Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Porcheron, E.*; Leblois, Y.*; Journeau, C.*; Delacroix, J.*; Molina, D.*; Suteau, C.*; Berlemont, R.*; Bouland, A.*; Lallot, Y.*; Roulet, D.*; et al.
Proceedings of International Topical Workshop on Fukushima Decommissioning Research (FDR2022) (Internet), 5 Pages, 2022/10
One of the important challenges for the decommissioning of the damaged reactors of the Fukushima Daiichi Nuclear Power Station (1F) is the fuel debris retrieval. The URASOL project, which is undertaken by a French consortium consisting of ONET Technologies, CEA, and IRSN for JAEA/CLADS, is dedicated to acquiring basic scientific data on the generation and characteristics of radioactive aerosols from the thermal or mechanical processing of fuel debris simulant. Heating process undertaken in the VITAE facility simulates some representative conditions of thermal cutting by LASER. For mechanical cutting, the core boring technique is implemented in the FUJISAN facility. Fuel debris simulants have been developed for inactive and active trials. The aerosols are characterized in terms of mass concentration, real time number concentration, mass size distribution, morphology, and chemical properties. The chemical characterization aims at identifying potential radioactive particles released and the associated size distribution, both of which are important information for assessing possible safety and radioprotection measures during the fuel debris retrieval operations at 1F.
Journeau, C.*; Molina, D.*; Brackx, E.*; Berlemont, R.*; Tsubota, Yoichi
Proceedings of International Topical Workshop on Fukushima Decommissioning Research (FDR2022) (Internet), 5 Pages, 2022/10
CEA has manufactured a series of Fukushima Daiichi fuel debris simulants, either with depleted uranium oxide or with hafnium oxide as a surrogate of UO
. In ex-vessel compositions resulting from an interaction between corium and concrete, the oxidic phase density becomes lighter than that of the metallic phase, which segregates at the bottom. Three of these metallic phases have been mechanically cut at CEA Cadarache with handsaw and with core boring tool in FUJISAN facility. It appeared that two of these metallic blocks were extremely hard to cut (one from a fabrication with uranium oxide, the other from a simulant block) while the last one was more easily cut. The similarities and differences in metallographic analyses (SEM-EDS and XRD) of these three metal blocks will be presented and discussed. This experience provides useful learnings in view of the cutting and retrieval of fuel debris from Fukushima Daiichi.
Zhou, Q.*; Saito, Takumi*; Suzuki, Seiya; Yano, Kimihiko; Suzuki, Shunichi*
Journal of Nuclear Science and Technology, 58(4), p.461 - 472, 2021/04
Times Cited Count：6 Percentile：70.8(Nuclear Science & Technology)Tachibana, Mitsuo; Shiraishi, Kunio; Yanagihara, Satoshi
JAERI-Tech 2001-014, 42 Pages, 2001/03
In the JPDR dismantling demonstration project, the dismantling activities were conducted for the purpose of verification of remote dismantling machines and collection of various kinds of data on work activities. These lessons were categorized into safety consideration, waste treatment and work efficiency by analyzing the data on work activities. Exemplified are necessities of facility information, efficiency of mock-up tests for evaluation of remote dismantling procedures. There will be useful for implementing other decommissioning projects in safe and efficiency. This report describes the measure taken for remote dismantling activities and the lessons learned from the dismantling activities.
