EP0273182A1 - Method of cleaning a container - Google Patents

Method of cleaning a container Download PDF

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Publication number
EP0273182A1
EP0273182A1 EP87117112A EP87117112A EP0273182A1 EP 0273182 A1 EP0273182 A1 EP 0273182A1 EP 87117112 A EP87117112 A EP 87117112A EP 87117112 A EP87117112 A EP 87117112A EP 0273182 A1 EP0273182 A1 EP 0273182A1
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EP
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Prior art keywords
container
cleaning
dissolved
hydrazine
agent
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EP87117112A
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German (de)
French (fr)
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EP0273182B1 (en
Inventor
Klaus Kuhnke
Alexander Dr. Langner
Klaus Dipl.-Chem. Pflugbeil
Kurt Dipl.-Ing. Schindler
Dorothea Dipl.-Ing. Moldenhauer
Siegfried Dr. Köhler
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Siemens AG
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Siemens AG
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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B08—CLEANING
    • B08B—CLEANING IN GENERAL; PREVENTION OF FOULING IN GENERAL
    • B08B3/00—Cleaning by methods involving the use or presence of liquid or steam
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23G—CLEANING OR DE-GREASING OF METALLIC MATERIAL BY CHEMICAL METHODS OTHER THAN ELECTROLYSIS
    • C23G1/00—Cleaning or pickling metallic material with solutions or molten salts
    • C23G1/14—Cleaning or pickling metallic material with solutions or molten salts with alkaline solutions
    • C23G1/19—Iron or steel
    • 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
    • G21F9/001—Decontamination of contaminated objects, apparatus, clothes, food; Preventing contamination thereof

Definitions

  • the invention relates to a method for cleaning a container, in particular a steam generator in a nuclear power plant, wherein iron oxide located in the container is dissolved by a complexing acid.
  • the materials of the container and especially the materials of the supply lines are exposed to a high risk.
  • the acid attacks the metal surfaces of the tanks and pipes. If the work is carried out in the neutral range, however, the cleaning process is only slightly effective.
  • a multi-stage process the so-called Mark III process, is also known, which is carried out alternately in the acidic and in the neutral range. This complex cleaning process takes a lot of time and causes very high costs.
  • the invention is therefore based on the object of developing a method for cleaning a container, in particular a steam generator, which, with very good effectiveness, minimizes attacks by the cleaning chemicals on the materials of the container and the lines.
  • a dissolved salt which consists of an acid acting as a complexing agent, volatile alkalizing agents and a reducing agent and has an alkaline reducing effect, at temperatures between 150 ° C and 250 ° C and just below the decomposition temperature of Complexing agent is introduced for the purpose of iron complexation and that the iron oxide is then removed as a dissolved iron complex by emptying the container.
  • the iron is complexed and thus the container is cleaned with great effectiveness in the alkaline range.
  • the acid causes the complex to form.
  • the volatile alkalizing agent and the reducing agent on the one hand raise the pH value of the cleaning solution to the alkaline range and on the other hand bring about reducing conditions in the steam generator. These reducing conditions are necessary on the one hand to reduce trivalent iron to divalent iron and on the other hand to reduce the harmful effects of the cleaning solution on the metal surfaces of the container.
  • the temperature in the container to be cleaned according to the invention to a value between 150 ° C. and 250 ° C., which is only slightly below the decomposition temperature of the complexing agent, the desired iron complexation in the alkaline range is only made possible.
  • the pH value of the cleaning solution is of crucial importance for optimal cleaning efficiency. A pH value that is too low would lead to a high removal of base metal from unalloyed and low-alloyed materials in the container. If the pH is too high, the iron solubility is greatly reduced.
  • An optimal cleaning success with low base metal removal on unalloyed and low-alloyed works substances is achieved with the cleaning method according to the invention at a pH between 9.0 and 9.5 and at a temperature between 170 ° C and 220 ° C.
  • the advantage is achieved that in only one process step and with great effectiveness the container is freed from iron oxide deposits without the surfaces of the container and the feed pipes being attacked or even damaged by acids. Containers and pipes are not attacked by the alkaline chemical solution.
  • the cleaning process according to the invention can be carried out 40 times faster and causes only a tenth of the costs incurred there.
  • nitrilotriacetic acid which is known per se, is used as the complex-forming acid.
  • Suitable volatile alkalizing agents are preferably ammonia, hydrazine, morpholine or a mixture of the substances mentioned. Hydrazine, for example, is used as the reducing agent. Hydrazine can thus act as a volatile alkalizing agent and as a reducing agent.
  • the dissolved salt is adjusted to a pH greater than 9.6 by a further addition of volatile alkalizing agent and then metered into the container.
  • the optimum pH for cleaning which is between 9.0 and 9.5, is adjusted by partially evaporating the volatile alkalizing agent and water in the container.
  • the pH is to be controlled via the composition of the metered solution and the duration of the evaporation of the alkalizing agent.
  • the evaporation process advantageously results in homogeneous mixing of the solution in the container.
  • part of the solution in the container is evaporated for a limited time. This creates a flow within the container, which leads to even better contact between the cleaning solution and the surfaces to be cleaned.
  • alkalizing agents e.g. Hydrazine
  • the dissolved salt to be dosed is degassed, for example, before dosing and 0.1% to 5% hydrazine is added to it as a reducing agent. Hydrazine is also regularly metered into the container during cleaning, so that a hydrazine concentration of 10 to 500 milligrams per gram is set there.
  • the container is emptied.
  • the container is pressed empty, for example by an inert gas, in particular by nitrogen or water vapor. This prevents iron oxide from being formed again by penetrating atmospheric oxygen.
  • a possible proportion of copper in the deposits in the container does not interfere with the method according to the invention as long as it is less than 10%.
  • the copper can then be removed after the iron oxide has been removed in accordance with the invention.
  • the advantage of the invention is that containers, in particular steam generators of a nuclear power plant, can be reliably freed from iron oxide deposits in a short time and at low cost while protecting the metal surfaces.
  • a particular advantage can be seen in the fact that only a downtime of approximately 12 hours is required for a complete cleaning of a steam generator.
  • impurities which have been introduced and deposited in the form of salts in the container in continuous operation are effectively removed.
  • damage to the low and unalloyed base metals by etching is also excluded.
  • the chemicals required for the method according to the invention cause considerably lower costs than other cleaning methods.

Abstract

Die Erfindung betrifft ein Verfahren zum Reinigen eines Be­hälters, insbesondere eines Dampferzeugers in einem Kernkraft­werk, wobei im Behälter befindliches Eisenoxid durch eine kom­plexbildende Säure aufgelöst wird. Es ist vorgesehen, daß in den Behälter ein gelöstes Salz, das aus einer als Komplexbild­ner wirkenden Säure, flüchtigen Alkalisierungsmitteln und einem Reduktionsmittel besteht, bei Temperaturen zwischen 150°C und 250°C und knapp unterhalb der Zersetzungstemperatur des Komplex­bildners zum Zweck der Eisenkomplexierung eingebracht wird. Das Eisenoxid wird dann als gelöster Eisenkomplex durch Entleeren des Behälters entfernt. The invention relates to a method for cleaning a container, in particular a steam generator in a nuclear power plant, wherein iron oxide located in the container is dissolved by a complexing acid. It is envisaged that a dissolved salt, which consists of an acid acting as a complexing agent, volatile alkalizing agents and a reducing agent, is introduced into the container at temperatures between 150 ° C and 250 ° C and just below the decomposition temperature of the complexing agent for the purpose of iron complexation . The iron oxide is then removed as a dissolved iron complex by emptying the container.

Description

Die Erfindung betrifft ein Verfahren zum Reinigen eines Be­hälters, insbesondere eines Dampferzeugers in einem Kern­kraftwerk, wobei im Behälter befindliches Eisenoxid durch eine komplexbildende Säure aufgelöst wird.The invention relates to a method for cleaning a container, in particular a steam generator in a nuclear power plant, wherein iron oxide located in the container is dissolved by a complexing acid.

Derartige Reinigungsverfahren sind bekannt. Dem zu reini­genden Behälter werden dabei komplexbildende Säuren zugeführt, die abgelagerte Eisenoxide durch Komplexierung auflösen. Alle bekannten derartigen Reinigungsverfahren arbeiten im sauren oder im neutralen Bereich und bei Temperaturen unter 100°C.Such cleaning methods are known. Complex-forming acids are added to the container to be cleaned, which dissolve deposited iron oxides by complexation. All known cleaning processes of this type work in the acidic or in the neutral range and at temperatures below 100.degree.

Durch die beim Bekannten verwendete saure Reinigungslösung wer­den die Werkstoffe des Behälters und besonders auch die Werk­stoffe der Zuführungsleitungen einer hohen Gefährdung ausge­setzt. Die Säure greift die Metalloberflächen von Behälter und Leitungen an. Falls im neutralen Bereich gearbeitet wird, er­zielt man jedoch nur eine geringe Wirksamkeit des Reinigungs­verfahrens.Due to the acidic cleaning solution used in the known, the materials of the container and especially the materials of the supply lines are exposed to a high risk. The acid attacks the metal surfaces of the tanks and pipes. If the work is carried out in the neutral range, however, the cleaning process is only slightly effective.

Es ist auch bereits ein Mehrstufen-Verfahren, das sogenannte Mark-III-Verfahren bekannt, das abwechselnd im sauren und im neutralen Bereich durchgeführt wird. Dieses aufwendige Reini­gungsverfahren nimmt sehr viel Zeit in Anspruch und verursacht sehr hohe Kosten.A multi-stage process, the so-called Mark III process, is also known, which is carried out alternately in the acidic and in the neutral range. This complex cleaning process takes a lot of time and causes very high costs.

Der Erfindung liegt daher die Aufgabe zugrunde, ein Verfahren zum Reinigen eines Behälters, insbesondere eines Dampferzeugers zu entwickeln, das bei sehr guter Wirksamkeit Angriffe der Rei­nigungschemikalien auf die Werkstoffe des Behälters und der Leitungen minimiert.The invention is therefore based on the object of developing a method for cleaning a container, in particular a steam generator, which, with very good effectiveness, minimizes attacks by the cleaning chemicals on the materials of the container and the lines.

Die Aufgabe wird erfindungsgemäß dadurch gelöst, daß in den Be­hälter ein gelöstes Salz, das aus einer als Komplexbildner wir­kenden Säure, flüchtigen Alkalisierungsmitteln und einem Reduk­tionsmittel besteht und alkalisch reduzierend wirkt, bei Tempe­raturen zwischen 150°C und 250°C und knapp unterhalb der Zer­setzungstemperatur des Komplexbildners zum Zweck der Eisenkom­plexierung eingebracht wird und daß dann das Eisenoxid als ge­löster Eisenkomplex durch Entleeren des Behälters entfernt wird.The object is achieved in that in the container a dissolved salt, which consists of an acid acting as a complexing agent, volatile alkalizing agents and a reducing agent and has an alkaline reducing effect, at temperatures between 150 ° C and 250 ° C and just below the decomposition temperature of Complexing agent is introduced for the purpose of iron complexation and that the iron oxide is then removed as a dissolved iron complex by emptying the container.

Mit dem erfindungsgemäßen Verfahren erfolgt die Eisenkomplexie­rung und damit die Reinigung des Behälters bei großer Wirksam­keit im alkalischen Bereich. Die Säure bewirkt dabei die Kom­plexbildung. Das flüchtige Alkalisierungsmittel und das Reduk­tionsmittel heben einerseits den pH-Wert der Reinigungslösung bis in den alkalischen Bereich an und bewirken andererseits reduzierende Bedingungen im Dampferzeuger. Diese reduzierenden Bedingungen sind notwendig, um einerseits dreiwertiges Eisen zu zweiwertigem Eisen zu reduzieren und um andererseits schädliche Einwirkungen der Reinigungslösung auf die Metall­oberflächen des Behälters zu verringern. Durch das erfindungs­gemäße Einstellen der Temperatur im zu reinigenden Behälter auf einen Wert zwischen 150°C und 250°C, der nur wenig unterhalb der Zersetzungstemperatur des Komplexbildners liegt, wird die gewünschte Eisenkomplexierung im alkalischen Bereich erst er­möglicht.With the method according to the invention, the iron is complexed and thus the container is cleaned with great effectiveness in the alkaline range. The acid causes the complex to form. The volatile alkalizing agent and the reducing agent on the one hand raise the pH value of the cleaning solution to the alkaline range and on the other hand bring about reducing conditions in the steam generator. These reducing conditions are necessary on the one hand to reduce trivalent iron to divalent iron and on the other hand to reduce the harmful effects of the cleaning solution on the metal surfaces of the container. By setting the temperature in the container to be cleaned according to the invention to a value between 150 ° C. and 250 ° C., which is only slightly below the decomposition temperature of the complexing agent, the desired iron complexation in the alkaline range is only made possible.

Für einen optimalen Wirkungsgrad der Reinigung ist neben der Temperatur auch der pH-Wert der Reinigungslösung von ent­scheidender Bedeutung. Ein zu niedriger pH-Wert würde zu ei­nem hohen Grundmetallabtrag an unlegierten und niedrig le­gierten Werkstoffen im Behälter führen. Ein zu hoher pH-Wert hat eine starke Verminderung der Eisenlöslichkeit zur Folge.In addition to the temperature, the pH value of the cleaning solution is of crucial importance for optimal cleaning efficiency. A pH value that is too low would lead to a high removal of base metal from unalloyed and low-alloyed materials in the container. If the pH is too high, the iron solubility is greatly reduced.

Ein optimaler Reinigungserfolg bei gleichzeitigem niedrigem Grundmetallabtrag an unlegierten und niedrig legierten Werk­ stoffen wird mit dem erfindungsgemäßen Reinigungsverfahren bei einem pH-Wert zwischen 9,0 und 9,5 und bei einer Temperatur zwischen 170°C und 220°C erreicht.An optimal cleaning success with low base metal removal on unalloyed and low-alloyed works substances is achieved with the cleaning method according to the invention at a pH between 9.0 and 9.5 and at a temperature between 170 ° C and 220 ° C.

Mit der Erfindung wird der Vorteil erzielt, daß in nur einem Verfahrensschritt und mit großer Wirksamkeit der Behälter von Eisenoxidablagerungen befreit wird, ohne daß die Oberflächen des Behälters und der Zuleitungsrohre durch Säuren angegriffen oder sogar beschädigt werden. Behälter und Rohre werden durch die alkalische chemische Lösung nicht angegriffen. Gegenüber dem bekannten Mehrstufen-Verfahren ist das erfindungsgemäße Reinigungsverfahren 40 mal schneller durchführbar und verur­sacht nur ein Zehntel der dort anfallenden Kosten.With the invention the advantage is achieved that in only one process step and with great effectiveness the container is freed from iron oxide deposits without the surfaces of the container and the feed pipes being attacked or even damaged by acids. Containers and pipes are not attacked by the alkaline chemical solution. Compared to the known multi-stage process, the cleaning process according to the invention can be carried out 40 times faster and causes only a tenth of the costs incurred there.

Als komplexbildende Säure wird beispielsweise die an sich bekannte Nitrilotriessigsäure eingesetzt. Geeignete flüchtige Alkalisierungsmittel sind vorzugsweise Ammoniak, Hydrazin, Morpholin oder eine Mischung der genannten Substanzen. Als Reduktionsmittel wird beispielsweise Hydrazin verwendet. Hydra­zin kann also als flüchtiges Alkalisierungsmittel und als Re­duktionsmittel wirken.For example, nitrilotriacetic acid, which is known per se, is used as the complex-forming acid. Suitable volatile alkalizing agents are preferably ammonia, hydrazine, morpholine or a mixture of the substances mentioned. Hydrazine, for example, is used as the reducing agent. Hydrazine can thus act as a volatile alkalizing agent and as a reducing agent.

Beispielsweise wird das gelöste Salz vor dem Einbringen in den zu reinigenden Behälter durch einen weiteren Zusatz von flüch­tigem Alkalisierungsmittel auf einen pH-Wert, der größer als 9,6 ist, eingestellt und dann in den Behälter dosiert. Nach oder während der Dosierung wird der für die Reinigung optimale pH-Wert, der zwischen 9,0 und 9,5 liegt, durch teilweises Ver­dampfen des flüchtigen Alkalisierungsmittels und von Wasser im Behälter eingestellt. Durch diese pH-Wert-Steuerung wird vor­teilhaft eine Komplexbildung und damit ein Abtrag bereits in der meist sehr langen Zuführungsleitung zum Behälter vermieden, was eine verringerte Reinigungsleistung im Behälter selbst zur Folge hätte.For example, before being introduced into the container to be cleaned, the dissolved salt is adjusted to a pH greater than 9.6 by a further addition of volatile alkalizing agent and then metered into the container. After or during the dosing, the optimum pH for cleaning, which is between 9.0 and 9.5, is adjusted by partially evaporating the volatile alkalizing agent and water in the container. This pH value control advantageously prevents complex formation and thus removal in the usually very long feed line to the container, which would result in reduced cleaning performance in the container itself.

Der pH-Wert ist über die Zusammensetzung der dosierten Lösung und über die Dauer des Verdampfens des Alkalisierungsmittels zu steuern. Durch den Verdampfungsvorgang wird gleichzeitig vorteil­haft eine homogene Durchmischung der Lösung im Behälter erzielt.The pH is to be controlled via the composition of the metered solution and the duration of the evaporation of the alkalizing agent. The evaporation process advantageously results in homogeneous mixing of the solution in the container.

Beispielsweise wird während des Reinigungsvorganges, der maxi­mal 12 Stunden lang dauert, zeitlich begrenzt ein Teil der im Behälter befindlichen Lösung verdampft. Dadurch wird eine Strö­mung innerhalb des Behälters erzeugt, was zu einem noch besseren Kontakt zwischen der Reinigungslösung und den zu reinigenden Oberflächen führt. Die durch das Verdampfen hervorgerufene Absenkung des pH-Wertes wird durch regelmäßige Zudosierung von Alkalisierungsmitteln, z.B. Hydrazin, kompensiert.For example, during the cleaning process, which lasts a maximum of 12 hours, part of the solution in the container is evaporated for a limited time. This creates a flow within the container, which leads to even better contact between the cleaning solution and the surfaces to be cleaned. The decrease in pH caused by evaporation is compensated for by regular addition of alkalizing agents, e.g. Hydrazine, compensated.

Damit während der gesamten Reinigungsdauer reduzierende Bedin­gungen stets vorherrschen, wird das zu dosierende gelöste Salz beispielsweise vor der Dosierung entgast und es wird ihm 0,1 % bis 5 % Hydrazin als Reduktionsmittel zugegeben. Auch während der Reinigung wird regelmäßig Hydrazin in dem Behälter dosiert, so daß dort eine Hydrazinkonzentration von 10 bis 500 Milligramm pro Gramm eingestellt wird.To ensure that reducing conditions always prevail throughout the cleaning period, the dissolved salt to be dosed is degassed, for example, before dosing and 0.1% to 5% hydrazine is added to it as a reducing agent. Hydrazine is also regularly metered into the container during cleaning, so that a hydrazine concentration of 10 to 500 milligrams per gram is set there.

Nachdem das Eisenoxid aufgelöst ist, wird der Behälter ent­leert. Zur Vermeidung von Lufteintritt beim Entleeren wird der Behälter beispielsweise durch ein inertes Gas, insbesondere durch Stickstoff oder Wasserdampf leergedrückt. Damit wird ver­hindert, daß durch eindringenden Luftsauerstoff erneut Eisen­oxid gebildet wird.After the iron oxide has dissolved, the container is emptied. In order to avoid air entry during emptying, the container is pressed empty, for example by an inert gas, in particular by nitrogen or water vapor. This prevents iron oxide from being formed again by penetrating atmospheric oxygen.

Ein möglicher Kupferanteil an den Ablagerungen im Behälter stört das erfindungsgemäße Verfahren nicht, solange er kleiner als 10 % ist. Eine Entfernung des Kupfers ist dann nach der er­findungsgemäßen Entfernung des Eisenoxides möglich.A possible proportion of copper in the deposits in the container does not interfere with the method according to the invention as long as it is less than 10%. The copper can then be removed after the iron oxide has been removed in accordance with the invention.

Falls der Kupferanteil an den Ablagerungen im Behälter größer als 10 % ist, ist es notwendig, das Kupfer vor der erfindungs­gemäßen Auflösung des Eisenoxides zu entfernen. Dazu ist das in der europäischen Patentanmeldung 01 98 340 beschriebene Reini­gungsverfahren geeignet.If the copper content of the deposits in the container is greater than 10%, it is necessary to remove the copper before the iron oxide is dissolved according to the invention. The cleaning method described in European patent application 01 98 340 is suitable for this.

Mit der Erfindung wird der Vorteil erzielt, daß Behälter, ins­besondere Dampferzeuger eines Kernkraftwerkes bei Schonung der Metalloberflächen in kurzer Zeit und mit geringen Kosten zuver­lässig von Eisenoxidablagerungen zu befreien sind. Gerade bei Kernkraftwerken ist ein besonderer Vorteil darin zu sehen, daß für eine vollständige Reinigung eines Dampferzeugers nur eine Stillstandszeit von ca. 12 Stunden benötigt wird. Außerdem werden mit dem Verfahren nach der Erfindung im Behälter im Dauerbetrieb eingetragene und abgelagerte in Form von Salzen anfallende Verunreinigungen wirksam entfernt. Mit dem scho­nenden erfindungsgemäßen Verfahren ist zudem eine Beschädigung der niedrig- und unlegierten Grundmetalle durch Verätzen aus­geschlossen. Schließlich verursachen die für das erfindungsge­mäße Verfahren benötigten Chemikalien im Vergleich zu anderen Reinigungsverfahren erheblich geringere Kosten.The advantage of the invention is that containers, in particular steam generators of a nuclear power plant, can be reliably freed from iron oxide deposits in a short time and at low cost while protecting the metal surfaces. In the case of nuclear power plants in particular, a particular advantage can be seen in the fact that only a downtime of approximately 12 hours is required for a complete cleaning of a steam generator. In addition, with the method according to the invention, impurities which have been introduced and deposited in the form of salts in the container in continuous operation are effectively removed. With the gentle method according to the invention, damage to the low and unalloyed base metals by etching is also excluded. Finally, the chemicals required for the method according to the invention cause considerably lower costs than other cleaning methods.

Claims (9)

1. Verfahren zum Reinigen eines Behälters, insbesondere eines Dampferzeugers in einem Kernkraftwerk, wobei im Behälter be­findliches Eisenoxid durch eine komplexbildende Säure aufge­löst wird, dadurch gekennzeichnet, daß in den Behälter ein gelöstes Salz, das aus einer als Komplex­bildner wirkenden Säure, flüchtigen Alkalisierungsmitteln und einem Reduktionsmittel besteht und alkalisch reduzierend wirkt, bei Temperaturen zwischen 150°C und 250°C und knapp unterhalb der Zersetzungstemperatur des Komplexbildners zum Zweck der Eisenkomplexierung eingebracht wird und daß dann das Eisenoxid als gelöster Eisenkomplex durch Entleeren des Behälters ent­fernt wird.1. A method for cleaning a container, in particular a steam generator in a nuclear power plant, wherein iron oxide in the container is dissolved by a complexing acid, characterized in that in the container a dissolved salt, which consists of an acid acting as a complexing agent, volatile alkalizing agents and Reducing agent exists and has an alkaline reducing effect, is introduced at temperatures between 150 ° C and 250 ° C and just below the decomposition temperature of the complexing agent for the purpose of iron complexation and that the iron oxide is then removed as a dissolved iron complex by emptying the container. 2. Verfahren nach Anspruch 1, dadurch gekenn­zeichnet, daß die als Komplexbildner wirkende Säure Nitrilotriessigsäure ist.2. The method according to claim 1, characterized in that the acid acting as a complexing agent is nitrilotriacetic acid. 3. Verfahren nach Anspruch 1, dadurch gekenn­zeichnet, daß das flüchtige Alkalisierungsmittel Ammoniak, Hydrazin und/oder Morpholin ist.3. The method according to claim 1, characterized in that the volatile alkalizing agent is ammonia, hydrazine and / or morpholine. 4. Verfahren nach Anspruch 1, dadurch gekenn­zeichnet, daß das Reduktionsmittel Hydrazin ist.4. The method according to claim 1, characterized in that the reducing agent is hydrazine. 5. Verfahren nach den Ansprüchen 1 bis 4, dadurch ge­kennzeichnet, daß das gelöste Salz vor dem Ein­bringen in den Behälter durch einen weiteren Zusatz von flüch­tigem Alkalisierungsmittel auf einen pH-Wert größer als 9,6 eingestellt und dann in den Behälter dosiert wird und daß nach oder während der Dosierung ein für die Reinigung optimaler pH­Wert zwischen 9,0 und 9,5 durch teilweises Verdampfen des flüchtigen Alkalisierungsmittels und von Wasser im Behälter eingestellt wird.5. The method according to claims 1 to 4, characterized in that the dissolved salt before being introduced into the container by a further addition of volatile alkalizing agent to a pH greater than 9.6 and then metered into the container and that after or during dosing, a pH value between 9.0 and 9.5, which is optimal for cleaning, is set by partially evaporating the volatile alkalizing agent and water in the container. 6. Verfahren nach den Ansprüchen 1 - 4, dadurch ge­kennzeichnet, daß der Behälterinhalt teilweise verdampft wird, damit eine homogene Verteilung des Inhaltes im Behälter erfolgt.6. The method according to claims 1-4, characterized in that the container content is partially evaporated so that a homogeneous distribution of the content takes place in the container. 7. Verfahren nach den Ansprüchen 1 - 4, dadurch ge­kennzeichnet, daß vor dem Einbringen in den Be­hälter das gelöste Salz entgast und mit 0,1 % bis 5 % Hydrazin versetzt wird und daß während der Reinigung regelmäßig Hydrazin zudosiert wird und dadurch eine Hydrazinkonzentration zwischen mg/kg und 500 mg/kg im Behälter eingestellt wird.7. The method according to claims 1-4, characterized in that before the introduction into the container, the dissolved salt is degassed and mixed with 0.1% to 5% hydrazine and that hydrazine is regularly added during cleaning and thereby a hydrazine concentration between mg / kg and 500 mg / kg is set in the container. 8. Verfahren nach den Ansprüchen 1 - 4, dadurch ge­kennzeichnet, daß beim Entleeren des Behälters dieser durch ein inertes Gas, insbesondere durch Stickstoff oder Wasserdampf leergedrückt wird.8. The method according to claims 1-4, characterized in that when the container is emptied it is emptied by an inert gas, in particular by nitrogen or water vapor. 9. Verfahren nach den Ansprüchen 1 - 4, dadurch ge­kennzeichnet, daß bei einer Kupferkonzentration größer als 10 % in den Ablagerungen im Behälter das Kupfer vor der Auflösung des Eisenoxides entfernt wird.9. The method according to claims 1-4, characterized in that at a copper concentration greater than 10% in the deposits in the container, the copper is removed before the iron oxide is dissolved.
EP87117112A 1986-12-01 1987-11-19 Method of cleaning a container Revoked EP0273182B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE3640428 1986-12-01
DE3640428 1986-12-01

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EP0273182A1 true EP0273182A1 (en) 1988-07-06
EP0273182B1 EP0273182B1 (en) 1991-07-31

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EP87117112A Revoked EP0273182B1 (en) 1986-12-01 1987-11-19 Method of cleaning a container

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US (1) US5164015A (en)
EP (1) EP0273182B1 (en)
JP (1) JPS63143276A (en)
KR (1) KR950013495B1 (en)
CA (1) CA1316799C (en)
DE (1) DE3771859D1 (en)
ES (1) ES2023397B3 (en)

Cited By (10)

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DE4117625A1 (en) * 1991-05-29 1992-12-03 Siemens Ag Cleaning and decontamination of carbon@ steel surfaces - by treatment with aq. soln. of ascorbic and picolinic acid
EP0527908A1 (en) * 1990-04-30 1993-02-24 Arch Development Corporation New formulations for iron oxides dissolution
EP0570766A1 (en) * 1992-05-18 1993-11-24 Siemens Aktiengesellschaft Process for cleaning a closed container
EP0616051A1 (en) * 1993-03-15 1994-09-21 Siemens Aktiengesellschaft Cleaning process
WO1999061179A1 (en) * 1998-05-22 1999-12-02 Siemens Aktiengesellschaft Method for cleaning a container
DE10238730A1 (en) * 2002-08-23 2004-03-04 Framatome Anp Gmbh Process for cleaning the steam generator of a pressurized water reactor
DE102004054471B3 (en) * 2004-11-11 2006-04-27 Framatome Anp Gmbh Cleaning process for removal of magnetite-containing deposits from a pressure vessel of a power plant
WO2008107072A1 (en) * 2007-03-07 2008-09-12 Areva Np Gmbh Method for removing deposits containing magnetite and copper from containers in industrial and power plants
DE102008005199A1 (en) 2008-01-18 2009-07-30 Areva Np Gmbh Process for cleaning a heat exchanger
EP2418023A1 (en) * 2010-08-13 2012-02-15 Siemens Aktiengesellschaft Method for concluding chemical power plant cleaning

Families Citing this family (3)

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DE4131766A1 (en) * 1991-09-24 1993-03-25 Siemens Ag Decontamination of nuclear power station prim. cycle to remove metal oxide - by adding chelating agent to prim. coolant to dissolve contaminated oxide
KR101014751B1 (en) * 2008-09-26 2011-02-15 한국전력공사 Chemistry washing method of steam generator
JP6093551B2 (en) 2012-11-06 2017-03-08 株式会社貝印刃物開発センター razor

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DE1517473A1 (en) * 1964-11-19 1969-12-11 Nalco Chemical Co Process for removing scale and preventing scale formation
DE1517406A1 (en) * 1962-07-23 1970-01-15 Dow Chemical Co Scale removal, passivation of iron, metals, and compounds that are suitable for passivation
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GB2113254A (en) * 1982-01-18 1983-08-03 Dearborn Chemicals Co Process for cleaning the jacket of a glass-lined reactor
EP0158566A1 (en) * 1984-04-05 1985-10-16 Electricite De France Process for eliminating deposits in a steam generator of a nuclear pressurized water reactor

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DE1517406A1 (en) * 1962-07-23 1970-01-15 Dow Chemical Co Scale removal, passivation of iron, metals, and compounds that are suitable for passivation
DE1517473A1 (en) * 1964-11-19 1969-12-11 Nalco Chemical Co Process for removing scale and preventing scale formation
US3627687A (en) * 1968-02-09 1971-12-14 Dow Chemical Co Cleaning of ferrous metal surfaces
DE2114839A1 (en) * 1970-04-01 1971-10-14 Unilever Nv Process for cleaning and degreasing metals with liquid cleaning agents
CA1062590A (en) * 1976-01-22 1979-09-18 Her Majesty In Right Of Canada As Represented By Atomic Energy Of Canada Limited Reactor decontamination process
GB2113254A (en) * 1982-01-18 1983-08-03 Dearborn Chemicals Co Process for cleaning the jacket of a glass-lined reactor
EP0158566A1 (en) * 1984-04-05 1985-10-16 Electricite De France Process for eliminating deposits in a steam generator of a nuclear pressurized water reactor

Cited By (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0527908A1 (en) * 1990-04-30 1993-02-24 Arch Development Corporation New formulations for iron oxides dissolution
EP0527908A4 (en) * 1990-04-30 1993-04-14 Arch Development Corporation New formulations for iron oxides dissolution
DE4117625A1 (en) * 1991-05-29 1992-12-03 Siemens Ag Cleaning and decontamination of carbon@ steel surfaces - by treatment with aq. soln. of ascorbic and picolinic acid
EP0570766A1 (en) * 1992-05-18 1993-11-24 Siemens Aktiengesellschaft Process for cleaning a closed container
EP0616051A1 (en) * 1993-03-15 1994-09-21 Siemens Aktiengesellschaft Cleaning process
WO1999061179A1 (en) * 1998-05-22 1999-12-02 Siemens Aktiengesellschaft Method for cleaning a container
GB2354773A (en) * 1998-05-22 2001-04-04 Siemens Ag Method for cleaning a container
GB2354773B (en) * 1998-05-22 2003-04-30 Siemens Ag Method for cleaning a container
US6695927B1 (en) 1998-05-22 2004-02-24 Siemens Aktiengesellschaft Method and cleaning solution for cleaning a container
DE10238730A1 (en) * 2002-08-23 2004-03-04 Framatome Anp Gmbh Process for cleaning the steam generator of a pressurized water reactor
DE102004054471B3 (en) * 2004-11-11 2006-04-27 Framatome Anp Gmbh Cleaning process for removal of magnetite-containing deposits from a pressure vessel of a power plant
WO2008107072A1 (en) * 2007-03-07 2008-09-12 Areva Np Gmbh Method for removing deposits containing magnetite and copper from containers in industrial and power plants
US7931753B2 (en) 2007-03-07 2011-04-26 Areva Np Gmbh Method for removing deposits containing magnetite and copper from containers in industrial and power plants
DE102008005199A1 (en) 2008-01-18 2009-07-30 Areva Np Gmbh Process for cleaning a heat exchanger
DE102008005199B4 (en) * 2008-01-18 2014-01-23 Areva Gmbh Process for cleaning a heat exchanger
EP2418023A1 (en) * 2010-08-13 2012-02-15 Siemens Aktiengesellschaft Method for concluding chemical power plant cleaning
WO2012019793A1 (en) * 2010-08-13 2012-02-16 Siemens Aktiengesellschaft Method for completing a chemical power plant cleaning
CN103221155A (en) * 2010-08-13 2013-07-24 西门子公司 Method for completing a chemical power plant cleaning
RU2568033C2 (en) * 2010-08-13 2015-11-10 Сименс Акциенгезелльшафт Method of completing chemical cleaning of electric power plant
US9302300B2 (en) 2010-08-13 2016-04-05 Siemens Aktiengesellschaft Method for completing a chemical power plant cleaning

Also Published As

Publication number Publication date
EP0273182B1 (en) 1991-07-31
US5164015A (en) 1992-11-17
DE3771859D1 (en) 1991-09-05
KR880007138A (en) 1988-08-26
ES2023397B3 (en) 1992-01-16
KR950013495B1 (en) 1995-11-08
JPH0588317B2 (en) 1993-12-21
CA1316799C (en) 1993-04-27
JPS63143276A (en) 1988-06-15

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