Alkaline nuclear waste

D. T. Hobbs, Technical Report on the Electrochemical Treatment of Alkaline Nuclear Wastes. DOE Report WSRC-TR 94-0287 (1994). Review. 

Kocherginsky NM, Zhang YK, and Stuck JW. D2EHPA based strontium removal from strongly alkaline nuclear waste. Desalination, 2002 144(1-3) 267-272. 

The ABEC resins are also now being marketed by ElChrom for the analysis of technetium in alkaline solution. This same resin, in a larger bead size, is currently being tested for the removal of technetium from alkaline nuclear waste storage tanks. 

UOP molecular sieves (UOP) has developed the lonsiv family of ion exchange resins for the extraction of radionuclides from wastewater. lonsiv TIE-96 is composed of a titanium-coated zeolite (Ti-zeolite) and is used to separate plutonium, strontium, and cesium from alkaline supernatant and sludge wash solutions. The technology was developed by Pacific Northwest Laboratory (PNL) for use at the West Valley, New York, nuclear waste facility. The technology is commercially available. 

Wood, D.J., Tranter, T.J., Todd, T.A. 1995. Effect of the interference of alkali and alkaline earth metal ions on the extraction of 90Sr from acidic nuclear waste solutions by 18-crown-6 derivatives in 1-octanol. Solvent Extr. Ion Exch. 13 (5) 829-844. 

Extraction of tetrahedral pertechnetate anion from aqueous solutions using several crown ethers is well known. The coextraction of cesium (or strontium) and technetium from nuclear waste by calix[4]arene-crown-6 has been reported from alkaline media. Although technetium in its common pertechnetate form does not complex directly with crown ethers, pertechnetate extraction may be facilitated by crown ethers as the coanion of sodium (for alkaline nitrate waste). Pertechnetate at trace levels in the waste may be more than a 1000-fold more extractable than the smaller nitrate anion in ion-pair extraction processes.87... 

Confirmation of this explanation is unequivocally provided by the presence in the reactor zones of at least half of the more than 30 fission products of uranium. Although soluble salts, such as tho.se of the alkali and alkaline earth metals, have been leached out, lanthanide and platinum metals remain along with traces of trapped krypton and xenon. Most decisively, the observed distribution of the various isotopes of these elements is that of fission products as opposed to the distribution normally found terrestrially. The reasons for the retention of these elements on this particular site is clearly germane to the problem of the long-term storage of nuclear wastes, and is therefore the subject of continuing study. 

The properties of hydrated titanium dioxide as an ion-exchange (qv) medium have been widely studied (51—55). Separations include those of alkaH and alkaline-earth metals, zinc, copper, cobalt, cesium, strontium, and barium. The use of hydrated titanium dioxide to separate uranium from seawater and also for the treatment of radioactive wastes from nuclear-reactor installations has been proposed (56). 

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