Gamma radiation sources have a limited useful life tied to the isotope’s half-life. When the activity falls below the level required for the measurement, we replace the source while retaining the housing and mount.
Work steps
- Planning and notification to SSM
- Transport of the new source under ADR Class 7
- Removal of the spent source, encapsulation for return
- Installation and verification of the new source
- Shipment of the spent source to an authorised recipient
- Documentation and reporting
When to plan a recharge
Typically 1–2 half-lives before the signal becomes too weak for stable measurement. Co-60 is the isotope we work with most often — with a half-life of 5.3 years, recharges are planned relatively frequently. For Cs-137 (30 years) they are planned less often. Recharging is scheduled long-term in the maintenance programme.