WO1997035324A1 - Method for preparing highly radioactive materials for transmutation and/or burn-up - Google Patents

Method for preparing highly radioactive materials for transmutation and/or burn-up Download PDF

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Publication number
WO1997035324A1
WO1997035324A1 PCT/EP1997/001214 EP9701214W WO9735324A1 WO 1997035324 A1 WO1997035324 A1 WO 1997035324A1 EP 9701214 W EP9701214 W EP 9701214W WO 9735324 A1 WO9735324 A1 WO 9735324A1
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WIPO (PCT)
Prior art keywords
impregnation
substances
pellets
liquid
carrier material
Prior art date
Application number
PCT/EP1997/001214
Other languages
German (de)
French (fr)
Inventor
Claude Fuchs
Serge Fourcaudot
Karl Richter
Joseph Somers
Original Assignee
Europäische Atomgemeinschaft (Euratom)
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Europäische Atomgemeinschaft (Euratom) filed Critical Europäische Atomgemeinschaft (Euratom)
Priority to EP97908208A priority Critical patent/EP0888623B1/en
Priority to DE59703801T priority patent/DE59703801D1/en
Priority to JP9533110A priority patent/JP2000506976A/en
Priority to AT97908208T priority patent/ATE202235T1/en
Priority to DK97908208T priority patent/DK0888623T3/en
Publication of WO1997035324A1 publication Critical patent/WO1997035324A1/en
Priority to GR20010401450T priority patent/GR3036593T3/en

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Classifications

    • 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
    • G21F9/04—Treating liquids
    • G21F9/06—Processing
    • G21F9/14—Processing by incineration; by calcination, e.g. desiccation
    • 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
    • G21F9/30—Processing
    • G21F9/32—Processing by incineration

Definitions

  • the invention relates to a method for preparing highly radioactive substances for transmutation and / or combustion by irradiation in a nuclear facility.
  • the transmutation and combustion of highly radioactive substances are used in particular in the context of nuclear disposal.
  • radioactive substances with a significantly reduced half-life which lose their radiological danger in manageable periods, or substances with less radiologically dangerous radiation are produced.
  • the object of the invention is therefore to specify a method in which no or hardly any toxic dust is produced and a very homogeneous distribution of the highly radioactive substances is achieved, so that hot spots during the Radiation can be avoided.
  • the mechanical stability of the pellets in order to ensure their integrity during the entire irradiation.
  • This can be achieved in that the core of the pellets remains free from the highly radioactive substances by means of a suitable time limitation of the impregnation process and the mechanical stability of the pellet is thus maintained. It may also be useful to leave out a part of the surface of the pellets during the impregnation, so that the core located in the center of the pellet does not generate any splitting heat during irradiation, which increases the mechanical stability. This can be done either by only partially immersing the pellets in the soaking liquid or by partially providing them with a layer impermeable to the soaking liquid before soaking.
  • Powders, granulate particles or microspheres can be used as the porous carrier material, such as, for example, oxides of uranium, plutonium, thorium, yttrium, cerium and mixtures of these and other oxides, for example spinel and YAG (yttrium aluminum garnet).
  • oxides of uranium, plutonium, thorium, yttrium, cerium for example spinel and YAG (yttrium aluminum garnet).
  • spinel and YAG yttrium aluminum garnet
  • the various isotopes of plutonium, americium, neptunium, curium and other actinides and fission products, for example technetium, are suitable as substances to be transmuted and burned. These substances are brought into liquid form either by melting or by chemical dissolving in a suitable solvent.
  • the carrier material must be sufficiently porous to be soaked with this liquid substance. In addition, this carrier material must not essentially be dissolved during the impregnation with the liquid substance.
  • the mechanical shape of the carrier material depends on the desired degree of impregnation. Powders and granules come into question which have arisen from precipitation or conversion processes, microspheres which have been produced by a so-called drop to particle conversion process (sol-gel), or moldings which have been compacted from powders, granules or microspheres . Is the backing material in the form of
  • Powders, granules or microspheres then this material is brought into the desired shape after impregnation by mechanical pressure or vibration.
  • pellets are pressed and prebaked from the carrier material in powder form before the impregnation.
  • Such pellets have a porosity of about 40% and can easily be soaked. In the simplest case, they are immersed in a melt or solution of the highly radioactive substance. You place them on a grid in a defined position and slowly immerse them in the liquid. The impregnation rate depends on the dimension of the pores, the viscosity and surface tension of the liquid, the wettability of the pellet material and the duration of the impregnation. If you value a very homogeneous distribution of the Liquid in the pellet can then interfere with gas bubbles trapped in the pellet, leaving unimpregnated zones. This problem can be solved by creating a negative pressure in the impregnation container before the impregnation liquid is supplied and suctioning off such gas bubbles.
  • the impregnation only reach the outer layer of the pellets. This can be achieved by a suitable choice of the impregnation period, so that the impregnation only reaches a certain depth in the pellets.
  • a protective layer impermeable to the liquid can also be applied to part of the surface of the pellet in order to prevent the liquid from penetrating at this point and thus to obtain a central cylindrical core in the pellets which cannot be reached by the impregnation. This has the advantage that fission energy when the highly radioactive substances are irradiated in the nuclear plant preferably occurs as heat on the pellet surface and can be easily dissipated, while the solid core of the pellet prevents it from decaying.
  • the highly radioactive substance present in liquid form in the pellet can be converted into a desired form (for example oxide, nitride or carbide) by heat treatment, after which sintering can take place.
  • the carrier material can, as mentioned, consist of microspheres which are produced, for example, by the sol-gel process. Because of their high porosity (about 80%), they are particularly suitable when very intensive impregnation is desired. So you can fill a cylindrical column with the microspheres and then add a nitrate solution of the highly radioactive substance. The dimensions of the column are chosen so that no critical conditions arise. After the impregnation has ended, the remaining nitrate solution of the radioactive substance is pumped back into a storage tank.
  • the one in the beads remaining part of this substance is then converted into an oxide, nitride or carbide. This conversion takes place in a suitable atmosphere in commercially available ovens or with the aid of microwaves.
  • the beads are then pressed into the shape desired for radiation in the nuclear facility.
  • the soaking of the beads and their subsequent pressing into the pellet form can take place completely automatically, so that the workers are not endangered by additional radiation. This process also does not create dust from highly toxic substances.
  • the method is well suited for a remote-controlled and largely automatic sequence.

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • General Engineering & Computer Science (AREA)
  • High Energy & Nuclear Physics (AREA)
  • Environmental & Geological Engineering (AREA)
  • Solid-Sorbent Or Filter-Aiding Compositions (AREA)
  • Compositions Of Oxide Ceramics (AREA)
  • Physical Or Chemical Processes And Apparatus (AREA)
  • Saccharide Compounds (AREA)
  • Agricultural Chemicals And Associated Chemicals (AREA)
  • Compounds Of Alkaline-Earth Elements, Aluminum Or Rare-Earth Metals (AREA)
  • Medicines Containing Material From Animals Or Micro-Organisms (AREA)

Abstract

The invention concerns a method of preparing highly radioactive materials for transmutation and/or burn-up by irradiation in a nuclear plant. The invention proposes that the materials are first converted into liquid form by melting or chemical dissolution and a porous carrier material which is essentially insoluble in the liquefied materials is impregnated with the liquefied materials and then heated in such a way that the materials are converted into the finally required chemical form and density.

Description

VERFAHREN ZUR VORBEREITUNG VON HOCHRADIOAKTIVEN STOFFEN FÜR EINE TRANSMUTATION UND/ODER VERBRENNUNG METHOD FOR PREPARING HIGH RADIOACTIVE SUBSTANCES FOR TRANSMUTATION AND / OR BURNING
Die Erfindung bezieht sich auf ein Verfahren zur Vorbereitung von hochradioaktiven Stoffen für eine Transmu¬ tation und/oder Verbrennung durch Bestrahlung in einer Nu¬ klearanlage. Die Transmutation und Verbrennung von hochradioakti¬ ven Stoffen werden insbesondere im Rahmen der nuklearen Ent¬ sorgung eingesetzt. Als Ergebnis der Transmutation und Ver¬ brennung werden radioaktive Stoffe mit deutlich verringerter Halbwertzeit, die ihre radiologische Gefährlichkeit in über- schaubaren Zeiträumen verlieren, oder Stoffe mit geringerer radiologisch gefährlicher Strahlung erzeugt.The invention relates to a method for preparing highly radioactive substances for transmutation and / or combustion by irradiation in a nuclear facility. The transmutation and combustion of highly radioactive substances are used in particular in the context of nuclear disposal. As a result of the transmutation and combustion, radioactive substances with a significantly reduced half-life, which lose their radiological danger in manageable periods, or substances with less radiologically dangerous radiation are produced.
Es wäre nun möglich, ähnlich den Prozessen bei der Herstellung von Kernbrennstoffen die zu transmutierenden oder zu verbrennenden Stoffe in Pulverform zu bringen, mit inaktiven Pulvern zu vermischen, zu Tabletten (Pellets, Tar¬ gets) zu verpressen und in Hüllrohre zu verschweißen, die dann zur Transmutation oder Verbrennung in eine Nuklearanla¬ ge eingesetzt werden. Bei diesem Verfahren entsteht jedoch ein radiologisch hochgiftiger Staub, der sich in den heißen Zellen oder Handschuhkästen niederschlägt und eine zusätzli¬ che Strahlenbelastung für die in diesem Bereich tätigen Be¬ schäftigten darstellt. Außerdem besteht die Gefahr einer unvollkommenen Vermischung der Pulver und damit von Hei߬ punkten bei der anschließenden Bestrahlung in der Nuklear- anläge, die zu einem vorzeitigen Abbruch des Transmutations- bzw. Verbrennungsvorgangs zwingen können.It would now be possible, similar to the processes in the production of nuclear fuels, to bring the materials to be transmuted or burned in powder form, to mix them with inactive powders, to compress them into tablets (pellets, targets) and to weld them in cladding tubes, which then be used for transmutation or combustion in a nuclear plant. With this method, however, a radiologically highly toxic dust is formed which is deposited in the hot cells or glove boxes and represents an additional radiation exposure for the employees working in this area. There is also the risk of incomplete mixing of the powders and thus of hot spots during the subsequent irradiation in the nuclear plant, which can force the transmutation or combustion process to be terminated prematurely.
Aufgabe der Erfindung ist es daher, ein Verfahren anzugeben, bei dem gar kein oder kaum ein giftiger Staub entsteht und eine sehr homogene Verteilung der hochradioak- tiven Stoffe erreicht wird, so daß Heißpunkte bei der Be- Strahlung vermieden werden.The object of the invention is therefore to specify a method in which no or hardly any toxic dust is produced and a very homogeneous distribution of the highly radioactive substances is achieved, so that hot spots during the Radiation can be avoided.
Diese Aufgabe wird erfindungsgemäß durch ein Verfah¬ ren gelöst, wie es im Anspruch 1 definiert ist und im we¬ sentlichen darin besteht, ein geeignetes poröses Trägermate- rial mit den in flüssige Form gebrachten hochradioaktiven Stoffen zu tränken. Wenn das Trägermaterial pulver- oder partikelförmig vorliegt, wird es vorzugsweise nach der Trän¬ kung zu Pellets gepreßt. Liegt dagegen das Trägermaterial bereits in Pelletform vor der Tränkung vor, dann ist es gün- stig, dieses vor der Tränkung zu entgasen, um eine gleichmä¬ ßige Verteilung des radioaktiven Materials im Trägermaterial zu erleichtern.This object is achieved according to the invention by a method as defined in claim 1 and which consists essentially in impregnating a suitable porous carrier material with the highly radioactive substances brought into liquid form. If the carrier material is in powder or particle form, it is preferably pressed into pellets after impregnation. If, on the other hand, the carrier material is already in pellet form before the impregnation, it is advantageous to degas it before the impregnation in order to facilitate a uniform distribution of the radioactive material in the carrier material.
In manchen Anwendungen ist es wichtig, die mechani¬ sche Stabilität der Pellets zu verbessern, um deren Integri- tat während der ganzen Bestrahlung zu gewährleisten. Dies kann dadurch erreicht werden, daß der Kern der Pellets durch geeignete zeitliche Beschränkung des Tränkungsprozesses von den hochradioaktiven Stoffen freibleibt und damit die mecha¬ nische Stabilität des Pellets erhalten bleibt. Weiter kann es sinnvoll sein, einen Teil der Ober¬ fläche der Pellets beim Tränken auszusparen, so daß bei der Bestrahlung der im Zentrum des Pellets befindliche Kern kei¬ ne Spaltungswärme erzeugt, was die mechanische Stabilität erhöht. Dies kann geschehen, indem entweder die Pellets nur teilweise in die Tränkflüssigkeit eingetaucht werden oder indem sie vor dem Tränken teilweise mit einer für die Tränk- flüssigkeit undurchlässigen Schicht versehen werden.In some applications it is important to improve the mechanical stability of the pellets in order to ensure their integrity during the entire irradiation. This can be achieved in that the core of the pellets remains free from the highly radioactive substances by means of a suitable time limitation of the impregnation process and the mechanical stability of the pellet is thus maintained. It may also be useful to leave out a part of the surface of the pellets during the impregnation, so that the core located in the center of the pellet does not generate any splitting heat during irradiation, which increases the mechanical stability. This can be done either by only partially immersing the pellets in the soaking liquid or by partially providing them with a layer impermeable to the soaking liquid before soaking.
Die Erfindung wird nun anhand einiger bevorzugter Ausführungsbeispiele näher erläutert. Als poröses Trägermaterial können Pulver, Granulatp¬ artikel oder Mikrokügelchen verwendet werden, wie beispiels¬ weise Oxide von Uranium, Plutonium, Thorium, Yttrium, Cer und Mischungen dieser und anderer Oxide, z.B. Spinell und YAG (Yttrium Aluminium Granat). Diese Liste ist jedoch kei- neswegs erschöpfend und hängt von der Art der zu transmutie- renden oder zu verbrennenden Stoffe ab. Auch Karbide und Nitride der erwähnten und anderer Elemente kommen ggf. in Frage. Als zu transmutierende und zu verbrennende Stoffe kommen die verschiedenen Isotope von Plutonium, Americium, Neptunium, Curium und andere Actiniden sowie Spaltprodukte, z.B. Technetium, in Frage. Diese Stoffe werden entweder durch Schmelzen oder durch chemisches Lösen in einem geeig¬ neten Lösungsmittel in flüssige Form gebracht.The invention will now be explained in more detail with the aid of some preferred exemplary embodiments. Powders, granulate particles or microspheres can be used as the porous carrier material, such as, for example, oxides of uranium, plutonium, thorium, yttrium, cerium and mixtures of these and other oxides, for example spinel and YAG (yttrium aluminum garnet). However, this list is by no means exhaustive and depends on the type of transmutated rendering or burning substances. Carbides and nitrides of the mentioned and other elements may also be considered. The various isotopes of plutonium, americium, neptunium, curium and other actinides and fission products, for example technetium, are suitable as substances to be transmuted and burned. These substances are brought into liquid form either by melting or by chemical dissolving in a suitable solvent.
Das Trägermaterial muß ausreichend porös sein, um durch diesen flüssigen Stoff getränkt werden zu können. Au¬ ßerdem darf dieses Trägermaterial bei der Tränkung durch den flüssigen Stoff im wesentlichen nicht gelöst werden. Die mechanische Form des Trägermaterials hängt von dem gewünsch¬ ten Tränkungsgrad ab. Es kommen Pulver und Granulate in Fra- ge, die durch Ausfällung oder Umwandlungsprozesse entstanden sind, Mikrokügelchen, die durch ein sogenanntes Tropfen zu Partikel Konversionsverfahren (Sol-Gel) hergestellt wurden, oder Formlinge, die aus Pulvern, Granulaten oder Mikrokügel¬ chen verdichtet wurden. Liegt das Trägermaterial bei der Tränkung in Form vonThe carrier material must be sufficiently porous to be soaked with this liquid substance. In addition, this carrier material must not essentially be dissolved during the impregnation with the liquid substance. The mechanical shape of the carrier material depends on the desired degree of impregnation. Powders and granules come into question which have arisen from precipitation or conversion processes, microspheres which have been produced by a so-called drop to particle conversion process (sol-gel), or moldings which have been compacted from powders, granules or microspheres . Is the backing material in the form of
Pulvern, Granulaten oder Mikrokügelchen vor, dann wird die¬ ses Material nach der Tränkung durch mechanischen Druck oder Vibration in die gewünschte Form gebracht.Powders, granules or microspheres, then this material is brought into the desired shape after impregnation by mechanical pressure or vibration.
In einer möglichen Ausführungsform werden vor der Tränkung aus dem Trägermaterial in Pulverform Pellets ge¬ preßt und vorgebrannt. Solche Pellets besitzen eine Porosi¬ tät von etwa 40% und können einfach getränkt werden. Im ein¬ fachsten Fall werden sie in eine Schmelze oder Lösung des hochradioaktiven Stoffs eingetaucht. Dabei legt man sie in einer definierten Lage auf ein Gitter und taucht dieses langsam in die Flüssigkeit. Die Tränkungsrate hängt von der Dimension der Poren, der Viskosität und Oberflächenspannung der Flüssigkeit, der Benetzbarkeit des Pelletmaterials und der Tränkungsdauer ab. Legt man Wert auf eine sehr homogene Verteilung der Flüssigkeit in dem Pellet, dann können Gasblasen stören, die in dem Pellet eingeschlossen sind, so daß ungetränkte Zonen verbleiben. Dieses Problem kann gelöst werden, indem man vor der Zufuhr der Tränkflüssigkeit in dem Tränkbehälter einen Unterdruck herstellt, und solche Gasblasen absaugt.In one possible embodiment, pellets are pressed and prebaked from the carrier material in powder form before the impregnation. Such pellets have a porosity of about 40% and can easily be soaked. In the simplest case, they are immersed in a melt or solution of the highly radioactive substance. You place them on a grid in a defined position and slowly immerse them in the liquid. The impregnation rate depends on the dimension of the pores, the viscosity and surface tension of the liquid, the wettability of the pellet material and the duration of the impregnation. If you value a very homogeneous distribution of the Liquid in the pellet can then interfere with gas bubbles trapped in the pellet, leaving unimpregnated zones. This problem can be solved by creating a negative pressure in the impregnation container before the impregnation liquid is supplied and suctioning off such gas bubbles.
In manchen Anwendungen ist es jedoch erwünscht, daß die Tränkung nur die äußere Schicht der Pellets erreicht. Dies kann erreicht werden durch eine geeignete Wahl der Tränkungsdauer, so daß die Tränkung nur bis zu einer be- stimmten Tiefe in die Pellets reicht. Man kann auch eine für die Flüssigkeit undurchlässige Schutzschicht auf einen Teil der Oberfläche des Pellets aufbringen, um an dieser Stelle das Eindringen der Flüssigkeit zu verhindern und damit einen durch die Tränkung nicht erreichbaren zentralen zylindri- sehen Kern in den Pellets zu erhalten. Dies hat den Vorteil, daß Spaltenergie bei der Bestrahlung der hochradioaktiven Stoffe in der Nuklearanlage bevorzugt an der Pelletoberflä¬ che als Wärme auftritt und leicht abgeführt werden kann, während der feste Kern des Pellets verhindert, daß dieses zerfällt.In some applications, however, it is desirable that the impregnation only reach the outer layer of the pellets. This can be achieved by a suitable choice of the impregnation period, so that the impregnation only reaches a certain depth in the pellets. A protective layer impermeable to the liquid can also be applied to part of the surface of the pellet in order to prevent the liquid from penetrating at this point and thus to obtain a central cylindrical core in the pellets which cannot be reached by the impregnation. This has the advantage that fission energy when the highly radioactive substances are irradiated in the nuclear plant preferably occurs as heat on the pellet surface and can be easily dissipated, while the solid core of the pellet prevents it from decaying.
Nach dem Tränken kann der in flüssiger Form im Pellet vorliegende hochradioaktive Stoff durch eine Wärmebehandlung in eine gewünschte Form (z.B. Oxid, Nitrid oder Karbid) um¬ gewandelt werden, worauf eine Sinterung erfolgen kann. In einer anderen Ausführungsform kann das Trägermate¬ rial wie erwähnt aus Mikrokügelchen bestehen, die z.B. nach dem Sol-Gel-Verfahren hergestellt sind. Wegen ihrer hohen Porosität (etwa 80%) eignen sie sich besonders gut, wenn eine sehr intensive Tränkung gewünscht ist. So kann man eine zylindrische Säule mit den Mikrokügelchen füllen und dann eine Nitratlösung des hochradioaktiven Stoffes zugeben. Die Abmessungen der Säule werden so gewählt, daß keine kriti¬ schen Bedingungen entstehen. Nach Beendigung der Tränkung wird die verbleibende Nitratlösung des radioaktiven Stoffs in einen Speichertank zurückgepumpt. Der in den Kügelchen verbleibende Teil dieses Stoffes wird dann in ein Oxid, Nitrid oder Karbid verwandelt. Diese Umwandlung erfolgt unter geeigneter Atmosphäre in handelsüblichen Öfen oder mit Hilfe von Mikrowellen. Danach werden die Kügelchen in die für die Bestrahlung in der Nuklearanlage gewünschte Form gepreßt.After the impregnation, the highly radioactive substance present in liquid form in the pellet can be converted into a desired form (for example oxide, nitride or carbide) by heat treatment, after which sintering can take place. In another embodiment, the carrier material can, as mentioned, consist of microspheres which are produced, for example, by the sol-gel process. Because of their high porosity (about 80%), they are particularly suitable when very intensive impregnation is desired. So you can fill a cylindrical column with the microspheres and then add a nitrate solution of the highly radioactive substance. The dimensions of the column are chosen so that no critical conditions arise. After the impregnation has ended, the remaining nitrate solution of the radioactive substance is pumped back into a storage tank. The one in the beads remaining part of this substance is then converted into an oxide, nitride or carbide. This conversion takes place in a suitable atmosphere in commercially available ovens or with the aid of microwaves. The beads are then pressed into the shape desired for radiation in the nuclear facility.
Das Tränken der Kügelchen und deren anschließendes Pressen in die Pelletform können völlig automatisch erfol¬ gen, so daß die Beschäftigten nicht durch zusätzliche Strah- lung gefährdet werden. Auch entsteht bei diesem Verfahren kein Staub von hochgiftigen Stoffen.The soaking of the beads and their subsequent pressing into the pellet form can take place completely automatically, so that the workers are not endangered by additional radiation. This process also does not create dust from highly toxic substances.
Anstelle des Tränkens der Kügelchen in einer Säule kann man auch die Kügelchen in einem Korb in die Flüssigkeit eintauchen oder man kann die Kügelchen bewegen oder umrühren und zugleich mit dem flüssigen Stoff besprühen.Instead of soaking the beads in a column, you can also immerse the beads in a basket in the liquid or you can move or stir the beads and at the same time spray with the liquid substance.
Die entscheidenden Vorteile des erfindungsgemäßen Verfahrens sind folgende:The decisive advantages of the method according to the invention are as follows:
1 - Beschränkung der Verfahrensschritte, bei denen hochradioaktive Stoffe eingesetzt werden, auf die Verflüssi- gung und auf die Tränkung.1 - Limitation of the process steps in which highly radioactive substances are used to liquefaction and impregnation.
2 - Das Verfahren eignet sich gut für einen fernge¬ steuerten und weitgehend automatischen Ablauf.2 - The method is well suited for a remote-controlled and largely automatic sequence.
3 - Es entsteht kaum giftiger Staub oder radioaktiver Abfall. 4 - Die Strahlungsbelastung der Beschäftigten wird erheblich verringert. 3 - There is hardly any toxic dust or radioactive waste. 4 - The radiation exposure of employees is significantly reduced.

Claims

ANSPRÜCHE EXPECTATIONS
1. Verfahren zur Vorbereitung von hochradioaktiven Stoffen für eine Transmutation und/oder Verbrennung durch Bestrah¬ lung in einer Nuklearanlage, dadurch gekennzeichnet, daß die Stoffe durch Schmelzen oder chemische Auflösung in flüssige Form gebracht werden, daß ein poröses Trägermaterial, das für die Stoffe in der flüssigen Form praktisch unlöslich ist, mit den in flüssige Form gebrachten Stoffen getränkt und dann einer solchen Wärmebehandlung unterworfen wird, daß die Stoffe in die letztlich gewünschte chemische Form umge¬ wandelt werden.1. A process for the preparation of highly radioactive substances for transmutation and / or combustion by irradiation in a nuclear facility, characterized in that the substances are brought into liquid form by melting or chemical dissolution that a porous carrier material which is responsible for the substances in the liquid form is practically insoluble, impregnated with the substances brought into the liquid form and then subjected to such a heat treatment that the substances are converted into the chemical form ultimately desired.
2. Verfahren nach Anspruch 1, dadurch gekennzeichnet, daß das Trägermaterial pulver- oder partikelförmig ist und daß es nach der Tränkung und der Wärmebehandlung durch mechani¬ schen Druck oder Vibration in die gewünschte Form gebracht wird.2. The method according to claim 1, characterized in that the carrier material is powder or particulate and that it is brought into the desired shape after the impregnation and the heat treatment by mechanical pressure or vibration.
3. Verfahren nach Anspruch 1, dadurch gekennzeichnet, daß das Trägermaterial bereits als Formung, z.B. Pellets, vor¬ liegt.3. The method according to claim 1, characterized in that the carrier material already as a molding, e.g. Pellets.
4. Verfahren nach Anspruch 3, dadurch gekennzeichnet, daß der Formung vor und während des Tränkvorgangs zusätzlich entgast wird.4. The method according to claim 3, characterized in that the molding is additionally degassed before and during the impregnation process.
5. Verfahren nach Anspruch 3, dadurch gekennzeichnet, daß die Tränkung zeitlich so beschränkt wird, daß der Kern der Pellets von der Tränkflüssigkeit freibleibt.5. The method according to claim 3, characterized in that the impregnation is limited in time so that the core of the pellets remains free of the impregnating liquid.
6. Verfahren nach Anspruch 3, dadurch gekennzeichnet, daß die Pellets beim Tränken nur teilweise in die Tränkflüssig- keit eingetaucht werden.6. The method according to claim 3, characterized in that the pellets are only partially soaked in the soaking liquid. be immersed.
7. Verfahren nach Anspruch 3, dadurch gekennzeichnet, daß die Pellets vor dem Tränken teilweise mit einer für die Tränkflüssigkeit undurchlässigen Schicht versehen werden.7. The method according to claim 3, characterized in that the pellets are partially provided with a layer impermeable to the impregnating liquid before the impregnation.
8. Verfahren nach einem der Ansprüche 1 bis 7, dadurch ge¬ kennzeichnet, daß abschließend eine Wärmebehandlung (Sinte¬ rung) erfolgt. 8. The method according to any one of claims 1 to 7, characterized in that finally a heat treatment (sintering) takes place.
PCT/EP1997/001214 1996-03-19 1997-03-10 Method for preparing highly radioactive materials for transmutation and/or burn-up WO1997035324A1 (en)

Priority Applications (6)

Application Number Priority Date Filing Date Title
EP97908208A EP0888623B1 (en) 1996-03-19 1997-03-10 Method for preparing highly radioactive materials for transmutation and/or burn-up
DE59703801T DE59703801D1 (en) 1996-03-19 1997-03-10 METHOD FOR PREPARING HIGH RADIOACTIVE SUBSTANCES FOR TRANSMUTATION AND / OR BURNING
JP9533110A JP2000506976A (en) 1996-03-19 1997-03-10 Preparation of highly radioactive materials for conversion and / or combustion
AT97908208T ATE202235T1 (en) 1996-03-19 1997-03-10 METHOD FOR PREPARING HIGHLY RADIOACTIVE SUBSTANCES FOR TRANSMUTATION AND/OR COMBUSTION
DK97908208T DK0888623T3 (en) 1996-03-19 1997-03-10 Process for the preparation of highly radioactive substances for transmutation and / or burnout
GR20010401450T GR3036593T3 (en) 1996-03-19 2001-09-11 Method for preparing highly radioactive materials for transmutation and/or burn-up

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
LU88727 1996-03-19
LU88727A LU88727A1 (en) 1996-03-19 1996-03-19 Process for the preparation of highly radioactive substances for transmutation and / or combustion

Publications (1)

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WO1997035324A1 true WO1997035324A1 (en) 1997-09-25

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PCT/EP1997/001214 WO1997035324A1 (en) 1996-03-19 1997-03-10 Method for preparing highly radioactive materials for transmutation and/or burn-up

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EP (1) EP0888623B1 (en)
JP (1) JP2000506976A (en)
AT (1) ATE202235T1 (en)
CA (1) CA2249347A1 (en)
DE (1) DE59703801D1 (en)
DK (1) DK0888623T3 (en)
ES (1) ES2159115T3 (en)
GR (1) GR3036593T3 (en)
LU (1) LU88727A1 (en)
PT (1) PT888623E (en)
WO (1) WO1997035324A1 (en)

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2262854A1 (en) * 1974-02-28 1975-09-26 Commissariat Energie Atomique
DE2438921A1 (en) * 1974-07-22 1976-02-26 Aerojet General Corp N D Ges D METHOD AND DEVICE FOR TREATMENT OF WASTE PRODUCTS OF LOW RADIOACTIVITY
EP0156562A2 (en) * 1984-03-07 1985-10-02 Ngk Insulators, Ltd. Liquid material drying method and apparatus
EP0185931A2 (en) * 1984-12-25 1986-07-02 Ebara Corporation Method and apparatus for processing waste matter

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2262854A1 (en) * 1974-02-28 1975-09-26 Commissariat Energie Atomique
DE2438921A1 (en) * 1974-07-22 1976-02-26 Aerojet General Corp N D Ges D METHOD AND DEVICE FOR TREATMENT OF WASTE PRODUCTS OF LOW RADIOACTIVITY
EP0156562A2 (en) * 1984-03-07 1985-10-02 Ngk Insulators, Ltd. Liquid material drying method and apparatus
EP0185931A2 (en) * 1984-12-25 1986-07-02 Ebara Corporation Method and apparatus for processing waste matter

Also Published As

Publication number Publication date
LU88727A1 (en) 1997-09-19
PT888623E (en) 2001-10-31
DE59703801D1 (en) 2001-07-19
ATE202235T1 (en) 2001-06-15
DK0888623T3 (en) 2001-09-03
CA2249347A1 (en) 1997-09-25
EP0888623A1 (en) 1999-01-07
JP2000506976A (en) 2000-06-06
GR3036593T3 (en) 2001-12-31
EP0888623B1 (en) 2001-06-13
ES2159115T3 (en) 2001-09-16

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