Enhanced safeguards via solution monitoring

Solution monitoring is defined as the essentially continuous monitoring of solution level, density, and temperature in all tanks in the process that contain, or could contain, safeguards-significant quantities of nuclear material. This report describes some of the enhancements that solution monitoring could make to international safeguards. The focus is on the quantifiable benefits of solution monitoring, but qualitatively, solution monitoring can be viewed as a form of surveillance. Quantitatively, solution monitoring can in some cases improve diversion detection probability. For example, the authors show that under certain assumptions, solution monitoring can be used to reduce the standard deviation of the annual material balance, σMB, from approximately 17 kg to approximately 4 kg. Such reduction in σMB will not always be possible, as they discuss. However, in all cases, solution monitoring would provide assurance that the measurement error models are adequate so that one has confidence in his estimate of σMB. Some of the results in this report were generated using data that were simulated with prototype solution monitoring software that they are developing. An accompanying document describes that software