EP0139955B1 - Procédé pour fixer les composants gazeux radioactifs des gaz d'échappement - Google Patents

Procédé pour fixer les composants gazeux radioactifs des gaz d'échappement Download PDF

Info

Publication number
EP0139955B1
EP0139955B1 EP84109730A EP84109730A EP0139955B1 EP 0139955 B1 EP0139955 B1 EP 0139955B1 EP 84109730 A EP84109730 A EP 84109730A EP 84109730 A EP84109730 A EP 84109730A EP 0139955 B1 EP0139955 B1 EP 0139955B1
Authority
EP
European Patent Office
Prior art keywords
zeolite
range
temperature
water content
fixation
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.)
Expired
Application number
EP84109730A
Other languages
German (de)
English (en)
Other versions
EP0139955A2 (fr
EP0139955A3 (en
Inventor
Ralf-Dieter Dr. Penzhorn
Reinhard Dr. Kroebel
Peter Schuster
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.)
Forschungszentrum Karlsruhe GmbH
Original Assignee
Kernforschungszentrum Karlsruhe GmbH
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 Kernforschungszentrum Karlsruhe GmbH filed Critical Kernforschungszentrum Karlsruhe GmbH
Publication of EP0139955A2 publication Critical patent/EP0139955A2/fr
Publication of EP0139955A3 publication Critical patent/EP0139955A3/de
Application granted granted Critical
Publication of EP0139955B1 publication Critical patent/EP0139955B1/fr
Expired legal-status Critical Current

Links

Images

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
    • G21F9/02—Treating gases

Definitions

  • the invention relates to a method for fixing radioactive, gaseous constituents of exhaust gases which are released during the reprocessing of irradiated or spent nuclear reactor fuel elements.
  • the nitrogen oxides are catalytically oxidized in a conventional device, absorbed in water and recycled as nitric acid. This is followed by particulate filters for removing the aerosols and an iodine absorber. An aerosol filter is then used again and C ⁇ Hy is then catalytically oxidized.
  • the CA 14 CO 3 obtained is then embedded in cement stone.
  • the typical composition of an exhaust gas from a reprocessing plant that reprocesses fuel elements from a gas-cooled high-temperature reactor is 95% C-14 contaminated C0 2 , 10 to 15 ppm Kr-85 contaminated krypton and approximately 60 ppm xenon.
  • C-14 is only a weak beta emitter, it poses a long-term risk due to its long half-life of 5730 years and its easy incorporability into the bio-cycle.
  • CO 2 is first removed the reaction with Ca (OH) 2 sludge is eliminated and the krypton is then removed using a fluorocarbon adsorption system.
  • the liquid loaded with Kr-85 is then placed in a scrubbing column where the krypton is separated from the liquid. After CO 2 removal, the gas flow is reduced to one twentieth of the original flow.
  • the gas then essentially consists only of nitrogen and oxygen.
  • C-14 can occur either as CO 2 or as a low molecular weight hydrocarbon.
  • CO 2 gas concentrations which contain traces of C-14 are to be expected in the range from 10 to 300 vpm.
  • the annual occurrence of C-14 different nuclear facilities depending on their performance is listed.
  • the product obtained from the CO 2 barium hydroxide octahydrate reaction must be incorporated in cement paste for final storage.
  • barium carbonate slurries can be introduced directly into the cement slurry after settling without first transferring the carbonate to the dry state.
  • a possible objection to the removal of C-14 in the form of BaCOg / cement hardening is the presence of soluble bicarbonate.
  • the cement slurry with its high pH provides protection for the BaC0 3 against attack by C0 2 . However, this protection will lapse if all of the Ca (OH) 2 in the cement slurry has been converted to CaC0 3 or if the cement paste has been dissolved or destroyed.
  • the iodine retained in the iodine absorber or the iodine compounds sorbed there on a silica-based carrier impregnated on a silver nitrate are solidified with the sorption material.
  • the invention has for its object to provide a less complex, easy to carry out fixation process for the radioactive, gaseous components of exhaust gases from the reprocessing of irradiated or spent nuclear reactor fuel elements, with which both the individual species of these components 14 CO 2 , 14 CH 4 , radioactive iodine isotopes, HTO vapor as well as any mixtures of these species in the molecular form in which they occur, ie without chemical conversion prior to fixation, can be irreversibly solidified in a matrix resistant to radioactive radiation, elevated temperature and leaching in water or saline solutions . In this case, irreversible means that there is practically no release of the gaseous constituents before the matrix is heated to temperatures at which it is decomposed or destroyed.
  • the zeolite is dried to a water content of 0.6 to 5% by weight, in the case of HTO fixation to a water content of 0.6 to 22% by weight .-%.
  • Mordenite as the fixation matrix can be used in the sodium-exchanged form and in the hydrogen-exchanged form.
  • the evacuation can be in the temperature range from 373 K to 473 K when using mordenite Na if the evacuation time is 16 hours. Good results with mordenite-Na were obtained if either evacuation was carried out at 473 K for 16 hours and the fixation of C0 2 took place at 793 K or if the vacuum was evacuated at 423 K for 16 hours and fixed at 923 K.
  • mordenite-H is used to fix CO 2 , the residual water content is advantageously set to 8% by weight or less.
  • the fixing temperatures can be between 823 and 923 K. A fixation of CO 2 in mordenite-H, which can be described as good, was obtained after 16 hours of evacuation at 373 K and a subsequent fixation at 923 K.
  • the residual water content should not be higher than 10% by weight.
  • a fixation temperature in the range of 733 K to 823 K is preferably used to fix CO 2 in clinoptilolite.
  • Table 5 shows that, although to a lesser extent, clinoptilolite, mordenite-Na and mordenite-H can be loaded with CO 2 and that this gas can be permanently fixed in the matrix mentioned.
  • FIG. 1 shows the dependence of the load on the fixing pressure used.
  • the fixation matrix it was evacuated at 473 K for 16 hours.
  • the loading curve was recorded at a fixation temperature of 793 K.
  • Zeolite 5A pellets were conditioned under vacuum at 440 K for the subsequent fixation of H 2 0. The duration of this pretreatment was 16 hours, the residual water content was 3.5% by weight.
  • a simulated, non-radioactive gas mixture which contained krypton and water vapor was then brought into contact with the zeolite 5A pellets and 20 standard cm 3 / g krypton with about 1% by weight H 2 0 at 790 K and a krypton pressure of 244 bar immobilized or fixed in the glazed zeolite.
  • HTO-labeled water was brought into contact with a zeolite 4A exchanged for a water content of 15 to 16% pretreated and isochorically heated in an autoclave at temperatures in the range from 420 K to 673 K.
  • the amount of water fixed after an aftertreatment at 420 K was, for example, 1% by weight at 420 K and 573 K and about 0.6% by weight at 673 K.
  • the tritium exchange rate was 0.017% per hour at room temperature, with HTO / H 2 O loaded zeolite samples are constantly circulated in water.
  • the experiment was carried out as described in Experiment 10, except that 3.5 kg of 5A zeolite were used as the fixation matrix.
  • the pretreatment also caused a residual water content of 2.3% by weight.
  • the specific surface area of the 5A zeolite was 480 m 2 / g.
  • the CO 2 was introduced into the autoclave under a sorption pressure of 1 bar.
  • Fixation pressure 198 bar, fixation temperature approx. 790 K.
  • a load of 32.9 standard cm 3 / g was found.
  • the surface area of the 5A amorphous zeolite after fixation was only 3 m 2 / g.

Landscapes

  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • High Energy & Nuclear Physics (AREA)
  • Solid-Sorbent Or Filter-Aiding Compositions (AREA)
  • Separation Of Gases By Adsorption (AREA)
  • Treating Waste Gases (AREA)

Claims (4)

1. Procédé pour la fixation des constituants gazeux radioactifs de gaz de combustion qui sont libérés pendant le retraitement d'éléments combustibles irradiés ou calcinés de réacteur nucléaire, caractérisé en ce que les constituants gazeux sont du 14CO2, 14CH4, les isotopes radioactifs de l'iode ou la vapeur d'eau tritiée ou le mélange de deux ou plusieurs de ces espèces et en tant que principe unitaire ou sous forme de leur mélange, dans la forme moléculaire dans laquelle ils se produisent avec une et même matière, est fixé avec un ou le même agent de fixation, une Zéolite du groupe de la Mordénite, Clinoptilolite, chabasite et Zéolite de type 4 (ayant une largeur de pore de 0,4 nm ou 0,5 nm conformément aux étapes du procédé suivantes consécutives:
a) évacuation de la Zéolite à une température dans la zone de 3200K à 720 °K jusqu'à une teneur en eau résiduelle de 0,6 à 22% en poids ou séchage de la Zéolite avec un courant d'air à la température ambiante ou avec un courant d'air chauffé dont la température de situe dans une zone de la température ordinaire jusqu'à 820°K.
b) adsorption des composants à fixer des gaz de combustion après refroidissement de la Zéolite prétraitée dans une zone de températures entre -30°C et +25°C et/ou par utilisation d'une pression dans la zone située entre la pression atmosphérique et 10 bars.
c) fixation des constituants de gaz de combustion adsorbés dans la Zéolite à une température dans la zone allant de 610°K à 920°K et à une pression dans la zone allant de 5 bars à 12000 bars.
2. Procédé selon la revendication 1, caractérisé en ce que la Zéolite est séchée dans le cas de la fixation du 14CO2 ou du 14CH4, jusqu'à une teneur en eau de 0,5 à 5% en poids.
3. Procédé selon la revendication 1, caractérisé en ce que la Zéolite, dans le cas de la fixation de l'iode, est séchée jusqu'à une teneur en eau de 0,6 à 5% en poids.
4. Procédé selon la revendication 1, caractérisé en ce que la Zéolite, dans le cas de la fixation d'eau Tritiée, est séchée jusqu'à une teneur en eau de 0,6 à 22% en poids.
EP84109730A 1983-08-24 1984-08-16 Procédé pour fixer les composants gazeux radioactifs des gaz d'échappement Expired EP0139955B1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE3330460 1983-08-24
DE19833330460 DE3330460A1 (de) 1983-08-24 1983-08-24 Verfahren zur fixierung radioaktiver, gasfoermiger bestandteile von abgasen

Publications (3)

Publication Number Publication Date
EP0139955A2 EP0139955A2 (fr) 1985-05-08
EP0139955A3 EP0139955A3 (en) 1986-05-28
EP0139955B1 true EP0139955B1 (fr) 1988-12-28

Family

ID=6207276

Family Applications (1)

Application Number Title Priority Date Filing Date
EP84109730A Expired EP0139955B1 (fr) 1983-08-24 1984-08-16 Procédé pour fixer les composants gazeux radioactifs des gaz d'échappement

Country Status (2)

Country Link
EP (1) EP0139955B1 (fr)
DE (2) DE3330460A1 (fr)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3525772C1 (de) * 1985-07-19 1986-09-04 Gkss - Forschungszentrum Geesthacht Gmbh, 2054 Geesthacht Verfahren zur endlagerreifen Konditionierung von Tritium
GB9523517D0 (en) * 1995-11-17 1996-01-17 British Nuclear Fuels Plc Separation of gases
WO2013081564A2 (fr) * 2011-11-04 2013-06-06 Kirveli Aziz Produits à base de zéolite modifiée, active, hydrophobe (aimant l'air), naturelle et procédés de production correspondants

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS51133700A (en) * 1975-05-15 1976-11-19 Nippon Atom Ind Group Co Ltd Process for storing the radioactive rare gas
US4088737A (en) * 1976-11-02 1978-05-09 The United States Of America As Represented By The United States Department Of Energy Dry method for recycling iodine-loaded silver zeolite
DE2948515C2 (de) * 1979-12-01 1983-12-22 Kernforschungszentrum Karlsruhe Gmbh, 7500 Karlsruhe Verfahren zur Fixierung von radioaktiven Edelgasen
DE3011602A1 (de) * 1980-03-26 1981-10-08 Kernforschungsanlage Jülich GmbH, 5170 Jülich Verfahren und vorrichtung zur endlagerung von tritium, insbesondere tritiumabfaellen aus kernkraftwerken, mit der moeglichkeit der tritiumrueckgewinnung

Also Published As

Publication number Publication date
DE3475846D1 (en) 1989-02-02
EP0139955A2 (fr) 1985-05-08
DE3330460A1 (de) 1985-03-07
EP0139955A3 (en) 1986-05-28

Similar Documents

Publication Publication Date Title
EP0332964B1 (fr) Procédé pour l'élimination de l'iode et des composés de l'iode des gaz et des vapeurs en utilisant une zeolite X contenant de l'argent
DE3606316C2 (fr)
DE3841114C2 (de) Verfahren zur Herstellung eines Adsorptionsmittels zur Abtrennung und Gewinnung von CO
EP0379895B1 (fr) Procédé d'élimination d'iode et des composés de l'iode de gaz et de vapeurs contenant de l'hydrogène
US3658467A (en) System for total iodine retention
US4111833A (en) Activated carbon material
DE2519236A1 (de) Verfahren zum reinigen von gasfoermigen mischungen
DE2309447C3 (de) Verfahren zum Abtrennen und Konzentrieren von Krypton 85
DE2609299C2 (de) Vorrichtung zur Verfestigung von wäßrigen, radioaktiven Abfall-Lösungen in einem glas- oder keramikartigen Block
EP0118493B1 (fr) Fixation de materiaux anioniques au moyen d'un agent de complexage
DE2230257C3 (de) Verfahren zur Beseitigung von Stickstoffoxiden aus einem gasförmigen, Stickstoffoxide und Sauerstoff enthaltenden Gemisch
EP0448585A1 (fr) Procede de fabrication d'un catalyseur pour l'elimination des oxydes d'azote dans les gaz d'echappement.
DE3108991A1 (de) Verfahren zum abtrennen und sammeln von jod
DE2708005A1 (de) Verfahren zur entfernung von methyljodid hoch 131 -gas
DE2626065A1 (de) Clinoptilolith, verfahren zur herstellung und dessen verwendung
DE3873179T2 (de) Verfahren und einrichtung zur reinigung eines tritium enthaltenden gases.
EP0139955B1 (fr) Procédé pour fixer les composants gazeux radioactifs des gaz d'échappement
DE3606317A1 (de) Verfahren und vorrichtung zur dekontamination des abgases des brennstoffkreislaufs eines fusionsreaktors von tritium und/oder deuterium in chemisch gebundener form enthaltenden abgas-bestandteilen
WO2014135138A2 (fr) Procédé pour décontaminer des radionucléides provenant de matériaux carbonés et/ou graphitiques irradiés aux neutrons
DE2621598A1 (de) Verfahren zur behandlung von radioaktiven abgasen
EP0245588A2 (fr) Procédé de purification poussée du molybdène de fission
DE3901784A1 (de) Verfahren und adsorptionsmittel zur entfernung von jod und/oder organischen jod-verbindungen aus gasen und/oder daempfen
Maeck et al. Application of Metal Zeolites to Radioiodine Air Cleaning Problems
DE3525772C1 (de) Verfahren zur endlagerreifen Konditionierung von Tritium
Park et al. Adsorption and desorption characteristics of methyl iodide on silver ion-exchanged synthetic zeolite at high temperature

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

Designated state(s): BE CH DE FR GB LI

17P Request for examination filed

Effective date: 19850318

PUAL Search report despatched

Free format text: ORIGINAL CODE: 0009013

AK Designated contracting states

Kind code of ref document: A3

Designated state(s): BE CH DE FR GB LI

17Q First examination report despatched

Effective date: 19880126

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 FR GB LI

REF Corresponds to:

Ref document number: 3475846

Country of ref document: DE

Date of ref document: 19890202

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

Payment date: 19900530

Year of fee payment: 7

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

Ref country code: CH

Payment date: 19900628

Year of fee payment: 7

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

Ref country code: FR

Payment date: 19900828

Year of fee payment: 7

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

Ref country code: BE

Payment date: 19900921

Year of fee payment: 7

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

Ref country code: DE

Payment date: 19910301

Year of fee payment: 8

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

Ref country code: GB

Effective date: 19910816

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

Ref country code: LI

Effective date: 19910831

Ref country code: CH

Effective date: 19910831

Ref country code: BE

Effective date: 19910831

BERE Be: lapsed

Owner name: KERNFORSCHUNGSZENTRUM KARLSRUHE G.M.B.H.

Effective date: 19910831

GBPC Gb: european patent ceased through non-payment of renewal fee
PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Effective date: 19920430

REG Reference to a national code

Ref country code: CH

Ref legal event code: PL

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST

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

Ref country code: DE

Effective date: 19930501