Transparency Technologies and the Naval Nuclear Fuel Cycle

To support international and bilateral nuclear arms-control efforts, technical communities are now examining a variety of non-intrusive measurements on items with sensitive or classified properties. The underlying physics is well understood, but the need to protect and limit the data output while providing enough information to provide sufficient confidence in the results of the measurements raises technical challenges. This paper investigates the option of extending ongoing and evolving transparency efforts on to non-intrusive verification of the proliferation-attractive naval fuel cycle. Highly enriched uranium (HEU) is used for the propulsion of submarines and some surface vessels, most notably in the USA and Russia.2 Naval fuel represents constitute 10 to 15% of all HEU stocks worldwide. Russia alone may hold as much as 80 to 85 metric tons of HEU for naval propulsion.3 The radiation levels of the fresh naval fuel are low and the enrichment levels make it potentially attractive for nuclear weapon production. With highly enriched naval fuel, as low as 10 fuel assemblies have been suggested sufficient to supply enough highly enriched uranium for a bomb.4 No bi- or multilateral verification is envisioned on these sensitive fuel cycles, and naval fuel transparency is a novel feature in international nuclear arms control. However, while international nuclear arms-control stands ready to move beyond strategic delivery systems and to address excessive stockpiles of weapons-grade fissile material, it will, sooner or later encounter the highly enriched uranium naval stockpiles.5 Thus, eventually, this material will somehow have to be accounted for and some assurances given that it is not being diverted to weapons.6