Residual inventory of nuclear materials remaining in processing facilities (holdup) in recognized as an insidious problem for safety of plat operations and safeguarding of special nuclear materials (SNM). This paper reports on an experimental study where a well-known method of radioanalytical chemistry, namely tracer technique, was successfully used to improve nondestructive measurements of holdup of nuclear materials in a variety of plant equipment. Such controlled measurements can improve the sensitivity of measurements of residual inventories of nuclear materials in process equipment by several orders of magnitude and the good quality data obtained lend themselves to developing mathematical models of holdup of SNM during stable plant operations.
Effects of ionizing radiations on organic ion exchangers are recognized as a vexing problem in the processing of special nuclear materials and high specific activity radioactive waste forms. An extensive literature survey, started in 1976 and updated periodically, indicates that radiation decomposition of ion exchange materials has the potential for a variety of undesirable consequences. It is also apparent from this survey that systematic efforts to identify and resolve these problems and to develop radiation resistant ion exchangers are extremely limited. There is, however, widely scattered information in the literature that is useful in designing and operating ion-exchange-based process systems with reasonable assurance of safety. The compilation of experimental data presented in this paper can contribute to better design and safer operations of synthetic organic ion exchange systems at nuclear material processing facilities.
Neutron activation analyses of wood shavings from tree rings have shown that plant tissues grown through periods of varying
environmental conditions keep permanent records of the trace elements they received through nutrients from their immediate
surroundings. Detailed examination of several species of trees, along with dendrochronological data, suggest the possibilities
of utilizing this technique for pollution monitoring as well as for developing valuable information for environmental modelling.
The plutonium processing facility at Los Alamos has adopted the strategic goal of becoming a facility that processes plutonium in a way that produces only environmentally benign waste streams. Pollution prevention through source reduction and environmentally sound recycling are being pursued. General approaches to waste reductions are administrative controls, modification of process technologies, and additional waste polishing. Recycling of waste materials, such as spent acids and salts, are technical possibilities and are being pursued to accomplish additional waste reduction. Liquid waste stream polishing to remove final traces of plutonium and hazardous chemical constituents is accomplished through (a) process modifications, (b) use of alternative chemicals and sorbents for residue removal, (c) acid recycling, and (d) judicious use of a variety of waste polishing technologies. Technologies that show promise in waste minimization and pollution prevention are identified. Working toward this goal of pollution prevention is a worthwhile endeavor, not only for Los Alamos, but for the Nuclear Complex of the future.
A comprehensive literature survey on the radiation stability of ion exchangers resulted in the publication of an extensive data compilation on the effects of ionizing radiation on synthetic organic ion exchangers in this journal (Vol. 97, No. 1). This paper is a brief review of the majorfindings of this literature survey along with similar information on synthetic inorganic ion exchangers. The primary goal of this literature survey is to review present knowledge on the effects of ionizing radiations on synthetic ion exchange materials used in radiochemical processing. Although there are gaps in our knowledge of the mechanisms of radiolytic changes in ion exchangers, the information available in the literature shows some general trends and similarities in observed qualitative effects by different types of organic and inorganic ion exchange materials. These trends and observations have been formulated into a set of qualitative and semi-quantitative statements that can be useful to potential users of ion exchange materials in nuclear material processing and radioactive waste management. Present knowledge, of the behavior of ion exchangers under the influence of ionizing radiations is too limited to justify quantitative predictive modeling.
The possibility of using characteristic X-rays from radioactive elements in activation analysis was investigated during this
work with particular emphasis on (n, γ) products. At least 27 of 56 elements investigated during this work were found to yield
themselves to activation analysis employing characteristic X-rays from electron capture or internal conversion processes during
In presenting the results, a survey made of several elements and the limits of detection of 21 elements have been reported.
Specific applications of this method were studied for the analysis of copper in a variety of samples (ores, minerals, steels,
spent lubricants and human blood).
The results of this investigation show that the use of characteristic X-rays in activation analysis has several advantages
because the energies of these radiations are closely related to the periodicity of the elements themselves.
The trace element profiles of the scalp hair of cancer patients were measured and compared with those of healthy people. Significant
differences were observed for several elements, especially for Au, I and Se.
An examination of neutron activation analysis as a method to develop trace element profiles of human hair for use in criminal
investigations was undertaken using modern instrumental methods and specially designed analytical procedures. A survey of
hair samples from a group of 300 volunteers, involving nearly 12,000 elemental analyses, indicates that while neutron activation
analysis data have distinct potentials to develop useful forensic evidence, there are several limitations to its routine applications
as a forensic evidence due to extensive data generation required to satisfy the requirements of the statistical techniques
used during this investigation. A brief discussion of experimental methods followed by a detailed description of the statistical
techniques used in individualizing human hair is presented.
An investigation of the potentials of neutron activation analysis for the routine analysis of trace elements present in atmospheric
pollutants is discussed. Various techniques including sequential air sampling, multiple neutron irradiation, high resolution
γ-ray spectrometry, chemical isolation, high flux neutron irradiation and X-ray spectrometry have been employed to determine
the levels of Pb, Al, V, I, Cl, Mn, Cu, Br, Na, La, Mo, Au, Cr, Fe, Ni, Se, Zn, Ag and Co in atmospheric pollutants. The results
of the analysis of nearly two hundred samples collected from the Buffalo New York area during 1968–1969 are reported.
Highly specific neutron activation analysis procedures involving post irradiation chemical separations were developed for
the determination of Cu, Hg, Zn, Cd, As, Se and Cr in fish tissues. The procedures developed were used to determine the levels
of these biologically active elements in some of the commercially important fish species of Lake Erie. The nuclear analytical
procedures developed generally involved the irradiation of fish tissues followed by wet-ashing in the presence of nonradioactive
carriers From the homogeneous solution of the tissue digest, the elements of interest were chemically isolated and the radio-activities
were measured by scintillation gamma ray spectrometry. The results reported include both the determination of the precision
and accuracies of each of these elemental analyses and a survey of these seven elements in nine major fish species of Lake