学术报告：Nuclear Waste Treatment and Irradiation Effects on Magnetic Nanoclusters
报告题目：Nuclear Waste Treatment and Irradiation Effects on Magnetic Nanoclusters
报 告 人：You Qiang（Physics Department and Environmental Science Program, University of Idaho）
报告时间：2014年6月26日 （星期四）9:00
报告地点：嘉定园区学术活动中心302
报告摘要：
This talk will summarize research progress on nano-nuclear technology with focusing on two projects conducted recently in You Qiang’s group:
1) Advanced Magnetic Separation Nanotechnology for Nuclear Fuel Recycling
In order to meet future energy needs without polluting the environment by ejecting carbon dioxide, nuclear energy is one of the best sources of clean energy. The major concern, however, is the disposal of the nuclear waste, which needs to have a minimum impact on the environment. The current standard method of plutonium and uranium recovery by PUREX comes with certain disadvantages, such as the requirement of substantial tankage and reagents, and generation of significant amount of secondary waste, making this method inefficient. A fully closed fuel cycle where all actinides are recycled through the power reactors producing them could potentially reduce the repository storage space, the radioactivity of the waste, and further separate the trivalent actinides from lanthanides to avoid difficulties for subsequent transmutation. In this work, we demonstrated the separation of minor actinides using complex conjugates of MNPs with DTPA chelator. The uptake behavior of Am(III), Pu(IV), U(VI), and Np(V) from 0.1M NaNO3 solution was determined. The sorption results show the strong affinity of DTPA towards Am(III) and Pu(IV) by extracting 97% and 80% of actinides, respectively. The high removal efficiency of these long-term heat generating actinides can limit the amount of material that can be placed in a given amount of repository space and can also make the chelator conjugated MNPs an effective method for spent nuclear fuel separation. This is a simple, versatile, and compact process, which is cost efficient in terms of the materials and equipment used, and very low production of secondary waste can minimize the disposal costs and storage area.
2) Radiation Effects on Nanomaterials as Sensor for Nuclear Monitoring
Nuclear reactor under irradiation environment have to meet the standards of enhanced safety and economical compatibility. This research contributes to this objective through the understanding of irradiation induced nano-structural, electrical and magnetic property changes in nanomaterials. Fe3O4 and Fe-Fe3O4 nanoparticle (NP) granular films, created by our third generation nanocluster deposition system, were irradiated. Very interesting point is that the nano-structural evolution under irradiation features size growth, phase transition, particle aggregation, and formation of nanowire-like network as shown in our recent results of NP films, which makes a super-exponential decay of the electrical resistance of the films with irradiation dose, suggesting that this type of nanomaterials may possess an intrinsic merit for development of an ultra-high sensitive advanced online monitor for radiation detection.
报告人简介：
Dr. You Qiang is an adjunct professor in Environmental Science and tenured associate professor of Physics at the University of Idaho, Idaho, USA. He is chairman (2012-2013) and member of Idaho Academy of Science. He received his MS degree at Harbin Institute of Technology (HIT) and Chinese Academy of Space Technology (CAST) in 1985, and Ph.D. degree in 1997 at University of Freiburg, Germany. He was a research faculty at the University of Nebraska-Lincoln, USA, from 1999 to 2002. His research is focusing on physics of nanomagnetism and magnetic nanoparticles for more than 30 years. He applies the nanomaterials in nuclear energy, environmental science, including synthesis of monodispersive nanoclusters and nanocluster-assembled composites; characterization of magnetic and optical properties as well as transport properties by conductivity, optic and susceptibility, and theoretical investigation of magnetic nanoparticle interactions. He has published more than 100 refereed papers (AFM, JACS, PRB, APL, En&S…) and 4 book chapters, given more than 110 invited talks at international conferences, universities and institutions, and served as editor for several international scientific journals, member for international conferences and society committees, including MRS, CleanTech, NanoTech and IMC meetings. He organized and chaired more than 20 conferences and sessions such as INTERMAG, MMM, APS and NW-APS meetings.
相关附件