Magnox, Chapel Cross NPP, UK
Background
Top gas ducts transferred hot gas from the graphite core to the boilers (primary circuit).
- 820t: 4 reactors with 4 boilers/reactor
- Components de-planted and laid-down prior to contract
- Metallic components as surface-contaminated LLW. (Contamination up to 25,000 Bq/cm² / Doses rates up to 1.1 mSv/h /Dominating nuclides : Co-60, Cs-137, Pu-241, Sr-90)
- Elbows transported on road to the UK / RoRo ferry shipment to Sweden and finally road transport to site
- Gas duct assemblies transported and loaded to a chartered geared vessel for direct shipment to Cyclife Sweden site
Our proposal
- Initial segmentation
- Asbestos/insulation removal by dedicated crew in special tent
- Size reduction to allow decontamination and melting
- Inspection upon completed decontamination
- Stacking of material prior to melting
- Casting of ingots upon completion of slag removal ans sampling
Transcript
- Initial segmentation
- Asbestos / insulation removal by dedicated crew in a special tent
- Size reduction to allow decontamination and melting
- Inspection upon completed decontamination
- Stacking of material prior to melting
- Casting of ingots upo, completion og slag removal ans sampling
Customer benefits
- Fast removal from site
- Proven and safe solution
- Low total cost
Results
- All gantry material met criteria for direct general clearance: i.e. without melting.
- 127 melt batches were conducted in total: 98.4% of the produced ingots became subject to clearance and 96.4% recycling rate in the melting process
- >90% total recycling rate, considering all material shipped for disassembly and treatment