nuclear-news

The nuclear decommissioning process

Why decommissioning South Africa’s Koeberg nuclear plant won’t be easy  The Conversation,  Hartmut Winkler  Professor of Physics, University of Johannesburg, January 26, 2018  

“……..There are three stages in the rehabilitation of a nuclear facility.

1. The plant must be dismantled. This is complicated because most of the material in and around the plant is radioactive to varying degrees and therefore dangerous to anything exposed to it. Radioactivity reduces with time, but for some isotopes commonly found in nuclear waste, the drop in radiation levels can be very slow. Because of this a plant will only be dismantled years after it’s been switched off.
2. The dangerous nuclear waste, or high level waste must be reprocessed. Most of the material stays dangerous for decades but some isotopes retain high levels of radiation levels for thousands of years. A portion of nuclear waste can be converted into reusable or less radioactive forms through nuclear engineering processes. These processes are complex and there are only a few facilities in the world that can perform them. This means that South Africa’s high level waste will have to be transported overseas. Reprocessing facilities include La Hague in France and the Russian Mayak site, thought to be responsible for the 2017 ruthenium leak incident.
3. The remaining nuclear waste must be secured in storage, virtually forever. This needs an isolated site that can’t be damaged by natural disasters or other processes that could cause radioactive material to seep into the surrounding environment, especially ground water. This final storage need is a massive headache worldwide. An example is the German Gorleben final repository site. It’s been the scene of protests for decades, preventing any further storage of waste on the site.

There are a handful of cases where the first two stages have been completed, typically over periods of ten years. But completing the final storage phase of nuclear waste hasn’t been achieved for any former plants. Their most hazardous waste is still in temporary storage, sometimes even on site……… https://theconversation.com/why-decommissioning-south-africas-koeberg-nuclear-plant-wont-be-easy-89888

February 10, 2018 - Posted by Christina Macpherson | 2 WORLD, decommission reactor, Reference