Identification of Non-Pertechnetate Species in Hanford Tank Waste, Their Synthesis, Characterization, and Fundamental Chemistry

Schroeder, Norman C. ; Ashley, Kenneth R. ; Olivares, Jose A.

Los Alamos National Laboratory

关键词: Digestion;    12 Management Of Radioactive Wastes, And Non-Radioactive Wastes From Nuclear Facilities;    37 Inorganic, Organic, Physical And Analytical Chemistry;    Radioactive Wastes;    Wastes;   

DOI  :  10.2172/839103
RP-ID  :  EMSP-81988--2004
RP-ID  :  FG07-01ER63281
RP-ID  :  839103

美国|英语

来源: UNT Digital Library

【 摘 要 】

Technetium, as pertechnetate (TcO4 -), is a mobile species in the environment. This characteristic, along with its long half-life, (99Tc, t1/2 = 213,000 a) makes technetium a major contributor to the long-term hazard associated with low level waste (LLW) disposal. Technetium partitioning from the nuclear waste at DOE sites may be required so that the LLW forms meet DOE performance assessment criteria. Technetium separations assume that technetium exists as TcO4 - in the waste. However, years of thermal, chemical, and radiolytic digestion in the presence of organic material, has transformed much of the TcO4 - into unidentified, stable, reduced, technetium complexes. To successfully partition technetium from tank wastes, it will be necessary to either remove these technetium species with a new process, or reoxidize them to TcO4 - so that conventional pertechnetate separation schemes will be successful.