Section 120.340 - Underwater and Lay-barge Radiography(A) Underwater and/or lay-barge radiography shall not be performed unless specifically authorized in a license issued by the agency in accordance with 105 CMR 120.360.(B) In addition to the other requirements of 105 CMR 120.300, the following requirements apply to the performance of lay-barge radiography:(1) Cobalt-60 sources with activities in excess of 740 GBq (20 Ci) (nominal) and iridium-192 sources with activities in excess of 3.70 TBq (100 Ci) (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 lay-barges.