Industrial radiography, the non-destructive testing (NDT) technique used to inspect welds, pipelines, and structural components using radioactive gamma sources or X-ray machines, sits at the intersection of nuclear regulation, occupational safety, and transportation law. The Nuclear Regulatory Commission (NRC) governs gamma sources like iridium-192 and cobalt-60. X-ray machines fall under state health departments and the Occupational Safety and Health Administration (OSHA), not the NRC, because they generate radiation electrically rather than through nuclear decay. The majority of U.S. states have also signed formal agreements with the NRC to regulate radioactive materials within their own borders, becoming agreement states whose rules must be at least as strict as federal standards and in several cases are stricter. Texas inspected 171 radioactive materials licensees in one recent quarter and found violations in 27% of those inspections.
Reciprocity, Specific Licenses, and the Dose Limits in 10 CFR Parts 20 and 34
Moving across state lines with radioactive equipment requires filing Form NRC-241 with the relevant regulatory body at least three full calendar days before work begins. The reciprocity window is capped at 180 days per calendar year in any visiting jurisdiction. Crossing state lines without filing is legally equivalent to operating without a license. Companies performing industrial radiography do so under a specific license that covers named radioisotopes up to defined activity limits and requires the formal appointment of a radiation safety officer (RSO). In March 2026, the NRC proposed an $18,000 civil penalty against an Indiana company after inspectors found multiple security requirement violations, some of them willful.
Federal radiation safety rules set strict exposure limits for workers and the public during industrial radiography operations. Occupational workers can legally receive up to 5 rem of radiation exposure per year, while exposure limits are far lower for pregnant workers and the general public. But regulators stress that these limits are maximums, not acceptable targets. Under the industry’s “ALARA” principle — keeping exposure “as low as reasonably achievable” — companies are expected to actively reduce radiation exposure through shielding, limiting time near radioactive sources, and maintaining safe distances.
Separate federal rules governing radiography field operations require two-person crews, routine equipment inspections, ongoing maintenance, and continuous monitoring of restricted areas whenever radioactive sources are in use. Those requirements are receiving renewed attention after a fiscal year 2025 investigation by the NRC found that a radiographer failed to properly monitor a device containing radioactive iridium-192 while it was located in an unrestricted area.
Transport Index Requirements and the NRC's Pending Rule Revision
Every shipment of radioactive sources requires a freshly measured transport index (TI), calculated from the maximum dose rate at one meter from the package surface. Copying a previous day's TI onto new shipping papers is a specific, documented compliance failure that inspectors flag. The TI determines whether the package requires a yellow II or yellow III Department of Transportation (DOT) warning label. On May 18, 2026, the NRC published a proposed rule to modernize Part 34 industrial radiography requirements, with updates to reciprocity guidance also included. Public comments are open.
