Utilization of Process Monitoring Data in the Tokai Reprocessing Plant for Future Nuclear Security

摘要

Japanese regulation of reprocessing safety and security was revised in March 2012, and almost all requirements except for nuclear material accountancy and control described in the INFCIRC225/rev.5 are included into the regulation. Because Tokai Reprocessing Plant (TRP) has several nuclear facilities which contain Category Ⅰ or Ⅱ nuclear material, we have many things to do to meet the requirements within 2 years pursuant to the regulation. The requirements, for instance, include setting up of a limited access area around the protected area instead of guard area and setting up of secondary central alarm station (CAS) for unexpected fire and earthquake, and introduction of two person rule within an vital area and explosive material detection system at the entrance of an inner area. We have to complete all the requirements described in the regulation by the end of March 2014. In addition, we would like to establish more effective and efficient nuclear material security separately from the revised regulation. One of ideas we have is utilizing the process monitoring data for the nuclear material security. From a safety viewpoint, we have process monitoring systems to measure several kinds of data such as density, volume and radiation etc. depending on the material form. Those data includes information on Pu storage equipment in vital areas. Since our operators continuously observe the process monitoring data to know the operational condition including unusual change, we think that the various alarm information from the operators or equipments help to detect the risk of sabotage and unauthorized removal. As future challenge, we would like to establish a possible method of utilizing information which the process monitoring data provide us with because we believe the utilization of the process monitoring data in combination with the physical protection make it possible to give more effective and efficient nuclear material security.