Salt waste tanks

Ceramicrete stabilization of Tc, partitioned from high-level tank wastes, was demonstrated by Singh et al. [11]. The waste stream was a product of a complexation-elution process that separates Tc from HLW, such as supernatant from salt waste tanks at Hanford and Savannah River. A typical waste solution generated during the complexation-elution process contains 1 M NaOH, 1 M ethylenediamine, and 0.005 M Sn +. 

In 2001, the SRS announced its choice of CSSX as the baseline cesium-removal technology over small-tank precipitation (a small-scale version of the ITP process) and ion exchange with CST for its Salt Waste Processing Facility (SWPF) to go into operation in 2010 [22], An optimized solvent system, model, and flowsheet were developed and demonstrated in 2001 and 2002 [37,49], and a modular concept was developed by ORNL in 2003 [68], Thus, the past decade has seen the emergence and maturation of a powerful new technology based on a macrocyclic cation receptor designed to function in solvent extraction to meet the critical need of the USDOE for a means of cleanly separating Cs from alkaline tank waste. 

Brine salts Brine tank sludge Waste citric acid Waste hydrochloric acid Demister filters... 

Leaching of contaminants Eission products Tc, partitioned from high-level waste tanks, debris from contaminated pipes from K-25 plant at Oak Ridge Cs, from salt supernatant and sludge, silico-titanates, and wastewater Radioactive components Ra, Fernald silo waste, transuranics, simulated and actual Rocky Flats ash waste, wastewater... 

Leaching of matrix components Simulated salt waste streams (both supernatant and sludge) from Hanford tanks... 

The decontaminated supemate may be evaporated to a solid salt in a wiped film evaporator. For the design basis assumed in this study, the total volume of solidified salt would be about 100 million 1. (/ 25 million gal). Since the heat-producing isotopes will be removed, this material can be stored in large containers in bulk storage. It is expected that the decontamination of this material will be sufficient that the principal hazard in the salt cake will be the nitrate itself. The activity left in the salt may well be less than that left in waste tanks after final decontamination. On this basis, further processing of this material into a less leachable form would probably not be necessary. However, it is presently assumed that this material cannot be dispersed to the environment. 

Figure 2 is a photograph of salt cake laid down in one of the underground tanks. The estimated inventory and characteristics of the salt cake to be stored in the waste tanks by about 1980 are listed in Table IV. The composition range shown for salt cake is for air-dried material. In reality salt cake will likely contain varying amounts of interstitial recycle liquor and should be more properly termed "damp or "wet salt cake. 

In normal operation, the PRF generates about 120 m3 of salt waste solution per month. Currently, this waste solution is made alkaline and routed to underground storage tanks where it mixes with other Hanford defense waste liquors. An alternative waste treatment scheme is desirable to avoid converting large volumes of non-actinide waste to retrievable actinide waste (>10 nCi alpha activity/g) and also to help make the PRF independent of future tank farm management operations. 

In the same way, RS can be used in basins or rivers to detect or measure the concentration of several pollutants like nitrate or nitrite, due to intensive agriculture. This is applied for example to monitor the nitrate and nitrite in the nuclear waste tank. The principle of these sensors can be applied for several other salts or pollutants after a preliminary study to establish a reliable calibration. 

The molybdate method has also been applied for remote determination of silica in highly radioactive defense waste salt solutions of the Savannah River Site (SRS), which suffered the problems with sodium aluminum silicate scale forming in the evaporators used to remove excess process water from the high-level radioactive waste tank farm [4]. 

Mother liquor removed from the crystallizer is pumped under level control to the brine tank. Slurry discharged from the crystallizer is thickened to ca. 50 wt%. The liquor from the thickener is collected in the brine tank and pumped back to the leaching tank. The thickened slurry is redissolved in the Glauber s salt dissolving tank and pumped to a waste treatment system. 

In the United States, Hquid HLW from the reprocessing of defense program fuels was concentrated, neutralized with NaOH, and stored in underground, mild steel tanks pending soHdification and geologic disposal (see Tanks AND PRESSURE VESSELS). These wastes are a complex and chemically active slurry. Suspended in the supernatant Hquid are dissolver soHds which never went into solution, insoluble reaction products which formed in the tank, and salts which have exceeded their solubiHty limit. The kinetics of many of the reactions taking place are slow (years) so that the results of characterization... 

The capacity of any specific tank configuration, in terms of metric ton equivalents, is deterrnined by one of three parameters. (/) The solubiHty of waste salts. Precipitates can settle and cause thermal hot spots, which in turn can result in accelerated corrosion rates. Thus it is important to maintain the... 

Soda-ofen, m. soda furnace, black-ash furnace, -riickstande, m.pl. soda residues, tank waste (in the Leblanc process), -salz, n. soda salt (sodium salt), specif, sodium carbonate, -schmelze, /. black ash. -see, m. soda lake, -seife, /. soda soap, -stein, m. caustic soda, -wasser, n. soda water, -zahl, /. soda number. 

Biological destrnction of tank waste (BDTW) is a separation and volume-reduction technology designed to treat snpematant and slniced salt cake waste from nnderground storage tanks. These... 

W. P. Bloxam does not recommend the preparation of this salt by passing hydrogen sulphide into an alcoholic soln. of ammonia because a complex salt, (NH S.wNHiS, is obtained, and the crystals contain alcohol. R. Laming made an aq. soln. of ammonium hydrosulphide by heating ammonium carbonate or gas liquor with sodium sulphide P. Spence, by heating the tank waste from the Leblanc soda process or gas lime with ammonium salts in a stream of steam and J. J. Berzelius recommended subliming a mixture of ammonium chloride and potassium sulphide—not in excess. 

---