FUEL DEBRIS PROTOTYPE FABRICATION, CUTTING AND AEROSOL COLLECTION IN VIEW OF FUKUSHIMA DAIICHI FUEL DEBRIS RETRIEVAL SAFETY

Abstract

One of the keys of Fukushima Daiichi Nuclear Power Plant (1F) decommissioning steps is the estimation of the Airborne Release Fraction (ARF) during the removal of nuclear Fuel Debris (FD), to evaluate the potential exposure dose for workers and the public and thus contribute to define the equipment and mitigation means for FD retrieval.

The Dust Acquisition project, led by CRIEPI in collaboration with ONET/CEA/IRSN, aims to evaluate the ARF , a key parameter reflecting the amount of radioactive material suspended in the air. Specificity of this project is to study disc cutting in air of prototypic FD-simulants containing depleted uranium oxide. ONET/CEA/IRSN has designed, installed, and qualified a dedicated facility named FUJISAN2 located on the PLINIUS Platform at CEA Cadarache, aligned with the specifications and cutting conditions set by CRIEPI, facilitating data comparison between Japan and France sides. This paper presents the whole process developed by ONET/CEA/IRSN for this study with the capacity to manufacture specific compositions and supply corium samples for cutting, to perform cutting tests on FUJISAN2 and on-line dedicated aerosols measurements as well as sampling aerosols, to conduct material analysis of initial FD simulants and aerosols.