Patent EP0044692A2 successfully refreshed from Google Patents.
EP0044692A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Arrangements for containing waste material
Assignee: Australian Atomic Energy Commission
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Filing: 1981-07-14
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Granted: —
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Expires: 2001-07-14
Abstract
Abstract Nuclear reactor waste is immobilised as a synthetic rock structure formed by sintering under high temperature and pressure in a metal canister (5) which is sealed after filling. A thin walled metal canister (5) is located in a cavity (9) in a refractory support element (8) which restrains deformation of the canister and the reactor waste mixed as a minor proportion with material for forming the synthetic rock is introduced into the canister preferably in the form of pourable granules. Compaction rams (2, 3) compress the material and it is heated to form the synthetic rock. The canister (5) is sealed with a lid. The canister (5) is preferably elongated and the heating is preferably by water cooled induction coils (10) arranged in a series of overlapping heating zones in which the sintering takes place in sequence. The apparatus for the method preferably has a tapered bore 9 in the refractory support element (8) into which granular refractory material is packed in an initial step. After the process the canister (5) is ejected and the granules of refractory material collected and recycled by suitable equipment (20 to 24).
Inventors
- 👤 Eric John Ramm
- 👤 Alfred Edward Ringwood
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-04 16:38
CPC Classifications
G; G21; G21F; G21F9/00; G21F9/28; G21F9/30; G21F9/301; G21F9/302; G21F9/008; G21F9/34
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
175 words
A method for forming solid blocks which include synthetic rock in which nuclear reactor waste is immobilised, the method comprising:- (a) establishing a quantity of supply material (6) in a metal canister (5) , means (41 or 8, 9) being provided for preventing gross outward deformation of the metal canister during the method, the metal canister (5)being sufficiently heat and corrosion resistant to contain the supply material (6) during and after the method has been effected and the supply material comprising material for forming the synthetic rock and a minor proportion of nuclear reactor waste capable of being immobilised in the synthetic rock when densified into a block; (b) applying pressure to compress the supply material along an axis of the canister and applying heat to cause densification and the formation of a block of synthetic rock including the nuclear reactor waste; and (c) either before or after said densification step, sealing the canister with a metal cap (13) whereby the sealed canister is adapted to be placed in a suitable long term storage location.
Claim 2
Independent Claim
175 words
A method for forming solid blocks which include synthetic rock in which nuclear reactor waste is immobilised, the method comprising:- (a) establishing a quantity of supply material (6) in a metal canister (5) , means (41 or 8, 9) being provided for preventing gross outward deformation of the metal canister during the method, the metal canister (5)being sufficiently heat and corrosion resistant to contain the supply material (6) during and after the method has been effected and the supply material comprising material for forming the synthetic rock and a minor proportion of nuclear reactor waste capable of being immobilised in the synthetic rock when densified into a block; (b) applying pressure to compress the supply material along an axis of the canister and applying heat to cause densification and the formation of a block of synthetic rock including the nuclear reactor waste; and (c) either before or after said densification step, sealing the canister with a metal cap (13) whereby the sealed canister is adapted to be placed in a suitable long term storage location.
Claim 3
Dependent Claim
47 words
A method as claimed in claim 1 and further characterised by said means for preventing outward deformation comprising a bellows-like wall structure (41) in the metal canister (5), the metal canister being of generally cylindrical form and said pressure being applied along the axis of the canister.
Claim 4
Dependent Claim
37 words
A method as claimed in claim 2 and further characterised by locating a tubular screen (26) within the metal canister (5) and locating thermally insulating powder (27) between the screen and the interior wall of the canister.
Claim 5
Dependent Claim
43 words
A method as claimed in claim 2, and characterised by locating the metal canister (5) in an outer cylinder (40) and then applying said pressure to compress the metal canister, the compressed canister being looser than an interference fit in said outer cylinder.
Claim 6
Dependent Claim
34 words
A method as claimed in claim 1 and characterised by said means for preventing outward deformation comprising a refractory support element (8) having a cavity (9) in which said metal canister (5) is located.
Claim 7
Independent Claim
47 words
A method as claimed in any one of the preceding claims and further characterised by providing, in contact with the supply material, nickel, titanium, iron or other metal capable of providing a suitable oxygen potential to facilitate the effective incorporation of the waste into the synthetic rock.
Claim 8
Independent Claim
32 words
A method as claimed in any one of the preceding claims, and further characterised by forming the supply material into granulated form before loading the supply material into the metal canister (5).
Claim 9
Dependent Claim
56 words
A method as claimed in claim 7 and further characterised by loading the supply material (6) into thin-walled metal cans (14) which will remain solid at the densification temperature but will deform upon densification of the supply material as it forms synthetic rock, the metal cans (14) being loaded in sequence into the metal canister (5).
Claim 10
Dependent Claim
62 words
A method as claimed in claim 5 or claim 8 an4 further characterised by the metal canister (5) having substantially greater length than diameter and said densification is effected in a series of zones in sequence extending from one end of the metal canister by utilising a series of separately tapped electrical induction heating coils (10) or heating in turn each zone.
Claim 11
Dependent Claim
14 words
A method as claimed in claim 9 wherein the heating zones overlap one another.
Claim 12
Dependent Claim
57 words
A method as claimed in claim 5 or any one of claims 8 to 10, and further characterised by said refractory support element (8) having said cavity provided by a tapered bore, and locating granular refractory material (11) in the tapered annular space between the metal canister (5) and the tapered bore before said pressure is applied.
Claim 13
Dependent Claim
39 words
A method as claimed in claim 11 and further characterised by using vibration to compact the granular refractory material (11) and after the densification process ejecting the metal canister (5) and collecting and recycling the granular refractory material (11).
Claim 14
Independent Claim
29 words
A method as claimed in any one of the preceding claims wherein the canister used in the method is formed of stainless steel in accordance with Sandvik 253MA Grade.
Claim 15
Independent Claim
26 words
A method as claimed in any one of the preceding claims wherein the pressure applied to the supply material is in the region of 7 MPA.
Claim 16
Independent Claim
36 words
A method as claimed in any one of the preceding claims wherein the heating step is carried out to bring the supply material to a temperature of about 1260°C for a period of about 3 hours.
Claim 17
Dependent Claim
157 words
An apparatus for use in the method as claimed in claim 5 and characterised by a refractory support element (8) with a bore (9) in which the metal canister (5) containing the supply material (6) is adapted to be placed with a clearance space between the walls of the canister and the walls of the cavity, means (20, 21) for introducing granular refractory material (11) into the space between the metal canister (5) and the wall of the cavity, means for compacting the granules in the cavity whereby outward deformation of the metal under heat and pressure is substantially restrained, means (10) for applying heat in the densifying process to the supply material within the metal canister, means (2,3) for applying densifying pressure along an axis of the canister, means (3) for removing the canister after the sintering step and means (22, 23, 24) for collecting and reusing the granular material after removal of the canister (5).
Claim 18
Dependent Claim
37 words
Apparatus as claimed in claim 16, wherein the heating means (10) comprises a series (AG) of separately tapped water cooled induction heating _coils arranged to provide a series of overlapping heating zones to be utilised in sequence.
Claim 19
Dependent Claim
47 words
A disposable element comprising an exterior sealed metal canister (5) containing a densified synthetic rock mass including in the crystal structure a minor proportion of nuclear reactor waste, the element being the product of the method or apparatus as claimed in any one of the preceding claims.
References Cited (Backward Citations)
No citation records indexed.
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