Analytical Characterization of the Thorium Nitrate Stockpile

Mattus, CH

Oak Ridge National Laboratory

关键词: Low-Level Radioactive Wastes;    Oxidizers;    Stockpiles;    Emission Spectroscopy;    Barium;   

DOI  :  10.2172/840088
RP-ID  :  ORNL/TM-2003/54
RP-ID  :  AC05-00OR22725
RP-ID  :  840088

美国|英语

来源: UNT Digital Library

【 摘 要 】

For several years, Oak Ridge National Laboratory (ORNL) has been supporting the Defense Logistics Agency-Defense National Stockpile Center with stewardship of a thorium nitrate (ThN) stockpile. The effort for fiscal year 2002 was to prepare a sampling and analysis plan and to use the activities developed in the plan to characterize the ThN stockpile. The sampling was performed in June and July 2002 by RWE NUKEM with oversight by ORNL personnel. The analysis was performed by Southwest Research Institute of San Antonio, Texas, and data validation was performed by NFT, Inc., of Oak Ridge, Tennessee. Of the {approx} 21,000 drums in the stockpile, 99 were sampled and 53 were analyzed for total metals composition, radiological constituents (using alpha and gamma spectrometry), and oxidizing characteristics. Each lot at the Curtis Bay Depot was sampled. Several of the samples were also analyzed for density. The average density of the domestic ThN was found to be 1.89 {+-} 0.08 g/cm{sup 3}. The oxidizer test was performed following procedures issued by the United Nations in 1999. Test results indicated that none of the samples tested was a Division 5.1 oxidizer per Department of Transportation definition. The samples were analyzed for total metals following the U.S. Environmental Protection Agency methods SW-846-6010B and 6020 (EPA 2003) using a combination of inductively coupled plasma--atomic emission spectroscopy and inductively coupled plasma--mass spectroscopy techniques. The results were used to compare the composition of the eight Resource Conservation and Recovery Act metals present in the sample (arsenic, barium, cadmium, chromium, lead, mercury, selenium, and silver) to regulatory limits. None of the samples was found to be hazardous for toxicity characteristics. The radiological analyses confirmed, when possible, the results obtained by the inductively coupled plasma analyses. These results--combined with the historical process knowledge acquired on the material and the results of previous tests--classified the ThN as low-level radioactive waste for disposal purposes. This characterization was necessary to continue the efforts associated with disposition of the material at the Nevada Test Site, Mercury, Nevada. With the current work presented in this report, the analytical characterization phase is completed for this source material stockpile.