Upper internals arrangement for a pressurized water reactor
AssigneeWestinghouse Electric Corp.
InventorsERIC M. WEISEL, KENNETH V. MARGOTTA, DANIEL WALUS, THOMAS J. SCHILDKAMP, JOSEPH J. HAHN, MICHAEL D. HEIBEL
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Abstract
A telescoping guide for extraction and reinsertion support handling of in-core instrument thimble assemblies in the area above the upper support plate in the upper internals of a pressurized water reactor. The telescoping guides extend between the upper ends of the upper internals support columns and an axially movable instrumentation grid assembly which is operable to simultaneously raise the telescoping guides and extract the in-core instrument thimble assemblies from the reactor fuel assemblies.
Claims16
A pressurized water nuclear reactor comprising:
- a pressure vessel;
- an upper removable head for sealably engaging an upper opening in the pressure vessel;
- a core having an axial dimension supported within the pressure vessel;
- a plurality of nuclear fuel assemblies supported within the core;
- at least some of the fuel assemblies having at least one instrumentation tube extending axially therethrough;
- an upper core plate extending over the nuclear fuel assemblies;
- an upper support plate attached to either the upper removable head or the pressure vessel and extending across the upper opening in the pressure vessel;
- a plurality of support columns extending at least partially between the upper core plate and the upper support plate, at least some of the support columns being aligned axially with a corresponding instrumentation tube through an opening in the upper core plate;
- and
- an axially slidable sleeve extending through an upper end in at least some of the support columns that are aligned with the corresponding instrumentation tube, the sleeve being axially extendable from the corresponding support column through an opening in the upper support plate to an area above the upper support.
A nuclear electrical power generating facility having a pressurized water reactor nuclear steam supply system comprising:
- a pressure vessel;
- an upper removable head for sealably engaging an upper opening in the pressure vessel;
- a core having an axial dimension supported within the pressure vessel;
- a plurality of nuclear fuel assemblies supported within the core;
- at least some of the fuel assemblies having at least one instrumentation tube extending axially therethrough;
- an upper core plate extending over the nuclear fuel assemblies;
- an upper support plate attached to either the upper removable head or the pressure vessel and extending across the upper opening in the pressure vessel;
- a plurality of support columns extending at least partially between the upper core plate and the upper support plate, at least some of the support columns being aligned axially with a corresponding instrumentation tube through an opening in the upper core plate;
- and
- an axially slidable sleeve extending through an upper end in at least some of the support columns that are aligned with the corresponding instrumentation tube, the sleeve being axially extendable from the corresponding support column through an opening in the upper support plate to an area above the upper support plate.
A method of accessing a core having a plurality of elongated fuel assemblies enclosed within a pressure vessel of a pressurized water reactor, wherein at least some of the fuel assemblies have at least one instrumentation tube axially extending there through for housing in-core instrumentation and the core is covered by an upper internals package that is sealed within the pressure vessel by a removable head, the upper internals package including an upper core plate positioned over the fuel assemblies and an upper support plate spaced above and positioned over the upper core plate with a plurality of support columns extending axially between the upper core plate and the upper support plate with at least some of the support columns aligned with a corresponding one of the instrumentation tubes, the support columns aligned with the instrumentation tubes having a slidable sleeve that is moveable within the support columns and extendable above the upper support plate, the method comprising the steps of:
- removing the removable head from the pressure vessel;
- raising the slidable sleeves so that an upper portion thereof extends above the upper support plate;
- withdrawing the in-core instrumentation from the instrumentation tubes in the fuel assemblies so a lower most extremity of the in-core instrumentation is approximately at or above a midpoint in a width of the upper core plate;
- and
- removing the upper internals package to access the core.
Dependencies are inferred from the claim text.