Proper installation of lead shielding required for x-ray and nuclear medicine installations is crucial for safety of both staff and the general public.
The approved shielding design may be excellent on paper! But the lead shielding must be properly installed, with sufficient overlap of lead sheets, with the proper thicknesses of lead, covering all the planned areas and with proper wrapping of lead around areas of penetrations through the walls (e.g., electrical boxes and ventilation systems), for radiation shielding goals to be met. In addition, it is important to support lead well on installation, as it has a tendency to “sag” over time.
The Radiation Safety Institute of Canada has considerable expertise in assessment of lead shielding installations. This is ideally carried out in two phases. In Phase 1, a Radiation Safety Institute of Canada scientist or engineer will visually inspect the lead installation, prior to drywall being installed over the lead. This phase enables assessment of the supports used to fix the lead to the walls, enables visual assessment of the overlap of lead sheets and allows direct comparison of all areas with the planned amount of shielding. In Phase 2, the Radiation Safety Institute of Canada scientist or engineer will use a small, radioactive source and a sensitive detector to quantitatively assess the attenuation of walls, doors and lead-glass windows after all work is complete. This method is especially good at finding small gaps in lead shielding at penetrations and in evaluating the true attenuation value of the structures involved. In some cases, only phase 2 is performed, where it is not possible to delay installation of drywall before the Radiation Safety Institute of Canada representative arrives.
Lead shielding integrity testing may also be used to evaluate existing shielding prior to the installation of a new x-ray unit.
Shielding integrity testing provides one with an independent assessment that shielding was installed correctly by the contractor and assurance that levels of radiation will meet the design limits in the planned shielding document.
Contact us today to discuss assessing shielding integrity!
