Neptunium Valence Chemistry in Anion Exchange Processing

Kyser, Edward

Savannah River Site (S.C.)

关键词: Ascorbic Acid;    Neptunium;    Radioactive Waste Processing;    Hydrazine;    Storage;   

DOI  :  10.2172/890227
RP-ID  :  WSRC-TR-2003-00111
RP-ID  :  DE-AC09-96SR18500
RP-ID  :  890227

美国|英语

来源: UNT Digital Library

【 摘 要 】

The current anion resin in use in HB-Line Phase II, Reillex{trademark} HPQ, was tested in the laboratory under expected plant conditions for Np processing and was found to load between 50 and 70 g Np per liter of resin. Losses varied from 0.2 to 15 percent depending on a number of parameters. Hydrazine in the feed at 0.02 to 0.05 M appeared to keep the Np from oxidizing and increasing the losses within four to seven days after the FS addition. Losses of up to three percent were observed five days after FS addition when hydrazine was not used in the feed, compared with 0.3 percent when the feed was loaded immediately after FS addition. Based on these test results the following processing conditions are recommended: (1) Feed conditions: 8 M HNO{sub 3}, 0.02 M hydrazine, 0.05 M excess FS, less than 5 days storage of solution after FS addition. (2) Wash conditions: 100 liters of 8 M HNO{sub 3}, no FS, no hydrazine. (3) Elution conditions: 0.17 M HNO{sub 3}, 0.05 M hydrazine, no FS. (4) Precipitation feed conditions: 0.03 M excess ascorbic acid, no additional hydrazine, no FS, precipitation within three days.