A Proposal of Secure Non-destructive Detection System of Nuclear Materials in Heavily Shielded Objects and Interior Investigation System

Much development efforts have been done for non-destructive detection (NDD) systems at security checking points (bordres, airports and harbours). Among these points, large size freight cargo containers at harbours are the most volunurable items from security points of view because of their large volume and weight of cargo inside. Secure detection of nuclear materials (NMs) out of regulatory control hidden in heavily shielded objects (HSO) carried in freight cargo containers is the most difficult challenge in nuclear security. In addition to secure detection of NMs in HSO, detailed interior inspecdtion of heavily shielded suspicious objects is essential for safe distmantlement of them (avoiding fatal incidents at dismantlement, like explosions etc.) to take NMs out for nuclear forensics. Safe dismantlement and taking NMs (radioactive materials) are inevitable things. We propose a secure NM detection system with nuclear resonance fluorscence (NRF)-NDD (NRF-NDD) using mono-energetic high energy / high intensity gamma-rays with interior inspection capability (structure investigation and rough NM chracterization. We also propose a system for investigation of NMs parts using a D-T pulsed neutron source and active neutron NDA techniques for rough characterization of NMs and detection of explosives to dismantle the objects safely to have NMs for nuclear forensics.