Vapor space characterization of Waste Tank 241-C-103: Inorganic results from sample Job 7B (May 12-25, 1994)

Abstract

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

Vapor space characterization of waste Tank 241-C-107: Results from samples collected on 9/29/94

“…Inorganic sampling and analysis methods followed those described by Ligotke et al (1994) for samples obtained fiom C-103, a tank containing a relatively complex headspace composition. Method-validation measurements during that study did appear to validate the trapping analysis of NH3, but did not eliminate the possibility of interferences that could affect NO, results.…”

“…Nitrite blank levels used to correct data were 0.0158 f 0.0002 pmol in front and 0.0075 k 0.0003 pmol in back sorbent sections and were based on three blanks. Although spiked blanks were not tested, blanks spiked with 0.0064, 0.047, 0.11, and 0.74 pmol NO; during related sample jobs yielded percentage recoveries of 153 k 14%, 103 f 4%, 106 8%, and 111 f 7%, respectively (Clauss et al 1994;Ligotke et al 1994). No samples were reanalyzed to check repeatability.…”

Vapor space characterization of waste Tank 241-U-103: Results from samples collected on 2/15/95

“…Although spiked blanks were not tested, the percentage recoveries of three sets of blanks spiked with 12.2, 22.3, and 46.4 pmol of NH, were 101 & 4%, 109 k 2%, and 104 f 1 %, respectively, during related sample jobs (Clauss et al 1994;Ligotke et al 1994). The analyses of two samples were duplicated and yielded repeatabilities of 0 and & 6%.…”

“…Nitrite blank levels used to correct data were 0.0098 k 0.0009 pmol in front (three of six blanks analyzed) and 0.0061 f. 0.0006 pmol in back (two of six blanks analyzed) sorbent sections. Although spiked blanks were not tested, blanks spiked with 0.0064, 0.047, 0.11, and 0.74 pmol of NO; during related sample jobs yielded percentage recoveries of 153 f 14%, 103 * 4%, 106 rf 8 % , and 11 1 f 7%, respectively (Clauss et al 1994;Ligotke et al 1994). The analyses of'two samples were duplicated and yielded repeatabilities of & 0 and f 2 %.…”

Vapor space characterization of waste Tank 241-C-104: Results from samples collected on 2/17/94 and 3/3/94

“…It is important to note that both sampling and analytical procedures were developmental as Tank C-104 was one of the first four trial sample jobs. Differences in sample preparation, sampling, and sample handling, compared with subsequent jobs, varied from those used after April 1994 (Ligotke et al 1994). Analytical accuracy was estimated based on procedures used.…”