Samples of vapor obtained in May 1994 from the headspace of the Hanford single-shell waste storage tank 24 1-C-103 were analyzed for selected inorganic compounds at Pacific Northwest Laboratory. The work was performed to provide concentration information supporting safety and toxicological evaluations. The vapor samples were passed through analyte-specific solid sorbent traps which held the compounds by chernisorption until analysis. Samples were analyzed to determine the concentrations of ammonia, nitric oxide, nitrogen dioxide, sulfur oxides, and hydrogen cyanide. Samples were also analyzed to provide information on the total mass concentration of vapors in the headspace. A summary of results is shown in Table 1. Throughout the multi-week sample job, average ammonia concentrations were uniform and ranged between 296 and 3 10 ppmv. The actual ammonia concentrations were more than 10-fold greater than the recommended exposure limit (REL) of 25 ppmv. The results of nitric oxide, sulfur oxides, and hydrogen cyanide samples were-2,10.02, and 10.04 ppmv, respectively, and were less or much less than the recommended exposure levels. The concentration of nitrogen dioxide was subject to potential sampling and analytical errors, but was estimated to be less than or much less than 0.4 ppmv. Only the nitrogen dioxide results failed to meet the target analytical detection limit of one-tenth of the REL. Fifty of 55 inorganic samples yielded an average mass concentration of 42.1 f 2.7 mg/L. A series of 10 ammonia samples, also supported by gravimetric analyses, showed no sampling bias occurred between samples obtained from different sample ports. Company (WHC) provided technical guidance by issuing Letters of Instruction and Sampling and

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No abstract

Even though the interest in the corrosion of radwaste tanks goes back to the mid-1940 1 5 when waste storage was begun, and a fair amount of corrosion work has been done since then, the changes in processes and waste types have outpaced the development of new data pertinent to the new double shell tanks. As a consequence, Pacific Northwest laboratory {PNL) began a development of corrosion data on a broad base of waste compositions in 1980. The objective of the program was to provide operations personnel with corrosion rate data as a function of waste temperature and composition. The work performed in this program examined A-537 tank steel in Double Shell Slurry and Future PUREX Wastes, at temperatures between 40 and 180°C as well as in Hanford Facilities Waste at 25 and 50°C. In general, the corrosion rates were less than 1 mpy (0.001 inch/yr) and usually less than 0.5 mpy. Excessive corrosion rates (> 1 mpy) were only found in dilute waste compositions or in concentrated caustic compositions at temperatures above 140°C. Stress corrosion cracking was only observed under similar conditions. The results are presented as polynomial prediction equations with examples of the output of existing computer codes. The codes are not provided in the text but are available from the authors.

A suite of physical and chemical analyses has been performed in support of activities directed toward the resolution of an Unreviewed Safety Question concerning the potential for a floating organic layer in Hanford waste tank 241-C-103 to sustain a pool fire. The analysis program was the result of a Data Quality Objectives exercise conducted jointly with staff from Westinghouse Hanford Company and Pacific Northwest Laboratory (PNL). The organic layer has been analyzed for flash point, organic composition including volatile organics, inorganic anions and cations, radionuclides, and other physical and chemical parameters needed for a safety assessment leading to the resolution of the Unreviewed Safety Question. The aqueous layer underlying the floating organic material was also analyzed for inorganic, organic, and radionuclide composition, as well as other physical and chemical properties. This work was • conducted to PNL Quality Assurance impact level III standards (Good Laboratory Practices).°.°1 Peroxides Less than 2.5 gEquivalent/g Nitroalkanes No indication of nitroalkanes by RSST(a) experiment; less than 2 [tmol/g by infrared analysis Density 0.876 g/mL at 25°C, 0.868 g/mL at 44°C Viscosity 4 cP at 25°C, 2.5 cP at 40°C Gross alpha, beta Alpha = 547 pCi/g Beta = 1.05 x 106 pCi/[g 90Sr 5.5 x 105 pCi/g Alpha emitters 238pu = 90.2, 239+240pu = 194, 241Am = 179 (pCi/[g) Gamma emitters 6°Co = 7.45 x 10-4, 137Cs = 4.13 x 10-2, 154Eu = 3.17 x 10"4, 155Eu = 3.15 x 10.4' 241Am = 2.11 x 10.4 (_tCi/[g) aa Water content 1.31 wt% Ammonia 24 lxg NH3/g IC F, Cl, NO2, NO3, SO4, all <50 _tg/g ICP/AES Ag = 0.90, Al = 1.8, B = 11, Ca = 2.0, (2% HNO3 leach) Cd = 2.1, Cu = 2.2, Fe = 0.33, Na = 70, Ni = 9.9, P = 605 (_t_g) (a) RSST = Reactive system screening tool vi Contents