Environmental and economic assessment of the implementation of an automated nuclear interim waste store using novel monitoring platforms

Automation of radioactive waste stores could enable medium-long range monitoring in real-time or set intervals, increasing safety by reducing the need for manual inspections by workers. This study evaluates the environmental and economic impact of implementing two monitoring technologies - SiLiF/SciFi and LoRa - over the lifespan of an interim storage facility, from construction to end-of-life dismantling, including detailed analysis of the production, operational and disposal of the monitoring systems. Results show that the climate change impact of the full life cycle is 4741 t CO₂ eq. for LoRa and 4837 t CO₂ eq. for SiLiF/SciFi (95 and 97 kg CO₂ eq. per drum, respectively): the 2 % lower impact of the LoRa platform is due to its lower operational energy consumption. Store construction is the biggest contributor to overall environmental impacts, followed by production of the monitoring systems. Reducing the number of monitored drums and the size of the monitor support system could together reduce environmental impacts by 9 %. Replacing steel with HDPE for the monitor support system reduces the impact from 17.8 to only 1.9 kg CO₂ eq. (-89 %), plus >95 % reduction in all toxicity categories, metal depletion and land use. Evaluation of two scaled-up scenarios based on test configuration mock-ups reveals that monitoring costs an additional €9.5 M (LoRa) to €24 M (SiLiF/SciFi). Data herein allows real-world configurations to be evaluated based on case-specific sensor performance and operational requirements. Saving one mSv of worker dose is found to incur a carbon 'cost' of 23-37 kg CO₂ eq. and an economic cost of ~€18.48-48.42. The latter falls well within sectoral guidelines on dose reduction expenditure. Future research should explore the optimisation of monitor numbers, alternative materials and energy sources, long-term system reliability, and the socio-economic implications of saving worker dose vs incurring environmental costs.