Fast Reactors and Accelerator Driven Systems Knowledge Base

Conference Article: Neutronics design studies of an LBE cooled ATW blanket

Abstract

As part of the Advanced Accelerator Application (AAA) program in the US, preliminary trade studies have been performed at Argonne National Laboratory (ANL) and Los Alamos National Laboratory (LANL) to define and compare candidate Accelerator Transmutation of Waste (ATW) systems. The studies at ANL have focused primarily on the blanket component of the overall system, because the choice of blanket technologies is among the most important technical decisions faced in developing an ATW system. A wide range of potential transmuter designs has been investigated for lead-bismuth eutectic (LBE), sodium, and gas cooled systems. This paper summarizes the results of neutronic design studies of an LBE cooled ATW blanket. These studies have been focused primarily on achieving high discharge burnup while simultaneously achieving low burnup reactivity loss over an operating cycle. A fission-power level of 840 MWt is targeted, the same power level previously adopted for the PRISM Advanced Liquid Metal Reactor (ALMR). The blanket is assumed to be fueled with a non-uranium metallic dispersion fuel; pyrochemical techniques are used for recycle of residual transuranic actinides (TRU) in this fuel after irradiation. The key system objective of high discharge burnup is shown to be achievable in a configuration with comparatively high power density and relatively low burnup reactivity loss. System design and operating characteristics that satisfy these goals while meeting key thermal-hydraulic and materials-related design constraints have been preliminarily developed. Results of the performance evaluations indicate that an average discharge burnup of ~26% is achieved with a four year fuel residence time. Reactivity loss over the half-year cycle is 4.7%Δk. The peak fast fluence value at discharge, the TRU fraction in the charged fuel, and the peak coolant velocity are well within the assumed design limits. Owing to its use of non-uranium fuel, this proposed LBE cooled system can consume Light Water Reactor (LWR) discharge TRU at the maximum rate achievable per unit of fission energy produced (~1.0 g/MWd).

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Reference:

Proceedings of a Committee Meeting (TCM) on “Core Physics and Engineering Aspects of Emerging Nuclear Energy Systems for Energy Generation and Transmutation” held in Argonne, Illinois, U.S.A., 28 November - 1 December 2000

International Atomic Energy Agency, Vienna (Austria)

IAEA-TECDOC--1356, pp:83-93