Radiographic image storage and restoration. Final report

This report provides an analytical basis for defining the value of radiographs and for establishing criteria for rerecording by analog or digital methods. The analysis is supplemented by practical guidance for detecting and managing any degradation that may occur in the collection. Background data and examples are provided on both subjects. These include site experience in radiographic collection examination, early experience with rerecording, studies and surveys derived from U.S. NRC requirements or EPRI-sponsored work. Collectively, the data should be of value to radiographers, records management personnel, and engineers conducting structural integrity analyses using radiographic inspection or records data to assess crack-like flaws. One product of this work, the high energy radiographic sensitivity analysis (HERSA), will be available via EPRI NDE personnel at Charlotte, North Carolina. In addition, the NDE Center is currently developing a physical standard comprised of an assortment of targets which allow evaluation of various aspects of the digitization system (i.e., line pairs for resolution and stop wedges for contrast sensitivity). The standard will allow the user to quantify and benchmark system capabilities. Radiographic sensitivity can be quantitatively defined except for a single term that defines the interpreter acuity and training. Bounding values are known for both normalmore » and image enhancement situations, but practice recommendations must be derived from benchmark trials. Such trials are currently in process. Upon their completion, the NDE Center will release HERSA for general use.« less