Method for the containment of nuclear waste

Claim 1

A method of containing nuclear waste characterized by preparing a composition which comprises from 25 to 80% calculated as Si0 2 , of a compound having the general formula SiR m (OR') n X p , Si(OSiR 3 ) 4 , or mixtures thereof, partially hydrolyzed; up to 30%, calculated as the metal oxide, of a compound having the general formula AlR' (OR") X s , Mg(Al(OR) X , or mixtures thereof, par- tially hydrolyzed if hydrolyzable; from 5 to 20%, calculated as the metal oxide, of a compound having the general forumula BR' q (OR) r X s , or mixtures thereof, partially hydrolyzed; from 3 to 25%, calculated as the metal oxide, of a compound having the general formula MOR", MZR' 3 , or mixtures thereof, partially hydrolyzed if hydrolyzable, where the total calcium content, calculated as CaO, does not exceed 15%, and where each R is independently selected from alkyl to C 10 and alkanyl to C10, and each R' is independently selected from R and aryl, each R" is independently selected from R and hydrogen, each X is independently selected from chlorine and bromine, each M is independently selected from sodium, potassium, and lithium, each Z is independently selected from carbon and boron, m is 0 to 3, n is 0 to 4, p is 0 to 1, each q is independently selected from 0 to 3, each r is independently selected from 0 to 3, each s is independently selected from 0 to 1, and m + n + p = 4, q + r + s = 3, and t + u + v = 2, alcohol in a weight ratio to hydrolyzed alkoxide of from 0.5 to 3, calculated as alkoxide; and sufficient water to remove at least 99% of said alkanol as an azeotrope; boiling off said azeotrope; mixing up to 40%, based on solids in the product calculated as oxide, of said nuclear waste into said composition; evaporating the mixture to from 25 to 45% solids; and melting and cooling said mixture.

Claim 2

A method of containing nuclear waste characterized by preparing a composition which comprises from 25 to 80% calculated as Si0 2 , of a compound having the general formula SiR m (OR') n X p , Si(OSiR 3 ) 4 , or mixtures thereof, partially hydrolyzed; up to 30%, calculated as the metal oxide, of a compound having the general formula AlR' (OR") X s , Mg(Al(OR) X , or mixtures thereof, par- tially hydrolyzed if hydrolyzable; from 5 to 20%, calculated as the metal oxide, of a compound having the general forumula BR' q (OR) r X s , or mixtures thereof, partially hydrolyzed; from 3 to 25%, calculated as the metal oxide, of a compound having the general formula MOR", MZR' 3 , or mixtures thereof, partially hydrolyzed if hydrolyzable, where the total calcium content, calculated as CaO, does not exceed 15%, and where each R is independently selected from alkyl to C 10 and alkanyl to C10, and each R' is independently selected from R and aryl, each R" is independently selected from R and hydrogen, each X is independently selected from chlorine and bromine, each M is independently selected from sodium, potassium, and lithium, each Z is independently selected from carbon and boron, m is 0 to 3, n is 0 to 4, p is 0 to 1, each q is independently selected from 0 to 3, each r is independently selected from 0 to 3, each s is independently selected from 0 to 1, and m + n + p = 4, q + r + s = 3, and t + u + v = 2, alcohol in a weight ratio to hydrolyzed alkoxide of from 0.5 to 3, calculated as alkoxide; and sufficient water to remove at least 99% of said alkanol as an azeotrope; boiling off said azeotrope; mixing up to 40%, based on solids in the product calculated as oxide, of said nuclear waste into said composition; evaporating the mixture to from 25 to 45% solids; and melting and cooling said mixture.

Claim 7

A method according to any of claims 1 to 5, characterized in that the composition comprises from 40 to 50% calculated as SiO 2 , of Si(OR) 2 , partially hydrolyzed; from 20 to 30%, calculated as Al 2 O 3 , of A1( O H) 3 , A1203, Al(OR) 3 , or mixtures thereof, partially hydrolyzed if hydrolyzable; from 10 to 15%, calculated as B 2 0 3 , of B ( O R) 3 , partially hydrolyzed; from 10 to 15%, calculated as Na 2 0, of NaOH, Na 2 0, NaOR, partially hydrolyzed if hydrolyzable, or mixtures thereof; where each R is independently selected from alkyl to C 4 ; alkanol up to C 4 in a weight ratio of alkanol to partially hydrolyzed alkoxide of from 0.5 to 3, calculated as alkoxide; and sufficient water to remove at least 99% of said alkanol as an azeotrope; and characterized in that the mixture is evaporated to from 35 to 40% solids.

Claim 11

A method according to any of the preceding claims, characterized in that the nuclear waste is an aqueous sludge containing dissolved salts, and hydrated oxides and hydroxides of Al, Fe, Ni, Cr, Mg, Mn, Si, Na, Hg, Nd, Ce, Cs, Sr, Ti, Ca, V, Pu, Th, Zr, Mo, or mixtures thereof.

Claim 12

A method according to any of the preceding claims, characterized in that the amount of the nuclear waste mixed into the composition is from 25 to 35% solid nuclear waste based on product weight calculated as oxide.