![]() The shielding design solutions to these problems defined a need for prototypic or benchmark experiments to provide assurance of the predicted shielding performance of selected design solutions and the verification of design methodology. Specific design problems more » which have been addressed are in-vessel radial shielding to protect permanent core support structures, flux monitor system shielding to isolate flux monitoring systems for extraneous background sources, reactor vessel support shielding to allow personnel access to the closure head during full power operation, and primary heat transport system pipe chaseway shielding to limit intermediate heat transport system sodium system coolant activation. Achievement of feasible designs, while considering the mechanical, structural, nuclear, and thermal performance of the component or system, has required judicious trade-offs in radiation shielding performance. Studies conducted during the CRBRP design process involved the aspects of radiation shielding dealing with protection of components, systems, and personnel from radiation exposure. Radiation shielding design of the facility consists of a comprehensive design approach to assure compliance with design and government regulatory requirements. Liquid Metal Fast Breeder Reactor (LMFBR) program. The Clinch River Breeder Reactor Plant (CRBRP) is being designed as a fast breeder demonstration project in the U.S. The Nitka index, resolution, and unsharpness for evaluating image quality cars be derived by simple mathematical examination, if the response function of a system is known. Moreover, the spectra of radiation sources, the response function of scattered ray from objects to be radiographed, and the radiographed images with / sup 192/Ir source are calculated. Another method is to examine the state of the extending images of point or line objects. In order to determine the response function of film system, radiation intensity changing sinusoidally is focused on the films, and the sinusoidal density distribution is examined. Accordingly, the response function, in which the radiation penetration characteristics of theobjects to be radiographed and imagereceiving film system using radiation sources of /sup 170/ Tm, /sup 192/Ir, /su p 137/Cs, and /sup 60/ Co, and the optimum lead sensitizers more » for them are shown. In the gamma radiography, the films are exposed to secondary electrons generated by mutual action of the gamma -rays with lead foil sensitizers, thus a sort of signal transformation is carried out. Response functions are useful for the analysis of radiography systems for the quantitative evaluation of the transmission of information from objects to be radiographed to images on films. Applying it to the double wall method for steel pipes of 10.8-60.5mm in outer diameters, Yb-169 also distinguishes two more fine wires compared with Ir-192. Regarding the quality of images, Yb-169 distinguishes two more fine wires with a standard wire penetrometer than Ir-192 when it is applied for steel plates of 1-12mm thick. This enables inspectors to do the nondestructive tests simultaneously with other work during daytime. = -ray projector would be 5kg or less, about 1/2 of that of Ir-192. This more » document describes how the factors of distance and shielding have been used to assure personnel safety at all times. ![]() The maximum radiation dose rate limit will be 0.002 rem/hr. In all radiographic operations the primary consideration is for personnel safety. These factors are distance and shielding. Personnel protection from penetrating radiation, both x-ray and gamma ray, is accomplished by ingenious use, singly or in combination, of two factors which reduce radiation intensity. The hazard of using such a high energy sources in the immediate vicinity of working personnel has necessitated the need for a thorough evaluation of methods of protection. Co-60 gamma ray energy is 1.17 and 1.33 MeV and Ir-192 gamma ray is. ![]() This condition imposes rigorous radiation safety requirements since the gamma radiation sources chosen to be used for examination of the pressure boundary welds, Co-60 and Ir-192, are very energetic. In order to support the steam generator production schedule, the radiographic examinations must be performed without interrupting any other manufacturing or inspection operations taking place within a 20-ft radius from the source. Radiography is the primary method of Nondestructive Examination recognized by the ASME B and PV Code as providing objective evidence of volumetric examination of the pressure boundary welds that are present in the Clinch River Breeder Reactor Program (CRBRP) Steam Generator.
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