Neutron shielding panels for reactor pressure vessels

Abstract

In a nuclear reactor neutron panels varying in thickness in the circumferential direction are disposed at spaced circumferential locations around the reactor core so that the greatest radial thickness is at the point of highest fluence with lesser thicknesses at adjacent locations where the fluence level is lower. The neutron panels are disposed between the core barrel and the interior of the reactor vessel to maintain radiation exposure to the vessel within acceptable limits.

Description

[0001] Cross References to Related Applications [0002] This application claims priority to provisional application 60 / 992,158, filed December 4,2007. [0003] government interest [0004] This invention was made with Government support under Contract No. DE-FC07-051D14636 awarded by the Department of Energy. The government has certain rights in this invention. technical field [0005] The present invention relates generally to nuclear reactor internals, and more particularly to neutron shields for shielding nuclear reactor pressure vessels from excessive exposure to neutron flux. Background technique [0006] The primary side of a pressurized water cooled nuclear reactor power generation system includes a closed loop isolated from and in heat exchange relationship with a secondary side for generating useful energy. The primary side consists of: the reactor pressure vessel enclosing the core internal structure supporting multiple fuel assemblies containing fissionable...

AI Technical Summary

Problems solved by technology

As the size of the reactor increases, which requires larger thermal shields, the steel plates forming the shields can experience large temperature surges as they are heated, and the difference in thermal expansion between the shields and the core barrel Potentially distorting the means used to attach the neutron shield to the core barrel

Additionally, as the neutron shield becomes larger, the neutron shield may affect the pressure drop in the downcomer region between the core barrel and the reactor vessel, which in turn increases the pressure drop across the reactor vessel. The pressure drop and amount of flow turbulence created in the downcomer annulus

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