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Gas phase pulse radiolysis. [Reaction with hydroxyl radical]

Description: Gas phase pulse radiolysis, a technique which can be used to study many different phenomena in chemistry and physics, is discussed. As a source of small radicals, pulse radiolysis is important to the field of chemistry, particularly to combustion and atmospheric kinetics. The reactions of 1,3-butadiene, allene, ethylene and acetylene with OH are presented. 52 refs., 1 fig., 1 tab.
Date: January 1, 1987
Creator: Jonah, C.D.; Liu, Andong & Mulac, W.A.
Partner: UNT Libraries Government Documents Department

Pulse radiolysis of the lanthanide and actinide elements

Description: The rate constants for the reaction of e/sup -//sub aq/ with all the lanthanides have been examined in greater detail and spectra have been obtained of the resulting product +2 ions for several which have been as yet unreported. Rate constants have been determined for e/sup -//sub aq/ with a number of actinides, and spectra of transients and stable species resulting from a number of these reactions have been determined.
Date: January 1, 1976
Creator: Gordon, S.; Sullivan, J. C.; Mulac, W. A.; Cohen, D. & Schmidt, K. H.
Partner: UNT Libraries Government Documents Department

A new method for infrared imaging of air currents in and around critical hazard fume hoods

Description: Active, safe real-time method of measuring and recording the efficacy of vapor containment in and around critical hazard fume hoods has been developed. An infrared camera whose response is restricted to a spectral range that overlaps a strong absorption band in a nontoxic gas is used to render real-time video images of the presence and flow of the gas. The gas, nitrous oxide, is ejected in a continuous stream in and around fume hoods that are to be certified capable of containing hazardous fumes. The principal advantage is that various scenarios of air flow displacement in and outside the hood can be easily investigated; the principal limitation is the necessity of high tracer gas concentration to obtain strong visualizations.
Date: March 1, 1994
Creator: Mulac, W. A.; McCreary, J. R. & Schmalz, H.
Partner: UNT Libraries Government Documents Department

High temperature reaction kinetics

Description: During the last year the dependence of the apparent rate of OD + CO on water pressure was measured at 305, 570, 865 and 1223 K. An explanation was found and tested for the H/sub 2/O dependence of the apparent rate of OH(OD) + CO at high temperatures. The isotope effect for OH(D) with CO was determined over the temperature range 330 K to 1225 K. The reason for the water dependence of the rate of OH(OD) + CO near room temperatures has been investigated but no clear explanation has been found. 1 figure.
Date: January 1, 1985
Creator: Jonah, C.D.; Beno, M.F.; Mulac, W.A. & Bartels, D.
Partner: UNT Libraries Government Documents Department

Gas generation from Hanford grout samples

Description: In an extension of our work on the radiolytic processes that occur in the waste tanks at the Hanford site, we studied the gas generation from grout samples that contained nuclear waste simulants. Grout is one option for the long-term storage of low-level nuclear waste solutions but the radiolytic effects on grout have not been thoroughly defined. In particular, the generation of potentially flammable and hazardous gases required quantification. A research team at Argonne examined this issue and found that the total amount of gases generated radiolytically from the WHC samples was an order of magnitude higher than predicted. This implies that novel pathways fro charge migration from the solid grout to the associated water are responsible for gas evolution. The grout samples produced hydrogen, nitrous oxide, and carbon monoxide as well as nitrogen and oxygen. Yields of each of these substances were determined for doses that are equivalent to about 80 years storage of the grout. Carbon monoxide, which was produced in 2% yield, is of particular importance because even small amounts may adversely affect catalytic conversion instrumentation that has been planned for installation in the storage vaults.
Date: March 1, 1996
Creator: Jonah, C.D.; Kapoor, S.; Matheson, M.S.; Mulac, W.A. & Meisel, D.
Partner: UNT Libraries Government Documents Department

Radiolytic and Thermal Generation of Gases from Hanford Grout Samples : Interim Report

Description: Gamma irradiation of WHC-supplied samples of grouted Tank 102-AP simulated nonradioactive waste has been carried out at three dose rates, 0.25, 0.63, and 130 krad/hr. The low dose rate corresponds to that in the actual grout vaults; with the high dose rate, doses equivalent to more than 40 years in the grout vault were achieved. An average G(H2) = 0.047 molecules/100 eV was found, independent of dose rate. The rate of H2 production decreases above 80 Mrad. For other gases, G(N2) = 0.12, G(O2) = 0.026, G(N2O) = 0.011 and G(CO) = 0.0042 at 130 krad/hr were determined. At lower dose rates, N2 and O2 could not be measured because of interference by trapped air. The value of G(H2) is higher than expected, suggesting segregation of water from nitrate and nitrite salts in the grout. The total pressure generated by the radiolysis at 130 krad/h has been independently measured, and total amounts of gases generated were calculated from this measurement. Good agreement between this measurement and the sum of all the gases that were independently determined was obtained. Therefore, the individual gas measurements account for most of the major components that are generated by the radiolysis. At 90 C, H2, N2, and N2O were generated at a rate that could be described by exponential formation of each of the gases. Gases measured at the lower temperatures were probably residual trapped gases. An as yet unknown product interfered with oxygen determinations at temperatures above ambient. The thermal results do not affect the radiolytic findings.
Date: October 1993
Creator: Meisel, Dan; Jonah, Charles D.; Kapoor, S.; Matheson, Max S. & Mulac, W. A.
Partner: UNT Libraries Government Documents Department

Gas Generation from Hanford Grout Samples : Final Report

Description: The radiolytic yields of hydrogen nitrogen, oxygen, nitrous oxide, and carbon monoxide from two batches of WHC-supplied samples of grouted simulated waste have been (gamma) irradiated at several dose rates (0.025, 0.63 and 130 krad/h for hydrogen and 130 krad/h for all other gases). In one batch, the liquid waste simulant that was added to the grout included the original components that were added to Tank 102-AP (labeled "virgin" waste.) The second batch included a similar liquid waste simulant that was preirradiated to 35 Mrad prior to incorporation into the grout. It is believed that the preirradiated samples more closely represent radioactive waste that was stored in the tank for several years. The lowest dose rate corresponds approximately to that expected in the grout; with the high dose rate, doses equivalent to about 85 years storage in grout vaults were achieved. Most of the results on the batch of virgin samples have been reported recently (Report ANL 93/42). Here we report the results from the batch of preirradiated grout samples and compare the results from the two batches. The radiolytic yields of hydrogen and nitrogen are lower in the preirradiated than in the virgin grout. On the other hand G(oxygen) is higher in the preirradiated samples: 0.078 vs. 0.026. The yield of nitrous oxide is essentially the same, G(nitrous oxide) = 0.010, in both. The yields measured from both batches are significantly higher than previously reported values. At 90 C similar amounts of hydrogen were generated thermally from both batches of grout, whereas the total amounts of nitrogen and nitrous oxide were larger for the preirradiated than for the virgin grout samples. At lower temperatures the rate of generation was hardly measurable. Mass spectrometric analysis suggests that NO is thermally (but not radiolytically) released from the grout samples.
Date: March 1994
Creator: Jonah, Charles D.; Kapoor, S.; Matheson, Max S.; Mulac, W. A. & Meisel, Dan
Partner: UNT Libraries Government Documents Department

Radiolytic and thermal generation of gases from Hanford grout samples

Description: Gamma irradiation of WHC-supplied samples of grouted Tank 102-AP simulated nonradioactive waste has been carried out at three dose rates, 0.25, 0.63, and 130 krad/hr. The low dose rate corresponds to that in the actual grout vaults; with the high dose rate, doses equivalent to more than 40 years in the grout vault were achieved. An average G(H{sub 2}) = 0.047 molecules/100 eV was found, independent of dose rate. The rate of H2 production decreases above 80 Mrad. For other gases, G(N{sub 2}) = 0.12, G(O{sub 2}) = 0.026, G(N{sub 2}O) = 0.011 and G(CO) = 0.0042 at 130 krad/hr were determined. At lower dose rates, N{sub 2} and O{sub 2} could not be measured because of interference by trapped air. The value of G(H{sub 2}) is higher than expected, suggesting segregation of water from nitrate and nitrite salts in the grout. The total pressure generated by the radiolysis at 130 krad/h has been independently measured, and total amounts of gases generated were calculated from this measurement. Good agreement between this measurement and the sum of all the gases that were independently determined was obtained. Therefore, the individual gas measurements account for most of the major components that are generated by the radiolysis. At 90 {degree}C, H{sub 2}, N{sub 2}, and N{sub 2}O were generated at a rate that could be described by exponential formation of each of the gases. Gases measured at the lower temperatures were probably residual trapped gases. An as yet unknown product interfered with oxygen determinations at temperatures above ambient. The thermal results do not affect the radiolytic findings.
Date: October 1, 1993
Creator: Meisel, D.; Jonah, C. D.; Kapoor, S.; Matheson, M. S. & Mulac, W. A.
Partner: UNT Libraries Government Documents Department

Gas generation from Hanford grout samples. Final report

Description: The radiolytic yields of H{sub 2}, N{sub 2}, O{sub 2}, N{sub 2}O, and CO from two batches of WHC-supplied samples of grouted simulated waste have been {gamma} irradiated at several dose rates (0.025, 0.63 and 130 krad/h for H{sub 2} and 130 krad/h for all other gases). In one batch, the liquid waste simulant that was added to the grout included the original components that were added to Tank 102-AP (labeled ``virgin``waste.) The second batch included a similar liquid waste simulant that was preirradiated to 35 Mrad prior to incorporation into the grout. It is believed that the preirradiated samples more closely represent radioactive waste that was stored in the tank for several years. The lowest dose rate corresponds approximately to that expected in the grout; with the high dose rate, doses equivalent to about 85 years storage in grout vaults were achieved. Most of the results on the batch of virgin samples have been reported recently (Report ANL 93/42). Here we report the results from the batch of preirradiated grout samples and compare the results from the two batches. The radiolytic yields of H{sub 2} and N{sub 2} are lower in the preirradiated than in the virgin grout. On the other hand G(O{sub 2}) is higher in the preirradiated samples: 0.078 vs. 0.026. The yield of nitrous oxide is essentially the same, G(N{sub 2}O) =0.010, in both. The yields measured from both batches are significantly higher than previously reported values. At 90{degrees}C similar amounts of H{sub 2} were generated thermally from both batches of grout, whereas the total amounts of N{sub 2} and N{sub 2}O were larger for the preirradiated than for the virgin grout samples. At lower temperatures the rate of generation was hardly measurable. Mass spectrometric analysis suggests that NO is thermally (but not radiolytically) released from ...
Date: March 1, 1994
Creator: Jonah, C. D.; Kapoor, S.: Matheson, M. S.; Mulac, W. A. & Meisel, D.
Partner: UNT Libraries Government Documents Department

A new method for infrared imaging of air currents in and around critical hazard fume hoods

Description: A real time method of measuring and recording the efficacy of vapor containment in and around critical hazard fume hoods is being developed. An infrared camera whose response is restricted to a spectral range that overlaps a strong absorption band in a non-toxic gas is used to render real-time video images of the presence and flow of the gas. The gas, nitrous oxide, is ejected in a continuous stream in and around fume hoods that are to be certified capable of containing hazardous fumes. The principle advantage is that various scenarios of air flow displacement in and outside the hood can be easily investigated; the principle limitation is the necessity of high tracer gas concentration to obtain strong visualizations. We hope that this technique can be found to be an effective and safe method to test hoods in locations that were built before present regulations were promulgated.
Date: January 1, 1992
Creator: Mulac, W.A.; McCreary, J.R. (Argonne National Lab., IL (United States)) & Schmalz, H. (Argonne National Lab., IL (United States) Thermal Surveys, Inc., Rockford, IL (United States))
Partner: UNT Libraries Government Documents Department