Objective
CONDITIONED RADIOACTIVE WASTE HAS TO YEET THE SPECIFICATIONS AND ACCEPTANCE CRITERIA DEFINED BY NATIONAL REGULATORY AND MANAGEMENT AUTHORITIES. CONVENTIONAL GAMMA SCANNING IS ONE OF THE MOST WIDELY USES NON-DESTRUCTIVE TESTING METHODS FOR ROUTINE QUALITY CHECKING OF RADIOACTIVE WASTE DRUMS. ITS RANGE OF APPLICATION COVERS RAW WASTE PRIOR TC CONDITIONING AS WELL AS CONDITIONED WASTE PRIOR TO DISPOSAL OR INTERIM STORAGE.
THE ACCURACY AND RELIABILITY OF THE RESULTS OF CONVENTIONAL GAMMA S Q NNING MEASUREMENT' DEPEND STRONGLY ON THE FULFILYENT OF THE ASSUMPTION THAT THE GAMMA ATTENUATION IN THE WASTERMATRIX CAN BE PROPERLY CORRECTED. SUCH CORRECTIONS ARE USUALLY PERFORMED ON THE BASIS OF 'A PRIORI' KNOWLEDGE OF THE ATTENUATION PROPERTIES OF THE WASTE OR BY SIMPLY WEIGHING THE DRUM AND CALCULATING THE AVERAGE DENSITY. THESE ASSUYPTIONS ARE ONLY FILLED FOR WELL DEFINED WASTE PACKAGES. IN THE CASE OF HETEROGENEOUS ACTIVITY OR MATRIX DISTRIBUTIONS UNCERTAINTIES WILL BE INTRODUCED INTO THE MEASUREMENT RESULTS THAT CAN LEAD TO SIGNIFICANT ERRORS IN THE ACTIVITY DETERMINATION ESPECIALLY FOR WASTE WITH HIGHER MATRIX DENSITY.
TO OPTIMISE CONVENTIONAL GAMMA SCANNING IT IS NECESSARY TO CALCULATE AND TO REDUOE THESE SOURCES OF ERRORS AS GOOD AS POSSIBLE. THIS CAN BE ACHIEVED BY APPROPRIATE CORRE( TION TECHNIQUES FOR GAMMA ATTENUATIONS LIKE THE YETHOD OF TRANSMISSION CORRECTED GAMMA SCANNING. IN THE PROPOSED WORK PROGRAMME AN IMPROVED GAMMA SCANNING SYSTEM WTTT BE DESIGNED AND SET-UP BASED ON TRANSMISSION CQRRECTION. THE SYSTEM SET-UP WILL BE DONE BY UPGRADING EXISTING Y-SCANNERS (TWO SCANNERS ARE ENVISAGED) SO THAT MEASUREMENTS ON REAL WASTE DRUMS CAN BE CARRIED OUT. THE MAJOR UNCERTAINTIES AND POSSIBLE ERRORS OF GAMMA SCANNING MEASUREMENTS WILL BE EVALUATED AND THE PERFORYANCE OF THE IMPROVED SCANNING TECHNIQUE WILL BE QUANTIFIED COMPARED TO CONVENTIONAL GAMMA SCANNING. AS A RESULT OF THE PROJECT RECOMMENDATIONS WTTT, BE FORMULATED ON HOW TO PERFORM GAMMA SCANNING MORE ACCURATELY FOR CERTAIN RANGES OF APPLICATION. THESE GUIDELINES - WHICH COULD BE PUBLISHED AS 'EC-GUIDELINES FOR GAMMA SCANNING OF WASTE PACKAGES' - WITT HELP THE RESPECTIVE PEOPLE WHO PERFORM GAMMA MEASUREMENTS TO SET,FCT THOSE TECHNIQUES WHICH ARE BEST SUITED FOR A SPECIFIC QUALITY INSPECTION TASK, TO ESTIMATE POSSIBLE ERRORS AND TO SELECT APPROPRIATE MEASURES TO REDU OE UNCERTAINTIES.
THE RESULTS OF THE WORK PROGRAMME WILL BE OF INTEREST FOR NEARLY ALL APPLICATIONS IN WHICH NONDESTRUCTIVE GAMMA ASSAY SYSTEMS ARE USED TO MEASURE VOLUMETRIC RADIOACTIVE WASTE PACKAGES.
Programme(s)
Call for proposal
Data not availableFunding Scheme
CSC - Cost-sharing contractsCoordinator
52425 Juelich
Germany