Applications nuclear waste testing

The Met-Tech separation process is a liquid ion exchange process for the ex situ recovery, separation, and concentration of a wide range of heavy metals. The technology is commercially available and, according to the vendor, has been tested at the pilot scale. According to the vendor, future applications will be in soil remediation, acid mine drainage, and the recycling of spent nuclear waste. 

Plodinec, M. J. Wicks, G. G. 1994. Application of hydration thermodynamics to in-situ test results. In Barkatt, A. Van Konynenbourg, R. A. (eds) Scientific Basis for Nuclear Waste Management XVII. Materials Research Society Symposia Proceedings, 333, 145-157. 

There are inherent scale limitations in the time and space dimensions covered by laboratory studies. The applicability of the near field geochemical models derived from laboratory observations have to be applied to long-term, large-scale situations like the ones involved in the safety assessment of nuclear waste repositories. Hence, there is a need to test the models developed from laboratory investigations in field situations that are related to the ones to be encountered in repository systems. 

One possible application in which large amounts of rare earths and actinides would be processed occurs in some schemes for nuclear waste management. If it should prove to be advantageous to remove transplutonium elements from nuclear waste, for example, the recovery of Am and Cm from the much larger amounts of rare earths would be required. This problem has been investigated by the author in tracer tests with rare earth mixtures typical of fission products, using a heavy rare earth such as holmium as a stand-in for Am and Cm (Fig. 5). It is clear that the bulk of the holmium can be recovered in reasonable purity, and that the bulk of the lighter rare earths is effectively separated from the very small amount of heavy rare earths, Am, and Cm. 

Chapter 4 describes how the electrical nature of corrosion reactions allows the interface to be modeled as an electrical circuit, as well as how this electrical circuit can be used to obtain information on corrosion rates. Chapter 5 focuses on how to characterize flow and how to include its effects in the test procedure. Chapter 6 describes the origins of the observed distributions in space and time of the reaction rate. Chapter 7 describes the applications of electrochemical measurements to predictive corrosion models, emphasizing their use in the long-term prediction of corrosion behavior of metallic packages for high-level nuclear waste. Chapter 8 outlines the electrochemical methods that have been applied to develop and test the effectiveness of surface treatments for metals and alloys. The final chapter gives experimental procedures that can be used to illustrate the principles described. 

Besides the analysis of nuclear fuel and of radioactive waste materials, the determination of contamination and enrichment of selected radioactive nuclides, e.g., which is one of the most important environmental indicators of nuclear accidents, Se, Tc, Np, Pu, °Pu and "Am at ultratrace concentration levels, is useful for environmental monitoring of fallout from nuclear weapons testing, nuclear power plants or nuclear accidents. ". Selected application fields for the determination of natural and artificial long-lived radionuclides (LLR) and radionuclides investigated by mass spectrometric techniques are summarized in Tables 9.36 and 9.37, respectively. 

In this work we wish to report an application of the gel supported precipitation procedure, originally developed for the disposal of nuclear waste [10], to the preparation of zirconia spheres (0.01-2 mm). In addition to the controlled geometric form and the relatively large dimensions, this process allows to obtain large surface area materials starting from inexpensive salt precursors. As a preliminary test of their properties, these materials have been checked in the preparation of Pt catalysts for the low temperature catalytic combustion of hydrocarbons. This modified sol-gel technique is quite general and suitable for the preparation of a variety of materials of interest for catalytic applications. 

Kruger, J. and Rhyne, K., "Current Understanding of Pitting and Crevice Corrosion and Its Application to Test Methods for Determining the Corrosion Susceptibility of Nuclear Waste Metallic Containers, Nuclear and Chemical Waste Management, Vol. 3. No. 4, 1982, pp. 205-227. 

Requirements for Disposal. The National Security and Military Applications of Nuclear Energy Authorization Act (NSMA, 1980) established the current DOE program for disposal of defense transuranic waste at the WIPP facility in New Mexico. The Act specifically authorized test emplacements of waste for purposes of research and development. WIPPLWA (1992) then authorized permanent disposal of defense transuranic waste at this facility. The Act specifies that the WIPP facility may not be used for disposal of high-level waste, commercial transuranic waste, or any DOE non-defense transuranic... 

Another example of electrodialysis applied to the nuclear industry [27] is the recovery of NaOH and H2SO4 from the secondary liquid waste created by the regeneration of ion-exchange columns installed in LWRs. This application has been successfully demonstrated at a plant scale facility using simulated solutions. Long-term life tests on the ion-exchange membranes indicate a shorter life for anionic membranes than cationic membranes. 

There are many examples of the studies on SLM for nuclear applications in the literature. SLMs were tested for high-level radioactive waste treatment combined with removal of actinides and other fission products from the effluents from nuclear fuel reprocessing plants. The recovery of the species, such as uranium, plutonium, thorium, americium, cerium, europium, strontium, and cesium, was investigated in vari-ons extracting-stripping systems. Selective permeation... 

This method found application also in the field of the vitrification of hazardous waste, namely in the determination of optimal conditions for immobib-lization of the waste containing Sr and Cs from nuclear power plants, and in testing the durability of this glass towards hydrolytic corrosion [29,30]. 

There are very many applications of gamma-ray spectrometry. Having already discussed environmental measurements in Chapter 16, in this chapter I discuss a number which, to me, seem to be of particular interest. Each of them deserves a much broader treatment but time and space limit me to a general introduction. Each of them draws upon the principles developed in previous chapters, the idea being to illustrate how academic, and perhaps theoretical, ideas find their expression in practical uses. As it happens, the examples are related in the sense that in these applications gamma spectrometry could be said to help make ordinary life safer measurements in support of the Comprehensive Test Ban Treaty (CTBT) help to prevent the proliferation of nuclear weapons, waste monitoring helps to ensure that radioactive waste is disposed of properly and safeguards measurements make sure that nuclear material is properly accounted for. 

---