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One Step at a Time; The Staged Development of Geologic Repositories for High-Level Radioactive Waste

2003 · réf. 73918 — Washington DC: The National Academies Press 2003. Presumed First Edition First printing. Wraps. Very good. xiii 1 201 1 pages. Illustrations. Occasional footnotes. Recommendations. References. Glossary Format is approximately 8.5 inches by 11 inches. Recent decades have witnessed a continuing worldwide debate on the management of radioactive high-level waste and recent developments including both major advances and setbacks in various countries have led to an intensification of this debate. Geologic disposal involves placing high-level waste in a carefully selected deep underground repository where it remains isolated from the accessible environment for very long time periods until the waste no longer represents a hazard to humans or to the accessible environment. Disposal in a carefully sited and designed geologic repository is recognized by most of the international technical community including the National Research Council as a long-term management option for high-level waste that provides a high degree of safety and security. However geologic disposal of high-level waste has proven to be a major challenge for many nations. Delays and setbacks have been common often attributable to the difficulties of simultaneously addressing technical and societal challenges. High-level waste HLW is a type of nuclear waste created by the reprocessing of spent nuclear fuel. It exists in two main forms: First and second cycle raffinate and other waste streams created by nuclear reprocessing. Waste formed by vitrification of liquid high-level waste. Liquid high-level waste is typically held temporarily in underground tanks pending vitrification. Most of the high-level waste created by the Manhattan project and the weapons programs of the cold war exists in this form because funding for further processing was typically not part of the original weapons programs. Both spent nuclear fuel and vitrified waste are considered as suitable forms for long term disposal after a period of temporary storage in the case of spent nuclear fuel. HLW contains many of the fission products and transuranic elements generated in the reactor core and is the type of nuclear waste with the highest activity. HLW accounts for over 95% of the total radioactivity produced in the nuclear power process. In other words while most nuclear waste is low-level and intermediate-level waste such as protective clothing and equipment that have been contaminated with radiation the majority of the radioactivity produced from the nuclear power generation process comes from high-level waste. In the US HLW from reprocessing of spent fuel from electrical power stations amounts to less than 1% of the total volume of US HLW; the rest is defense related. Some other countries particularly France reprocess commercial spent fuel. High-level waste is very radioactive and therefore requires special shielding during handling and transport. Initially it also needs cooling because it generates a great deal of heat. Most of the heat at least after short-lived nuclides have decayed is from the medium-lived fission products cesium-137 and strontium-90 which have half-lives on the order of 30 years. A typical large 1000 MWe nuclear reactor produces 25-30 tons of spent fuel per year. If the fuel were reprocessed and vitrified the waste volume would be only about three cubic meters per year but the decay heat would be almost the same. It is generally accepted that the final waste will be disposed of in a deep geological repository and many countries have developed plans for such a site including France Japan and the United States. The National Academies Press paperback