Dose Rates from HASS (High Activity Sealed Sources)
Published: Dec 07, 2024
Source: Ionactive Radiation Protection Resource
In this resource we present example uses of HASS (High Activity Sealed Sources) together with their typical radioactivity and expected unshielded dose rate at 1m. The dose rate can be scaled linearly with activity (i.e. double the activity will double the dose rate etc). The dose rate can also be scaled with distance using the inverse square law (assuming a point source). The maths is not difficult, but feel free to use the Ionactive inverse square law widget (just take the dose rate from the table below, and multiply by the attenuation factor after selecting the distance you require).
Some of the figures below have been rounded to make the table clearer.
Dose Rates from HASS (High Activity Sealed Sources)
| Use | Radionuclide | Typical activity | Dose rate | Notes |
|---|---|---|---|---|
| Industrial Irradiation | Co-60 | 370 TBq | 113 Sv/h | Single source (one of many) |
| Industrial Irradiation | Cs-137 | 20-100 TBq | 1.5-7.5 Sv/h | Single source |
| Industrial radiography | Co-60 | 370 GBq - 11.1 TBq | 113 mSv/h - 3.4 Sv/h | Single source |
| Industrial radiography | Ir-192 | 370-740 GBq | 42-84 mSv/h | Single source |
| Industrial radiography | Se-75 | 370-740 GBq | 17-34 mSv/h | Single source |
| Brachytherapy (HD) - medical | Ir-192 | 430 GBq | 48.6 mSv/h | Single source |
| Gamma Knife (stereotactic radiosurgery) -medical | Co-60 | 1 TBq | 306 mSv/h | Single source (one of many) |
| Calibrator (QA / industry) | Cs-137 | 1 TBq | 152 mSv/h | Single source |
| AmBe Neutron source | Am-241 | 111-666 GBq | 78-466 µSv/h | Single source |
Single source - denotes the data applies to a single source.
Single source (one of many) - denotes the data applies to a single source, but that this source is part of a larger source array.
A list of HASS source radionuclides and radioactivity thresholds can be found here : High Activity Sealed Sources (HASS) Radioactivity Thresholds.