Nuclear fuel element with strengthening during shipment

Claim 2

In a fuel assembly for a nuclear reactor comprising a plurality of elongated fuel tubes having their longitudinal axes substantially parallel and being arrayed in spaced rows, each row comprising more than one of said fuel tubes, the improvement for limiting bowing and vibration of said fuel tubes and damage to said tubes and the fuel pellets contained therein, which improvement comprises in combination with said assembly: a. a plurality of elongated fuel tube support bars, each of said bars being positioned within said assembly between adjacent rows of fuel tubes at a point located longitudinally intermediate the ends of the tubes thereof; b. each of said support bars being wider in one direction perpendicular to its length than the distance between the fuel tubes of said adjacent rows and each being thinner in another direction perpendicular to its length than the distance between the fuel tubes of said adjacent rows such that said bar may be freely inserted and removed from between said adjacent rows of fuel tubes when the support bar is oriented such that said one direction extends substantially parallel to the planes defined by said adjacent rows of fuel tubes; and c. each of said support bars having a plurality of spaced apart scallops in its opposite edges, each of said scallops being positioned in alignment with one of the fuel tubes in said adjacent rows to engagingly accept said one fuel tube when the support bar is oriented such that said one direction extends substantially perpendicular to the planEs defined by said adjacent rows of fuel tubes.

Claim 3

The improvement according to claim 1 wherein opposite sides of the fuel tube engaging surfaces of each of said scallops are chamfered to facilitate in-situ rotation of the support bar between said first mentioned orientation and said last mentioned orientation.

Claim 4

In a fuel assembly for a nuclear reactor comprising a plurality of elongated fuel tubes having their longitudinal axes substantially parallel and being arrayed in spaced rows, the improvement for limiting bowing and vibration of said fuel tubes and damage to said tubes and the fuel pallets contained therein, which improvement comprises in combination with said assembly: a. two series of support bars insertable between adjacent rows of the fuel tubes, each of said support bars being thinner in one direction perpendicular to its length than the spacing between the fuel tubes in said adjacent rows so as to be freely insertable between and removable from said adjacent rows in said array, each of said support bars being wider in another direction perpendicular to its length than the spacing between the fuel tubes in said adjacent rows, the bars of one series extending between alternate adjacent rows of fuel tubes and the bars of the other series being disposed between alternate adjacent rows extending perpendicularly to the rows between which said first series of bars is positioned; and b. each support bar having opposing semi-circular scalloped portions formed in opposite sides of the surface defined by said wider dimension, the curved surface of each scalloped portion being chamfered to facilitate in-situ rotation of the bar from a position where the surface defined by said wider dimension extends substantially parallel to the planes defined by the tubes of said adjacent rows to a position where said last mentioned surface extends substantially perpendicular to said planes to thereby cause the curved surface of each scalloped portion to engage the said tubes and to facilitate in-situ rotation of the bar back to said parallel oriented position for removal from between said adjacent rows.

Claim 5

In a fuel assembly for a nuclear reactor comprising a plurality of elongated fuel tubes having their longitudinal axes substantially parallel and being arrayed in spaced rows, the improvement for limiting bowing and vibration of said fuel tubes and damage to said tubes and the fuel pallets contained therein, which improvement comprises in combination with said assembly: a. two series of support bars insertable between adjacent rows of the fuel tubes, each of said support bars being thinner in one direction perpendicular to its length than the spacing between the fuel tubes in said adjacent rows so as to be freely insertable between and removable from said adjacent rows in said array, each of said support bars being wider in another direction perpendicular to its length than the spacing between the fuel tubes in said adjacent rows, the bars of one series extending between alternate adjacent rows of fuel tubes and the bars of the other series being disposed between alternate adjacent rows extending perpendicularly to the rows between which said first series of bars is positioned; and b. each support bar having opposing semi-circular scalloped portions formed in opposite sides of the surface defined by said wider dimension, the curved surface of each scalloped portion being chamfered to facilitate in-situ rotation of the bar from a position where the surface defined by said wider dimension extends substantially parallel to the planes defined by the tubes of said adjacent rows to a position where said last mentioned surface extends substantially perpendicular to said planes to thereby cause the curved surface of each scalloped portion to engage the said tubes and to facilitate in-situ rotation of the bar back to said parallel oriented position for removal from between said adjacent rows.

Claim 6

In a fuel assembly for a nuclear reactor comprising a plurality of elongated fuel tubes having their longitudinal axes substantially parallel and being arrayed in spaced rows and at least one fuel tube spacer device disposed in predetermined spaced relation throughout the length of said fuel tubes for restraining the individual tubes of said array from bowing and vibration during operation of the reactor, the improvement from limiting bowing and vibration of the fuel tubes during shipment before installation in said reactor, which improvement comprises in combination with said assembly: a. two series of support bars insertable between adjacent rows of the fuel tubes, each of said support bars being thinner in one direction perpendicular to its length than the spacing between the fuel tubes in said adjacent rows so as to be freely insertable between and removable from said adjacent rows in said array, each of said support bars being wider in another direction perpendicular to its length than the spacing between the fuel tubes in said adjacent rows, the bars of one series extending between alternate adjacent rows of fuel tubes and the bars of the other series being disposed between alternate adjacent rows extending perpendicularly to the rows between which said first series of bars is positioned; and b. each support bar having opposing semi-circular scalloped portions formed in opposite sides of the surface defined by said wider dimension, the curved surface of each scalloped portion being chamfered to facilitate in-situ rotation of the bar from a position where the surface defined by said wider dimension extends substantially parallel to the planes defined by the tubes of said adjacent rows to a position where said last mentioned surface extends substantially perpendicular to said planes to thereby cause the curved surface of each scallop portion to engage the said tubes and to facilitate in-situ rotation of the bar back to said parallel oriented position for removal from between said adjacent rows.

Claim 7

In a fuel assembly for a nuclear reactor comprising a plurality of elongated fuel tubes having their longitudinal axes substantially parallel and being arrayed in spaced rows and at least one fuel tube spacer device disposed in predetermined spaced relation throughout the length of said fuel tubes for restraining the individual tubes of said array from bowing and vibration during operation of the reactor, the improvement from limiting bowing and vibration of the fuel tubes during shipment before installation in said reactor, which improvement comprises in combination with said assembly: a. two series of support bars insertable between adjacent rows of the fuel tubes, each of said support bars being thinner in one direction perpendicular to its length than the spacing between the fuel tubes in said adjacent rows so as to be freely insertable between and removable from said adjacent rows in said array, each of said support bars being wider in another direction perpendicular to its length than the spacing between the fuel tubes in said adjacent rows, the bars of one series extending between alternate adjacent rows of fuel tubes and the bars of the other series being disposed between alternate adjacent rows extending perpendicularly to the rows between which said first series of bars is positioned; and b. each support bar having opposing semi-circular scalloped portions formed in opposite sides of the surface defined by said wider dimension, the curved surface of each scalloped portion being chamfered to facilitate in-situ rotation of the bar from a position where the surface defined by said wider dimension extends substantially parallel to the planes defined by the tubes of said adjacent rows to a position where said last mentioned surface extends substantially perpendicular to said planes to thereby cause the curved surface of each scallop portion to engage the said tubes and to facilitate in-situ rotation of the bar back to said parallel oriented position for removal from between said adjacent rows.