Computed Radiography Alternative to Conventional Film
Project Participants: General Dynamics Electric Boat
Project Start: February 2006
Conventional film radiography has been used for volumetric inspection of piping and structural welds, castings and various components used for construction, overhaul and repair of naval surface vessels and submarines and for more than fifty years. Computed radiography technology advancements promise to revolutionize industrial radiography procedures and standards. The technology has been embraced by the aerospace, automotive and electronics sectors but shipbuilding specifications do not address the use of computed radiography.
This General Dynamics Electric Boat (GDEB) project will demonstrate the benefits and capabilities of using computed radiography in lieu of conventional film radiography technology across all phases of ship lifecycle operations including new construction, maintenance, repair and overhaul. GDEB intends to expand the range of applications deemed suitable for computed radiography and to expand the technology base. Computed Radiography benefits include reduced processing costs, elimination of special film processing facilities, reduced hazardous waste disposal costs and reduced personnel radiation exposure. GDEB’s project will complement Northrop Grumman Newport News’ (NGNN) ongoing digital radiography project and leverage the testing data and image quality requirements established at NGNN as the benchmark for this project wherever possible. Computed Radiography images from weld specimens with known defects will be compared to conventional film radiography images of the same specimens completed under comparable circumstances. Weld specimens will be shared with Newport News in an attempt to broaden the population of specimens available.
The Computed Radiography System in place at GDEB will use imaging plates in sizes equivalent to standard film. This will allow imaging plates to be used shipboard as well as in shop type applications to provide a more “real life” comparison to film. Film images of various configuration welds will be “duplicated” using computed radiography. When possible, production welds will be radiographed using both film and computed radiography to provide a sufficient number of samples to be evaluated to make a reasonable assessment of the technology.
Upon completion of this project, Computed Radiography should be recognized as a valuable tool to reduce cost and improve efficiency when conducting industrial radiography related to the shipbuilding industry.