Document: NRC Regulatory Guide
Document ID: 688895c2-d1d9-44f3-9c79-3cf0daa88510
Document Type: regulatory_guide
Title: 
Source: NRC Regulatory Guide Division 4
Source URL: https://www.nrc.gov/docs/ML0037/ML003739541.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-4.5
CFR Part: 
CFR Title: 

Content:
to 50g of soil can be,readily analyzed by this procedure, Using normally available laboratory equipment and materials. Soil samples much larger than this tend to be unwieldy because special equipment and materials such as large centrifuges, large PTFE beakers, etc., are usually required. The analysis of large soil aliquots is desirable, however, because larger aliquots usually provide a more representative sample. In general, it would be poor practice to use aliquot sizes containing less than 10 g of soil unless smaller than 10 g samples are replicated. A. Principle Plutonium is extracted from soil with a combination of nitric, hydrofluoric, and hydrochloric acids in the presence of Pu-236 (or Pu-242) tracer. Plutonium is isolated by anion exchange and electrodeposited onto a stainless steel disc for determination by alpha spect romet ry. B. Reagents Ammonium hydroxide (28%) Ammonium iodide Boric acid Dowex I x 4 (100-200 mesh, nitrate form) anion resin Hydrochloric acid (38%) Hydrofluoric acid (48%) Iron carrier (10 mg/ml) Nitric acid (70%) Nitric acid (8N) Oclyt alcohol (Reagent grade) Pu-236 tracer (or Pu-242) Sodium bisulfite Sodium hydroxide (50% solution) Sodium nitrite C. Special Equipment Elect rodeposition apparatus Ion exchange column (-l1.3 cm ID x~ 15 .cm) Stainless steel disc (I.9-cm - 2.2-cm diam. polished on one side) PTFE beakers (250,400, 600 ml, etc.) PTFE stirring rods (-0.3 cm x - 12 cm) D. Extraction I. Weigh a l0-g soil aliquot into a 250-ml PTFE beaker. Add an appropriate quantity of Pu-236 tracer. (Note I at the end of this section.) 2. Add 60 ml of HNO 3(70%) and 30 ml of HF (48%). Digest on a hotplate with frequent stirring for about an hour. (Notes 2 and 3) 3. Remove from the hotplate and cool somewhat before adding 30 ml each of HNO3 and HF. Digest with some stirring for about an hour. 4. Remove from the hotplate and cool. Carefully add 20 ml of HCI (38%) and stir. Heat on a hotplate for 45 minutes with occasional stirring. 5. Add about