World Journal of Nuclear Science and Technology, 2012, 2, 89-105 http://dx.doi.org/10.4236/wjnst.2012.23015 Published Online July 2012 (http://www.SciRP.org/journal/wjnst) High-Level Nuclear Wastes and the Environment: Analyses of Challenges and Engineering Strategies Mukhtar Ahmed Rana Physics Division, Directorate of Science, PINSTECH, Islamabad, Pakistan Email:
[email protected],
[email protected] Received February 11, 2012; revised April 2, 2012; accepted April 19, 2012 ABSTRACT The main objective of this paper is to analyze the current status of high-level nuclear waste disposal along with presen- tation of practical perspectives about the environmental issues involved. Present disposal designs and concepts are ana- lyzed on a scientific basis and modifications to existing designs are proposed from the perspective of environmental safety. A new concept of a chemical heat sink is introduced for the removal of heat emitted due to radioactive decay in the spent nuclear fuel or high-level radioactive waste, and thermal spikes produced by radiation in containment materi- als. Mainly, UO2 and metallic U are used as fuels in nuclear reactors. Spent nuclear fuel contains fission products and transuranium elements which would remain radioactive for 104 to 108 years. Essential concepts and engineering strate- gies for spent nuclear fuel disposal are described. Conceptual designs are described and discussed considering the long-term radiation and thermal activity of spent nuclear fuel. Notions of physical and chemical barriers to contain nu- clear waste are highlighted. A timeframe for nuclear waste disposal is proposed and time-line nuclear waste disposal plan or policy is described and discussed.