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A sodium-cooled, 500-MW (electric) prototype fast breeder reactor (PFBR) is under construction in Kalpakkam, India. The PFBR core houses various subassemblies that are supported vertically inside the core by the sleeves provided in the grid plate. A small radial gap exists between the grid plate sleeve and the foot to facilitate easy handling of subassemblies. It is natural that there will be some leakage flow through this radial gap into the hot and cold pools of the PFBR. To minimize this leakage flow, top and bottom labyrinths are provided on the foot of the subassemblies. The total leak flow rate permitted from the top labyrinth is 195 kg/s, whereas the leak flow rate allowed through the bottom labyrinth is 436 kg/s. Labyrinthtype sealing devices have been developed by carrying out experimental studies. Based on various parametric studies, the labyrinth geometry was optimized. It was found that apart from the clearance between the foot and sleeve, important parameters affecting pressure drop are groove profile, groove pitch, groove-depth-to-width ratio, etc. Taking into account the outcome of these studies, helical square grooved labyrinths have been designed and manufactured for PFBR. This paper presents the details of the similarity criteria followed, experimental methodology applied, and results obtained from the experiments along with their transposability to reactor conditions. [ABSTRACT FROM AUTHOR]

Abstract: Shields around core and blankets form major part of reactor assembly in fast reactors. Among the advanced shield materials considered for use in future FBRs, planned to be constructed in India, Ferro-boron is a cheap and indigenously available material. This paper reports the results of experiments conducted in the south end neutron beam of KAMINI reactor on the fast, epithermal and thermal neutron flux attenuation behaviour of Ferro-boron with different percentages of boron as well as boron carbide. The attenuation factors were found over a thickness of 20-30cm for the measured reaction rates of Pt195 (n,n’) Pt195m, Cd111 (n, n’) Cd111m, Rh103(n,n’) Rh103, In115 (n,n’) In115m, Hf180(n,n’)Hf180m, Cu63 (n,) Cu64, Na23 (n,) Na24, Mn55 (n,) Mn56 and Au197 (n,) Au198 reactions representative of fast, epithermal and thermal neutron fluxes. A comparative analysis with the neutron attenuation behaviour measured in boron carbide powder is also made. [Copyright &y& Elsevier]

Abstract: Sodium cooled fast breeder reactors constitute the second stage of India''s three -stage nuclear energy programme, for effective utilization of the country''s limited reserves of natural uranium and exploitation of its large reserves of thorium. The Fast Breeder Test Reactor (FBTR) at Indira Gandhi Centre for Atomic Research (IGCAR), Kalpakkam, is a loop type, sodium cooled fast reactor. Its main aim is to provide experience in fast reactor operation, large scale sodium handling and to serve as a test bed for irradiation of fast reactor fuels & materials. FBTR was built on the lines of the French Rapsodie-Fortissimo reactor, with modifications to make it a generating plant. FBTR went critical on 18th Oct 1985 with a small core of 22 fuel subassemblies of a unique, high Pu carbide fuel. The core was rated for 10.5 MWt. The TG was rolled and synchronized to the grid in July 1997. Reactor power was progressively increased by enlarging the core, to reach 18.6 MWt. Several challenges in reactor operation came on the way, which were successfully overcome. A large number of modifications were carried out to improve the plant performance. The reactor coolant used (Sodium) is highly reactive when exposed to atmosphere and also becomes highly active on exposure to neutron radiation. These properties of sodium make it essential to handle it carefully and safely within a leak tight containment. During course of operation of the reactor, a number of sodium laden components viz. pumps, valves, cold traps, Rupture discs, level probes, shielding plugs, control rod drive mechanisms, experimental assemblies, piping etc. are required to be removed for various maintenance, modification and replacement jobs. This paper details the experience with operation and maintenance of India''s only one fast reactor power station. [Copyright &y& Elsevier]

Abstract: The growing energy needs of India can be fulfilled only by judicious mix of all the fuel resources. It is possible to achieve energy security and sustainability through the introduction of fast reactors in an expeditious manner and closing the fuel cycle. This approach is inevitable in view of the limited uranium resources in India. The Fast Breeder Test Reactor (FBTR) built by India uses mixed carbide as fuel and the 500 MW(e) Fast Breeder Reactor Project (PFBR), to be operational in 2010, will use mixed oxide as fuel. It has also been decided that fast reactors beyond 2020, with enhanced safety features and having better economy, will use metallic fuel. Having successfully operated FBTR with carbide fuels, we need to develop the fuel cycles for both the mixed oxide fuel in the near future and the metallic fuel expeditiously. The progress achieved so far and the plans for implementation are discussed in this paper. [Copyright &y& Elsevier]

It is nearly fifty years since the beginning of the fast reactor development programme in India. Nuclear energy has substantial higher potential especially when fast breeder reactors are brought into play even with moderate reserves of uranium as is the case with India. While a beginning was made by setting up the Fast Breeder Test Reactor (FBTR) operating at Kalpakkam since 1985, there is an imperative need to build a robust fast reactor programme as the second stage of India's much publicised three stage nuclear power programme. This article focuses first on challenges and gains from FBTR followed by current status of the Prototype Fast Breeder Reactor, PFBR at Kalpakkam. It then elaborates on evolution of its current design, development of components, delays suffered during its commissioning, and emphasis to retain technical expertise in this totally new technology. Finally it suggests a way forward to maintain relevance of the programme by accelerating advanced fuel development with high breeding ratio. • Indian Fast Reactor programme background, Choice of sodium cooled (fast) reactor, Fast Breeder Test Reactor (FBTR), Fuel development, Gains from FBTR. • Prototype Fast Breeder Reactor (PFBR), Design evolution, Timeline of programme, Engineering data related to FBTR and PFBR, Component manufacture and testing. • Sodium circuits commissioning, Difficulties faced, Delays, Utilizing expertise of retired persons involved in FBTR and R&D. • Future challenges, Metal fuel development, Need for commissioning authority to oversee commissioning. • Planning future reactor work with advanced fuel. [ABSTRACT FROM AUTHOR]