Development of Glovebox Cleanout Assistance Tool (BCAT) by using Distributed Source-Term Analysis (DSTA)

Nakamichi, Hideo; Beddingfield, D. H.*; Nakamura, Hironobu ; Mukai, Yasunobu ; Kurita, Tsutomu 

The Distributed Source-Term Analysis (DSTA) technique provides user with knowledge of the location of neutron-producing materials and the magnitude of activity in the large volume to be evaluated. We aimed that this technique can be used to identify the physical location and activity of holdup in the glove box. By using relationships between source and volume determined by MCNPX calculation, we developed a Glove Box Cleanout Assistance Tool (BCAT). The tool can be applied to the operator during cleanout to increase recovered material, to decrease unmeasured inventory, and to perform the cleanout effectively in order to reduce operator radiation-exposure. In order to demonstrate the BCAT performance, neutron measurements were performed around actual glovebox environment. As a result of the analysis, not only the more concrete holdup locations and the activities that we experimentally estimate the place to recover were determined, but also the new hidden holdup could be found out. This knowledge provides new effective cleanout methodology. Consequently, it is expected that the nuclear material accountancy for entire bulk-handling facility can be improved.