Zirconium waste

Typical physical, chemical, and radiochemical properties of calcined solids from acid aluminum waste and fluoride-bearing zirconium waste are given in Table V. Other components in the calcine, e.g., actinide elements, can be calculated on the basis of the analyses of the liquid waste. 

Physical Properties Aluminum Waste Zirconium Waste... 

Zirconium phosphate [13772-29-7] also absorbs cesium and other radioactive-decay daughter products, and has been proposed as part of permanent disposal systems for nuclear fuel waste processing. 

The zone elution method has been used for quantitative estimation or recovery of heavy metals in plants and vegetable juices [29], mercury (11) in river and waste waters [52], zinc in different environmental samples [46], nickel and copper in alloys [53], zirconium in Mg-Al alloys [22], cobalt, zinc, nickel, and copper in natural water and alloy samples [54], thiocyanate in spiked photogenic waste water [55], and aluminum in bauxite ores [42],... 

In situ densitometry has been the most preferred method for quantitative analysis of substances. The important applications of densitometry in inorganic PLC include the determination of boron in water and soil samples [38], N03 and FefCNfg in molasses [56], Se in food and biological samples [28,30], rare earths in lanthanum, glass, and monazite sand [22], Mg in aluminum alloys [57], metallic complexes in ground water and electroplating waste water [58], and the bromate ion in bread [59]. TLC in combination with in situ fluorometry has been used for the isolation and determination of zirconium in bauxite and almnimun alloys [34]. The chromatographic system was silica gel as the stationary phase and butanol + methanol + HCl -H water -n HF (30 15 30 10 7) as the mobile phase. 

An extension of the reduction-chlorination technique described so far, wherein reduction and chlorination occur simultaneously, is a process in which the oxide is first reduced and then chlorinated. This technique is particularly useful for chlorinating minerals which contain silica. The chlorination of silica (Si02) by chlorine, in the presence of carbon, occurs above about 1200 °C. However, the silica present in the silicate minerals readily undergoes chlorination at 800 °C. This reaction is undesirable because large amounts of chlorine are wasted to remove silica as silicon tetrachloride. Silica is, therefore, removed by other methods, as described below, before chlorination. Zircon, a typical silicate mineral, is heated with carbon in an electric furnace to form crude zirconium carbide or carbonitride. During this treatment, the silicon in the mineral escapes as the volatile oxide, silicon monoxide. This vapor, on contact with air, oxidizes to silica, which collects as a fine powder in the furnace off-gas handling system ... 

In applications of TRUEX technology to the removal of actinides from hydrochloric acid media, CMPO will extract vanadium, iron, copper, zinc, gallium, zirconium, molybdenum, tin, and lead under the same conditions under which it will extract targeted actinides. The wastes extracted by the TRUEX process will require additional treatment before they may be safely disposed. 

Sheetz, B. E., Agrawal, D. K., Breval, E. Roy, R. 1994. Sodium zirconium phosphate (NZP) as a host structure for nuclear waste immobilization A review. Waste Management, 14, 489-505. 

Kamizono, H., Hayakawa, I. Muraoka, S. 1991. Durability of zirconium-containing ceramic waste forms in water. Journal of the American Ceramic Society, 74, 863-864. 

The results of the tests on Zr-bearing waste acid showed that acceptable Zr removal could be achieved at 90Z stoichiometry (0.83 g NaF/g Zr). Zirconium removal averaged 85Z except at low impeller tip speeds during solid dispersal and reaction when it... 

System 1 is based on MC8 (0.065 M) but needs the addition of TBP (1.5 M) in the organic phase and the introduction of oxalic acid in the liquid waste to prevent the extraction of zirconium by TBP. It has been pointed out that the addition of oxalic acid is necessary for the PALADIN process, previously implemented for the extraction of minor actinides. The addition of TBP which extracts several cations, leads to a lesser selectivity of the solvent. 

Shishkin, D.N., Galkin, B.Ya.,Fedorov,Yu.S.,Zilberman, B.Ya.,Shmidt,O.V.Partitioning of high-level waste with an extractant based on chlorinated cobalt dicarbollide and dibu-tylphosphoric acid zirconium salt. Radiochemistry (2003), 45 (6), 577-580. 

NRC has issued an assessment of potential doses to the public associated with the distribution, use, and disposal of exempt products or materials containing low levels of source or byproduct material (Schneider et al., 2001) (see Section 4.1.2.5.2). In a case involving disposal of large volumes of zircon sand produced in processing of zirconium-bearing minerals, the estimated annual dose to a future on-site resident at a disposal site was 100 p.Sv, due to the elevated levels of thorium and uranium. In all other cases, however, the estimated annual dose was substantially less than 10 xSv. Since the volumes of exempt material were large in many cases, this analysis indicates that substantial volumes of waste that contains low levels of radionuclides are potentially exemptible. 

Zirconium TBA assessment of zirconium (ZrCU), considered of use as a P-precipitating agent to reduce the eutrophication potential of pig manure wastes to receiving environments. A,B,F (Couture et al., 1989)... 

Reactions for Spillage and Waste Disposal ZrCI, h- 4H20 Zr(OH)4 + 4HC1 zirconium hydroxide (insoluble)... 

This is a batch process that is made complex by the fuel cladding and radioactivity. A typical fuel assembly for a PWR contains about 250, 0.37-inch zirconium-clad rods 12-feet long containing in total about 1200 lb of U02. The assembled rods are mechanically sheared into 1- to 2-inch lengths and dropped into a perforated basket. This is placed in the dissolver tank where the uranium oxide is dissolved as discussed above. The basket then is removed from the dissolver, and the zirconium hulls and associated hardware therein are dumped into containers, compressed, sealed, and sent to transuranic waste storage. Ultimately, they will go to a disposal facility. 

From power reactors with no reprocessing, the high-level waste consists of assemblies of zirconium-clad spent fuel rods to be packaged in stainless steel canisters. If the spent fuel is reprocessed, then the high-level waste will be converted to a silicate glass form similar to that from defense operations. The uranium... 

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