Plenary Talk 1
Monday, January 4, 2010 / 09:45 – 10:45 hrs
Advanced Reactor Development and its Challenges in the Indian Perspective
R. K. Sinha
Director, Reactor Design & Development Group
Bhabha Atomic Research Centre, Trombay, Mumbai, 400085, India.
rksinha@barc.gov.in
ABSTRACT
Since its introduction in the 1950s, nuclear energy has grown in stature and maturity and currently generates about 14% of the world electricity generation. Nuclear power will continue to play a significant role in the global energy mix, in the context of the enhanced worldwide environmental concern about global warming attributed to the generation of greenhouse gases, due to the burning of fossil fuels. Nuclear energy is the only non-greenhouse gas emitting power source that can be deployed on a large scale. Several non-electricity applications of nuclear energy have also emerged. Typical examples are hydrogen generation, desalination to produce potable water, transportable small reactors for remote areas. Besides, current Light Water Reactor (LWR) and Heavy Water Reactor (HWR) technologies have reached a state of saturation in terms of plant efficiency and economic competitiveness. In view of these developments, several international initiatives are currently underway for developing new advanced reactor systems. This includes the International Project on Innovative Nuclear Reactors and Fuel Cycles (INPRO) and Generation-IV Industrial Forum (GIF) initiatives. The main goals of these initiatives include economic competitiveness, sustainability, enhanced safety and reliability and proliferation resistance.
In the backdrop of the above international developments, India is consolidating its three-stage nuclear power programme, which incorporates the main goals of current international initiatives. What is more surprising is that it was formulated almost fifty years ago, taking into account of the indigenous resource base and long term sustainability of nuclear power. The first stage consisting of heavy water reactors has reached maturity with 17 operating reactors, while the second stage consisting of fast breeder reactors has been launched with the construction of PFBR. To develop the technologies required for the third stage, development of the Advanced Heavy Water Reactor has been taken up. Apart from mastering the thorium fuel cycle, AHWR incorporates key changes in thermal hydraulics to enhance safety and reliability. Compact High Temperature Reactor is being developed for the demonstration of technologies required for very high temperature reactor for process heat and hydrogen generation applications. Research and development on supercritical water cooled reactor and the molten salt reactor technologies are also ongoing.
The Advanced Reactor concepts incorporate several passive systems, mainly to enhance the operational safety and elimination of severe accidents and hence reduction of off-site planning. However, many of them are first-of-a-kind in design and incorporation of them requires extensive validation to evaluate their performance and reliability because of complex thermal hydraulics involved. Some key thermal hydraulic issues in this regard are multi-dimensional natural circulation, thermal stratification, boiling and condensation heat transfer phenomena in natural circulation condition, etc.
The advanced reactor designs with diverse coolants and fuel materials have several challenges in the field of thermal hydraulics, neutronics, heat transfer and computational fluid dynamics (CFD). Besides, these reactors require several coupled computations, which are outside the capability of present day system codes like RELAP5. This invited talk addresses these issues systematically.
