[en] Tests were performed to evaluate the accuracy, precision and response time of certain commercially available handheld toxic gas monitors. The tests were conducted by PNNL in the Chemical Chamber Test Facility for CH2MHill Hanford Company. The instruments were tested with a set of dilute test gases including ammonia, nitrous oxide, and a mixture of organic vapors (acetone, benzene, ethanol, hexane, toluene and xylene). The certified gases were diluted to concentrations that may be encountered in the outdoor environment above the underground tank farms containing radioactive waste at the U.S. Department of Energy's Hanford site, near Richland, Washington. The challenge concentrations are near the lower limits of instrument sensitivity and response time. The performance test simulations were designed to look at how the instruments respond to changes in test gas concentrations that are similar to field conditions

[en] Tests were performed to evaluate the accuracy, precision and response time of certain commercially available handheld toxic gas monitors. The tests were conducted by PNNL in the Chemical Chamber Test Facility for CH2MHill Hanford Company. The instruments were tested with a set of dilute test gases including ammonia, nitrous oxide, and a mixture of organic vapors (acetone, benzene, ethanol, hexane, toluene and xylene). The certified gases were diluted to concentrations that may be encountered in the outdoor environment above the underground tank farms containing radioactive waste at the U.S. Department of Energy's Hanford site, near Richland, Washington. The challenge concentrations are near the lower limits of instrument sensitivity and response time. The performance test simulations were designed to look at how the instruments respond to changes in test gas concentrations that are similar to field conditions

[en] Semi-volatile chemicals associated with nuclear processes (e.g., the reprocessing of uranium to produce plutonium for nuclear weapons, or the separation of actinides from processing waste streams), can provide sticky residues or signatures that will attach to piping, ducting, soil, water, or other surface media. Volatile compounds, that are more suitable for electro-optical sensing, have been well studied. However, the semi-volatile compounds have not been well documented or studied. A majority of these semi-volatile chemicals are more robust than typical gaseous or liquid chemicals and can have lifetimes of several weeks, months, or years in the environment. However, large data gaps exist concerning these potential signature compounds and more research is needed to fill these data gaps so that important signature information is not overlooked or discarded. This report investigates key semi-volatile compounds associated with nuclear separations, identifies available chemical and physical properties, and discusses the degradation products that would result from hydrolysis, radiolysis and oxidation reactions on these compounds.

[en] General discussion of effluents from nuclear material reprocessing operations and the opportunity to detect important effluents in the near-field domain. The proliferation of nuclear weapons is a major international security threat. It is important to be able to detect nuclear processing operations that could enable either proliferant nations or subnational groups to obtain materials needed to develop and deploy nuclear weapons. In the ideal world, detection technologies would be available that could reliably detect, locate, and quantify all targeted reprocessing operations from large standoff distances. But this 'magic tri-corder' technology does not exist. Monitoring may be performed by a combination of remote (i.e., large standoff distances), intermediate range, and near-field measurements. In situations where cooperative monitoring is practical, the intermediate and near-field measurements may be fairly easy to implement. In non-cooperative situations, the intermediate and near-field measurements are necessarily more challenging. Chemical effluents released to the environment from nuclear processing plants can provide evidence of on-going processing operations. For some persistent effluents, environmental residuals can provide evidence of former operations. While the effluents may be monitored for occupational safety or environmental compliance, they may also be exploited to gain insights into the operations that produced effluents. Critical processes targeted in this report include chemical reprocessing operations that extract plutonium (Pu) and other Special Nuclear Materials (SNM) from irradiated nuclear fuel. Further, the report focuses on the opportunity to exploit important, persistent process chemical effluent signatures that can be found near nuclear material processing plants and their supporting facilities to support more effective nuclear non-proliferation monitoring. The U.S. PUREX (Plutonium and Uranium Recovery by EXtraction) process and operations serve as the basis for this discussion as the PUREX process was disclosed during the Atoms for Peace era, and it has been adopted by many nations in the subsequent years. This report describes: (1) Key chemical groups employed in the PUREX and nuclear materials reprocessing operations that offer significant process insights and exhibit persistence in the environment after release from the facility; (2) Effluent release sources from the Hanford PUREX operation and its associated support facilities; (3) Plume propagation after the effluent plumes are released from process stacks and the probability that under some common atmospheric conditions, the plume likely reaches the ground within several kilometers of the stack; (4) The importance of considering the fate of chemicals in the environment to ensure that detection methods target viable signatures and in likely locations in the environment; and (5) Results of a preliminary analysis of soil samples collected near the Hanford PUREX plant and its associated supporting facilities that confirmed the presence of persistent chemical residues indicative of the PUREX plant processes. In summary, the near-field domain around potential nuclear material reprocessing operations offers a valuable opportunity to detect chemical signatures that can be very important for understanding facility operations, including probable processes being employed

[en] Self-assembled monolayers of carbamoylphosphonic acids (acetamide phosphonic acid and propionamide phosphonic acid) on mesoporous silica supports were studied as potential absorbents for heavy and transition metal ions in aqueous wastes. The adsorption capacity, selectivity, and kinetics of the materials in sequestering metal ions, including Cd2+, Co2+, Cu2+, Cr3+, Pb2+, Ni2+, Zn2+, and Mn2+, were measured in batch experiments with excess sodium ion. The solution pH ranged from 2.2 to 5.5. The kinetics study shows that the adsorption reached equilibrium in seconds, indicating that there is little resistance to mass transfer, intraparticle diffusion, and surface chemical reaction. The competitive adsorption study found the phosphonic acid-SAMMS to have an affinity for divalent metal ions in decreasing order of Pb2+ > Cu2+ > Mn2+ > Cd2+ > Zn2+ > Co2+ > Ni2+. The measured Cd2+ adsorption isotherm was of the Langmuirian type and had a saturation binding capacity of 0.32 mmol/g

[en] Surfactant templated synthesis of mesoporous ceramics provides a versatile foundation upon which to create high efficiency environmental sorbents. These nanoporous ceramic oxides condense a huge amount of surface area into a very small volume. The ceramic oxide interface is receptive to surface functionalization through molecular self-assembly. The marriage of mesoporous ceramics with self-assembled monolayer chemistry creates a powerful new class of environmental sorbent materials called self-assembled monolayers on mesoporous supports (SAMMS). These SAMMS materials are highly efficient sorbents, whose interfacial chemistry can be fine-tuned to selectively sequester a specific target species, such as heavy metals, tetrahedral oxometallate anions and radionuclides. Details addressing the design, synthesis and characterization of SAMMS materials specifically designed to sequester actinides, of central importance to the environmental clean-up necessary after 40 years of weapons grade plutonium production, as well as evaluation of their binding affinities and kinetics are presented

[en] The synthesis of carbamoylphosphonate silanes (CMPO analogs) designed for sequestering actinide cations in self-assembled monolayers on mesoporous supports (SAMMS) is described