Behavior of technetium in nuclear waste vitrification processes
نویسنده
چکیده
Nearly 100 tests were performed with prototypical melters and off-gas system components to investigate the extents to which technetium is incorporated into the glass melt, partitioned to the off-gas stream, and captured by the off-gas treatment system components during waste vitrification. The tests employed several simulants, spiked with 99mTc and Re (a potential surrogate), of the low activity waste separated from nuclear wastes in storage in the Hanford tanks, which is planned for immobilization in borosilicate glass. Single-pass technetium retention averaged about 35 % and increased significantly with recycle of the off-gas treatment fluids. The fraction escaping the recycle loop was very small.
منابع مشابه
Tc and Re behavior in borosilicate waste glass vapor hydration tests.
Technetium, found in some nuclear wastes (such as those generated from spent fuel reprocessing), is of particular concern with regard to long-term waste storage because of its long half-life (2.13 x 10(5) years) and high mobility in the environment. One method of stabilization of such waste is through vitrification to produce a durable borosilicate glass matrix. The fate of Tc under hydrotherma...
متن کاملImpeding 99Tc(IV) mobility in novel waste forms
Technetium ((99)Tc) is an abundant, long-lived radioactive fission product whose mobility in the subsurface is largely governed by its oxidation state. Tc immobilization is crucial for radioactive waste management and environmental remediation. Tc(IV) incorporation in spinels has been proposed as a novel method to increase Tc retention in glass waste forms during vitrification. However, experim...
متن کاملProcesses for Treatment of Heavy Metals in Ash from Municipal Solid Waste Incinerators
Modem municipal waste combustors (MWC's) process approximately 100 million tons of refuse each year in the United States, Europe and Japan, producing 30 million tons of ash. The incineration process has the effect of concentrating the toxic heavy metals normally present in municipal refuse. As a result, the ash may require treatment to reduce the quantity or the mobility of heavy metals within ...
متن کاملModel for the conversion of nuclear waste melter feed to glass
The rate of batch-to-glass conversion is a primary concern for the vitrification of nuclear waste, as it directly influences the life cycle of the cleanup process. This study describes the development of an advanced model of the cold cap, which augments the previous model by further developments on the structure and the dynamics of the foam layer. The foam layer on the bottom of the cold cap co...
متن کاملAutomated Sampling and Sample Pneumatic Transport of High Level Tank Wastes at the Hanford Waste Treatment Plant
This paper describes the development work, and design and engineering tasks performed, to provide a fully automated sampling system for the Waste Treatment Plant (WTP) project at the Hanford Site in southeastern Washington State, USA. WTP is being built to enable the emptying and immobilization of highly active waste resulting from processing of irradiated nuclear fuel since the 1940s. The Hanf...
متن کامل