiés en utilisant des boitiers suivant l'invention comme conteneurs de transport.The invention applies not only to the storage of fuel assemblies for a water nuclear reactor but it also applies to the transport of irradiated materials using boxes according to the invention as transport containers.
Claims (12)
qu'on réalise un revêtement constitué par du carbure de bore enrobé par du nickel sur la surface externe de l'enveloppe tubulaire, les caches empêchant le dépôt de revêtement dans la zone voisine des génératrices le long desquelles elles sont disposées,par projection à haute température d'une poudre constituée par des grains de carbure de bore B4C dont la surface externe est entièrement revêtue d'une couche de nickel qu'on déforme à froid l'enveloppe tubulaire, après revêtement, de façon à lui donner la forme d'un boitier parallélépipédique dont les arêtes corres- nondent aux génératrices le long desquelles les caches évitant le dépôt de revêtement ont été disposés.4.- A method of producing a housing according to any one of claims 1, 2 and 3, characterized in that one realizes a tubular envelope with a thickness between 1.5 and 2.5 mm, qu 'there are along four generators arranged in two perpendicular axial planes, covers over the entire length of the tubular casing,
that a coating consisting of boron carbide coated with nickel is produced on the external surface of the tubular casing, the covers preventing the deposition of coating in the region near the generators along which they are arranged, by high projection temperature of a powder constituted by grains of boron carbide B4C whose external surface is entirely coated with a layer of nickel which is deformed cold the tubular envelope, after coating, so as to give it the form of a parallelepipedic box, the edges of which correspond to the generators along which the covers preventing the deposit of coating have been placed.
Applications Claiming Priority (4)
Application Number | Priority Date | Filing Date | Title |
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FR8027857 | 1980-12-31 | ||
FR8027857 | 1980-12-31 | ||
FR8027860 | 1980-12-31 | ||
FR8027860 | 1980-12-31 |
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EP0055679A2 true EP0055679A2 (en) | 1982-07-07 |
EP0055679A3 EP0055679A3 (en) | 1982-09-01 |
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ID=26222158
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EP81402101A Withdrawn EP0055679A3 (en) | 1980-12-31 | 1981-12-31 | Container for under water storage of irradiated fuel assemblies, and method to realize such a container |
Country Status (5)
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EP (1) | EP0055679A3 (en) |
BR (1) | BR8108942A (en) |
ES (3) | ES279675Y (en) |
WO (1) | WO1982002453A1 (en) |
YU (1) | YU305181A (en) |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO1995030990A1 (en) * | 1994-05-09 | 1995-11-16 | Siemens Aktiengesellschaft | Container for absorbing neutron radiation |
WO1996036972A1 (en) * | 1995-05-16 | 1996-11-21 | Metallveredlung Gmbh & Co. Kg | Process for producing shielding components to absorb the neutrons generated in the nuclear reaction of radioactive materials |
WO1998059344A1 (en) * | 1997-06-24 | 1998-12-30 | Metallveredlung Gmbh & Co. Kg | Process for producing a neutron-absorbing coating |
EP1087408A1 (en) * | 1999-09-27 | 2001-03-28 | Metallveredlung GmbH & Co. KG | Process for producing a neutron-absorbing coating |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0016252A1 (en) * | 1979-02-21 | 1980-10-01 | The Carborundum Company | A method of manufacturing a neutron absorbing article and neutron absorbing articles |
US4238299A (en) * | 1979-08-24 | 1980-12-09 | Kennecott Copper Corporation | Tubing with copper-boron carbide composite facing and methods for its production |
-
1981
- 1981-12-22 YU YU305181A patent/YU305181A/en unknown
- 1981-12-30 ES ES1981279675U patent/ES279675Y/en not_active Expired
- 1981-12-31 WO PCT/FR1981/000175 patent/WO1982002453A1/en unknown
- 1981-12-31 EP EP81402101A patent/EP0055679A3/en not_active Withdrawn
- 1981-12-31 BR BR8108942A patent/BR8108942A/en unknown
-
1982
- 1982-04-05 ES ES511154A patent/ES8506411A1/en not_active Expired
- 1982-04-05 ES ES511155A patent/ES511155A0/en active Granted
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0016252A1 (en) * | 1979-02-21 | 1980-10-01 | The Carborundum Company | A method of manufacturing a neutron absorbing article and neutron absorbing articles |
US4238299A (en) * | 1979-08-24 | 1980-12-09 | Kennecott Copper Corporation | Tubing with copper-boron carbide composite facing and methods for its production |
Non-Patent Citations (4)
Title |
---|
CHEMICAL ABSTRACTS, Vol. 54, 1960, colonne 22056b Columbus, Ohio, (US) & Proc. U.N. Intern. Conf. Peaceful uses At. Energy, 2nd, Geneva, 1958 5, 382-9. BRADBURY et al.: "Composite Neutron-Absorbing Materials for Control Rod and Screening Applications". * |
CHEMICAL ABSTRACTS, Vol. 59, 1963, colonne 12367, Resume h Columbus Ohio (US) & U.S. At.Energy Comm. GEAP-3946; 69 pp. (1962) WILLIAMSON et al.: "Application of Boron-Carbide Nickel Dispersion to a Prototype Control Rod". * |
CHEMICAL ABSTRACTS, Vol. 61, 1964, colonnes 12902h, 12903a Columbus, Ohio, (US) & U.S. At. Energy Comm. GEAP-4296, 36 pp. (1963) MEGERTH et al.: "Environmental Testing of a B4C-Ni Prototype Control Rod". * |
CHEMICAL ABSTRACTS, Vol. 85, 1976, page 329, Resume 164966a Columbus Ohio (US) & Fiz.Khim.Obrab.Mater. 1976, (3), 70-3 VAISTUKH et al.: "Mechanism of the Formation of Coatings from Clad Powders during Spraying". * |
Cited By (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO1995030990A1 (en) * | 1994-05-09 | 1995-11-16 | Siemens Aktiengesellschaft | Container for absorbing neutron radiation |
DE4416362C2 (en) * | 1994-05-09 | 2002-09-26 | Framatome Anp Gmbh | absorber part |
WO1996036972A1 (en) * | 1995-05-16 | 1996-11-21 | Metallveredlung Gmbh & Co. Kg | Process for producing shielding components to absorb the neutrons generated in the nuclear reaction of radioactive materials |
WO1998059344A1 (en) * | 1997-06-24 | 1998-12-30 | Metallveredlung Gmbh & Co. Kg | Process for producing a neutron-absorbing coating |
EP1087408A1 (en) * | 1999-09-27 | 2001-03-28 | Metallveredlung GmbH & Co. KG | Process for producing a neutron-absorbing coating |
WO2001024198A1 (en) * | 1999-09-27 | 2001-04-05 | Metallveredlung Gmbh & Co. Kg | Method for producing a coating for absorption of neutrons produced in nuclear reactions of radioactive materials |
Also Published As
Publication number | Publication date |
---|---|
ES511154A0 (en) | 1984-11-16 |
WO1982002453A1 (en) | 1982-07-22 |
BR8108942A (en) | 1982-12-14 |
ES8506411A1 (en) | 1984-11-16 |
ES8506412A1 (en) | 1984-11-16 |
ES511155A0 (en) | 1984-11-16 |
ES279675Y (en) | 1985-06-01 |
EP0055679A3 (en) | 1982-09-01 |
ES279675U (en) | 1984-11-16 |
YU305181A (en) | 1986-04-30 |
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