Analysis of large soil samples for actinides

1. A method of analyzing soil samples for the presence of actinides comprising the steps of:

a) collecting a soil sample;

b) leaching said soil with an acid;

c) collecting the leachate;

d) fusing the collected leachate with a base at an elevated temperature;

e) precipitating the fused leachate with iron hydroxide and adding cerium to enhance actinide precipitation;

f) adding complexing agents to complex the carbonate followed by acid dissolution;

g) re-precipitating with cerium fluoride to further separate the actinides from the soil matrix;

h) oxidizing any uranium present to prevent uranium precipitation;

i) adding cerium and hydrofluoric acid to precipitate the actinides;

j) redissolving the cerium fluoride precipitate;

k) separating the plutonium, americium, and curium using stacked cartridges; and

l) assaying the plutonium, americium, and curium by alpha spectrometry.

2. A method of analyzing soil samples for the presence of actinides comprising the steps of:

a) collecting a soil in a sample of at least about 100 grams;

b) leaching said soil with nitric and hydrochloric acids;

c) centrifuging and filtering to collect the leachate, said leachate containing plutonium, americium, and curium;

d) fusing the collected leachate with sodium hydroxide at an elevated temperature;

e) precipitating the fused leachate with iron hydroxide and adding cerium for facilitating chemical recoveries;

f) adding titanium chloride reductant and barium to complex the carbonate followed by acid dissolution;

g) further separating the actinides from the soil matrix by precipitating the recovered reactants from the foregoing step with cerium fluoride;

h) adding hydrogen peroxide to oxidize any uranium present and prevent uranium precipitation;

i) adding cerium and hydrofluoric acid to precipitate the actinides with cerium;

j) redissolving the cerium fluoride precipitate;

k) separating the plutonium, americium, and curium using the stacked cartridge process; and

l) assaying said actinides by alpha spectrometry.

3. The method of claim 2 wherein the weight of the collected sample of soil is in the range from about 100 grams to about 200 grams.

4. The method of claim 3 wherein in step d about 20 grams of sodium hydroxide is added to the leachate in a zirconium crucible at a temperature of about 600° C.