|SRA Key Topic||SRA Topic||SRA Topic priority|
|Waste form and their behaviours (Topic 2 in the SRA)
Release from ILW and their detailed characterization (Topic 2.2 in the SRA)
Explanation of the contents of the activity
C-14 is produced inside nuclear power plants, and the produced amount depends somewhat on the type of reactor (it is higher for a gas cooled reactor and lower for a Candu type reactor, LWR being in between). It can be found mainly in the fuel (either the fuel itself or the "hardware" of the fuel assemblies) or, to a lesser extent, in the coolant (also in the graphite moderator for the gas cooled reactors). The part contained in the coolant is then filtered into the spent resins. These resins are the major contributor to the C-14 inventory in LLW repositories.
This C-14, whatever its location, can be in organic or inorganic form, and the release can be either gaseous or not.
One can state that :
- Work has been undertaken on this subject for graphite waste (LLW-LL) inside the "Carbonate" project (on-going characterization work inside European countries)
- Work has also been undertaken on the carbon-14 content of metallic objects (ILW) (Andra)
- Work has also been undertaken on LLW-SL other than graphite waste, such as ion exchange resins (SKB)
Comments received :
- Confirm which wastes require detailed characterisation of C-14, as this may or may not be needed depending on the waste type and C-14 form. (NAGRA)
- We have a preference to work on gaseous release of C-14. We have an active experimental programme on-going in this area to investigate the release of C-14 (g) from irradiated steel and graphite. We intend in the future to expand this programme to also consider reactive metals (e.g. irradiated uranium). Collaboration in this area would be excellent and is a very high priority work area within our own research programme. (NDA)
Short description of activity
The work would be broken down into two steps :
- A review of the state of the art in Europe on the subject of C-14 characterization
- A technical project.