Classifications

• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C43/00—Alloys containing radioactive materials
• • G—PHYSICS
  • G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
  • G21C—NUCLEAR REACTORS
  • G21C3/00—Reactor fuel elements and their assemblies; Selection of substances for use as reactor fuel elements
  • G21C3/42—Selection of substances for use as reactor fuel
  • G21C3/58—Solid reactor fuel Pellets made of fissile material
  • G21C3/60—Metallic fuel; Intermetallic dispersions
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
  • Y02E30/00—Energy generation of nuclear origin
  • Y02E30/30—Nuclear fission reactors

Definitions

• uranium metal in the alpha phase at the time of in-pile irradiation are of minimum extent when the grain of the metal is fine and without preferential orientation.
• a standard method of refining of the grain structure of pure uranium consists in carrying out after casting an annealing treatment in the beta phase followed by quenching.
• .a treatment of this kind vis effective only in the case of small samples and remains ineffective when performed on solid rods.
• the fine grain structure which is obtained by means of this method is not stable under the influence of irradiation and thermal cycling.
• the present invention relates to uranium alloys which carry low proportions of alloying constituents and which have a fine and uniform grain structure in the alpha phase, said alloys being intended to be directly employed in a nuclear reactor in the as-cast state and without any need of subsequent heat treatment.
• Melting is performed in a crucible, for example of graphite with a lining of aluminum oxide or of calcium zirconate.
• the uranium metal and its addition elements are melted together in vacuo (for example a vacuum of to 10" millimeters of mercury) and maintained in' the molten state for a certain period of time in order to achieve homogeneity of the bath; the casting operation is then carried out, again in vacuo and at a temperature which is advantageously comprised between 1180 and 1450 C.
• vacuo for example a vacuum of to 10" millimeters of mercury
• the casting is effected in molds which can either be at room temperature or which are preferably preheated, this latter case having the advantage of preventing the formation of pores during solidification of the metal.
• molds which can either be at room temperature or which are preferably preheated, this latter case having the advantage of preventing the formation of pores during solidification of the metal.
• the following temperature ranges can be employed for the preheating process: base of the molds: 300 to 800 0; top of the molds: 600 to 1100 C., the top of the molds being always at a temperature which is higher than that of the base in order to prevent premature solidification in the top portion.
• the alloys of the invention are of particular interest in that they make it possible to obtain a fine grain structure in the alpha phase irrespective of the rate of cooling, said cooling rate being preferably comprised between 300 C./hr. and 700 C./hr.; the alloy has a fine alpha-phase grain structure even if the cooling rate reaches low values of the order of C./hr.
• the structure .which is obtained in the as-cast state is uniform and the average grain size is 0.3 mm., and in all cases smaller than 1 mm.
• a uranium alloy comprising by weight 0.10 to 0.30% molybdenum, 0.05 to 0.20% chromium, 0.01 to 0.05% iron, the remainder being uranium.

Landscapes

• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Materials Engineering (AREA)
• Mechanical Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Dispersion Chemistry (AREA)
• Plasma & Fusion (AREA)
• General Engineering & Computer Science (AREA)
• High Energy & Nuclear Physics (AREA)
• Manufacture And Refinement Of Metals (AREA)

Applications Claiming Priority (1)

Publications (1)

Family

ID=8810067

Family Applications (1)

Country Status (11)

Cited By (3)

Family Cites Families (1)

• 1963
  • 1963-08-07 FR FR943982A patent/FR1378895A/fr not_active Expired
• 1964
  • 1964-07-21 LU LU46582D patent/LU46582A1/xx unknown
  • 1964-07-21 US US384254A patent/US3258333A/en not_active Expired - Lifetime
  • 1964-07-23 NL NL6408466A patent/NL6408466A/xx unknown
  • 1964-07-28 BE BE651085A patent/BE651085A/xx unknown
  • 1964-08-04 DE DEC33569A patent/DE1233146B/de active Pending
  • 1964-08-05 GB GB31842/64A patent/GB1013249A/en not_active Expired
  • 1964-08-06 CH CH1028064A patent/CH429961A/fr unknown
  • 1964-08-07 DK DK391164AA patent/DK105620C/da active
  • 1964-08-18 OA OA50266A patent/OA00200A/xx unknown
• 1966
  • 1966-08-07 ES ES0302908A patent/ES302908A1/es not_active Expired

Non-Patent Citations (1)

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