Section 144-220-E-D-20 - Requirements for underwater, offshore platform, and lay-barge radiographyA. Underwater, offshore platform, and/or lay-barge radiography shall not be performed unless specifically authorized in a license issued by the Agency in accordance with E.4 of this Part.B. In addition to the other requirements of this section, the following requirements apply to the performance of offshore platform or lay-barge radiography.(1) Cobalt-60 sources with activities in excess of 20 curies (740 GBq)(nominal) and iridium-192 sources with activities in excess of 100 curies (3.7 TBq)(nominal) shall not be used in the performance of offshore platform or lay-barge radiography.(2) Collimators shall be used for all industrial radiographic operations performed on offshore platforms or lay-barges.10-144 C.M.R. ch. 220, § E-D-20