Patent EP0352928A1 successfully refreshed from Google Patents.
US4093682A
Expired / Lapsed
US
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Process for the production of block-shaped fuel elements for high temperature reactors
Assignee: Hobeg Hochtemperaturreaktor Brennelement GmbH
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Filing: 1977-02-14
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Granted: 1978-06-06
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Expires: 1997-02-14
Abstract
Abstract Block fuel element for high temperature reactors are produced by hot molding of a granulated graphite material consisting of natural graphite powder, synthetic graphite powder, phenolformaldehyde binder resin and stearic acid as a lubricant together with fissile and fertile coated fuel particles to a hexagonal block shape with cooling channels for helium gas and subsequent heat treatment of the molded block to a max. temperature of about 2000° C. In order to displace the air from the die, an organic compound (air displacement agent) e.g., hydrocarbon, alcohol, phenol, aldehyde, ketone ether of amine is built into the granulated graphite material having a very low vapor pressure at room temperature which increases to about 760 Torr at molding temperature of about 180° C and condensed into a liquid phase while the forming pressure is applied.
Inventors
- 👤 Milan Hrovat
- 👤 Lothar Rachor
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 05:53
CPC Classifications
G; G21; G21C; G21C21/00; G21C21/02; Y; Y02; Y02E; Y02E30/00; Y02E30/30
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
139 words
In a process for the production of a hexagonally shaped block-fuel element for a gas cooled high temperature reactor by hot molding a granulated graphite material consisting essentially of a mixture of natural graphite, synthetic graphite and binder resin together with fissile and fertile coated fuel particles together with stearic acid as a lubricant to form molded blocks and wherein the blocks are subsequently heat treated and wherein the outer hexagonal shape of the block fuel element and the cooling gas channels are produced by molding, the improvement comprising incorporated into the matrix powder prior to molding an organic compound having a very low vapor pressure at room temperature and a vapor pressure of about 760 Torr at the molding temperature, of not over 200° C, said organic compound again being liquifiable under moderate pressure at the molding temperature.
Claim 2
Dependent Claim
139 words
In a process for the production of a hexagonally shaped block-fuel element for a gas cooled high temperature reactor by hot molding a granulated graphite material consisting essentially of a mixture of natural graphite, synthetic graphite and binder resin together with fissile and fertile coated fuel particles together with stearic acid as a lubricant to form molded blocks and wherein the blocks are subsequently heat treated and wherein the outer hexagonal shape of the block fuel element and the cooling gas channels are produced by molding, the improvement comprising incorporated into the matrix powder prior to molding an organic compound having a very low vapor pressure at room temperature and a vapor pressure of about 760 Torr at the molding temperature, of not over 200° C, said organic compound again being liquifiable under moderate pressure at the molding temperature.
Claim 3
Dependent Claim
21 words
A process according to claim 1 wherein the organic compound has a vapor pressure less than 10 Torr at room temperature.
Claim 4
Dependent Claim
19 words
A process according to claim 1 wherein the organic compound has a boiling point of 131° to 212° C.
Claim 5
Dependent Claim
16 words
A process according to claim 3 wherein the pressing temperature is from 135° to 200° C.
Claim 6
Dependent Claim
20 words
A process according to claim 1 wherein the organic compound is a hydrocarbon, alcohol, phenol, amine, aldhyhde, ketone or ether.
Claim 7
Dependent Claim
18 words
A process according to claim 5 wherein the amount of organic compound is 0.2 to 2 weight %.
Claim 8
Dependent Claim
14 words
A process according to claim 6 wherein the organic compound is an aliphatic alcohol.
Claim 9
Dependent Claim
19 words
A process according to claim 7 wherein the aliphatic alcohol is an alkanol of 5 to 9 carbon atoms.
Claim 10
Dependent Claim
14 words
A process according to claim 8 wherein the alkanol is a hexanol or octanol.
Claim 11
Dependent Claim
15 words
A process according to claim 9 wherein the alkanol is hexanol-1, hexanol-2, octanol-1 or octanol-2.
Claim 12
Dependent Claim
58 words
A process according to claim 10 wherein prior to the granulating there are included the steps of preparing a mixture of molten stearic acid, the organic compound and 2 to 10% by weight of all of the matrix powder, cooling this mixture, grinding and homogeneously dry mixing the resultant powder with the remainder of the resinated matrix powder.
Claim 13
Dependent Claim
13 words
A process according to claim 11 wherein the alkanol is hexanol-1 or octanol-1.
Claim 14
Dependent Claim
55 words
A process according to claim 6 wherein prior to the granulating there are included the steps of preparing a mixture of molten stearic acid, the organic compound and 2 to 10% by weight of all the matrix powder, cooling this mixture, grinding and homogeneously mixing the powder formed with the remainder of the matrix powder.
Claim 15
Dependent Claim
55 words
A process according to claim 1 wherein prior to the granulating there are included the steps of preparing a mixture of molten stearic acid, the organic compound and 2 to 10% by weight of all the matrix powder, cooling this mixture, grinding and homogeneously mixing the powder formed with the remainder of the molding powder.
Claim 16
Dependent Claim
42 words
A process according to claim 14 wherein the block is a hexagonal prism having a height of 700 to 1000 mm, a width over the flats of 360 mm and the heavy metal content is between 3 and 20 kg per block.
Claim 17
Dependent Claim
84 words
A process according to claim 15 wherein the fuel element has a loading of fissile and fertile coated fuel particles below the maximum, and there are included the steps of heating 1 to 10% of the matrix powder consisting essentially of natural graphite, synthetic graphite and binder resin to 800° C with exclusion of air, to carbonize the resin and adding this carbonized mixture in place of at least a portion of the molding powder added to the molten stearic acid and organic compound.
Claim 18
Dependent Claim
15 words
A process according to claim 15 wherein the block contains 72 to 108 cooling channels.
Claim 19
Dependent Claim
15 words
A process according to claim 1 wherein the binder resin is a phenol formaldehyde resin.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-06-05 | 1981-12-05 | 1982-06-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-06-05 | 1985-12-05 | 1986-06-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-06-05 | 1989-12-05 | 1990-06-06 | $7700.00 | Window Closed / Lapsed |