The Experts below are selected from a list of 204 Experts worldwide ranked by ideXlab platform
S C Chetal - One of the best experts on this subject based on the ideXlab platform.
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steam generators for future fast Breeder Reactors
Energy Procedia, 2011Co-Authors: R Nandakumar, S Athmalingam, V Balasubramaniyan, S C ChetalAbstract:Abstract The operating experience of fast Reactors worldwide has highlighted the need for reliable performance of Steam Generator (SG) as it is one of the most critical components deciding the plant availability. Based on design, development and manufacture of steam generator for 500 MWe Prototype Fast Breeder Reactor (PFBR) and also the reassuring operational feedback from experimental Steam Generator Test Facility (SGTF), the concept of integral once through SG with mod. 9Cr 1Mo as principle material of construction is retained for future FBRs. SG is a vertical counter flow shell & tube heat exchanger with sodium on shell side and water / steam in tubes. For future FBRs, the present design of SG for PFBR is reassessed and optimised based on manufacturing experiences with focus on improved economics and enhanced safety. Various key aspects like selection of number of SG modules per secondary sodium loop, tube length, heat transfer area margin and optimization of tube size are discussed in the paper. The results of CFD studies carried out with a 30 sector model coupled with an in-house code (DESOPT) to investigate on thermal and flow distribution of such longer steam generators at different operating conditions are also highlighted. Through detailed optimisation studies, it is concluded that 3 SG per loop with each having 433 tubes of 30 m long, 12.6 mm ID and 2.4 mm wall thickness for a design life of 60 years provides economical configuration leading to a saving of ∼25% in total cost. Further, enhanced safety is ensured by reduction of ∼40% tube to tube-sheet joints as compared with PFBR SG.
Hiroshi Sekimoto - One of the best experts on this subject based on the ideXlab platform.
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performance of natural uranium and thorium fueled fast Breeder Reactors fbrs for 233u fissile production
Progress in Nuclear Energy, 2008Co-Authors: Peng Hong Liem, Naoyuki Takaki, Hiroshi SekimotoAbstract:Abstract The performance of natural uranium and thorium-fueled fast Breeder Reactors (FBRs) for producing 233U fissile material, which does not exist in nature, is investigated. It is recognized that excess neutrons from FBRs with good neutron economic characteristics can be efficiently used for producing 233U. Two distinct metallic fuel pins, one with natural uranium and another with natural thorium, are loaded into a large sodium-cooled FBR. 233U and the associated-U isotopes are extracted from the thorium fuel pins. The FBR itself is self-sustained by plutonium produced in the uranium fuel pins. Under the equilibrium state, both uranium and thorium spent fuels are periodically discharged with a certain discharge rate and then separated. All discharged fission products are removed and all discharged actinides are returned to the FBRs except the discharged uranium utilized for fresh fuel of the other thorium-cycled Reactors. 233U-production rate of the FBRs as a function of both the uranium–thorium fuel pins fraction in the core and the discharge fuel burnup is estimated. The result shows that larger fraction of uranium pins is better for the FBR criticality while larger fraction of thorium fuel pins and lower fuel burnup give higher 233U production rate.
R Nandakumar - One of the best experts on this subject based on the ideXlab platform.
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steam generators for future fast Breeder Reactors
Energy Procedia, 2011Co-Authors: R Nandakumar, S Athmalingam, V Balasubramaniyan, S C ChetalAbstract:Abstract The operating experience of fast Reactors worldwide has highlighted the need for reliable performance of Steam Generator (SG) as it is one of the most critical components deciding the plant availability. Based on design, development and manufacture of steam generator for 500 MWe Prototype Fast Breeder Reactor (PFBR) and also the reassuring operational feedback from experimental Steam Generator Test Facility (SGTF), the concept of integral once through SG with mod. 9Cr 1Mo as principle material of construction is retained for future FBRs. SG is a vertical counter flow shell & tube heat exchanger with sodium on shell side and water / steam in tubes. For future FBRs, the present design of SG for PFBR is reassessed and optimised based on manufacturing experiences with focus on improved economics and enhanced safety. Various key aspects like selection of number of SG modules per secondary sodium loop, tube length, heat transfer area margin and optimization of tube size are discussed in the paper. The results of CFD studies carried out with a 30 sector model coupled with an in-house code (DESOPT) to investigate on thermal and flow distribution of such longer steam generators at different operating conditions are also highlighted. Through detailed optimisation studies, it is concluded that 3 SG per loop with each having 433 tubes of 30 m long, 12.6 mm ID and 2.4 mm wall thickness for a design life of 60 years provides economical configuration leading to a saving of ∼25% in total cost. Further, enhanced safety is ensured by reduction of ∼40% tube to tube-sheet joints as compared with PFBR SG.
P. A. Chellapandi - One of the best experts on this subject based on the ideXlab platform.
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computational fluid dynamic studies on gas entrainment in fast Breeder Reactors
Energy Procedia, 2011Co-Authors: K Satpathy, K Velusamy, P. A. ChellapandiAbstract:Primary sodium pools in fast Reactors are covered with argon. There is strong potential for argon gas entrainment into sodium and associated reactivity perturbations if the free surface velocity is large. Basic CFD studies have been carried out on ideal models and the threshold value of free surface sodium velocity that avoids gas entrainment is arrived at employing the VOF method. Subsequently, 3-D CFD studies have been carried out for PFBR hot pool and the free s urface velocity is estimated to be 1.15 m/s. To reduce this value below the threshold limit, a horizontal baffle device has been identified.
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Fluid-structure interaction in fast Breeder Reactors
The Journal of the Acoustical Society of America, 2004Co-Authors: A. A. Mitra, D. N. Manik, P. A. ChellapandiAbstract:A finite element model for the seismic analysis of a scaled down model of Fast Breeder reactor (FBR) main vessel is proposed to be established. The reactor vessel, which is a large shell structure with a relatively thin wall, contains a large volume of sodium coolant. Therefore, the fluid structure interaction effects must be taken into account in the seismic design. As part of studying fluid‐structure interaction, the fundamental frequency of vibration of a circular cylindrical shell partially filled with a liquid has been estimated using Rayleigh’s method. The bulging and sloshing frequencies of the first four modes of the aforementioned system have been estimated using the Rayleigh–Ritz method. The finite element formulation of the axisymmetric fluid element with Fourier option (required due to seismic loading) is also presented.
Peng Hong Liem - One of the best experts on this subject based on the ideXlab platform.
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performance of natural uranium and thorium fueled fast Breeder Reactors fbrs for 233u fissile production
Progress in Nuclear Energy, 2008Co-Authors: Peng Hong Liem, Naoyuki Takaki, Hiroshi SekimotoAbstract:Abstract The performance of natural uranium and thorium-fueled fast Breeder Reactors (FBRs) for producing 233U fissile material, which does not exist in nature, is investigated. It is recognized that excess neutrons from FBRs with good neutron economic characteristics can be efficiently used for producing 233U. Two distinct metallic fuel pins, one with natural uranium and another with natural thorium, are loaded into a large sodium-cooled FBR. 233U and the associated-U isotopes are extracted from the thorium fuel pins. The FBR itself is self-sustained by plutonium produced in the uranium fuel pins. Under the equilibrium state, both uranium and thorium spent fuels are periodically discharged with a certain discharge rate and then separated. All discharged fission products are removed and all discharged actinides are returned to the FBRs except the discharged uranium utilized for fresh fuel of the other thorium-cycled Reactors. 233U-production rate of the FBRs as a function of both the uranium–thorium fuel pins fraction in the core and the discharge fuel burnup is estimated. The result shows that larger fraction of uranium pins is better for the FBR criticality while larger fraction of thorium fuel pins and lower fuel burnup give higher 233U production rate.