GB2046499A - Encapsulation of radioactive waste - Google Patents
Encapsulation of radioactive waste Download PDFInfo
- Publication number
- GB2046499A GB2046499A GB7912210A GB7912210A GB2046499A GB 2046499 A GB2046499 A GB 2046499A GB 7912210 A GB7912210 A GB 7912210A GB 7912210 A GB7912210 A GB 7912210A GB 2046499 A GB2046499 A GB 2046499A
- Authority
- GB
- United Kingdom
- Prior art keywords
- waste
- encapsulating material
- cement
- radioactive waste
- encapsulating
- 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.)
- Withdrawn
Links
- 239000002901 radioactive waste Substances 0.000 title claims abstract description 10
- 238000005538 encapsulation Methods 0.000 title description 6
- 239000000463 material Substances 0.000 claims abstract description 22
- 239000002699 waste material Substances 0.000 claims abstract description 14
- 238000000034 method Methods 0.000 claims abstract description 11
- 239000007788 liquid Substances 0.000 claims abstract description 10
- 239000000178 monomer Substances 0.000 claims abstract description 5
- 239000000057 synthetic resin Substances 0.000 claims abstract description 5
- 229920003002 synthetic resin Polymers 0.000 claims abstract description 5
- 239000011343 solid material Substances 0.000 claims abstract description 3
- 239000004568 cement Substances 0.000 claims description 8
- 239000000839 emulsion Substances 0.000 claims description 7
- 239000000945 filler Substances 0.000 claims description 7
- 239000011347 resin Substances 0.000 claims description 7
- 229920005989 resin Polymers 0.000 claims description 7
- 239000004814 polyurethane Substances 0.000 claims description 5
- 229920002635 polyurethane Polymers 0.000 claims description 5
- 229920005906 polyester polyol Polymers 0.000 claims description 4
- 238000009833 condensation Methods 0.000 claims description 2
- 230000005494 condensation Effects 0.000 claims description 2
- 125000005442 diisocyanate group Chemical group 0.000 claims description 2
- 239000002245 particle Substances 0.000 claims description 2
- 238000012644 addition polymerization Methods 0.000 abstract 1
- 238000012643 polycondensation polymerization Methods 0.000 abstract 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 9
- PPBRXRYQALVLMV-UHFFFAOYSA-N Styrene Chemical compound C=CC1=CC=CC=C1 PPBRXRYQALVLMV-UHFFFAOYSA-N 0.000 description 4
- 239000000203 mixture Substances 0.000 description 4
- 239000003456 ion exchange resin Substances 0.000 description 3
- 229920003303 ion-exchange polymer Polymers 0.000 description 3
- 238000002156 mixing Methods 0.000 description 3
- 230000002285 radioactive effect Effects 0.000 description 3
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 2
- 239000010426 asphalt Substances 0.000 description 2
- -1 but not exclusively Substances 0.000 description 2
- 239000003999 initiator Substances 0.000 description 2
- 238000009736 wetting Methods 0.000 description 2
- NWUYHJFMYQTDRP-UHFFFAOYSA-N 1,2-bis(ethenyl)benzene;1-ethenyl-2-ethylbenzene;styrene Chemical compound C=CC1=CC=CC=C1.CCC1=CC=CC=C1C=C.C=CC1=CC=CC=C1C=C NWUYHJFMYQTDRP-UHFFFAOYSA-N 0.000 description 1
- 239000005057 Hexamethylene diisocyanate Substances 0.000 description 1
- 239000011398 Portland cement Substances 0.000 description 1
- 229910002092 carbon dioxide Inorganic materials 0.000 description 1
- 239000001569 carbon dioxide Substances 0.000 description 1
- 150000001768 cations Chemical class 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 239000003431 cross linking reagent Substances 0.000 description 1
- 238000000605 extraction Methods 0.000 description 1
- 239000003063 flame retardant Substances 0.000 description 1
- 238000009408 flooring Methods 0.000 description 1
- 239000012530 fluid Substances 0.000 description 1
- 239000008187 granular material Substances 0.000 description 1
- 230000005484 gravity Effects 0.000 description 1
- 231100001261 hazardous Toxicity 0.000 description 1
- RRAMGCGOFNQTLD-UHFFFAOYSA-N hexamethylene diisocyanate Chemical compound O=C=NCCCCCCN=C=O RRAMGCGOFNQTLD-UHFFFAOYSA-N 0.000 description 1
- 238000005342 ion exchange Methods 0.000 description 1
- 239000012948 isocyanate Substances 0.000 description 1
- 150000002513 isocyanates Chemical class 0.000 description 1
- 238000002386 leaching Methods 0.000 description 1
- 239000011344 liquid material Substances 0.000 description 1
- 229920000642 polymer Polymers 0.000 description 1
- 238000006116 polymerization reaction Methods 0.000 description 1
- 229920005862 polyol Polymers 0.000 description 1
- 150000003077 polyols Chemical class 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 150000003254 radicals Chemical class 0.000 description 1
- 238000009877 rendering Methods 0.000 description 1
- 239000011435 rock Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 239000004094 surface-active agent Substances 0.000 description 1
- 239000000725 suspension Substances 0.000 description 1
- 239000006188 syrup Substances 0.000 description 1
- 235000020357 syrup Nutrition 0.000 description 1
- 229920001169 thermoplastic Polymers 0.000 description 1
- 239000004416 thermosoftening plastic Substances 0.000 description 1
- 229920006305 unsaturated polyester Polymers 0.000 description 1
- 238000001291 vacuum drying Methods 0.000 description 1
- 239000011800 void material Substances 0.000 description 1
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
- G21F9/28—Treating solids
- G21F9/30—Processing
- G21F9/301—Processing by fixation in stable solid media
- G21F9/307—Processing by fixation in stable solid media in polymeric matrix, e.g. resins, tars
-
- 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
- G21F9/16—Processing by fixation in stable solid media
- G21F9/167—Processing by fixation in stable solid media in polymeric matrix, e.g. resins, tars
Landscapes
- Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- High Energy & Nuclear Physics (AREA)
- Processing Of Solid Wastes (AREA)
Abstract
A method for encapsulating a particulate radioactive waste which comprises suspending the waste in a viscous liquid encapsulating material which comprises one or more synthetic resin monomers or prepolymers and setting the encapsulating material by addition or condensation polymerization to form a solid material in which the waste is dispersed.
Description
SPECIFICATION
Encapsulation of radioactive waste
This invention relates to the encapsulation of radioactive waste, e.g. spent ion-exchange resins which have been used in extraction processes involving radioactive elements, and which retain a low level of radioactivity. Encapsulation serves, inter alia to prevent leaching out of the waste by surrounding water and may also increase the overall density so that dumping on the sea bed is facilitated.
Generally, granular, powder or pa rticu late waste is mixed into a fluid encapsulating material which is then set to form a block.
Prior proposals for the encapsulation of radioactive waste have used either cement or bitumen as the encapsulating material. Whilst bitumen has advantages over cement, it does have disadvantages when it comes to encapsulating radioactive ionexchange resins. In particular, the resins generally have to be dried before encapsulation. This adds one or more handling operations in the process of disposing of such waste materials, with the attendant hazards which such handling operations entail, and often involves vacuum drying at elevated temperatures, which adds to plant and process costs. Such wastes commonly contain 50% by weight water.
in accordance with one aspect of the invention, we have discovered that radioactive wastes, particularly, but not exclusively, water wet radioactive ion exchange wastes, can be encapsulated by suspending the waste in a viscous liquid encapsulating material which comprises one or more monomers or prepolymers and setting the encapsulating material by addition or condensation polymerisation to form a solid material in which the waste is dispersed.
According to another aspect the invention provides a block of synthetic resin material in which there are encapsulated dispersed particles or pieces of radioactive waste.
If the waste contains water, the liquid encapsulating material should wet its surface and should therefore have surface-active or wetting properties. Frequently, however, a surface-active agent is already present in the encapsulating material, for example if one of the monomer or prepolymers is in aqueous emulsion form. In such a case a further wetting agentwould not be necessary.
In practice the encapsulating material will contain a filler e.g. in the range 20-80% by weight of the liquid material, and it has been found that the most suitable fillers are those which are capable of taking up water e.g. Portland cement or a Portland cement-aggregate mixture. This is particularly the case where the synthetic resin is a polyurethane as the cement will take up the carbon dioxide produced by reaction of the isocyanate with water and thus reduce porosity in the set product.
The set resin is desirably non-thermoplastic so athree-dimensional or cross-linked resin is preferably used; one could specifically include a cross-linking agent but it is often convenient to use a polyfunctional monomer or prepolymer. Addition polymerisation reactions may be induced by including a free
radical initiator in a manner well known in the
polymer art.
The liquid encapsulating material may for exam
ple comprise styrene or a styrene-unsaturated
polyester mixture, together with a conventional
initiator such as a peroxy compound. However it
should be borne in mind that the liquid encapsulat
ing material should be sufficiently viscous to permit suspension of the waste and yet not so viscous as to inhibit mixing. A system should therefore be used which retains the required viscosity for a convenient time. Also, styrene produces a flammable vapour which makes handling somewhat hazardous.
The preferred system is a polyurethane system,
particularly a polyurethane system using a diisocyanate and an aqueous polyol emulsion, particularly a polyester-polyol emulsion. Such a system which we have found to be particularly suitable is
Ucrete marketed by Honeywill-Atlas Limited. This material is sold in three packs, two containing liquid resin components and the third containing selected fillers. For present purposes a cement or cement aggregate filler is used together with Ucrete Packs 1 and 2 which contain a polyester-polyol emulsion (15-40% by weight water) and MDI (hexamethylene diisocyanate).
Example Aviscous liquid encapsulating material of 'golden syrup' consistency was made up at warm room temperature as follows using Ucrete components:
Poss.
% Variation
Polyester-Polyol aqueous emulsion 25 1040 (15-40%) MDI 25 10-40 Filler (cement-crushed rock 50 20-80
aggregate mixture)
The emulsion was mixed with the MDI and mixing
was continued for 1 minute; the filler was then
mixed in and mixing was continued allowed to stand
for 4 minutes after which there was mixed in 25%
(possible variation 10-30%) dry weight of ion
exchange resin radioactive waste containing about
50% water. The mixture was then allowed to set into
blocks which had a compressive strength of about 20
MN/m2 after a curing time of 1-4 hours. Curing was
exothermic but a 300 litre sample remained consid
erably below 100"C. The blocks had a specific gravity
over 1.2 and were non-flammable (without addition
of flame retardants). They contained little or no free
water, were substantially homogeneous and had a
very low void content.
Ucrete is sold as a specialist flooring and wall
rendering material and it will be appreciated that
such applications require many of the properties
which are desirableforthe present invention e.g.
strength, viscosity in liquid form, curing time, non
flammability, chemical resistance etc.
Other materials which are known for these appli
cations are also particularly suitable for the purposes
of the present invention e.g. the materials disclosed
in U.K. Patent Specification 1 065053.
While the invention is primarily intended for
encapsulating granular material, it could also be
used for encapsulating broken-up pieces of equip
ment such as ladles.
Claims (12)
1. A block of cross-linked synthetic resin material
in which there are encapsulated dispersed particles
or pieces of radioactive waste.
2. A block according to Claim 1 wherein the resin
is a polyurethane.
3. A block according to Claim 1 or 2, which con
tains cement as a filler.
4. A block according to Claim 1 substantially as
described in the Example.
5. A method for encapsulating a particulate radioactive waste which comprises suspending the waste in a viscous'liquid encapsulating material which comprises one or more synthetic resin monomers or prepolymers and setting the encapsulating material by addition or condensation polymerisation to form a solid material in which the waste is dispersed.
6. A method according to Claim 5 wherein the encapsulating material contains cement or cement aggregate.
7. A method according to Claim 5 or6 wherein the set resin is cross-linked.
8. A method according to any of Claims 5 to 7, wherein the set resin is a polyurethane.
9. A method according to Claim 8, wherein the liquid encapsulating material comprises an aqueous polyester-polyol emulsion and a diisocyanate.
10. A method according to any of Claims 5 to 9, which is carried out without the application of heat.
11. A method according to Claim 5 substantially as described in the Example.
12. Encapsulated waste produced by a method according to any of Claims 5 to 11.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB7912210A GB2046499A (en) | 1979-04-06 | 1979-04-06 | Encapsulation of radioactive waste |
| GB8010360A GB2047946B (en) | 1979-04-06 | 1980-03-27 | Process for the encapsulation of radioactive wastes |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB7912210A GB2046499A (en) | 1979-04-06 | 1979-04-06 | Encapsulation of radioactive waste |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB2046499A true GB2046499A (en) | 1980-11-12 |
Family
ID=10504406
Family Applications (2)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB7912210A Withdrawn GB2046499A (en) | 1979-04-06 | 1979-04-06 | Encapsulation of radioactive waste |
| GB8010360A Expired GB2047946B (en) | 1979-04-06 | 1980-03-27 | Process for the encapsulation of radioactive wastes |
Family Applications After (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB8010360A Expired GB2047946B (en) | 1979-04-06 | 1980-03-27 | Process for the encapsulation of radioactive wastes |
Country Status (1)
| Country | Link |
|---|---|
| GB (2) | GB2046499A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2145405A (en) * | 1983-08-23 | 1985-03-27 | Barrow Investments | Process for the preparation of waste for transport and/or storage |
| US7114880B2 (en) | 2003-09-26 | 2006-10-03 | Carter Jr Ernest E | Process for the excavation of buried waste |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4424148A (en) * | 1981-02-17 | 1984-01-03 | United States Gypsum Company | Process for preparing wastes for non-pollutant disposal |
| AT401122B (en) * | 1994-05-09 | 1996-06-25 | Oesterr Forsch Seibersdorf | Method for stabilizing ion exchange resins loaded with radioactive materials, and products stabilized in such a way |
| FR2724757B1 (en) * | 1994-09-21 | 1996-12-06 | Commissariat Energie Atomique | POWDERED WASTE PACKAGING BLOCK AND METHOD FOR MANUFACTURING SUCH A BLOCK |
| DE4439173A1 (en) * | 1994-11-07 | 1996-05-09 | C & E Consulting Und Engineeri | Immobilisation of harmful materials in dust or particle form |
| WO2000077793A1 (en) * | 1999-06-14 | 2000-12-21 | Paul Scherrer Institut | Disposal of radioactive materials |
| US9018432B2 (en) | 2012-10-25 | 2015-04-28 | Barnhardt Manufacturing Company | Processing radioactive waste for shipment and storage |
| CN106935306A (en) * | 2016-10-13 | 2017-07-07 | 中国辐射防护研究院 | A kind of device for processing radioactive waste ion exchange resin |
-
1979
- 1979-04-06 GB GB7912210A patent/GB2046499A/en not_active Withdrawn
-
1980
- 1980-03-27 GB GB8010360A patent/GB2047946B/en not_active Expired
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2145405A (en) * | 1983-08-23 | 1985-03-27 | Barrow Investments | Process for the preparation of waste for transport and/or storage |
| US7114880B2 (en) | 2003-09-26 | 2006-10-03 | Carter Jr Ernest E | Process for the excavation of buried waste |
Also Published As
| Publication number | Publication date |
|---|---|
| GB2047946B (en) | 1982-09-29 |
| GB2047946A (en) | 1980-12-03 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| WAP | Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1) |