Salt waste volume reduction by sodium removal

Burger, L.L.; Ryan, J.L.; Swanson, J.L.; Bray, L.A.

doi:10.2172/4330145

Cited by 5 publications

(17 citation statements)

References 6 publications

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“…Ryan (Burger et al 1973) observed some volatilization from the nitrate/nitrite system at 1075 K to 1125 K and a large loss at 1200, K to 1225 K. Volatilization as N%0 would require about 117 kJ/mol (Glassner 1958). However, N%O has negligible volatility at 1200 K (Brewer and Margrave 1955).…”

Section: Thermal Data For Compoundsmentioning

confidence: 99%

Calculation of reaction energies and adiabatic temperatures for waste tank reactions

Burger¹

1993

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SummaryContinual concern has been expressed over potentially hazardous exothermic reactions that might occur in Hanford Site underground waste storage tanks. These tanks contain many different oxidizable compounds covering a wide range of concentrations. Several compounds may be in concentrations and quantities great enough to be considered a hazard in that they could undergo rapid and energetic chemical reactions with nitrate and nitrite salts that are present it heated to the initiating or critical temperature. The chemical hazards are a function of several interrelated factors, including the amount of energy (heat) produced, how fast it is produced, and the thermal absorption and heat transfer properties of the system. The reaction path(s) will determine the amount of energy produced and kinetics will determine the rate that it is produced. The tanks also contain many inorganic compounds inert to oxidation. These compounds act as diluents and can inhibit exothermic reactions because of their heat capacity and thus, in contrast to the oxidizable compounds, provide mitigation of hazardous reactions.In this report the energy that may be released when various organic and inorganic compounds react is computed as a function of the reaction-mix composition and the temperature. The enthalpy, or integrated heat capacity, of these compounds and various reaction products is presented as a function of temperature; the enthalpy of a given mixture can then be equated to the energy release from various reactions to predict the maximum temperature which may be reached. This is estimated for several different compositions. Alternatively, the amounts of various diluents required to prevent the temperature from reaching a critical value can be estimated. Reactions W i g different paths, forming different products such as N20 in place of N2 are also considered, as are reactions where an excess of caustic is present. Oxidants other than nitrate and nitrite are considered briefly.The relative available energy per unit mass of the various oxidizable compounds, or "fuels," that may be present ranges from 1 to about 25. Stoichiometric mixes with oxidant, e.g., fuel plus the required amount of sodium nitrate (NaNO,) for a complete reaction, compared on a mass basis, also show large differences. This "energy density" covers a range of 1 to about 5.A consequence of different stoichiometries for different fuels is that an excess of sodium nitrate or nitrite for one reactant may be a deficiency for another. This is significant since excess nitrate or nitrite is an excellent heat sink, especially at elevated temperatures.The efficiency of various compounds as heat sinks, i.e., their enthalpies, vary greatly. In the wastes water is the most significant material at temperatures up to slightly above 100°C. From 100°C to about 300°C the greatest effect is probably from hydrated salts, with some contribution from concentrated caustic solutions. The loss of water from these materials requires a large energy input, some 50% to 100% greater than f...

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Section: Thermal Data For Compoundsmentioning

confidence: 99%

Calculation of reaction energies and adiabatic temperatures for waste tank reactions

Burger¹

1993

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“…The reaction rate is the same for either an oxygen or argon atmosphere (Bond and Jacobs, 1968) and reaches equilibrium within two hours at 700°C (Burger et al, 1973). The reaction is endothermic (Bond and Jacobs, 1966).…”

Section: Pvtd T3b-95-210mentioning

confidence: 98%

“…Sodium nitrate and sodium nitrite have also been reported to volatilize by Burger et al (1973). It was observed that a large fraction of the material vaporized at a temperature of approximately 65OOC during their experiments.…”

Section: Pvtd T3b-95-210mentioning

confidence: 99%

“…Above 545"C, sodium peroxide decomposes to 0 2 and Na20 (Rode and Golder, 1956). But, Burger et al (1973) found that it was stable even at high temperatures. Burger et al (1973) found evidence of H202 in water leaches from holding NaNO3 at 85OOC for 4 hours, which indicates the presence of Na202 in the melt.…”

Section: Pvtd T3b-95-210mentioning

confidence: 99%

“…But, Burger et al (1973) found that it was stable even at high temperatures. Burger et al (1973) found evidence of H202 in water leaches from holding NaNO3 at 85OOC for 4 hours, which indicates the presence of Na202 in the melt. Abe et al (1983) also proposed that Na202is formed in the melt under an argon atmosphere but only as an intermediate.…”

Section: Pvtd T3b-95-210mentioning

confidence: 99%

See 2 more Smart Citations

Hanford low-level waste process chemistry testing data package

Smith¹,

Tracey²,

Darab³

et al. 1996

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Chemistry of application of calcination/dissolution to the Hanford tank waste inventory

Delegard¹,

Elcan²,

Hey³

1994

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Approximately 330,000 motric tons of sodium-rich radioactive waste originating from separation of plutonium from irradiated uranium fuel are stored in underground tanks at the U.S. Department of Energy (DOE) Hanford Site in Washington State. Fractionation of the waste into low-level waste (LIN) and high-level waste (HLW) streams is envisioned via partial water dissolution and limited radionuclide extraction operations. Under optimum conditions, LLWwould contain most of the chemical bulk while HLWwould contain virtually all of the transuranic and fission product activity. The fractionation will be followed by production of durable waste forms (e.g., glass) for separate long-term storage of LLWand HLWfractions. Under this fractionation scheme, the water-insoluble solids, including insoluble radionuclides plus soluble radionuclides separated from the LLW fraction, will go tothe HLWfraction. Calcination at around 850 =C, followed by water dissolution, has been proposed as an alternative initial treatment of Hanford Site waste to improve • waste dissolution and the envisioned LLW/HLWsplit. Results of literature and laboratory studies are reported on the application of calcination/dissolution (C/D) to the fractionation of the HanfordSite tank waste inventory. Both simulated and genuine HanfordSite waste materials were used in the lab tests.

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Salt waste volume reduction by sodium removal

Cited by 5 publications

References 6 publications

Calculation of reaction energies and adiabatic temperatures for waste tank reactions

Calculation of reaction energies and adiabatic temperatures for waste tank reactions

Hanford low-level waste process chemistry testing data package

Chemistry of application of calcination/dissolution to the Hanford tank waste inventory

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