Articles written in Sadhana
Volume 32 Issue 3 June 2007 pp 215-234
Investigations conducted based on seismic soil-structure interaction analysis of a massive concrete structure supported on a raft foundation are presented in this paper. Linear transient dynamic analysis is carried out using ﬁnite element method and imposing transmitting boundary conditions at far ﬁeld of layered elastic half-space. Analysis is conducted in two phases, namely:
free-ﬁeld analysis of the layered half-space and
seismic analysis of the structure by including soil-structure interaction effects.
In the ﬁrst phase, a simple and novel technique is used to establish free-ﬁeld excitation at a depth in the half-space. In the second phase, seismic soil-structure interaction analysis of the structure is carried out for the free-ﬁeld excitation determined in phase-I. Stress resultants experienced by the raft and the stresses at the interface between the rock and raft are evaluated. Critical examination of the results indicates tensile stresses of considerable magnitude at few locations in the rock-raft interface. Typical stress responses at the interface are presented and discussed in the paper.
Volume 35 Issue 2 April 2010 pp 97-128
Thermal hydraulics plays an important role in the design of liquid metal cooled fast breeder reactor components, where thermal loads are dominant. Detailed thermal hydraulic investigations of reactor components considering multi-physics heat transfer are essential for choosing optimum designs among the various possibilities. Pool hydraulics is multi-dimensional in nature and simple one-dimensional treatment for the same is often inadequate. Computational Fluid Dynamics (CFD) plays a critical role in the design of pool type reactors and becomes an increasingly popular tool, thanks to the advancements in computing technology. In this paper, thermal hydraulic characteristics of a fast breeder reactor, design limits and challenging thermal hydraulic investigations carried out towards successful design of Indian Prototype Fast Breeder Reactor (PFBR) that is under construction, are highlighted. Special attention is paid to phenomena like thermal stratiﬁcation, thermal stripping, gas entrainment, inter-wrapper ﬂow in decay heat removal and multiphysics cellular convection. The issues in these phenomena and the design solutions to address them satisfactorily are elaborated. Experiments performed for special phenomena, which are not amenable for CFD treatment and experiments carried out for validation of the computer codes have also been described.
Volume 38 Issue 5 October 2013 pp 795-815
The paper brings out the advantages of fast breeder reactor and importance of developing closed nuclear fuel cycle for the large scale energy production, which is followed by its salient safety features. Further, the current status and future strategy of the fast reactor programme since the inception through 40 MWt/13 MWe Fast Breeder Test Reactor (FBTR), is highlighted. The challenges and achievements in science and technology of FBRs focusing on safety are described with the particular reference to 500 MWe capacity Prototype Fast Breeder Reactor (PFBR), being commissioned at Kalpakkam. Roadmap with comprehensive R&D for the large scale deployment of Sodium Cooled Fast Reactor (SFRs) and timely introduction of metallic fuel reactors with emphasis on breeding gain and enhanced safety are being brought out in this paper.