Lead iron phosphate glass as a containment medium for disposal of high-level nuclear waste
First Claim
1. A nuclear containment composition resulting from the solidification of a melt of (1) a lead phosphate glass consisting essentially of, in weight percent, 45-66% PbO, 34-55% P2 O5, (2) a radioactive metal oxide mixture incorporated in said glass, and (3) an effective corrosion-inhibiting concentration up to 9% Fe2 O3 incorporated in said glass, based on the total weight of said composition.
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Abstract
Lead-iron phosphate glasses containing a high level of Fe2 O3 for use as a storage medium for high-level radioactive nuclear waste. By combining lead-iron phosphate glass with various types of simulated high-level nuclear waste, a highly corrosion resistant, homogeneous, easily processed glass can be formed. For corroding solutions at 90° C., with solution pH values in the range between 5 and 9, the corrosion rate of the lead-iron phosphate nuclear waste glass is at least 102 to 103 times lower than the corrosion rate of a comparable borosilicate nuclear waste glass. The presence of Fe2 O3 in forming the lead-iron phosphate glass is critical. Lead-iron phosphate nuclear waste glass can be prepared at temperatures as low as 800° C., since they exhibit very low melt viscosities in the 800° to 1050° C. temperature range. These waste-loaded glasses do not readily devitrify at temperatures as high as 550° C. and are not adversely affected by large doses of gamma radiation in H2 O at 135° C. The lead-iron phosphate waste glasses can be prepared with minimal modification of the technology developed for processing borosilicate glass nuclear wasteforms.
37 Citations
3 Claims
- 1. A nuclear containment composition resulting from the solidification of a melt of (1) a lead phosphate glass consisting essentially of, in weight percent, 45-66% PbO, 34-55% P2 O5, (2) a radioactive metal oxide mixture incorporated in said glass, and (3) an effective corrosion-inhibiting concentration up to 9% Fe2 O3 incorporated in said glass, based on the total weight of said composition.
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3. An improved process for the containment of radioactivity comprising:
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(a) forming a melt, at a temperature in the range of 800°
C. to 1,500°
C., of a lead glass composition consisting essentially of 45-66% PbO, 34-55% P2 O5 or a compound readily decomposable to P2 O5 and an effective corrosion - inhibiting concentration of up to 9% Fe2 O3 ; and(b) incorporating up to 20%, based on the weight of the glass composition of a radioactive metal oxide mixture and then solidifying the melt.
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Specification
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- Resources
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Current AssigneeUnited States Of America As Represented By The Department Of Energy
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Original AssigneeUnited States Of America As Represented By The Department Of Energy
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InventorsSales, Brian C., Boatner, Lynn A.
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Primary Examiner(s)Terapane, John F.
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Assistant Examiner(s)Caress, Virginia B.
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Application NumberUS06/870,296Time in Patent Office1,145 DaysField of Search252/628, 252/629, 252/478, 501/22, 501/24, 501/32, 501/45, 501/73, 501/74, 501/155US Class Current588/11CPC Class CodesC03C 3/16 containing phosphorusG21F 9/305 Glass or glass like matrix ...
