Year
2016
Abstract
The objectives of the IAEA safeguards are the timely detection of a diversion of a significant quantity of nuclear material and deterrence of such diversion or misuse through the risk of early detection. In the future, this could include verification of the amount of plutonium being produced by a State, and thereby the amount of plutonium produced at a given reactor site. The concept of nuclear archeology, as an example the Isotope Ratio Method (IRM), could be employed as one facet of this verification regime to give a quantifiable estimate of the plutonium produced in a given reactor at any point in the lifetime of that facility. Isotope ratio methods have been used to estimate total fluence at research reactors by measuring samples from structural aluminum supports, measuring impurities in aluminum and zirconium components, and measuring natural impurities in graphite at graphite moderated reactors. This research investigated the design of a fluence monitor for small modular reactors (SMRs) that has desirable nuclear and chemical characteristics to improve the implementation, precision, and applicability of the IRM for implementation as part of a future safeguards agreement. This approach has the potential advantages of avoiding the difficulties from sampling structural materials, avoiding isotopes that activate, and avoiding isotopes that could result in isobaric interferences with the isotopes of interest during the mass spectroscopy measurements.