Disused sealed sources

Sealed radioactive sources are radioactive material that is permanently sealed in a capsule or container. They are common in many industries, including medicine, agriculture and research. 

When they fall out of use, we classify them as disused.

Quantities

Table 9: Number of disused sealed sources reported in 2024 inventory
Organisation / group Existing Future Total
ANSTO 2,980 - 2,980
CSIRO 266 - 266
Defence 2,210 730 2,940
ARPANSA 58 - 58
Other Commonwealth government 166 73 239
State and territory government and regulators 11,700 106 11,806
Total  17,380 909 18,289
Disused and sealed sources by organisation. Data table on next tab.

The number of disused sealed sources held by each organisational group in the 2024 inventory, separated by future and existing waste.

Number of sealed sources in 2024 by organisation
Organisation Number of sealed sources  Existing waste / Future waste
State / Territory 11729 Legacy
ANSTO 2982 Legacy
Defence 2213 Legacy
Defence 730 Future
CSIRO 266 Legacy
Other Commonwealth Govt 171 Legacy
State / Territory 106 Future
Other Commonwealth Govt 73 Future
ARPANSA 58 Legacy

Information in Table 9 and Figure 12 has come from waste holders, supplemented by Australia’s Joint Convention report for some states and territories. 

Numbers reported by most organisations have not changed significantly since 2021. Increases or decreases in numbers are generally due to:

  • sources being taken out of service (and thus becoming disused)
  • disused sources in storage being disposed or recycled. 

The large increase in the total number is due to the inclusion of all states and territories. This has come from either:

  • direct reporting to ARWA
  • the Joint Convention report.

In 2021, the report only included states and territories that reported data directly to ARWA.

Disused and sealed sources by radionuclide. Data table on next tab.

The number of disused sealed sources by radionuclide in the 2024 inventory.

Number of sealed sources in 2024 by radionuclide
Nuclide Number of sealed sources
Am-241 7232
Co-60 2984
Ra-226 1538
Kr-85 1340
Th-232 1215
Sr-90 1032
Cs-137 892
Ni-63 697
H-3 356
Mixed 239
U (natural) 142
Ba-133 85
Tl-204 71
Pu-239 65
C-14 59
Pu-238 46
Na-22 43
Co-57 36
Pb-210 28
Am-241/Be 20
Eu-152 17
U-238 16
Fe-55 15
U (depleted) 13
Cf-252 11
Cl-36 11
Mn-54 11
Uranium (depleted) 11
Pm-147 10
Am-241/Be+/Cs-137 9
Cm-244 9
Hg-203 8
I-129 8
Ir-192 7
Cd-109 5
Po-210 5
Bi-207 4
Gd-153 4
Th (nat) 4
U (nat) 4

Most of the sealed sources contain americium-241 (7230 items, Figure 13). Many of these sources are disused smoke detectors that state and territory regulators have collected and stored.

We have not included disused sources containing other radionuclides that have even fewer numbers than those shown in Figure 13.

Uncertainties

  • Many of the reported sources do not have an associated measurement date for the activity.
  • Many of the reported activity values are the original source activity, with few having been measured recently. 

Therefore, the true current activity values for some sources are likely to be much lower. This is especially the case for short-lived sources. For these reasons, we have not included activity information for sealed sources.