SAFEGUARDING IN PROCESS INVENTORY IN BULK HANDLING FACILITIES THROUGH SURVEILLANCE OF OPERATING RECORDS

Achievement of a timeliness goal shorter than a year, in the safeguarding of in process inventories, in large bulk handling facilities dealing with direct use materials, is one of the difficult tasks of International Safeguards. The basic approach has been, up to now, to try to do so through monthly accountancy verifications (DYMAC, NRTMA, etc...). But this raises many problems of intrusiveness, accuracy of measurements, representativity of samples, independence of verifications, etc... Suggested approaches through extensive use of usual C/S devices, were in many cases disappointing, because of the number of possible diversion routes. The paper suggests another type of surveillance approach, based on human and instrumented surveillance of selected Operating Records. The provisions of paragraphs 52, 54b, and 58a of Infcirc 153 are not only a means to verify the basis of Accounting Records, but can also be used very effectively, in order to demonstrate, through appropriate surveillance, and without the need for frequent material balances, that nuclear materials remains present in the facility.