Waste disposal drivers for a range of nuclear power systems

This work considers the effect of two possible influences on the development of advanced fuel cycles; uranium economy and the cost of disposal. With the global rise in energy demand there is increased pressure to move to low CO2 energy mixes to curb anthropogenic climate change. Nuclear power has been identified as a key energy source in this transition, and as such many studies on the effect of adopting different reactor and fuel cycle combinations have been undertaken. Results are often specific to existing facilities or aim to fulfil national policy, so are of limited use outside of the study. Though closed fuel cycles are recognised for their efficiency and ability to reduce the waste inventory deployment will require extensive investment. Understanding of uranium availability, fuel cycles and disposal is necessary to determine if advanced fuel cycles may become economically competitive. Extraction of uranium from seawater may allow LWRs to remain competitive, but current estimates for the most mature technology (amidoxime braid) put a cost over 10x today's uranium price. Developments to this system are still unlikely to get close to the current cost of uranium. Commercial deployment of this technology will require extensive instalments (545 km3 seawater per annum to fuel 1 GWe LWR) and is likely to face legal challenges arising from resource rights and environmental protection legislation. Five standalone fuel cycles of differing recycling configurations have been modelled using the tool ORION. The heat generating wastes arising have been quantified, with radiotoxic inventory and thermal output at three disposal timepoints. The thermal modelling tool BADGER was used to calculate fuel cycle disposal footprints. These dimensions were used to estimate the cost of disposal for each nuclear programme. Any degree of fuel cycle closure appears an effective way to manage the inventory at disposal with up to 95 % radiotoxicity and thermal reduction achieved with a closed fuel cycle and 200 years' cooling. Facility footprint varies greatly with degree of closure, though this is not strongly reflected in disposal cost as both number of canisters and area requirement are factors. The cost of disposal accounted for 6.8 % of overall project cost for an open fuel cycle (5.6 - 9.8 % with min/max footprint variants). It can be expected that adopting any type of reprocessing or advanced reactor system will significantly increase front-end costs and is unlikely to be offset by reduction in disposal cost. Currently an open fuel cycle appears to be the most economically favourable system, as neither uranium availability nor advantages to disposal present significant drivers for change.