UNDERGROUND NUCLEAR PARKS: A POTENTIAL NEW USE FOR UNDERGROUND SPACE

Expanding nuclear power generation is viewed increasingly as a means to reduce carbon dioxide emissions and provide abundant, reliable electricity. Underground siting of nuclear power plants and nuclear fuel cycle facilities is an alternative to continued exclusive reliance on surface siting and is a potential new use for underground space. A promising approach is the underground nuclear park (UNP). UNPs would be highly secure underground facilities for generating multi-gigawatt levels of baseload electricity with options for peaking electricity, hydrogen and/or process heat. UNPs would include collocated, multiple nuclear power plants and nuclear fuel cycle facilities such as spent fuel storage, nuclear waste disposal (repository), and perhaps reprocessing, enrichment, and fuel fabrication facilities, assuming a closed fuel-cycle policy. UNPs would be sited in appropriate hydrological and geological settings, deep within bedrock units having properties suitable for construction of large underground openings needed to house the nuclear power plants and other underground facilities. Inherent advantages of the UNP approach--automatically realized by being deep underground--include enhanced radiation shielding provided by the rock mass, robust physical security against aircraft and missile attack, and an increased margin of containment safety against low-probability, high-consequence reactor accidents. Other advantages include preservation of surface aesthetics, less environmental impact, greater seismic resistance, greater public acceptance, and reduced nuclear waste transportation cost and controversy. In addition, recent work indicates the potential for the UNP approach to achieve lower capital and operating costs relative to conventional surface-sited nuclear power plants. For example, the rock mass surrounding UNP openings would be a preexisting natural structural material providing shelter for the nuclear reactors, equipment, and materials, thereby avoiding much of the commodity (concrete and steel) and labor cost required to construct the containment structure and other buildings at surface-sited nuclear power plants. Concepts for UNPs in bedded salt and granitic rock will be presented, along with ideas for UNP-based energy systems.