This volume is a continuation of the five volumes of "The Chemistry of the Actinide and Transactinide Elements" (published 2006). It expounds on topics in actinide science that are undergoing rapid scientific developments and that are germane to the safe development of nuclear energy in the 21st century, from nuclear fuels to the environmental science and management of waste. The scope of Volume 6 encompasses: actinides in the geosphere, subsurface interactions of actinides species with microorganisms, chemistry of nuclear fuels, actinide waste forms and radiation effects, analytical chemistry of plutonium, actinide chalcogenide compounds, molecular spectroscopy and reaction of the actinide ions in the gas phase and rare gas matrices, and hydrothermal synthesis of actinide compounds. This volume is written by active practitioners and recognized experts in their specialty areas. Each of the topics represents the current state of knowledge in this fascinating area of science and technology.

This volume is a continuation of the five volumes of "The Chemistry of the Actinide and Transactinide Elements" (published 2006). It expounds on topics in actinide science that are undergoing rapid scientific developments and that are germane to the safe development of nuclear energy in the 21st century, from nuclear fuels to the environmental science and management of waste.

The scope of Volume 6 encompasses: actinides in the geosphere, subsurface interactions of actinides species with microorganisms, chemistry of nuclear fuels, actinide waste forms and radiation effects, analytical chemistry of plutonium, actinide chalcogenide compounds, molecular spectroscopy and reaction of the actinide ions in the gas phase and rare gas matrices, and hydrothermal synthesis of actinide compounds.

This volume is written by active practitioners and recognized experts in their specialty areas. Each of the topics represents the current state of knowledge in this fascinating area of science and technology.

The present volume describes the general properties of the thorium atom and ions, the thermodynamics of its compounds and solutions, the behavior of solutions and solid com pounds under the influence of its own radiation as well as an external radiation field, and spectroscopic data in great detail. The different chapters are of special interest to scientists who work in these fields, and also in the corresponding fields of other elements. In some special fields there exists a detailed knowledge of this radioelement whereas in other fields, such as M6Bbauer spectra, lower oxidation states, or radiation stability, there are large gaps. Due to the fact that the significance 23 of thorium as a breeder fuel ( 2"fh to be converted to fissile 233U after thermal neutron capture) has decreased within the last decade, the behavior of thorium is not as yet so thoroughly investigated as the heavier radioactive element uranium. Many of these data, however, are not only of academic interest, e.g., the knowledge of atomic spectra is needed for some analytical methods, especially in the trace concentration region. Due to the noble gaS-like electronic configuration of the tetravalent ion, there are no absorption bands in the visible region so that in general spectra and data are very scarce. This volume is a very detailed and critically reviewed compilation, written by experts from the Federal Republic of Germany, Belgium, and the United States.