IDAHO FALLS, Idaho (AP) — A cleanup contractor says three Idaho workers involved in a radiological incident at a U.S. Department of Energy site earlier this year did not receive internal exposure.

A spokesman for contractor Fluor Idaho said Thursday that biological assessments on the workers found no reportable internal contamination despite radioactive material contaminating the skin and clothing of the worker.

Flour Idaho took over for contractor CH2M-WG Idaho, also known as CWI, in June.

The incident happened May 10 as workers were cutting into a box to remove and repackage radioactive debris.

The Post Register reports that a similar external exposure occurred in late June to a single employee. An internal investigation was conducted and officials decided that future welders would be required to wear both the fire-resistant layer of protective clothing plus a layer of anti-contamination clothing on the outside.