Year
1999
Abstract
It is envisaged that the SNRI (Shot Notice Random Inspection) will be introduced into all Japanese LEU fuel fabrication facilities shortly as a part of IAEA's measures for SSS (Strengthened Safeguards System). The JNF (Japan Nuclear Fuel Co.,Ltd) LEU fuel fabrication plant has been chosen for trial application of SNRI concept prior to applying to other facilities. Accordingly the procedures for implementing SNRI have been developed followed by installation of mailbox computer, preparation of the system to transmit required data elements to the facility to the inspectorates, NDA Equipment and necessary licensing for the use and store of the neutron source. Since the first SNRI took place in January 1998, several SNRIs have been actually carried out and it was demonstrated that the SNRI procedures developed for JNF work satisfactorily, meet the IAEA's safeguards goal and the SNRI concept greatly improves the effectiveness of safeguards. Now however it is time to pay more attention to improvement of efficiency that is the one of two objectives of SSS measures. This paper addresses the relationship between the detection probabilities and various inspection parameters ad concludes that there are possibilities for improvement of efficiency by reducing inspection frequency without deteriorating the detection probabilities.