WO1998059344A1 - Process for producing a neutron-absorbing coating - Google Patents
Process for producing a neutron-absorbing coating Download PDFInfo
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- WO1998059344A1 WO1998059344A1 PCT/EP1997/003309 EP9703309W WO9859344A1 WO 1998059344 A1 WO1998059344 A1 WO 1998059344A1 EP 9703309 W EP9703309 W EP 9703309W WO 9859344 A1 WO9859344 A1 WO 9859344A1
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- boron
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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
- G21F1/00—Shielding characterised by the composition of the materials
- G21F1/02—Selection of uniform shielding materials
- G21F1/08—Metals; Alloys; Cermets, i.e. sintered mixtures of ceramics and metals
Definitions
- the invention relates to a method for producing a coating for absorbing the neutrons formed during the nuclear reaction of radioactive materials.
- the invention also relates to a shielding element produced by the method.
- absorber elements are usually produced in the form of various types of shafts, canisters, pipes or a similar configuration which surround an object which emits neutrons and thereby shield it.
- the use of such absorber elements enables, for example, the compact storage of neutron-emitting elements, in particular fuel elements from nuclear power plants.
- a fuel assembly storage rack is known from EP 0 385 1 87 A1, in which absorber sheets form a number of shafts which enclose the fuel assemblies over their entire length.
- These absorber elements are shafts or pipes made of a neutron absorbing material, for example boron steel, a stainless steel with a boron content of 1 to 2%.
- boron steel for example boron steel
- stainless steel with a boron content of 1 to 2%.
- these absorber elements are extremely cost-intensive and the efficiency is limited due to the limited proportion of boron.
- the Boron content can be increased up to 8%, but the costs also increase by a factor of about 10, so that such pipes cannot be used economically.
- a composite absorber element which has a thin carrier film or a thin carrier plate on which a polymer matrix is applied, in which boron carbide particles are embedded.
- Glass fiber-reinforced polymer is preferably used as the material of the carrier film or the carrier plate.
- the boron carbide particles are evenly distributed on the surface of the polar matrix, with a boron concentration of up to 0.1 g / cm 2 .
- this absorber element has a thickness of up to 7 mm, is in the form of a film or sheet and is suspended between an inner wall and an outer wall. It is not clear from US Pat. No. 4,221,862 whether a homogeneous distribution of the boron carbide particles arranged on the surface of the polymer matrix is ensured over a long period, in particular with regard to possible abrasion on the surface.
- EP 0 01 6 252 A1 describes a method for producing a neutron-absorbing absorber element.
- boron carbide is applied to a substrate together with a metallic substance by means of plasma spraying, the boron carbide being incorporated into a matrix made of a metallic substance.
- the procedure is also carried out so that oxidation of the boron is avoided.
- the absorber element produced in this way is said to be stable with respect to a liquid medium, such as is present in a fuel pool.
- the thickness of the layer of metal and boron carbide applied by means of plasma spraying is at least 500 ⁇ m.
- the proportion of boron carbide is approximately 50% by volume.
- Aluminum, copper and stainless steel can be considered as the metallic substance, the substrate containing the same metallic substance as the sprayed-on layer.
- a relatively thick layer on boron carbide is required, in particular the thickness of the layer is 3 to 6 mm.
- boron steel The production of boron steel is extremely complex.
- the steel is melted and boron is enriched up to 1 0 -valence by means of complex processes and mixed with the melted steel.
- the result is a boron steel with 1.1 to 1.4% by weight boron.
- This steel is very difficult to machine, is extremely brittle and is difficult to weld.
- Shielding elements made from it have an extremely high weight with average absorption properties.
- inner storage containers, so-called baskets, made of boron steel are known for the intermediate storage of fuel elements, which have a weight of approximately 10 tons.
- the present invention is based on the object of specifying a method for producing a coating or shielding elements for absorbing the neutrons formed in the nuclear reaction of radioactive materials, which method is economical and simple to use and increases the effectiveness of the absorption , allows greater variability with regard to the base materials and shape of the shielding elements, and in particular the manufacture allows lighter shielding elements with at least the same absorption qualities.
- a method for producing a coating for absorbing the neutrons formed during the nuclear reaction of radioactive materials is proposed, at least part of a shielding element consisting of a base material being provided with a boron nickel layer on its surfaces intended for this in a boron-containing dispersion bath is, during the coating process at least occasionally a relative movement between the surface to be coated and the dispersion bath is generated.
- boron nickel layer in a dispersion bath with temporary relative movement between the surface to be coated and the dispersion bath brings very good results.
- the boron can be incorporated in the nickel matrix in orders of magnitude of> 20 vol.%, Even ⁇ 40 vol.%.
- the boron can be present as boron carbide (B 4 C) or, according to a particularly advantageous proposal of the invention, as boron in elementary form in the dispersion. When using elemental boron, much larger boron deposits can be achieved.
- the absorption layers are in the order of 350 to 500 ⁇ m, which is extremely thin.
- Inorganic base material for example steel, titanium, copper, nickel and the like, is advantageously used. Despite its organic character and thus its susceptibility to neutron radiation, it can be used as a base material Carbon fiber material can be considered. Carbon fiber material has the particular advantage that the absorption element can be produced by electroplating.
- the shielding element in the finished state or in individual parts. Due to the independence from the base material, very easily editable materials can be used. On the other hand, very complicated shapes of shielding elements, containers, baskets and the like can also be completely prefabricated and then coated according to the invention.
- the base material can be prefabricated as a finished part or individual part, so that finished shielding elements can be formed from the individual parts.
- the coating in the dispersion bath is either chemical or electrolytic.
- the relative movement between the surface to be coated and the dispersion bath can take place, for example, by moving the element to be coated in the dispersion bath.
- elements such as boron are such that it is practically not economically feasible to circulate or pump around the dispersion. Any circulation or Pumping unit would be worn out in no time.
- the relative movement is intended to ensure continued thorough mixing or repeated mixing of the dispersion, and on the other hand to direct the dispersion to the surface to be coated.
- the entire coating system can also be moved for the purpose of generating the relative movement. For example, it is conceivable to carry out the coating in a kind of drum.
- the surface to be coated is arranged in the dispersion bath facing upward.
- the surface to be coated is arranged in the dispersion bath in such a way that the particles in the dispersion sink to the surface due to gravity.
- This arrangement according to the invention in particular in combination with the temporary generation of a relative movement between the surface and the dispersion bath, favors excellent coating results.
- the coating process be carried out in a glass tub. This ensures that the dispersion bath is particularly clean.
- the invention provides an easy to carry out, economical and very effective method for producing shielding elements for neutron absorption, which in particular makes shielding elements independent of the base material that are considerably lighter than known shielding elements with comparable absorption effects.
- the invention also relates to shielding elements produced by the described method. These are characterized in that they have a boron / nickel coating with a proportion of boron in elemental form or boron carbide greater than 20% by volume or by 40% by volume.
- the layer thickness is 350 to 500 ⁇ m, the layer being formed on an inorganic base material such as steel, titanium, copper or the like.
- the training takes place chemically or electrolytically.
- the shielding element can have been coated in the finished form or can be composed of individual coated individual parts.
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Abstract
Description
VERFAHREN ZUR HERSTELLUNG EINER BESCHICHTUNG ZUR ABSORPTION VON NEUTRONEN METHOD FOR PRODUCING A COATING FOR ABSORBING NEUTRON
Die Erfindung betrifft ein Verfahren zur Herstellung einer Beschichtung zur Absorption der bei der Kernreaktion radioaktiver Materialien entstehenden Neutronen. Die Erfindung betrifft auch ein nach dem Verfahren hergestelltes Abschirmelement.The invention relates to a method for producing a coating for absorbing the neutrons formed during the nuclear reaction of radioactive materials. The invention also relates to a shielding element produced by the method.
Für die Behandlung der insbesondere aus dem Gebiet der Kernreaktortechnik stammenden radioaktiven Materialien werden diese je nach Aufgabenstellung, Material und Zustand beispielsweise zum Wechsel und/oder zur Überprüfung sowie zum Transport und/oder Lagerung zur Vermeidung von weiteren Kernreaktionen durch die zwangsläufig abgestrahlten Neutronen voneinander abgeschirmt. Zur Erreichung einer gewünschten Neutronenabsorption werden üblicherweise Absorberelemente in Form verschiedenartiger Schächte, Kanister, Rohre oder ähnlicher Konfiguration hergestellt, die einen Neutronen aussendenden Gegenstand umgeben und ihn dadurch abschirmen. Der Einsatz solcher Absorberelemente ermöglicht beispielsweise die kompakte Lagerung Neutronen abgebender Elemente, insbesondere Brennelemente aus Kernkraftanlagen.For the treatment of the radioactive materials, in particular from the field of nuclear reactor technology, these are shielded from one another depending on the task, material and condition, for example for changing and / or for checking and for transport and / or storage in order to avoid further nuclear reactions by the neutrons which are inevitably emitted. To achieve a desired neutron absorption, absorber elements are usually produced in the form of various types of shafts, canisters, pipes or a similar configuration which surround an object which emits neutrons and thereby shield it. The use of such absorber elements enables, for example, the compact storage of neutron-emitting elements, in particular fuel elements from nuclear power plants.
Aus der EP 0 385 1 87 A1 ist ein Brennelement-Lagergestell bekannt, bei dem Absorberbleche eine Anzahl von Schächten bilden, die die Brennelemente über deren gesamter Länge umschließen. Bei diesen Absorberelementen handelt es sich um Schächte bzw. Rohre aus einem Neutronen absorbierenden Material, zum Beispiel Borstahl, einem Edelstahl mit einem Boranteil von 1 bis 2 %. Abgesehen von dem erforderlichen Hersteliungsaufwand sind diese Absorberelemente überaus kostenintensiv und der Wirkungsgrad ist wegen des beschränkten Boranteils begrenzt. Bei dem Versuch, den Boranteil zu erhöhen, wurde die Abscheidung einer Bor-Nickel-Legierung überprüft. Der Boranteil kann zwar auf bis zu 8 % erhöht werden, jedoch erhöhen sich auch die Kosten etwa um den Faktor 1 0, so daß ein wirtschaftlicher Einsatz derartiger Rohre nicht in Frage kommen kann.A fuel assembly storage rack is known from EP 0 385 1 87 A1, in which absorber sheets form a number of shafts which enclose the fuel assemblies over their entire length. These absorber elements are shafts or pipes made of a neutron absorbing material, for example boron steel, a stainless steel with a boron content of 1 to 2%. Apart from the required manufacturing effort, these absorber elements are extremely cost-intensive and the efficiency is limited due to the limited proportion of boron. In an attempt to increase the boron content, the deposition of a boron-nickel alloy was checked. The Boron content can be increased up to 8%, but the costs also increase by a factor of about 10, so that such pipes cannot be used economically.
Für andere Aufgaben, beispielsweise den Transport und/oder die Lagerung radioaktiver Materialien, werden Verfahren eingesetzt, bei welchen auf den metallischen Oberflächen von Behältern Nickelschichten abgeschieden werden.For other tasks, for example the transport and / or storage of radioactive materials, processes are used in which nickel layers are deposited on the metallic surfaces of containers.
In der US-PS 4 21 8 622 ist ein zusammengesetztes Absorberelement beschrieben, welches eine dünne Trägerfolie oder ein dünnes Trägerblech aufweist, auf das eine Polymermatrix aufgetragen ist, in die Borcarbid-Partikel eingelagert sind. Als Material der Trägerfolie bzw. des Trägerblechs wird bevorzugt glasfaserverstärktes Polymer verwendet. Die Borcarbid-Partikel sind gleichmäßig an der Oberfläche der Polimärmatrix verteilt, mit einer Borkonzentration von bis zu 0, 1 g/cm2. Bei einer Verwendung des zusammengesetzten Absorberteils in einem Brennelement-Lagergestell hat dieses Absorberelement eine Dicke von bis zu 7 mm, ist in Form einer Folie oder eines Blechs ausgestaltet und zwischen einer inneren Wand und einer äußeren Wand aufgehängt. Ob eine homogene Verteilung der an der Oberfläche der Polymermatrix angeordneten Borcarbid-Partikel über eine längere Zeit gewährleistet ist, insbesondere im Hinblick auf einen möglichen Abrieb an der Oberfläche, kann der US-PS 4 21 8 622 nicht entnommen werden.In US Pat. No. 4,221,862, a composite absorber element is described, which has a thin carrier film or a thin carrier plate on which a polymer matrix is applied, in which boron carbide particles are embedded. Glass fiber-reinforced polymer is preferably used as the material of the carrier film or the carrier plate. The boron carbide particles are evenly distributed on the surface of the polar matrix, with a boron concentration of up to 0.1 g / cm 2 . When the composite absorber part is used in a fuel assembly storage rack, this absorber element has a thickness of up to 7 mm, is in the form of a film or sheet and is suspended between an inner wall and an outer wall. It is not clear from US Pat. No. 4,221,862 whether a homogeneous distribution of the boron carbide particles arranged on the surface of the polymer matrix is ensured over a long period, in particular with regard to possible abrasion on the surface.
In der EP 0 01 6 252 A1 ist ein Verfahren zur Herstellung eines neutronenabsorbierenden Absorberelementes beschrieben. In dem Verfahren wird mittels Plasmasprühens Borcarbid zusammen mit einer metallischen Substanz auf ein Substrat aufgebracht, wobei das Borcarbid in eine Matrix aus einer metallischen Substanz eingebunden wird. Das Verfahren erfolgt zudem so, daß eine Oxidation des Bors vermieden wird. Das so hergestellte Absorberelement soll gegenüber einem flüssigen Medium, wie es beispielsweise in einem Brennelement-Lagerbecken vorliegt, stabil sein. Die Dicke der mittels Plasmasprühens aufgebrachten Schicht aus Metall und Borcarbid beträgt mindestens 500 μm. Der Anteil des Borcarbids beträgt etwa 50 Vol.-%. Als metallische Substanz kommen Aluminium, Kupfer und rostfreier Stahl in Betracht, wobei das Substrat dieselbe metallische Substanz wie die aufgesprühte Schicht enthält. Zur Erreichung einer wirksamen Neutronenabsorption ist eine relativ dicke Schicht auf Borcarbid erforderlich, insbesondere beträgt die Dicke der Schicht 3 bis 6 mm.EP 0 01 6 252 A1 describes a method for producing a neutron-absorbing absorber element. In the method, boron carbide is applied to a substrate together with a metallic substance by means of plasma spraying, the boron carbide being incorporated into a matrix made of a metallic substance. The procedure is also carried out so that oxidation of the boron is avoided. The absorber element produced in this way is said to be stable with respect to a liquid medium, such as is present in a fuel pool. The thickness of the layer of metal and boron carbide applied by means of plasma spraying is at least 500 μm. The proportion of boron carbide is approximately 50% by volume. Aluminum, copper and stainless steel can be considered as the metallic substance, the substrate containing the same metallic substance as the sprayed-on layer. In order to achieve effective neutron absorption, a relatively thick layer on boron carbide is required, in particular the thickness of the layer is 3 to 6 mm.
Aus der DE-AS 1 037 302 und der DE 2 361 363 ist es bekannt, Rohre, insbesondere Konservendosen, auf ihrer Außenfläche auf elektrolytischem Wege mit Absorbermaterial zum Schutz gegen radioaktive Strahlungen zu versehen. Hinsichtlich der verfahrenstechnischen Vorgänge und Vorrichtungen zur technischen Durchführung der physikalisch-chemischenFrom DE-AS 1 037 302 and DE 2 361 363 it is known to provide pipes, in particular cans, with electrolytic absorber material on their outer surface for protection against radioactive radiation. With regard to the procedural processes and devices for the technical implementation of the physico-chemical
Zustandsänderungen und Stoffwandlungen zum Aufbringen der Absorbermaterialien können aus der DE-AS-1 037 302 und der DE 2 361 363 keine Informationen entnommen werden.Changes in state and material transformations for applying the absorber materials cannot be taken from DE-AS-1 037 302 and DE 2 361 363.
Aus der EP 0 055 679 A2 sind Verfahren zur Herstellung von Abschirmelementen bekannt, wobei Borcarbid entweder in einem Plasmabeschichtungsverfahren auf die Oberfläche des Abschirmelementes aufgebracht, oder nach einer elektrolytischen oder chemischen Vorvernickelung des Abschirmelementes Borcarbid als Pulver auf die Oberfläche gestreut und das Abschirmelement anschließend elektrolytisch oder chemisch nachvernickelt wird. Nach diesen Verfahren lassen nur geringe Borcarbidmgengen in Größenordnungen um 20 Gew.-% in bezug auf Nickel auf die Oberfläche aufbringen. Es bedarf somit sehr starker Schichten, so daß diese vorbekannten Verfahren unwirtschaftlich sind. In der Praxis wurden diese Verfahren nicht weiter eingesetzt, da sie verfahrenstechnisch auch nicht konkret realisierbar sind. Das Auftragen eines Pulvers auf eine Oberfläche im Sinne von Aufstreuen ist keine Maßnahme, die eine gesicherte industrielle Produktion gewährleistet.Methods for producing shielding elements are known from EP 0 055 679 A2, boron carbide either being applied to the surface of the shielding element in a plasma coating process, or after electrolytic or chemical pre-nickel plating of the shielding element, boron carbide is scattered as a powder on the surface and the shielding element is then electrolytically or is chemically nickel-plated. According to these processes, only small amounts of boron carbide in the order of 20% by weight with respect to nickel can be applied to the surface. Very thick layers are therefore required, so that these previously known methods are uneconomical. In practice these methods are no longer used, since they are also not technically feasible in terms of process technology. The application of a powder to a surface in the sense of sprinkling is not a measure that guarantees secure industrial production.
Sämtliche vorbekannten Verfahren und danach hergestellten Abschirmelemente können als unwirtschaftlich im Sinne von großen Herstellungskosten und einem großem Materialaufwand angesehen werden. Darüber hinaus ist die Variabilität der Form der Abschirmelemente und die Erweiterung der Einsatzmöglichkeiten eingeschränkt.All previously known methods and shielding elements produced thereafter can be regarded as uneconomical in the sense of high manufacturing costs and a large amount of material. In addition, the variability of the shape of the shielding elements and the expansion of the possible uses are restricted.
Die Herstellung von Borstahl ist überaus aufwendig. Der Stahl wird aufgeschmolzen und Bor wird durch aufwendige Verfahren bis hin zur 1 0- Wertigkeit angereichert und mit dem aufgeschmolzenen Stahl vermengt. Es ergibt sich ein Borstahl mit 1 , 1 bis 1 ,4 Gew.-% Bor. Dieser Stahl läßt sich sehr schlecht bearbeiten, ist überaus spröde und läßt sich schlecht schweißen. Daraus hergestellte Abschirmelemente haben ein äußerst hohes Gewicht bei durchschnittlichen Absorptionseigenschaften. Beispielsweise sind aus Borstahl hergestellte Lagerinnenbehälter, sogenannte Körbe, für die Zwischenlagerung von Brennelementen bekannt, die ein Gewicht von ca. 1 0 t aufweisen.The production of boron steel is extremely complex. The steel is melted and boron is enriched up to 1 0 -valence by means of complex processes and mixed with the melted steel. The result is a boron steel with 1.1 to 1.4% by weight boron. This steel is very difficult to machine, is extremely brittle and is difficult to weld. Shielding elements made from it have an extremely high weight with average absorption properties. For example, inner storage containers, so-called baskets, made of boron steel are known for the intermediate storage of fuel elements, which have a weight of approximately 10 tons.
Ausgehend von dem vorbekannten Stand der Technik liegt der vorliegenden Erfindung die A u f g a b e zugrunde, ein Verfahren zur Herstellung einer Beschichtung bzw. von Abschirmelementen zur Absorption der bei der Kernreaktion radioaktiver Materialien entstehenden Neutronen anzugeben, welches wirtschaftlich und einfach anwendbar ist, die Effektivität der Absorption erhöht, hinsichtlich der Basismaterialien und Form der Abschirmelemente größere Variabilität zuläßt und insbesondere die Herstellung leichterer Abschirmelemente bei mindestens gleichen Absorptionsqualitäten ermöglicht.Starting from the known prior art, the present invention is based on the object of specifying a method for producing a coating or shielding elements for absorbing the neutrons formed in the nuclear reaction of radioactive materials, which method is economical and simple to use and increases the effectiveness of the absorption , allows greater variability with regard to the base materials and shape of the shielding elements, and in particular the manufacture allows lighter shielding elements with at least the same absorption qualities.
Zur technischen L ö s u n g dieser Aufgabe wird vorgeschlagen ein Verfahren zur Herstellung einer Beschichtung zur Absorption der bei der Kernreaktion radioaktiver Materialien entstehenden Neutronen, wobei wenigstens ein Teil eines aus einem Basismaterial bestehenden Abschirmelementes an seinen dafür vorbestimmten Oberflächen in einem Bor enthaltenden Dispersionsbad mit einer Bornickelschicht versehen wird, wobei während des Beschichtungsvorganges wenigstens zeitweise eine Relativbewegung zwischen der jeweils zu beschichtenden Oberfläche und dem Dispersionsbad erzeugt wird.For the technical solution to this problem, a method for producing a coating for absorbing the neutrons formed during the nuclear reaction of radioactive materials is proposed, at least part of a shielding element consisting of a base material being provided with a boron nickel layer on its surfaces intended for this in a boron-containing dispersion bath is, during the coating process at least occasionally a relative movement between the surface to be coated and the dispersion bath is generated.
Überraschenderweise hat sich gezeigt, daß die Ausbildung einer Bornickelschicht in einem Dispersionsbad bei zeitweiser Relativbewegung zwischen zu beschichtender Oberfläche und dem Dispersionsbad sehr gute Ergebnisse mit sich bringt. Im Gegensatz zu den bisher erreichten Einlagerungen läßt sich das Bor in der Nickelmatrix in Größenordnungen von > 20 Vol.-%, sogar ≥ 40 Vol.-% einbauen. Das Bor kann als Borcarbid (B4C) oder gemäß einem besonders vorteilhaften Vorschlag der Erfindung als Bor in Elementarform in der Dispersion enthalten sein. Bei Verwendung von elementarem Bor lassen sich noch sehr viel größere Boreinlagerungen erzielen.Surprisingly, it has been shown that the formation of a boron nickel layer in a dispersion bath with temporary relative movement between the surface to be coated and the dispersion bath brings very good results. In contrast to the deposits achieved so far, the boron can be incorporated in the nickel matrix in orders of magnitude of> 20 vol.%, Even ≥ 40 vol.%. The boron can be present as boron carbide (B 4 C) or, according to a particularly advantageous proposal of the invention, as boron in elementary form in the dispersion. When using elemental boron, much larger boron deposits can be achieved.
Es ergibt sich somit aufgrund der hohen Einlagerungsraten eine sehr viel größere Effektivität. Die Absorptionsschichten liegen in Größenordnungen von 350 bis 500 μm, was äußerst dünn ist. Darüber hinaus ist ein besonderer Vorteil die Unabhängigkeit des Verfahrens vom Basismaterial. In vorteilhafter Weise ist anorganisches Basismaterial einzusetzen, beispielsweise Stahl, Titan, Kupfer, Nickel und dergleichen. Trotz seines organischen Charakters und damit der Anfälligkeit gegen Neutronenstrahlung kann als Basismaterial Kohlefasermaterial in Betracht gezogen werden. Kohlefasermaterial hat den besonderen Vorteil der galvanotechnischen Herstellbarkeit des Absorptionselementes.This results in a much greater effectiveness due to the high storage rates. The absorption layers are in the order of 350 to 500 μm, which is extremely thin. In addition, the independence of the process from the base material is a particular advantage. Inorganic base material, for example steel, titanium, copper, nickel and the like, is advantageously used. Despite its organic character and thus its susceptibility to neutron radiation, it can be used as a base material Carbon fiber material can be considered. Carbon fiber material has the particular advantage that the absorption element can be produced by electroplating.
Auch besteht erfindungsgemäß die Möglichkeit, das Abschirmelement in fertiggestelltem Zustand oder in Einzelteilen zu fertigen. Aufgrund der Unabhängigkeit vom Basismaterial können sehr einfach bearbeitbare Materialien verwendet werden. Andererseits lassen sich auch sehr komplizierte Formen von Abschirmelementen, Behälter, Körbe und dergleichen, vollständig vorfertigen und anschließend erfindungsgemäß beschichten.According to the invention, there is also the possibility of producing the shielding element in the finished state or in individual parts. Due to the independence from the base material, very easily editable materials can be used. On the other hand, very complicated shapes of shielding elements, containers, baskets and the like can also be completely prefabricated and then coated according to the invention.
Wegen der hohen Einbaurate ist die Abschirmung äußerst effektiv, so daß die Schichten extrem dünn sein können. Somit sind Gewichtseinsparungen um bis zu 80 % in bezug auf nach herkömmlichen Verfahren herstellbare Abschirmelemente möglich. Die derzeit im sogenannten Castor-Programm zur Brennelementlagerung verwendeten Lagerinnenbehälter (Körbe) von bisher 1 0 t lassen sich nach dem erfindungsgemäßen Verfahren nunmehr in Größenordnungen von 2,5 bis 3 t herstellen.Because of the high installation rate, the shielding is extremely effective, so that the layers can be extremely thin. Weight savings of up to 80% in relation to shielding elements which can be produced using conventional methods are thus possible. The internal storage containers (baskets) currently used in the so-called Castor program for fuel element storage of up to 1 0 t can now be produced in the order of 2.5 to 3 t using the method according to the invention.
Das Basismaterial kann als Fertigteil oder Einzelteil vorgefertigt werden, so daß aus den Einzelteilen fertige Abschirmelemente gebildet werden können. Die Beschichtung im Dispersionsbad erfolgt entweder chemisch oder elektrolytisch.The base material can be prefabricated as a finished part or individual part, so that finished shielding elements can be formed from the individual parts. The coating in the dispersion bath is either chemical or electrolytic.
Die Relativbewegung zwischen der zu beschichtenden Oberfläche und dem Dispersionsbad kann beispielsweise durch eine Bewegung des zu beschichtenden Elementes im Dispersionsbad erfolgen. Bekanntermaßen sind Elemente wie Bor so beschaffen, daß ein Umwälzen oder Umpumpen der Dispersion praktisch nicht wirtschaftlich möglich ist. Jegliches Umwälz- oder Umpumpaggregat würde in kürzester Zeit verschlissen sein. Dennoch soll durch die Relativbewegung einerseits eine weiterhin gute Durchmischung oder eine wiederholte Durchmischung der Dispersion erreicht werden, andererseits eine gerichtete Zuleitung der Dispersion auf die zu beschichtende Oberfläche. Neben der Bewegung des Elementes selbst kann auch die gesamte Beschichtungsanlage zum Zwecke der Erzeugung der Relativbewegung bewegt werden. So ist beispielsweise die Durchführung der Beschichtung in einer Art Trommel denkbar.The relative movement between the surface to be coated and the dispersion bath can take place, for example, by moving the element to be coated in the dispersion bath. As is known, elements such as boron are such that it is practically not economically feasible to circulate or pump around the dispersion. Any circulation or Pumping unit would be worn out in no time. Nevertheless, on the one hand, the relative movement is intended to ensure continued thorough mixing or repeated mixing of the dispersion, and on the other hand to direct the dispersion to the surface to be coated. In addition to the movement of the element itself, the entire coating system can also be moved for the purpose of generating the relative movement. For example, it is conceivable to carry out the coating in a kind of drum.
Mit besonderem Vorteil wird mit der Erfindung vorgeschlagen, daß die zu beschichtende Oberfläche in dem Dispersionsbad nach oben weisend angeordnet wird. Damit ist gemeint, daß die zu beschichtende Oberfläche derart im Dispersionsbad angeordnet wird, daß aufgrund der Schwerkraft die in der Dispersion befindlichen Partikel auf die Oberfläche absinken. Diese erfindungsgemäße Anordnungsweise, insbesondere in Kombination mit der zeitweisen Erzeugung einer Relativbewegung zwischen der Oberfläche und dem Dispersionsbad, begünstigt hervorragende Beschichtungsergebnisse.It is particularly advantageous with the invention that the surface to be coated is arranged in the dispersion bath facing upward. This means that the surface to be coated is arranged in the dispersion bath in such a way that the particles in the dispersion sink to the surface due to gravity. This arrangement according to the invention, in particular in combination with the temporary generation of a relative movement between the surface and the dispersion bath, favors excellent coating results.
Mit besonderem Vorteil wird mit der Erfindung vorgeschlagen, daß das Beschichtungsverfahren in einer Glaswanne durchgeführt wird. Hierdurch wird eine besondere Reinheit des Dispersionsbades gewährleistet.It is particularly advantageous with the invention that the coating process be carried out in a glass tub. This ensures that the dispersion bath is particularly clean.
Mit der Erfindung wird ein einfach durchführbares, wirtschaftliches und sehr effektives Verfahren zur Herstellung von Abschirmelementen zur Neutronenabsorption angegeben, welches insbesondere basismaterialunabhängig Abschirmelemente herstellbar macht, die bei vergleichbaren Absorptionswirkungen erheblich leichter sind als bekannte Abschirmelemente. Die Erfindung betrifft darüber hinaus nach dem beschriebenen Verfahren hergestellte Abschirmelemente. Diese sind gekennzeichnet dadurch, daß sie eine Bor-/Nickel-Beschichtung aufweisen mit einem Anteil an Bor in Elementarform oder Borcarbid größer 20 Vol.-% beziehungsweise um 40 Vol.- %. Die Schichtdicke liegt bei 350 bis 500 μm, wobei die Schicht auf einem anorganischen Basismaterial wie Stahl, Titan, Kupfer oder dergleichen ausgebildet ist. Die Ausbildung erfolgt chemisch beziehungsweise elektrolytisch. Das Abschirmelement kann in fertiggestellter Form beschichtet worden sein oder aus einzelnen beschichteten Einzelteilen zusammengestellt sein.The invention provides an easy to carry out, economical and very effective method for producing shielding elements for neutron absorption, which in particular makes shielding elements independent of the base material that are considerably lighter than known shielding elements with comparable absorption effects. The invention also relates to shielding elements produced by the described method. These are characterized in that they have a boron / nickel coating with a proportion of boron in elemental form or boron carbide greater than 20% by volume or by 40% by volume. The layer thickness is 350 to 500 μm, the layer being formed on an inorganic base material such as steel, titanium, copper or the like. The training takes place chemically or electrolytically. The shielding element can have been coated in the finished form or can be composed of individual coated individual parts.
In einem Versuch wurden herkömmliche Stahlplatten in einem Nickel/Borcarbid-Dispersionsbad elektrolytisch beschichtet. Dabei wurden die Platten alle halbe Stunde in dem Bad gewendet und zeitweise auf und nieder bewegt, um einerseits eine Relativbewegung zwischen den Oberflächen und dem Dispersionsbad zu erzeugen, andererseits die jeweils zu beschichtende Oberfläche nach oben weisend im Bad anzuordnen. Es konnte Borcarbid im Bereich von 40 Vol.-% in die Nickelmatrix eingebaut werden, wie anschließende Analysen ergaben. In an experiment, conventional steel plates were electrolytically coated in a nickel / boron carbide dispersion bath. The plates were turned every half hour in the bath and occasionally moved up and down in order to create a relative movement between the surfaces and the dispersion bath on the one hand, and to arrange the surface to be coated facing upwards in the bath on the other. Boron carbide in the range of 40% by volume could be incorporated into the nickel matrix, as subsequent analyzes showed.
Claims
Priority Applications (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CZ19994539A CZ291292B6 (en) | 1997-06-24 | 1997-06-24 | Process for producing a coating for absorbing neutrons |
| DE59712320T DE59712320D1 (en) | 1997-06-24 | 1997-06-24 | METHOD FOR PRODUCING A COATING FOR ABSORPTION OF NEUTRONS |
| PCT/EP1997/003309 WO1998059344A1 (en) | 1997-06-24 | 1997-06-24 | Process for producing a neutron-absorbing coating |
| EP97930391A EP0996953B1 (en) | 1997-06-24 | 1997-06-24 | Process for producing a neutron-absorbing coating |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| PCT/EP1997/003309 WO1998059344A1 (en) | 1997-06-24 | 1997-06-24 | Process for producing a neutron-absorbing coating |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| WO1998059344A1 true WO1998059344A1 (en) | 1998-12-30 |
Family
ID=8166669
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| PCT/EP1997/003309 Ceased WO1998059344A1 (en) | 1997-06-24 | 1997-06-24 | Process for producing a neutron-absorbing coating |
Country Status (4)
| Country | Link |
|---|---|
| EP (1) | EP0996953B1 (en) |
| CZ (1) | CZ291292B6 (en) |
| DE (1) | DE59712320D1 (en) |
| WO (1) | WO1998059344A1 (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1087408A1 (en) * | 1999-09-27 | 2001-03-28 | Metallveredlung GmbH & Co. KG | Process for producing a neutron-absorbing coating |
| US6389093B1 (en) | 1999-06-19 | 2002-05-14 | Gnb Gesellschaft Fur Nuklear-Behalter Mbh | Storage/transport container for spent nuclear-fuel elements |
| RU2232438C2 (en) * | 1999-09-27 | 2004-07-10 | Металлферэдлунг Гмбх Унд Ко. Кг | Method for producing coat absorbing neutrons resulting from reaction of radioactive materials |
| DE102011108990A1 (en) * | 2011-08-01 | 2013-02-07 | Dieter Methling | Fuel element storage rack for container, has receiving slots, neutron-absorbing metal alloy of structural elements, and coating containing boron, gadolinium , cadmium, samarium, europium or dysprosium, coated on structural elements |
| US12051516B1 (en) * | 2020-09-01 | 2024-07-30 | GeoPlasma, LLC | Method of manufacturing advanced composites and coatings for radiation environment shielding |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4238299A (en) * | 1979-08-24 | 1980-12-09 | Kennecott Copper Corporation | Tubing with copper-boron carbide composite facing and methods for its production |
| EP0055679A2 (en) * | 1980-12-31 | 1982-07-07 | Framatome | Container for under water storage of irradiated fuel assemblies, and method to realize such a container |
| 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 |
-
1997
- 1997-06-24 DE DE59712320T patent/DE59712320D1/en not_active Expired - Lifetime
- 1997-06-24 EP EP97930391A patent/EP0996953B1/en not_active Expired - Lifetime
- 1997-06-24 CZ CZ19994539A patent/CZ291292B6/en not_active IP Right Cessation
- 1997-06-24 WO PCT/EP1997/003309 patent/WO1998059344A1/en not_active Ceased
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4238299A (en) * | 1979-08-24 | 1980-12-09 | Kennecott Copper Corporation | Tubing with copper-boron carbide composite facing and methods for its production |
| EP0055679A2 (en) * | 1980-12-31 | 1982-07-07 | Framatome | Container for under water storage of irradiated fuel assemblies, and method to realize such a container |
| 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 |
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6389093B1 (en) | 1999-06-19 | 2002-05-14 | Gnb Gesellschaft Fur Nuklear-Behalter Mbh | Storage/transport container for spent nuclear-fuel elements |
| 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 |
| RU2232438C2 (en) * | 1999-09-27 | 2004-07-10 | Металлферэдлунг Гмбх Унд Ко. Кг | Method for producing coat absorbing neutrons resulting from reaction of radioactive materials |
| CZ297053B6 (en) * | 1999-09-27 | 2006-08-16 | Metallveredlung Gmbh & Co. Kg | Method for producing a coating for absorption of neutrons produced in nuclear reactions of radioactive materials |
| US7295646B1 (en) | 1999-09-27 | 2007-11-13 | Metallveredlung Gmbh & Co. Kg | Method for producing a coating for absorption of neutrons produced in nuclear reactions of radioactive materials |
| DE102011108990A1 (en) * | 2011-08-01 | 2013-02-07 | Dieter Methling | Fuel element storage rack for container, has receiving slots, neutron-absorbing metal alloy of structural elements, and coating containing boron, gadolinium , cadmium, samarium, europium or dysprosium, coated on structural elements |
| US12051516B1 (en) * | 2020-09-01 | 2024-07-30 | GeoPlasma, LLC | Method of manufacturing advanced composites and coatings for radiation environment shielding |
| US12283385B1 (en) | 2020-09-01 | 2025-04-22 | GeoPlasma, LLC | Advanced composites and coatings for radiation environment shielding |
Also Published As
| Publication number | Publication date |
|---|---|
| CZ291292B6 (en) | 2003-01-15 |
| DE59712320D1 (en) | 2005-06-23 |
| EP0996953B1 (en) | 2005-05-18 |
| CZ453999A3 (en) | 2000-04-12 |
| EP0996953A1 (en) | 2000-05-03 |
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