Authors:E. Gladney, D. Perrin, R. Robinson, and P. Trujillo
Concentrations of forty-one elements were determined in NBS Urban Air Particulate material using neutron activation, atomic absorption, and instrumental combustion methods. The usefulness of this reference material is evaluated as a function of composition, certified value availability, matrix format, and cost.
Authors:C. U. Aniz, P. P. Robinson, K. K. Abdul Rashid, and T. D. Radhakrishnan Nair
The kinetics of the reduction of nickel, cobalt and copper ferrites was studied by the temperature programmed reduction method at different heating rates in hydrogen atmosphere. The activation energy values of the reduction processes were calculated using the non-isothermal isoconversional method according to the Kissinger-Akahira-Sunose equation and the dependence of apparent activation energy on the degree of conversion was determined. The carbon monoxide oxidation activities of all the three samples were determined at various temperatures up to 140 °C. An interesting correlation between the apparent activation energies for the reduction process was observed. The decreasing trend of activation energy on the ‘extent of conversion’ in all cases showed that the reduction is a multi-step process involving a reversible process followed by an irreversible step.
Authors:D. Robertson, V. Thomas, H. Rieck, D. Haggard, W. Reece, J. Pappin, W. Hensley, D. Brown, C. Thomas, and P. Robinson
Battelle, Pacific Northwest Laboratories has recently developed, tested and field-demonstrated a technology for the direct assay of transuranic radionuclides (TRU), fission products, and activation products in a variety of radwaste packages generated at commercial nuclear power plants. This technology involves non-destructive passive neutron counting for determination of nanocurie/gram quantities of the TRU radionuclides. Direct gamma spectrometry combined with thermoluminescent dosimetry (TLD) and correlation analysis is also utilized to determine the concentrations of the fission and activation products present in the radwaste packages. Employing counting times of 10 to 20 minutes, a complete analysis of all radionuclides specified for assay by the U.S. Nuclear Regulatory Commission (in 10CFR61) prior to shallow-land disposal of commercial radwastes can be measured at concentrations at least tenfold below the least restrictive Class A waste catagory.