Non-intrusive Isotope Detection with Nuclear Resonance Fluorescence

Detection of nuclear material with isotopic specificity is of utmost importance in homeland security and in the fields of non-proliferation, safeguards and nuclear forensics. Non-intrusive methods are important to improve efficiency and speed of response while not damaging the items being examined, their encapsulations and methods of transport. Nuclear Resonance Fluorescence (NRF) provides these capabilities. The nuclear excitations involved are unique for any isotope in nuclear material configurations. The photon energies involved are in the MeV range and are thus very penetrating. Data are presented for the excitations of 235U, 238U, 237Np and 239Pu demonstrating the potential of NRF in gram and larger quantities. Both scattering and transmission modalities are discussed as applicable in diverse situations. Intense sources of photon beams are available and the development of novel yet practical sources is discussed demonstrating a rapidly growing opportunity for performance. The detection of the constituents of fuel rods is discussed as a means of determining origin of manufacture through quantities of materials such as Sn, Zr and other metals and the constituencies of oxides, chlorides and other compounds. The global origins of materials can be related to the isotopic abundances and this feature is further developed for shielding materials as an example. The inclusion of NRF technologies in power reactors, processing and refinement facilities may be very useful in mitigating problems of material loss and inventory accounting for the management of reprocessing, refinement, transport and flow of nuclear materials.