US3929565A — Nuclear reactor with groups of elongated absorber…

Claim 1

Independent Claim 271 words

A NUCLEAR REACTOR HAVING A CORE INCLUDING A PLURALITY OF FUEL ASSEMBLIES EACH CONTAINING A SUBSTANTIALLY EQUAL QUANTITY OF NUCLEAR FUEL, A PLURALITY OF CONTROL RODS HAVING LONGITUDINAL AXES SUBSTANTIALLY PARALLEL WITH LONGITUDINAL AXES OF THE FUEL ASSEMBLIES, A GROUP OF ELONGATED ABSORBER UNITS CARRIED BY EACH SAID CONTROL RODS FOR DISPLACEMENT INTO SAID OUT OF THE CORE, SAID GROUP ABSORBER UNITS AND THE ABSORBER UNITS IN SAID GROUP EACH HAVING A CENTER OF GRAVITY AND A LONGITUDINAL AXIS SUBSTANTIALLY PARALLEL WITH THE LONGITUDINAL AXES OF THE FUEL ASSEMBLIES, SAID GROUP INCLUDING A CENTRAL ABSORBER UNIT HAVING ITS CENTER OF GRAVITY SUBSTANTIALLY COINCIDENT WITH THE CENTER OF GRAVITY OF THE GROUP AND A PLURALITY OF OUTER ABSORBER UNITS HAVING THEIR CENTERS OF GRAVITY SUBSTNATIALLY EQUALLY SPACED FROM THE CENTER OF GRAVITY OF THE GROUP AND SYMMETRICALLY ARRANGED THEREAROUND, THERE BEING ABSORBER UNITS OF AT LEAST TWO OF SAID GROUPS LOCATED WITHIN OR IMMEDIATELY ADJACENT EACH FUEL ASSEMBLY, AND AT LEAST SOME OF THE ABOSRBER UNITS OF ONE OF SAID GROUPS CARRIED BY ONE CONTROL ROD BEING LOCATED WITHIN OR IMMEDIATELY ADJACENT DIFFERENT FUEL ASSEMBLIES, AND, WHERE A SIS THE DISTANCE BETWEEN THE LONGITUDINAL AXIS THROUGH THE CENTER OF GRAVITY OF THE GROUP OF ABSORBER UNITS MOUNTED ON ONE CONTROL ROD AND THE LONGITUDINAL AXIS THROUGH THE CENTER OF GRAVITY OF AN OUTER ABSORBER UNIT OF THE SAME GROUP AND B IS THE DISTANCE BETWEEN THE LONGITUDINAL AXIS OF THE CONTROL ROD AND THE LONGITUDINAL AXIS OF THE NEAREST ABSORBER UNIT OF AN ADJACENT CONTROL ROD, THERE BEING A RATIO BETWEEN A AND B SUCH THAT (A/B) IS AT LEAST 1/ 2.

Claim 2

Dependent Claim 271 words

A NUCLEAR REACTOR HAVING A CORE INCLUDING A PLURALITY OF FUEL ASSEMBLIES EACH CONTAINING A SUBSTANTIALLY EQUAL QUANTITY OF NUCLEAR FUEL, A PLURALITY OF CONTROL RODS HAVING LONGITUDINAL AXES SUBSTANTIALLY PARALLEL WITH LONGITUDINAL AXES OF THE FUEL ASSEMBLIES, A GROUP OF ELONGATED ABSORBER UNITS CARRIED BY EACH SAID CONTROL RODS FOR DISPLACEMENT INTO SAID OUT OF THE CORE, SAID GROUP ABSORBER UNITS AND THE ABSORBER UNITS IN SAID GROUP EACH HAVING A CENTER OF GRAVITY AND A LONGITUDINAL AXIS SUBSTANTIALLY PARALLEL WITH THE LONGITUDINAL AXES OF THE FUEL ASSEMBLIES, SAID GROUP INCLUDING A CENTRAL ABSORBER UNIT HAVING ITS CENTER OF GRAVITY SUBSTANTIALLY COINCIDENT WITH THE CENTER OF GRAVITY OF THE GROUP AND A PLURALITY OF OUTER ABSORBER UNITS HAVING THEIR CENTERS OF GRAVITY SUBSTNATIALLY EQUALLY SPACED FROM THE CENTER OF GRAVITY OF THE GROUP AND SYMMETRICALLY ARRANGED THEREAROUND, THERE BEING ABSORBER UNITS OF AT LEAST TWO OF SAID GROUPS LOCATED WITHIN OR IMMEDIATELY ADJACENT EACH FUEL ASSEMBLY, AND AT LEAST SOME OF THE ABOSRBER UNITS OF ONE OF SAID GROUPS CARRIED BY ONE CONTROL ROD BEING LOCATED WITHIN OR IMMEDIATELY ADJACENT DIFFERENT FUEL ASSEMBLIES, AND, WHERE A SIS THE DISTANCE BETWEEN THE LONGITUDINAL AXIS THROUGH THE CENTER OF GRAVITY OF THE GROUP OF ABSORBER UNITS MOUNTED ON ONE CONTROL ROD AND THE LONGITUDINAL AXIS THROUGH THE CENTER OF GRAVITY OF AN OUTER ABSORBER UNIT OF THE SAME GROUP AND B IS THE DISTANCE BETWEEN THE LONGITUDINAL AXIS OF THE CONTROL ROD AND THE LONGITUDINAL AXIS OF THE NEAREST ABSORBER UNIT OF AN ADJACENT CONTROL ROD, THERE BEING A RATIO BETWEEN A AND B SUCH THAT (A/B) IS AT LEAST 1/ 2.

Claim 3

Dependent Claim 25 words

A nuclear reactor as claimed in claim 1, in which the absorber units have parts remote from their centers and located symmetrically with respect thereto.

Claim 4

Dependent Claim 31 words

A nuclear reactor as claimed in claim 1, in which the absorber units each have a central part and wings extending outwardly from the central part and positioned between fuel assemblies.

Claim 5

Dependent Claim 23 words

A nuclear reactor as claimed in claim 3, in which the fuel assemblies are polygonal in cross-section and arranged in a polygonal lattice.

Claim 6

Dependent Claim 24 words

A nuclear reactor as claimed in claim 4, in which the fuel assemblies have spaces therebetween and the wings are movable in said spaces.

Claim 7

Dependent Claim 20 words

A nuclear reactor as claimed in claim 5, in which the wings extend substantially the whole length of the spaces.

Claim 8

Dependent Claim 29 words

A nuclear reactor as claimed in claim 3, in which the fuel assemblies are square in cross-section and arranged in a square lattice, and the absorber units are cruciform.

Claim 9

Dependent Claim 16 words

A nuclear reactor as claimed in claim 7, in which each group comprises five absorber units.

Claim 10

Dependent Claim 34 words

A nuclear reactor as claimed in claim 8, in which the centers of adjacent groups of absorber units are arranged in a square lattice tilted with respect to the lattice of the fuel assemblies.

Claim 11

Dependent Claim 15 words

A nuclear reactor as claimed in claim 9, in which (A/b) (1/ Square Root 5).

Claim 12

Dependent Claim 31 words

A nuclear reactor as claimed in claim 7, in which the fuel assemblies are arranged in square groups of four and the wings are positioned between such groups of fuel assemblies.

Claim 13

Dependent Claim 38 words

A nuclear reactor as claimed in claim 7, in which the lines joining the center of the central absorber unit to the centers of the outer absorber units are diagonal to the squares of the fuel assembly lattice.

Claim 14

Dependent Claim 41 words

A nuclear reactor as claimed in claim 7, in which the lines joining the center of the central absorber unit to the center of the outer absorber units are parallel to the sides of the squares of the fuel assembly lattice.

Claim 15

Dependent Claim 127 words

A nuclear reactor as claimed in claim 5, in which each of the four arms of the cross has a length which at the most is slightly less than s/2, where s is the length of the side of a fuel assembly, and the axis of each absorber unit is located between four adjacent corners in a group of four adjacent fuel assemblies so that each of a main portion of the fuel assemblies is surrounded by the wings of four absorber units, of which two diagonally opposite units are carried by one of the control rods and the two remaining ones are carried by two other control rods, whereas about every fifth fuel assembly is surrounded by four absorber units carried by four separate control rods.

Claim 16

Dependent Claim 36 words

A nuclear reactor as claimed in claim 3, in which the wings extend parallel to and perpendicular to the lines joining the center of the central absorber unit to the centers of the outer absorber units.

Claim 17

Dependent Claim 29 words

A nuclear reactor as claimed in claim 7, in which the inwardly directed wings of the outer absorber units are joined to the wings of the central absorber unit.

Claim 18

Dependent Claim 38 words

A nuclear reactor as claimed in claim 16, in which the distance between the center of the central absorber unit and the centers of the outer absorber units equals the length of a side of a fuel assembly.

Claim 19

Dependent Claim 39 words

A nuclear reactor as claimed in claim 16, in which the distance between the center of the central absorber unit and the centers of the outer absorber units equal twice the length of a side of a fuel assembly.

Claim 20

Dependent Claim 109 words

Nuclear reactor as claimed in claim 1, in which each fuel assembly comprises a plurality of elongated, parallel fuel rods arranged in a square lattice and a plurality of elongated tubes parallel to the fuel rods, each control rod within the central region of the reactor having five groups of absorber rods, four of the groups having their centers located in the corners of a square with the side 2s and the fifth group has its center point located centrally in the square, the absorber elements comprising control rod fingers and at least some of the tubes in the fuel assemblies constituting guide tubes for the control rod fingers.

Claim 21

Dependent Claim 45 words

Nuclear reactor as claimed in claim 19, in which each corner in the square is located in the center of a fuel assembly and each group comprises n2 control rod fingers arranged in a regular square lattice, where n is an integer greater than 1.

Claim 22

Dependent Claim 129 words

Nuclear reactor as claimed in claim 19, in which each corner in the square is located between four adjacent corners in a group of four adjacent fuel assemblies, and each group comprises n2 control rod fingers, where n is an even number, so that, of each group n2/4 fingers relates to each fuel assembly, each of a substantial porportion of the fuel assemblies within the central region of the core including guide tubes for four quarter groups of control rod fingers, of which quarter groups two diagonally opposite ones belong to one of the control rods and the two remaining ones to two other control rods, whereas about every fifth fuel assembly comprises guide tubes for four quarter groups of control rod fingers belonging to four separate control rods.

Claim 23

Dependent Claim 55 words

Nuclear reactor as claimed in claim 21, in which each corner of the square is located in the centre of a fuel assembly and at least each corner group comprises (n2 + 1)/2 control rod fingers arranged in a regular square lattice with a central finger, where n is an odd number greater than 1.

Claim 24

Dependent Claim 49 words

Nuclear reactor as claimed in claim 21, in which each corner in the square is located in the centre of a fuel assembly and that each group comprises (n2 - 1)/2 control rod fingers arranged in a regular square lattice, where n is an odd number greater than 1.

Claim 25

Dependent Claim 85 words

Nuclear reactor as claimed in claim 21, in which each corner of the square is located in the centre of a fuel assembly in every second control rod in the central region of the core at least every corner group comprises (n2+1)/2 control rod fingers arranged in a regular square lattice with a central finger, and each group in the remaining region of the core comprises (n2-1)/2 control rod fingers similarly arranged in a square lattice, where n is an odd number greater than 1.

Claim 26

Dependent Claim 34 words

Nuclear reactor as claimed in claim 21, in which each control rod finger is so thick that its guide tube has a diameter corresponding to twice the lattice spacing of the fuel rod lattice.

Claim 27

Dependent Claim 40 words

Nuclear reactor as claimed in claim 21, in which the tubes in the fuel assemblies are substantially uniformly distributed across the cross-section of the fuel assembly, alternate tubes in the fuel assemblies forming guide tubes for the control rod fingers.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1978-12-29	1979-06-30	1979-12-30	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1982-12-29	1983-06-30	1983-12-30	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1986-12-29	1987-06-30	1987-12-30	$7700.00	Window Closed / Lapsed

Nuclear reactor with groups of elongated absorber units carried by control rods

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