Thomas J Freeman

US Patent:

48204781, Apr 11, 1989

Filed:

Aug 25, 1987

Appl. No.:

7/089387

Inventors:

Thomas R. Freeman - Greensburg PA

Assignee:

Westinghouse Electric Corp. - Pittsburgh PA

International Classification:

G21C 710

US Classification:

376333

Abstract:

A control rod for use in a nuclear reactor core to provide xenon compensation includes an elongated inner cylindrical member and an elongated outer cylindrical member surrounding the inner member. Each of the members is composed of axially-extending, alternating black poison and nonpoison regions. Also, the inner member is axially movable relative to the outer member to adjust the degree to which the poison regions of the members overlap with the nonpoison regions thereof and thereby change the overall worth of the rod in an axially uniform manner. The inner cylindrical member has a solid cross-sectional configuration, whereas the outer cylindrical member has an annular cross-sectional configuration and concentrically surrounds the inner member. Each of the poison regions in the members is about the same axial height, while each of the nonpoison regions is about the same axial height. The guide thimble of a fuel assembly in which the control rod is placed has an annular stop being sized to support a lower end of the outer member for retaining the outer member in a stationary position therein, whereas the stop has a central hole sized to allow passage of a lower end of the inner member therethrough in order to move the inner member axially relative to the outer member to adjust the degree to which the poison regions of the members overlap with the nonpoison regions thereof and thereby change the overall worth of the rod.

US Patent:

46379150, Jan 20, 1987

Filed:

May 11, 1984

Appl. No.:

6/609250

Inventors:

Thomas M. Camden - Washington Township, Fayette County PA
Thomas R. Freeman - New Alexandria PA

Assignee:

Westinghouse Electric Corp. - Pittsburgh PA

International Classification:

G21C 332

US Classification:

376435

Abstract:

A nuclear fuel assembly, particularly advantageous for use in a pressurized water reactor, wherein each alternate fuel rod in the assembly is positioned with its fission gas plenum zone at the top of the assembly and the intervening alternate fuel rods are positioned with their fission gas plenum zones at the bottom of the assembly. All of the fuel rods are preferably axially coextensive. An axial blanket region may be formed by providing the fuel zone of each fuel rod with a small zone of natural or depleted uranium at a part of the fuel zone furthest from the fission gas plenum zone. A method of effectively lengthening the active length of a nuclear fuel assembly is also described.

US Patent:

46786287, Jul 7, 1987

Filed:

Mar 3, 1986

Appl. No.:

6/835672

Inventors:

Thomas R. Freeman - Greensburg PA

Assignee:

Westinghouse Electric Corp. - Pittsburgh PA

International Classification:

G21C 710

US Classification:

376333

Abstract:

A control arrangement which provides enthalpy rise compensation upon reduction of core power includes control rodlets arranged in a cluster. Each control rod cluster has a higher axial worth at an upper portion than at a lower portion thereof. Several different embodiments of control rod clusters are provided. In one embodiment, the worth of the control rod cluster varies in accordance with different lengths of the absorber material contained within its rodlets. In another embodiment, the worth of the control rod cluster varies in accordance with different variations in densities of the absorber material within its rodlets. In a third embodiment, the worth of the control rod cluster varies in accordance with different kinds of the absorber material within the rodlets. In a final embodiment, the worth of the control rod cluster varies in accordance with different variations in diameters of the absorber material within its rodlets.

US Patent:

47073292, Nov 17, 1987

Filed:

Jan 7, 1986

Appl. No.:

6/816780

Inventors:

Thomas R. Freeman - Greensburg PA

Assignee:

Westinghouse Electric Corp. - Pittsburgh PA

International Classification:

G21C 332
G21C 710

US Classification:

376449

Abstract:

A control rod for use in a nuclear reactor core to provide xenon compensation includes an elongated inner cylindrical member and an elongated outer cylindrical member surrounding the inner member. Each of the members is composed of axially-extending, alternating black poison and nonpoison regions. Also, the inner member is axially movable relative to the outer member to adjust the degree to which the poison regions of the members overlap with the nonpoison regions thereof and thereby change the overall worth of the rod in an axially uniform manner. The inner cylindrical member has a solid cross-sectional configuration, whereas the outer cylindrical member has an annular cross-sectional configuration and concentrically surrounds the inner member. Each of the poison regions in the members is about the same axial height, while each of the nonpoison regions is about the same axial height. The guide thimble of a fuel assembly in which the control rod is placed has an annular stop being sized to support a lower end of the outer member for retaining the outer member in a stationary position therein, whereas the stop has a central hole sized to allow passage of a lower end of the inner member therethrough in order to move the inner member axially relative the outer member to adjust the degree to which the poison regions of the members overlap with the nonpoison regions thereof and thereby change the overall worth of the rod.

US Patent:

47510439, Jun 14, 1988

Filed:

Sep 29, 1986

Appl. No.:

6/912664

Inventors:

Thomas R. Freeman - Greensburg PA
Brian H. Alsop - Penn Twp. PA
Donald G. Sherwood - Monroeville PA

Assignee:

Westinghouse Electric Corp. - Pittsburgh PA

International Classification:

G21C 1106

US Classification:

376400

Abstract:

A radial neutron reflector is disclosed for a light water nuclear reactor. The irregular space between the core periphery and the core barrel surrounding the core is filled with a structure comprising material other than hydrogen such as zirconia or stainless steel so as to displace the reactor water coolant in this region. The structure is provided with appropriately sized flow holes to pass reactor coolant therethrough and to balance the pressure within the structure to substantially coincide with the axial pressure profile at the core periphery.

US Patent:

46559957, Apr 7, 1987

Filed:

May 11, 1984

Appl. No.:

6/609252

Inventors:

Thomas R. Freeman - New Alexandria PA
John F. Wilson - Murrysville PA
Ronald P. Knott - North Huntingdon PA

Assignee:

Westinghouse Electric Corp. - Pittsburgh PA

International Classification:

G21C 1900

US Classification:

376267

Abstract:

A fuel assembly, particularly advantageous for use with a BWR, wherein the fuel bundle is adapted to be inserted into an envelope formed from a flow channel and a lower nozzle assembly. The fuel bundle is essentially axially symmetrical having identical top and bottom tie plates. Within the fuel bundle, alternate fission gas plenums are disposed at the top and bottom of the bundle respectively. During the refueling operation, the fuel bundle is removed from the reactor core, axially inverted and reinserted into the core for continued burn up. The invention takes advantage of the reactivity increase possible in a BWR when a partially burned fuel bundle is inverted.