Colloquium # 248
Mechanical Properties of Material at Extended Irradiation for Next Generation Nuclear Reactors

by B. K. Dutta from BARC/HBNI

Thursday, February 26th at 3:30PM,  Seminar room

The effect of irradiation on the mechanical response of metallic materials has been the subject of much study over the last five decades. These studies were motivated primarily by the need to understand the micro-structural evolution of structural materials for the purpose of lifetime extension of the existing fleet of nuclear reactors. More recently, the severe operational conditions in future fusion energy devices have stimulated their own set of irradiation studies. Due to the attractive properties, ferritic/martensitic steels are considered to be the prime candidates for radiation-tolerant structural components in next generation nuclear power design. As a consequence, body-centered cubic (bcc) Fe and several of its alloys have been the focus of extensive research efforts to estimate the change in mechanical properties, such as, yield stress, ultimate stress, ductility, fracture toughness, crack growth
resistance, etc.
A research program is being pursued in Reactor Safety Division of BARC to understand the irradiation damage in structural materials with an objective to assess damage at extended irradiation. The research program has experimental as well as analytical fronts. Experiments are being performed on miniaturized specimens of various sizes, shapes and under different modes of loadings to generate ASTM equivalent properties. Such efforts will provide a methodology to tests irradiated samples with minimum volume.

Multi-scale material modelling of irradiated materials is being performed as a part of analytical program. Various scales of simulations are molecular dynamics, dislocation dynamics, crystal plasticity and solid mechanics. Outputs from one scale are fed to the next higher level to continue with the simulation. The analytical results are tested with the results obtained from experimental program mentioned above. The established simulation modelling technique then can be used to estimate change in mechanical properties at extended irradiation.

About the speaker:

Prof. B. K. Dutta is a distinguished scientist, a senior professor and Dean of HBNI. Presently, he is leading Human Resource Development Department (HRDD) and Structural and Material Mechanics Section of BARC. He did his Bachelor of Engineering from NIT-Raipur, M.Tech from IIT-Kanpur and Ph.D. from IIT-Powai. His present fields of interests are: Fracture Mechanics and Structural Integrity Analysis, Finite Element Simulation of structural and thermal problems, Nuclear Fuel Modelling, Multi Scale Material Modelling and Minituarized Specimen Testing. He has more than three hundred technical publications, which include eighty-one papers in peer-reviewed journals.He is also an author of a book-chapter published by WIT press (UK). He is a Guest Editor of special volumes of International Journal on Nuclear Engineering and Design and Academy Proceedings in Engineering Sciences SADHANA. In his academic career Prof. Dutta has guided many Ph.D. Students, 3 of them have already completed and ten of them are in continuation of their work. He is awarded Technical Excellence award (1992) and Homi Bhabha award for Science and Technology (1997) by DAE.