As theˆrst step of inspection of the applicability of the PRODIA Code for dismantling activities in the decommissioning of FUGEN, manpower needs for dismantling activities in FUGEN conducted in 2008 were calculated with conventional calculation formulas developed from the data obtained from the JPDR decommissioning program. In this inspection, it was found that the actual data for the dismantling of feedwater heaters show the following two characteristic proˆles: 1) the actual data were signiˆcantly smaller than the results of the conventional calculation formulas and 2) the actual data for the dismantling of the 3rd feedwater heater were two times larger than those for the dismantling of the 4th one, although both data were almost of the same weight. In order to use the PRODIA Code for further dismantling activities in the decommissioning of FUGEN, the origin of these results was investigated. This investigation showed that both of the diŠerences in the work description between FUGEN and JPDR and between the 3rd feedwater heater of FUGEN and the 4th one produce these characteristic proˆles. Since this means that the conventional calculation formula for the dismantling of feedwater heaters has no applicability, it was considered necessary to construct a new calculation formula re‰ecting the work description of the dismantling of feedwater heaters in FUGEN. It was found that the calculation results with this new formula showed good agreement with the actual data of both the 3rd and 4th feedwater heaters. Based on theseˆndings, some case studies for the dismantling of feedwater heaters were conducted.

Evaluation models for determining the manpower needs for dismantling various types of equipment in uranium refining and conversion plant (URCP) have been developed. The models are widely applicable to other uranium handling facilities. Additionally, a simplified model was developed for easily and accurately calculating the manpower needs for dismantling dry conversion process–related equipment (DP equipment). It is important to evaluate beforehand project management data such as manpower needs to prepare an optimized decommissioning plan and implement effective dismantling activity. The Japan Atomic Energy Agency (JAEA) has developed the project management data evaluation system for dismantling activities (PRODIA code), which can generate project management data using evaluation models. For preparing an optimized decommissioning plan, these evaluation models should be established based on the type of nuclear facility and actual dismantling data. In URCP, the dry conversion process of reprocessed uranium and others was operated until 1999, and the equipment related to the main process was dismantled from 2008 to 2011. Actual data such as manpower for dismantling were collected during the dismantling activities, and evaluation models were developed using the collected actual data on the basis of equipment classification considering the characteristics of uranium handling facility.