Optimized Safeguards Approach at WOLSONG CANDU reactors site in ROK using Unattended Monitoring System(UMS)

摘要

An Unattended Monitoring System(UMS)has been designed and implemented by the IAEA for the verification of spent fuel bundles transfers from spent fuel ponds to Dry storage at Wolsong N.P.P.,Republic of Korea(ROK). The system which is a combination of NDA and Surveillance equipment is constituted of two underwater cameras,one underwater NDA system(gamma detectors)in the spent fuel pond,a Mobile Unit Neutron Detector(MUND)and an ALIP camera on the transfer flask and transport vehicle,respectively,and Silo Entry Gamma Monitors Detectors(SEGM)backed-up by two ALIP cameras at the SF canisters site. This system combined with a short notice inspection(SNI)regime together with a near-real time Mailbox Declaration is being used since September 1,2006.Its main objective is to maintain the Continuity of Knowledge of nuclear material being transferred from spent fuel bays in CANDU reactors to the dry storage in replacement of Human Surveillance.Its use has resulted in significant savings in term of IAEA inspection effort(PDIs),while maintaining safeguards effectiveness.