Surrogate formulations for thermal treatment of low-level mixed waste. Part 1: Radiological surrogates

Abstract

A-58 32 Characteristic viscous relaxation time for a 4-/zm particle expanding to 10 #m.. A-59 vii 7 radioactive Rb, Y, Re, Rh, and Pd and for the transuranics Np, Am, and Cm. We will not be concerned with these elements in the present report. Comments on surrogate cost are prominent in Table 2. We will return to this issue in Sect. 3.9. Table 2. Chemical stand-ins used to simulate nonradioactive high-level waste Waste constituent Reason for substitution Substitute used• to be substituted Rb Expense K Y and Re Expensive to simulate fission Commercially available rare earth product spectrum mixtures Tc No nonradioactive isotopes Mo Ru Expense Fe Rh Expense Co Pd Expense Ni :., C.s b Expense K U, Np, Pu, Am, No nonradioactive isotopes Rare earths and Cm • Substitutes shown are those that have been used in the Waste Fgation Program at Pacific Northwest Laboratory. b Substituted in engineering-scale testsonly. 33 HSC CHEMISTRY AND PHASE STABILITY DIAGRAMS The program HSC Chemistry°, l°contains a large chemical database and algorithms for calculations of reaction outcomes, heat and material balances, equilibrium compositions, phase stability diagrams, and electrochemical equilibria. The title "HSC" stands for enthaipy (H), entropy (S), and heat capacity (C). The programs and database have been developed and improved during a period of 10 years by Antti Roine and collaborators at Outokumpu Research Oy in Finland. The version used here is the latest, Version 1.10 for Windows, dated January 1, 1993. We have used HSC Chemistry extensively in this report. It appears to be the most accessible of a number of available programs including the excellent F*A*C*T package available through the McGill University Computing Center./1 We have obtained equivalent results using F*A*C*T and HSC for several calculations when input data and databases were the same. All calculations within either program yield thermodynamic equilibrium outcomes. HSC contains two databases, labeled "main" and "own." The user will normally add new or updated information, in the prescribed H, S, C format for a given temperature, to the "own" database. The program allots this precedence over information from the "main" database but searches both for all relevant input to a given calculation.

Gaseous and Particulate Emissions from a DC Arc Melter

“…Cerium is a nonvolatile metal that is used as a surrogate for plutonium and uranium. 6 Cedar shaving pet bedding material was added to simulate organic debris in half the tests.…”

Treatability study for removal of leachable mercury in crushed fluorescent lamps

“…Hypochlorous acid should also be effective in solubilizing certain radiological contaminants, if they are actually present in the waste stream. Gates et al (1995A) show that neither the hypochlorite/chloride nor iodine/iodide extraction systems solubilize appreciable ceric oxide (CeOJ (a nonradiological surrogate for insoluble uranium oxide; see also Stockdale et al, 1994); however, these systems should readily solubilize uranium contamination if it is present in the form of uranyl compounds. The other radionuclide of interest that could be present in waste at the K-25 Site is 99Tc-a weak beta emitter-that would be readily solubilized as the pertechnetate ion in oxic media (Pourbaix, 1974).…”

Evaluation of interim and final waste forms for the newly generated liquid low-level waste flowsheet

“…Cesium salts are relatively volatile, and significant quantities of cesium may partition to the off-gas during high-temperature thermal processing (Stockdale et al, 1994;Burger, 1995).…”