Determining the required thickness of lead materials for specific equipment operations and industrial processes is of critical importance. The shielding specifications must be determined by a radiation health physicist certified to perform this type of analysis. The factors involved include the type of emitting equipment or material, the distance between occupants and the radioactive source, and the frequency and strength of the envisioned radio-active emissions. The physicist's conclusions regarding proper lead shielding thicknesses can then be used to select the required lead-lined construction materials. Every component of shielded wall system must contain enough lead for the overall system to be effective.
Lead-lined construction materials include lead-lined drywall, paneling, wood and steel doors, door hardware and frames. Other installed wall elements, including lead glass windows, must have "lead equivalence" ratings offering protection levels on par with the other lead-lined wall materials utilized. As lead-lined drywall is attached to studs, any penetrations made by fasteners are covered and sealed with lead disks. Likewise, wall penetrations necessary for utility runs must be appropriately sealed and protected with special hardware. Lead core doors are much heavier than unprotected doors, and therefore special hardware, framing, and hinge systems need to be considered, due to both weight and shielding requirements. The door framing systems must also be lead-lined to ensure a complete protective barrier. Lead-lined doors and completed wall systems will have normal external finishes to match the appearance of unshielded building sections to the extent possible. Lead-lined enclosures for specific pieces of equipment and materials are sometimes used in lieu of, or in addition to, these construction techniques with lead-lined materials.
