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AssigneeNuScale Power, LLC
InventorsTamas Liszkai, Todd Sorensen
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Steam generator systems including tubesheet assemblies, such as for use in nuclear reactor systems, and associated devices and methods are described herein. A representative steam generator system can be installed in a nuclear reactor vessel positioned to house a primary coolant. The steam generator system can include a tubesheet assembly defining a plenum and comprising a tubesheet and a flexible connection portion coupling the tubesheet to the reactor vessel. The tubesheet can include a plurality of perforations fluidly coupled to the plenum. The steam generator system can further comprise a plurality of heat transfer tubes fluidly coupled to the perforations and configured to receive a flow of a secondary coolant. The connection portion can be more flexible than the tubesheet and the reactor vessel to reduce stresses on the tubesheet and the connections (e.g., tube-to-tubesheet (TTS) welds) between the tubes and the tubesheet during operation of the nuclear reactor system.
A tubesheet assembly for use in a nuclear reactor system including a reactor vessel extending along a longitudinal axis, the tubesheet assembly comprising:
The tubesheet assembly of claim 1 wherein the tubesheet is a circular flat plate having an inner surface positioned to face an interior of the reactor vessel and an outer surface positioned to face the plenum, wherein the tubesheet assembly includes a circular groove extending circumferentially about the tubesheet and defining the connection portion, and wherein the circular groove extends from the outer surface partially toward the inner surface.
The tubesheet assembly of claim 2 wherein the circular groove has a generally constant width and depth.
The tubesheet assembly of claim 1 wherein the tubesheet is a circular flat plate having an inner surface positioned to face an interior of the reactor vessel and an outer surface positioned to face the plenum, wherein the tubesheet has a first thickness in a direction between the inner surface and the outer surface, and wherein the connection portion has a second thickness, less than the first thickness, in the direction between the inner surface and the outer surface.
The tubesheet assembly of claim 4 wherein the first thickness is between about 2-6 times larger than the second thickness.
The tubesheet assembly of claim 1 wherein the reactor vessel extends along a longitudinal axis, and wherein the tubesheet is inclined relative to the longitudinal axis by an angle of about 30°.
The tubesheet assembly of claim 1 further comprising a removable cover plate configured to be coupled to the body to enclose the plenum.
The tubesheet assembly of claim 1 wherein the tubesheet includes an inner surface positioned to face an interior of the reactor vessel and an outer surface positioned to face the plenum, wherein the tubesheet assembly includes a first groove extending circumferentially about the tubesheet from the inner surface partially toward the outer surface and a second groove extending circumferentially about the tubesheet from the outer surface partially toward the inner surface, and wherein the first groove and the second groove define the connection portion.
The tubesheet assembly of claim 1 further comprising a port fluidly coupled to the plenum.
The tubesheet assembly of claim 1 wherein the connection portion includes an inner surface positioned to face an interior of the reactor vessel and an outer surface positioned to face the plenum, and wherein the outer surface of the connection portion has a curved shape.
The tubesheet assembly of claim 1 wherein the tubesheet assembly is integrally formed with the reactor vessel.
The tubesheet assembly of claim 1 wherein the reactor vessel extends along a longitudinal axis, and wherein the tubesheet is positioned generally parallel to the longitudinal axis.
A method of producing a tubesheet assembly for use in a nuclear reactor system including a reactor vessel extending along a longitudinal axis, the method comprising:
The method of claim 13 wherein forming the groove comprises milling the groove via a tool inserted into the plenum with a cover plate of the tubesheet assembly removed.
The method of claim 13 wherein forming the groove comprises forming a circular groove having a constant width and depth.
The method of claim 13 wherein forming the groove comprises forming a first groove extending circumferentially about the tubesheet from an inner surface of the tubesheet partially toward an outer surface of the tubesheet and forming a second groove extending circumferentially about the tubesheet from the outer surface partially toward the inner surface, and wherein the first groove and the second groove define the connection portion.
The method of claim 13 wherein the tubesheet has a first thickness, and wherein the connection portion has a second thickness less than the first thickness.
The method of claim 17 wherein the first thickness is between about 2-6 times larger than the second thickness.
The method of claim 13 wherein the tubesheet assembly is integrally formed with the reactor vessel.
The method of claim 13 further comprising coupling a plurality of heat transfer tubes to corresponding ones of the perforations.
Dependencies are inferred from the claim text.