Disused Sealed Sources: What to Do at End of Life
September 17, 2026
7 min read
DITEC Experts, Radiation Protection Team, ALDuha Institute for Training and Environmental Consulting
How sources end up forgotten
Almost no facility decides to keep a disused source indefinitely. What happens is smaller than that: a gauge is replaced and the old one is put aside until someone has time, a project ends, the radiation protection officer moves on, and three years later a source sits in a store belonging to a company that has forgotten it is licensed for it.
That is how an orphan source is created, and it is the scenario every regulator in the world is most anxious about. A source nobody is tracking can be sold with scrap, stolen, or found by someone who has no idea what it is.
A disused source is still a licensed source
Ending its working life changes nothing about its legal status. Until it has been transferred out through an authorised route and the regulator has been informed, it remains on the facility's inventory with every duty attached.
Decay is not a disposal route
Waiting for a source to decay away works only for short-lived nuclides, and only under an authorised decay-in-storage arrangement with a defined end point and a measurement to confirm it. Caesium-137 and americium-241, the nuclides in most industrial gauges, have half-lives measured in decades and centuries. Storing them until they are harmless is not a plan that any current employee will see completed.
What still applies while it sits there
- It stays on the inventory and is physically verified at the frequency the licence requires.
- It is stored in an authorised location, not wherever space happened to be free.
- Its leak testing continues at the required interval — decay does not exempt it.
- The licence covering it is kept valid, including through renewals.
- A named person remains responsible for it, which means handovers have to mention it.
The routes available
Solve it at purchase, not at disposal
The cheapest moment to deal with end of life is before the source arrives. A purchase or hire agreement that obliges the supplier to take the source back at end of life — and says who pays — converts a future regulatory problem into a commercial term agreed while you still have leverage.
Two other habits prevent most orphan sources: an inventory that is genuinely verified rather than copied forward each year, and a handover checklist that forces an outgoing radiation protection officer to walk the store with the incoming one.
Frequently asked questions
We found a source nobody knows about. What now?
Do not move it and do not try to identify it by opening anything. Restrict access to the area, survey it from a distance with a calibrated instrument if one is available, and notify the regulatory authority. Facilities that report a found source are dealing with an administrative problem; facilities whose found source turns up elsewhere are dealing with something much worse.
Can a disused source be sold as scrap metal?
Never. A sealed source in a scrap consignment is one of the most serious events in this field: it can be melted, contaminate an entire plant, and expose people who had no reason to expect it. Scrap yards and smelters in the region increasingly monitor their gates, and a detection there becomes a public incident.
The original supplier no longer exists. What then?
The route then runs through the national authority, and the facility should approach it early rather than wait. Options exist, but they take time to arrange, and the source remains the facility's responsibility throughout that time.
Does an expired source stop being dangerous?
The working life of a source is a commercial and technical judgement about whether it is still strong enough to do its job — not a statement that the radioactivity has gone. A source retired because it no longer gives a good reading can still be perfectly capable of causing harm.
Consulting and training
ALDuha Institute for Training and Environmental Consulting advises facilities in Qatar on inventory control, end-of-life planning for sealed sources and the regulatory steps involved, and trains radiation protection officers to keep a source register that will still be accurate after they have moved on.