Safeguards Approach for Detecting the Diversion of Nuclear Material at Dry Storage of CANDU Reactor

Considering the amount of nuclear material being stored at the dry storage of CANDU site, it goes without saying that emphasis should be placed on the possibility of diversion of nuclear material being safeguarded. The IAEA has applied dual containment and surveillance system, consisting of COBRA and metal seals, to the dry storage through the approval of DDG-SG of the Agency. However, in accordance with diversion scenarios coupled with recent strengthened safeguards, research and development is being under way to detect the diversion of nuclear material through the wall of the canister and underground tunnel. In response to the diversion scenarios, this paper proposes an alternative safeguards approach associated with the detection of diversion of nuclear material in the dry storage, particularly, considering both safeguards efficiency and verification activities in field as well as safeguards effectiveness. When any abnormal incidents such as malfunction of detectors, data transmission, or any other mechanical problems are revealed by the additional measure, a follow-up action is to verify the seals and the same with the existing way. In this connection, the necessity of installing complicated and additional safeguards equipment system should be re-evaluated in a systematic manner. In order to maintain the continuity of knowledge, the following is proposed. 1) The observation during the construction period of dry canisters is to be carried out. 2) If not possible to perform the above activity due to the lack of inspection efforts, then increased cooperation with the SSAC concerned is to be considered. 3) Alternative way is to install digital cameras at appropriate locations, which can be combined with other containment measures installed at dry storage. 4) In addition, the satellite images or seismometer could be utilized as a complementary measure for the existing safeguards measures.