Process for conversion of UF.sub.6 to UO.sub.2
AssigneeMitsubishi Kinzoku Kabushiki Kaisha
InventorsHiroshi Tanaka, Akio Umemura
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Abstract
A process for conversion of gaseous UF.sub.6 to UO.sub.2 powders by using a fluidized bed reaction apparatus comprising pyrohydrolizing gaseous UF.sub.6 and steam to obtain UO.sub.2 F.sub.2 particles, hydrating and dehydrating the UO.sub.2 F.sub.2 particles to UO.sub.2 F.sub.2 anhydride and reducing the UO.sub.2 F.sub.2 anhydride to UO.sub.2 powders. The obtained UO.sub.2 powders are suitable for production of nuclear fuels in power plant owing to its good ceramic properties, low fluorine contents and free flowability.
Claims6
A process for conversion of UF.sub.6 to UO.sub.2 by using a fluidized bed reaction apparatus comprising
- (a) a first step of pyrohydrolizing gaseous UF.sub.6 and steam in said fluidized bed to obtain UO.sub.2 F.sub.2 particles at temperatures of less than 400.degree. C.,
- (b) a second step of hydrating said UO.sub.2 F.sub.2 particles with water to UO.sub.2 F.sub.2 hydrate at temperatures of less than 100.degree. C.,
- (c) a third step of dehydrating said UO.sub.2 F.sub.2 hydrate by heating to UO.sub.2 F.sub.2 anhydride at temperatures of less than 200.degree. C.,
- (d) a fourth step of reducing said UO.sub.2 F.sub.2 anhydride with hydrogen gas or a mixture of hydrogen gas and steam to convert to UO.sub.2 powders at temperatures of less than 700.degree. C.
A process for conversion of UF.sub.6 to UO.sub.2 by using a fluidized bed reaction apparatus comprising
- (a) a first step of pyrohydrolizing gaseous UF.sub.6 and steam in said fluidized bed to obtain UO.sub.2 F.sub.2 particles at temperatures of less than 400.degree. C.,
- (b) a second step of hydrating said UO.sub.2 F.sub.2 particles with water to UO.sub.2 F.sub.2 hydrate at temperatures of less than 100.degree. C.,
- (c) a third step of dehydrating said UO.sub.2 F.sub.2 hydrate by heating to UO.sub.2 F.sub.2 anhydride at temperatures of less than 200.degree. C.,
- (d) a fourth step of calcining said UO.sub.2 F.sub.2 anhydride with steam to convert to UO.sub.3 or a mixture of UO.sub.3 and U.sub.3 O.sub.8 particles at temperatures of less than 700.degree. C.,
- (e) a fifth step of reducing said UO.sub.3 or said mixture of UO.sub.3 and U.sub.3 O.sub.8 with hydrogen gas or a mixture of hydrogen gas and steam to convert to UO.sub.2 powders at temperatures of less than 700.degree. C.
A process for conversion of UF.sub.6 to UO.sub.2 by using a fluidized bed reaction apparatus comprising
- (a) a first step of pyrohydrolizing gaseous UF.sub.6 and steam in said fluidized bed to obtain UO.sub.2 F.sub.2 particles at temperatures of less than 400.degree. C.,
- (b) a second step of hydrating said UO.sub.2 F.sub.2 particles with a solution added with ammonia, oxalic acid or hydrogen peroxide to UO.sub.2 F.sub.2 hydrate at temperatures of less than 100.degree. C.,
- (c) a third step of dehydrating said UO.sub.2 F.sub.2 hydrate by heating to UO.sub.2 F.sub.2 anhydride at temperatures of less than 200.degree. C.,
- (d) a fourth step of reducing said UO.sub.2 F.sub.2 anhydride with hydrogen gas or a mixture of hydrogen gas and steam to convert UO.sub.2 powders at temperatures of less than 700.degree. C.
A process for conversion of UF.sub.6 to UO.sub.2 by using a fluidized bed reaction apparatus comprising
- (a) a first step of pyrohydrolizing gaseous UF.sub.6 and steam in said fluidized bed to obtain UO.sub.2 F.sub.2 particles at temperatures of less than 400.degree. C.,
- (b) a second step of hydrating said UO.sub.2 F.sub.2 particles with a solution added with ammonia, oxalic acid or hydrogen peroxide to UO.sub.2 F.sub.2 hydrate at temperatures of less than 100.degree. C.,
- (c) a third step of dehydrating said UO.sub.2 F.sub.2 hydrate by heating to UO.sub.2 F.sub.2 anhydride at temperatures of less than 200.degree. C.,
- (d) a fourth step of calcining said UO.sub.2 F.sub.2 anhydride with steam to convert to UO.sub.3 or a mixture of UO.sub.3 and U.sub.3 O.sub.8 particles at temperatures of less than 700.degree. C.,
- (e) a fifth step of reducing said UO.sub.3 or said mixture of UO.sub.3 and U.sub.3 O.sub.8 with hydrogen gas or a mixture of hydrogen gas and steam to convert to UO.sub.2 powders at temperatures of less than 700.degree. C.
Dependencies are inferred from the claim text.