Process for massively hydriding zirconium-uranium fuel elements

Claim 1

A method of massively hydriding uranium-zirconium alloy, which comprises placing said alloy in a chamber, drawing a vacuum on said chamber, heating said alloy to a temperature of about 1, 600*-1,700* F. at a maximum rate of about 300* F. per hour, introducing hydrogen into said chamber at a flow rate of about 0.050-0.100 mgm. H2/gm. Zr/hr. while maintaining said temperature, until beta-delta phase transformation has occurred and the pressure in said system through hydrogen introduction has increased to a maximum of about 65 p.s.i.g., then isobarically cooling the resulting hydrided composition at a rate of about 10*-50* F. per hour, the pressure being maintained constant by introducing hydrogen into said chamber at a flow rate of about 0.10-0.30 mgm. H2/gm. Zr/hr., until an isochore of final desired composition is obtained, and then cooling said alloy to ambient conditions in said chamber without further hydrogen introduction.

Claim 2

A method of massively hydriding uranium-zirconium alloy which comprises placing said alloy in a chamber, evacuating said chamber to vacuum, slowly heating said alloy to a temperature of about 1,600*-1,700* F., slowly introducing hydrogen into said chamber while maintaining said temperature to increase the pressure therein to between ambient and a maximum of about 15 p.s.i.g., until the beta to delta phase transformation is completed, then further increasing the pressure in said chamber through hydrogen introduction until a first selected H/Zr ratio is obtained, slowly isobarically cooling the resulting hydrided body, the pressure being maintained uniform in said chamber during such cooling by hydrogen introduction, until a final preselected H/Zr ratio is obtained, and then slowly cooling said composition to ambient conditions without further hydrogen introduction.

Claim 3

A method for massively hydriding uranium-zirconium alloy, which comprises placing said alloy in a furnace, drawing a vacuum on said furnace, heating said alloy to a temperature of about 1, 600*-1,700* F at a rate of about 200* F per hour, introducing hydrogen into said chamber at a rate of about 0.075 mgm H2/gm Zr/hr, until a pressure of about 60 psig is reached at a temperature of about 1,650* F, then isobarically cooling the resulting hydrided composition at a rate of about 20* F per hour while maintaining constant pressure by introducing hydrogen into said chamber at a rate of about 0.13 mgm H2/gm Zr/hr, until a temperature of about 1,300* F is reached, cooling the resulting hydrided alloy to a temperature of about 1,000* F at a rate of about 50* F per hour without further introduction of hydrogen, and then cooling said alloy to ambient conditions in said furnace without further temperature or pressure regulation.

Claim 4

A method of massively hydriding uranium-zirconium alloy, which comprIses placing said alloy in a chamber, evacuating said chamber to vacuum, heating the alloy at a maximum rate of about 300* F. per hour to a temperature of about 1,600*-1,700* F., introducing hydrogen into said chamber at a flow rate of about 0.050-0.100 mgm. H2/gm. Zr/hr. while maintaining said temperature to increase the pressure therein to between ambient and a maximum of about 15 p.s.i.g., until the beta-delta phase change is completed, then further increasing the pressure in said chamber with hydrogen at said flow rate while maintaining said temperature, until a first selected H/Zr ratio is obtained, isobarically cooling the resulting hydrided body at a rate of about 10*-50* F. per hour, the pressure in said chamber being maintained constant with hydrogen introduced at a rate of about 0.100-0.300 mgm. H2/gm. Zr/hr., until an isochore of the final desired composition is obtained, and then slowly cooling said composition to ambient conditions in said chamber without further hydrogen introduction.

Claim 5

A method of massively hydriding uranium-zirconium alloy, which comprises placing said alloy in a chamber, evacuating said chamber to vacuum, heating the alloy to a temperature of about 1, 600*-1,700* F. at a rate of about 200* F. per hour, introducing hydrogen into said chamber at a flow rate of about 0.050-0.100 mgm. H2/gm. Zr/hr., while maintaining said temperature, increasing the pressure in said chamber to between atmospheric and about 15 p.s.i.g., until the beta-delta phase transformation is complete, then increasing the pressure in said chamber through hydrogen introduction at the aforesaid flow rate until a pressure of about 60 p.s.i.g. is reached, then isobarically cooling the resulting hydrided composition at a rate of about 10*-50* F. per hour, the pressure being maintained constant with hydrogen introduced at a flow rate of about 0.100-0.300 mgm. H2/gm. Zr/hr., until a temperature of about 1,300* F. is reached, and then slowly cooling said composition to ambient conditions in said chamber without further hydrogen introduction.