2 research outputs found
Recommended from our members
Gas generation and retention in Tank 101-SY: A summary of laboratory studies, tank data, and information needs
Chemical and radioactive wastes from processes used to separate plutonium from uranium are stored in underground tanks at the Hanford Site in Washington state. In March 1981, it was observed that the volume of wastes in Tank 101-SY slowly increased, followed by a rapid decrease and the venting of large quantities of gases. These cycles occurred every 8 to 15 weeks and continue to the present time. Subsequent analyses showed that these gases were composed primarily of hydrogen and nitrous oxide (N{sub 2}O). In response to the potential for explosion and release of hazardous materials to the environment, laboratory programs were initiated at Argonne National Laboratory (ANL), Georgia Institute of Technology (GIT), Pacific Northwest Laboratory (PNL), and Westinghouse Hanford Company (WHC), to develop a better understanding of the physical and chemical processes occurring in this waste tank. An aggressive sampling and analysis effort is also under way to characterize the wastes as fully as possible. These efforts will provide a technically defensible basis for safety analyses and future mitigation/remediation of the tank and its contents
Recommended from our members
A summary of available information on ferrocyanide tank wastes
Ferrocyanide wastes were generated at the Hanford site during the mid to late 1950s to make more tank space available for the storage of high level nuclear waste. The ferrocyanide process was developed as a method of removing {sup 137}Cs from existing waste solutions and from process solutions that resulted from the recovery of valuable uranium in waste tanks. During the coarse of the research associated with the ferrocyanide process, it was discovered that ferrocyanide materials when mixed with NaNO{sub 3} and/or NaNO{sub 2} exploded. This chemical reactivity became an issue in the 1980s when the safety associated with the storage of ferrocyanide wastes in Hanford tanks became prominent. These safety issues heightened in the late 1980s and led to the current scrutiny of the safety associated with these wastes and the current research and waste management programs. Over the past three years, numerous explosive test have been carried out using milligram quantities of cyanide compounds. These tests provide information on the nature of possible tank reactions. On heating a mixture of ferrocyanide and nitrate or nitrite, an explosive reaction normally begins at about 240{degrees}C, but may occur well below 200{degrees}C in the presence of catalysts or organic compounds that may act as initiators. The energy released is highly dependent on the course of the reaction. Three attempts to model hot spots in local areas of the tanks indicate a very low probability of having a hot spot large enough and hot enough to be of concern. The main purpose of this document is to inform the members of the Tank Waste Science Panel of the background and issues associated with the ferrocyanide wastes. Hopefully, this document fulfills similar needs outside of the framework of the Tank Waste Science Panel. 50 refs., 9 figs., 7 tabs