EP0589781A1 - Reduktor Dekontaminierendgel und sein Verwendung zur Dekontamination von Oberflächen - Google Patents

Reduktor Dekontaminierendgel und sein Verwendung zur Dekontamination von Oberflächen Download PDF

Info

Publication number
EP0589781A1
EP0589781A1 EP93402307A EP93402307A EP0589781A1 EP 0589781 A1 EP0589781 A1 EP 0589781A1 EP 93402307 A EP93402307 A EP 93402307A EP 93402307 A EP93402307 A EP 93402307A EP 0589781 A1 EP0589781 A1 EP 0589781A1
Authority
EP
European Patent Office
Prior art keywords
gel
oxidizing
agent
reducing
inorganic
Prior art date
Legal status (The legal status 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 status listed.)
Granted
Application number
EP93402307A
Other languages
English (en)
French (fr)
Other versions
EP0589781B1 (de
Inventor
Jean-Paul Gauchon
Paul Fuentes
Jean-Pierre Cizel
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Commissariat a lEnergie Atomique et aux Energies Alternatives CEA
Original Assignee
Commissariat a lEnergie Atomique CEA
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 Commissariat a lEnergie Atomique CEA filed Critical Commissariat a lEnergie Atomique CEA
Publication of EP0589781A1 publication Critical patent/EP0589781A1/de
Application granted granted Critical
Publication of EP0589781B1 publication Critical patent/EP0589781B1/de
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

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
    • G21F9/001—Decontamination of contaminated objects, apparatus, clothes, food; Preventing contamination thereof

Definitions

  • the subject of the present invention is a reducing decontaminating gel which can be used for radioactive decontamination of surfaces, in particular of metallic surfaces covered by a very adherent surface layer of metal oxides.
  • the metal surfaces of these primary circuits which are usually made of stainless steel, Incoloy or Inconel, are generally covered with deposits of iron, chromium and nickel oxides which can take various forms, for example in the form nickel ferrite NiFe 2 0 4 , magnetite Fe 3 0 4 , nickel ferrite and chromium, chromium ferrite FeCr 2 0 4 , nickel chromite NiCr 2 0 4 and chromium oxide Cr 2 0 3 .
  • an oxidizing decontaminating gel can be used, as described in FR-A-2 656 949.
  • this oxidizing gel which makes it possible to remove the radioactive elements deposited on the part as well as the encrusted elements on its surface, does not have sufficient effectiveness with respect to the adherent metal oxide layers deposited on the surface of alloys such as austenitic steels, the Inconel 600 and the Incoloy.
  • the oxide layers deposited on these metal surfaces contain radioactive elements such as 58 Co, 60 Co and 51 Cr which are emitters of gamma photons which it is therefore important to eliminate.
  • the present invention specifically relates to a reducing decontaminating gel which makes it possible to eliminate these adherent metal oxide layers.
  • a gel is a colloidal solution, the phases of which are difficult to define due to the molecular weight of the colloid and its large state of dispersion in solution.
  • This gel structure is obtained by adding component a) to an aqueous solution, that is to say an inorganic gelling agent which does not oxidize, resists components b) and c), and has a high specific surface. , for example greater than 100m 2 / g.
  • the content of gelling agent in the colloidal solution is chosen so as to obtain a viscosity sufficient to be able to maintain the gel in a layer on the surface of a part.
  • the gel has a viscosity at least equal to 350mPa.s at the time of use in order to be able to apply it easily on the surface of a part, for example by spraying with a gun.
  • the content of gelling agent represents 20 to 30% by weight of the solution; it depends in particular on the gelling agent used.
  • the gelling agent is based on alumina A1 2 0 3 and it can be obtained by hydrolysis at high temperature.
  • a gelling agent which can be used mention may be made of the product sold under the trade name Alumina C.
  • the inorganic base used in the decontaminating gel of the invention can in particular be NaOH or KOH.
  • NaOH is used in particular at concentrations of 7 to 10 mol / l to obtain a pH at least equal to 13.
  • the reducing agent used in the gel of the invention is a reducing agent having a normal redox potential E o less than -600mV / ENH (normal hydrogen electrode) in a strong base medium (pH ⁇ 13).
  • reducing agents By way of example of such reducing agents, mention may be made of borohydrides, sulfites, hydrosulfites, sulfides, hypophosphites, zinc and hydrazine.
  • borohydrides sulfites, sulfides, hydrosulfites or hypophosphites are used, these are generally in the form of metal salts, for example salts of alkali metals such as sodium.
  • the pH of the colloidal solution is preferably greater than or equal to 14 so that the borohydride remains stable.
  • Examples of reducing decontaminating gels according to the invention include gels in which the gelling agent is based on alumina, the inorganic base is NaOH and the reducing agent is sodium borohydride, sodium sulfide, sodium hydrosulfite or hydrazine.
  • the reducing decontaminating gels of the invention can be prepared in a simple manner by adding to an aqueous solution of component b), that is to say of the inorganic base, the reducing agent and the gelling agent. Generally, the reducing agent is added before the gelling agent.
  • the use, in the first step, of a reducing gel at pH ⁇ 13 in accordance with the invention makes it possible to weaken and move the adherent surface metal oxide layers which are not sensitive to the action oxidizing decontaminating gels.
  • oxides such as nickel ferrite NiFe 2 0 4 and magnetite Fe 3 0 4 to reduce Fe "'to Fe".
  • the action of the oxidizing gel in an acid medium for example HN0 3 at a concentration of 5 to 10 mol / l, makes it possible to oxidize the chromites which are rather within the deep oxide layer.
  • the simultaneous action of the oxidizing agent on the chromite and on the underlying metal facilitates decontamination.
  • the decontaminating gels described in particular in FR-A-2 656 949 are used as the oxidizing gel.
  • oxidizing gels By way of example of oxidizing gels, mention may be made of those in which the gelling agent is based on silica, the inorganic acid is nitric acid and the oxidizing agent is cerium sulphate.
  • the action of the reducing gel in the first step alone is not decisive, but following this first step of reducing treatment, the application of the oxidizing gel in an acid medium makes it possible to achieve average decontamination factors of 2, 7 instead of 1.2 when using the oxidizing gel alone.
  • the process of the invention is therefore very interesting because it allows excellent results to be obtained, when cold and with small amounts of reagent.
  • the application of the various gels to the metal surface to be decontaminated can be carried out by conventional methods, for example by spraying with a spray gun, by soaking and draining, by packaging or even by means of a brush.
  • the gel is applied by spraying with a spray gun, for example under a pressure (Airless compressor) at the level of the injector ranging from 50 to 100 kg / cm 2 .
  • demineralized water or an aqueous solution is usually used in which the gels used can be dissolved or in which they can form a detachable film which can be entrained by water.
  • the reducing gel R1 is deposited thereon by spraying with a spray gun so as to deposit 800g of gel per m 2 of surface and the gel is kept on the surface for 2 hours. .
  • a rinse is then carried out with demineralized water using 51 of water per m 2 of surface.
  • the oxidizing gel 01 is then applied to the thus rinsed surface by spraying with a spray gun as above and it is also maintained on the surface of the part for 2 hours using an amount of 800 g of gel per m 2 of surface.
  • a rinse is then carried out with demineralized water as above.
  • the activity of the surface is determined (in mrad / h).
  • the decontamination factors FD have also been given which correspond to the ratio of the initial activity to the final activity.
  • a contaminated part made of AISI 304 steel is treated using the decontaminating oxidizing gel 01.
  • Example 1 If we compare the results of Example 1 and Comparative Example 1, we see that the preliminary step of applying a reducing gel makes it possible to significantly improve the decontamination factor.
  • Example 2 the same procedure is followed as in Example 2, using the reducing gel R1 and the oxidizing gel 02 to decontaminate a part made of INCONEL 600.
  • the oxidizing gel is the oxidizing gel 02 in Table 2.

Landscapes

  • Engineering & Computer Science (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Food Science & Technology (AREA)
  • Physics & Mathematics (AREA)
  • General Engineering & Computer Science (AREA)
  • High Energy & Nuclear Physics (AREA)
  • Detergent Compositions (AREA)
  • Adhesives Or Adhesive Processes (AREA)
  • Chemically Coating (AREA)
  • Solid-Sorbent Or Filter-Aiding Compositions (AREA)
  • Cleaning And De-Greasing Of Metallic Materials By Chemical Methods (AREA)
EP19930402307 1992-09-23 1993-09-21 Dekontaminierendes Reduktorgel und seine Verwendung zur Dekontamination von Oberflächen Expired - Lifetime EP0589781B1 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR9211317 1992-09-23
FR9211317A FR2695839B1 (fr) 1992-09-23 1992-09-23 Gel décontaminant réducteur et son utilisation pour la décontamination de surface notamment d'installations nucléaires.

Publications (2)

Publication Number Publication Date
EP0589781A1 true EP0589781A1 (de) 1994-03-30
EP0589781B1 EP0589781B1 (de) 1999-03-31

Family

ID=9433783

Family Applications (1)

Application Number Title Priority Date Filing Date
EP19930402307 Expired - Lifetime EP0589781B1 (de) 1992-09-23 1993-09-21 Dekontaminierendes Reduktorgel und seine Verwendung zur Dekontamination von Oberflächen

Country Status (4)

Country Link
EP (1) EP0589781B1 (de)
DE (1) DE69324203T2 (de)
ES (1) ES2132203T3 (de)
FR (1) FR2695839B1 (de)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1997035323A1 (fr) * 1996-03-21 1997-09-25 Stmi - Societe Des Techniques En Milieu Ionisant Gel organomineral de decontamination et son utilisation pour la decontamination de surfaces
FR2827530A1 (fr) * 2001-07-17 2003-01-24 Commissariat Energie Atomique Procede de traitement d'une surface par un gel de traitement, et gel de traitement
US6852903B1 (en) * 2000-05-31 2005-02-08 The United States Of America As Represented By The Secretary Of The Army Decontamination of chemical warfare agents using a reactive sorbent
US8636848B2 (en) * 2005-10-05 2014-01-28 Commissariat A L'energie Atomique Vacuumable gel for decontaminating surfaces and use thereof
RU2569747C2 (ru) * 2010-07-02 2015-11-27 Коммиссариат А Л'Энержи Атомик Э О Энержи Альтернатив Гель для биологической деконтаминации и способ деконтаминации поверхностей посредством использования этого геля

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2798603B1 (fr) * 1999-09-20 2002-03-01 Tech En Milieu Ionisant Stmi S Gel organique de decontamination et son utilisation pour la decontamination de surfaces

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3080262A (en) * 1959-04-07 1963-03-05 Purex Corp Process for removal of radioactive contaminants from surfaces
WO1990008385A1 (fr) * 1989-01-19 1990-07-26 Commissariat A L'energie Atomique Procede de decontamination radioactive de surface metallique, notamment de portions de circuits primaires de reacteurs nucleaires refroidis a l'eau
FR2656949A1 (fr) * 1990-01-09 1991-07-12 Commissariat Energie Atomique Gel decontaminant et son utilisation pour la decontamination radioactive de surfaces.
WO1991017124A1 (en) * 1990-04-30 1991-11-14 Arch Development Corporation New formulations for iron oxides dissolution

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3080262A (en) * 1959-04-07 1963-03-05 Purex Corp Process for removal of radioactive contaminants from surfaces
WO1990008385A1 (fr) * 1989-01-19 1990-07-26 Commissariat A L'energie Atomique Procede de decontamination radioactive de surface metallique, notamment de portions de circuits primaires de reacteurs nucleaires refroidis a l'eau
FR2656949A1 (fr) * 1990-01-09 1991-07-12 Commissariat Energie Atomique Gel decontaminant et son utilisation pour la decontamination radioactive de surfaces.
WO1991017124A1 (en) * 1990-04-30 1991-11-14 Arch Development Corporation New formulations for iron oxides dissolution

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1997035323A1 (fr) * 1996-03-21 1997-09-25 Stmi - Societe Des Techniques En Milieu Ionisant Gel organomineral de decontamination et son utilisation pour la decontamination de surfaces
FR2746328A1 (fr) * 1996-03-21 1997-09-26 Stmi Soc Tech Milieu Ionisant Gel organomineral de decontamination et son utilisation pour la decontamination de surfaces
US6203624B1 (en) * 1996-03-21 2001-03-20 Stmi - Societe Des Techniques En Milieu Ionisant Organomineral decontamination gel and use thereof for surface decontamination
US6852903B1 (en) * 2000-05-31 2005-02-08 The United States Of America As Represented By The Secretary Of The Army Decontamination of chemical warfare agents using a reactive sorbent
FR2827530A1 (fr) * 2001-07-17 2003-01-24 Commissariat Energie Atomique Procede de traitement d'une surface par un gel de traitement, et gel de traitement
WO2003008529A1 (fr) * 2001-07-17 2003-01-30 Commissariat A L'energie Atomique Procede de traitement d'une surface par un gel de traitement, et gel de traitement
US7713357B2 (en) 2001-07-17 2010-05-11 Commissariat A L'energie Atomique Method for treating a surface with a treatment gel and treatment gel
US7718010B2 (en) 2001-07-17 2010-05-18 Commissariat A L'energie Atomique Method for treating a surface with a treatment gel, and treatment gel
US8636848B2 (en) * 2005-10-05 2014-01-28 Commissariat A L'energie Atomique Vacuumable gel for decontaminating surfaces and use thereof
RU2569747C2 (ru) * 2010-07-02 2015-11-27 Коммиссариат А Л'Энержи Атомик Э О Энержи Альтернатив Гель для биологической деконтаминации и способ деконтаминации поверхностей посредством использования этого геля

Also Published As

Publication number Publication date
FR2695839A1 (fr) 1994-03-25
EP0589781B1 (de) 1999-03-31
DE69324203D1 (de) 1999-05-06
ES2132203T3 (es) 1999-08-16
FR2695839B1 (fr) 1994-10-14
DE69324203T2 (de) 1999-09-30

Similar Documents

Publication Publication Date Title
AU617365B2 (en) Aluminium surface cleaning agent
US4226640A (en) Method for the chemical decontamination of nuclear reactor components
DE2364162C3 (de) Saure wäßrige Metallbehandlungslösung
EP0928489B1 (de) Organomineralgel zur dekontamination von oberflächen
DE69514107T2 (de) Verbesserte nichtchromatierte oxidbeschichtung für aluminiumsubstrate
CA2121691A1 (fr) Composition stabilisante de solutions de peroxydes inorganiques
US5873953A (en) Non-chromated oxide coating for aluminum substrates
WO1994024333A1 (de) Verfahren zur erhöhung der korrosionsbeständigkeit von nichtrostendem stahl
EP0589781B1 (de) Dekontaminierendes Reduktorgel und seine Verwendung zur Dekontamination von Oberflächen
US5766684A (en) Stainless steel acid treatment
US5858118A (en) Stainless steel alkali treatment
CH642475A5 (de) Verfahren zur chemischen dekontamination von bauteilen.
US9115433B2 (en) Method for the surface treatment of stainless steel
CA1046387A (en) Method and composition for cleaning the surface of ferrous metal
EP1472388B1 (de) Verfahren zum beizen von martensitischem oder ferritischem edelstahl
EP0596273B1 (de) Mittel zum Beizen der Oberfläche von Chromnickelstählen und Chromstählen sowie Verwendung des Mittels
EP0406098B1 (de) Verfahren zur Auflösung von auf einem Substrat deponierten Oxiden und Verwendung zur Dekontaminierung
US3391012A (en) Metal treating compositions and processes
DE2409649A1 (de) Verfahren zur behandlung von metalloberflaechen mittels mikroorganismen
FR2644618A1 (fr) Procede de decontamination de surfaces metalliques, notamment de parties constitutives d'un reacteur nucleaire a eau sous pression, et solutions de decontamination utilisees dans ce procede
DE19730372B4 (de) Reinigung und Entpassivierung von zu nitrierenden oder nitrocarburierenden Oberflächen mit leichten Säuren
SU1705405A1 (ru) Способ оксидировани алюмини и его сплавов
Srinivas Eco-friendly Chemical Polishing of Copper and Copper Alloys
JPH01176081A (ja) 原子炉配管等の表面処理方法
JP2008214756A (ja) 酸洗いされたジルコニウム−ニオブ合金からのニオブ第２相粒子付着物の除去

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): BE CH DE ES GB LI SE

17P Request for examination filed

Effective date: 19940905

GRAG Despatch of communication of intention to grant

Free format text: ORIGINAL CODE: EPIDOS AGRA

17Q First examination report despatched

Effective date: 19980610

GRAG Despatch of communication of intention to grant

Free format text: ORIGINAL CODE: EPIDOS AGRA

GRAH Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOS IGRA

GRAH Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOS IGRA

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): BE CH DE ES GB LI SE

REG Reference to a national code

Ref country code: CH

Ref legal event code: EP

REF Corresponds to:

Ref document number: 69324203

Country of ref document: DE

Date of ref document: 19990506

GBT Gb: translation of ep patent filed (gb section 77(6)(a)/1977)

Effective date: 19990603

REG Reference to a national code

Ref country code: ES

Ref legal event code: FG2A

Ref document number: 2132203

Country of ref document: ES

Kind code of ref document: T3

PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed
PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: BE

Payment date: 20000831

Year of fee payment: 8

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: SE

Payment date: 20000906

Year of fee payment: 8

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 20000920

Year of fee payment: 8

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: ES

Payment date: 20000922

Year of fee payment: 8

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: CH

Payment date: 20000927

Year of fee payment: 8

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 20000928

Year of fee payment: 8

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20010921

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: SE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20010922

Ref country code: ES

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20010922

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LI

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20010930

Ref country code: CH

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20010930

Ref country code: BE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20010930

REG Reference to a national code

Ref country code: GB

Ref legal event code: IF02

BERE Be: lapsed

Owner name: COMMISSARIAT A L'ENERGIE ATOMIQUE

Effective date: 20010930

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20020501

EUG Se: european patent has lapsed

Ref document number: 93402307.8

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 20010921

REG Reference to a national code

Ref country code: CH

Ref legal event code: PL

REG Reference to a national code

Ref country code: ES

Ref legal event code: FD2A

Effective date: 20021011