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Technical Options for the Advanced Liquid Metal Reactor

Description: This paper discusses the history and status of the ALMR research program. It presents applications of this technology to the plutonium disposition problem and the possible advantages and disadvantages of its future development and deployment. It also discusses related issues such as waste management and concerns about proliferation of plutonium material.
Date: May 1994
Creator: United States. Congress. Office of Technology Assessment.
Partner: UNT Libraries Government Documents Department

Progress in tritium retention and release modeling for ceramic breeders

Description: Tritium behavior in ceramic breeder blankets is a key design issue for this class of blanket because of its impact on safety and fuel self-sufficiency. Over the past 10-15 years, substantial theoretical and experimental efforts have been dedicated world-wide to develop a better understanding of tritium transport in ceramic breeders. Models that are available today seem to cover reasonably well all the key physical transport and trapping mechanisms. They have allowed for reasonable interpretation and reproduction of experimental data and have helped in pointing out deficiencies in material property data base, in providing guidance for future experiments, and in analyzing blanket tritium behavior. This paper highlights the progress in tritium modeling over the last decade. Key tritium transport mechanisms are briefly described along with the more recent and sophisticated models developed to help understand them. Recent experimental data are highlighted and model calibration and validation discussed. Finally, example applications to blanket cases are shown as illustration of progress in the prediction of ceramic breeder blanket tritium inventory.
Date: July 11, 1994
Creator: Raffray, A. R.; Federici, G.; Billone, M. C. & Tanaka, S.
Partner: UNT Libraries Government Documents Department

Capabilities of Reynolds stress turbulence model in applications to thermal stratification

Description: In the safety analysis of advanced fast breeder reactors, licensing authorities require that inherent safety capabilities be proved by numerical simulation with well-validated computer programs. Even in the worst case of loss of power to the primary pumps. natural convection circulation must provide, through intermediate heat exchangers. a heat sink sufficient to prevent coolant temperatures from reaching saturation and triggering development of a two-phase flow domain with subsequent induction of coolant capabilities and loss of com integrity. Numerical simulations of reactor coolant behavior require the modeling of turbulent flows in the critical transition phase between forced and natural convection. A Reynolds stress turbulence model (RSM) has been implemented in the COMMIX code, together with transport equations describing turbulent heat fluxes, variance of temperature fluctuations, and dissipation of turbulence kinetic energy. This article outlines the model, explains the verifications performed thus far. and discusses potential applications of the RSM in the analysis of thermal stratification in engineering systems. The problem of analyzing, thermal stratification and minimizing the impact of thermal stresses on structures is of concern in both nuclear and conventional industries.
Date: June 1, 1994
Creator: Chang, F. C. & Bottoni, M.
Partner: UNT Libraries Government Documents Department