A disused sealed radioactive source is an accident waiting to happen, if it is not stored securely, conditioned, or disposed of properly. When a source no longer has a useful purpose, it should be disposed of permanently if feasible. Keeping old sources just in case (for such uses as back-up to a current source, etc.) is not a good practice. They often are forgotten, not given proper leakage tests, and may eventually be lost or stolen. Sources that are no longer in use should be transferred to the national radioactive waste processing facility (waste operator).
Interim storage may be acceptable: if the facility is secure to prevent loss or theft; the source is properly conditioned so as to improve its shielding and stability; and proper records and periodic physical check of the sources in interim storage are made. Secure interim storage may not be feasible in a hospital or other medical facility, however. Given the possibility for such a source to be stolen, good security must be assured.
When a source no longer has any use, the regulatory authority should be notified and arrangements made for its disposition, either by:
Where neither of these is possible:
The source should be conditioned and stored securely at an interim waste processing and storage facility that is licensed by the regulatory authority.
Even though the disused source is housed in a teletherapy head, it will require conditioning for safe management. It is recommended that disused teletherapy sources be returned to the manufacturer or sent to a licensed waste processing facility.
Records for all disused sources should indicate the manner in which they were managed. These records should be maintained as required by the responsible regulatory authority and according the technical procedures of the waste operator.
The most effective means to prevent accidents with sealed radioactive sources is to adopt work habits that reduce the likelihood of a source becoming lost or stolen in the first place. The onus is on those professionals using sources to take the necessary steps to protect the public, the environment, and themselves from the serious consequences of an accident, each and every time they work with a radioactive source. Sources no longer in use should be transferred to a waste operator as soon as technically possible.