Method and apparatus for compacting spent nuclear reactor fuel rods

A method and apparatus for withdrawing spent fuel rods from a nuclear fuel rod assembly into a different nuclear fuel rod container wherein the spent fuel rods have a higher fuel rod density, whereby a greater number of spent fuel rods can be stored in a water-storage pool. The individual rods are moved from a fuel assembly and through a transition funnel by movable grippers at opposite ends of the funnel. One movable gripper reciprocates between gripping and release positions in a gap between the fuel assembly and the transition funnel. A stationary gripper can be located in the gap at the entry side of the funnel to hold the fuel rods while the movable gripper returns from a release position to the gripping position. Both grippers include members which can be pressed into frictional engagement with the spaced apart array of fuel rods. All of the fuel rods are withdrawn concurrently and are merged toward one another into a tighter array within the transition funnel and emerge as a bundle. A movable and a stationary bundle gripper are provided between the funnel and the storage container to advance the bundle of fuel rods into the container.

FIELD OF THE INVENTION 
This invention relates to a method and apparatus for compacting spent 
nuclear reactor fuel rods, and more particularly for preparing such spent 
fuel rods for long-term water pool storage. 
STATEMENT OF THE PRIOR ART 
Nuclear reactor installations employ nuclear fuel materials in the form of 
fuel rods which are supported in fuel rod assemblies. The fuel rods are 
metal pipes which are filled with nuclear fuel material and are about 
0.4-0.6 inch in diameter and from 8 to 15 feet in length. Groups of 64, 
128, 220 or more such fuel rods are assembled in a fuel rod assembly which 
includes grids for alignment and support of the fuel rods, a lower end 
fitting, an upper end fitting, and guide tubes. The fuel rod assembly is 
introduced into a nuclear reactor as the fuel source. After the nuclear 
fuel in the fuel rod assembly is spent to a pre-established level, the 
entire fuel rod assembly is withdrawn from the nuclear reactor and stored 
vertically in appropriate metal racks in a wet pool until the radioactive 
properties have dissipated sufficiently for transfer to other storage 
locations. 
Within the fuel rod assembly, the individual fuel rods are spaced apart in 
a pre-established array, usually a rectangular array. The fuel rod 
assemblies are spaced apart in the array and are maintained under water in 
the reactor for the purpose of moderating or slowing the neutrons. In the 
fuel rod assembly, the ratio of cross-sectional area of fuel rod to 
cross-sectional area of water is approximately 1:1. 
At the present time, spent nuclear fuel rod assemblies are withdrawn from 
the nuclear reactors and are stored vertically in appropriate storage 
racks under water in storage pools without any deliberate change in the 
fuel rod assembly. The fuel rod storage pools are filled with the spent 
fuel rod assemblies whose activity has dissipated as a result of extended 
storage in the pool. 
A number of suggestions have been made for removing long-term storage fuel 
rod assemblies from the pool and for withdrawing individual spent fuel 
rods from the fuel rod assembly and thereafter for assembling the 
individual spent fuel rods in new containers or canisters wherein the fuel 
rods are more closely aligned, i.e., more densely compacted, and for 
returning such newly-filled canisters to appropriate storage racks within 
a water storage pool for long-term storage or until appropriate fuel 
recovery processing is economically feasible. 
Some of the anticipated difficulties with the proposed fuel rod compacting 
processes which have been suggested arise from the knowledge that the 
actual fuel rods are twisted and bent out of alignment as a result of 
their long-term exposure in nuclear reactors. In some cases, the 
distortion may be as much as 5 inches in an 8-foot long rod. Such 
permanent distortion of the fuel rods will interfere with the proposed 
alignment techniques. The casing of the fuel rods should be handled by 
using procedures and equipment designed to accommodate embrittlement due 
to irradiation in the nuclear reactor. 
A further problem is that the long, thin fuel rods are whippy and therefore 
likely to impact with each other when pulled from the fuel assembly. Such 
impacting could cause fuel rod breakage. Moreover, the fuel rods may be 
difficult to manipulate. A still further problem relates to the inherent 
safety of compacting spent fuel rods. There is a possibility that the fuel 
rods might become spaced apart by a critical distance while removed from 
the fuel rod assembly and before compaction and confinement in a storage 
canister. Moreover, the fuel rods might be dropped in the water pool or 
broken due to embrittlement during multimanipulation before confinement in 
a storage container. Such possibilities should be precluded. 
SUMMARY OF THE INVENTION 
According to the present invention, a method and related apparatus are 
provided for transferring spent fuel rods from a fuel rod assembly in an 
underwater pool or in a hot cell directly into a fuel rod canister where 
the density of the fuel rods greatly exceeds the fuel rod density in the 
fuel rod assembly. As a result of the present invention, the spent fuel 
storage capacity in a particular water storage pool can be approximately 
doubled. Moreover, the fuel rod consolidation process of the present 
invention is carried out without altering the relative position of the 
fuel rods whereby after consolidation, the identity of a fuel rod is known 
at each position in the fuel rod canister which facilitates accounting 
procedures. 
According to the invention, an end of a fuel rod assembly is removed by 
cutting or otherwise and grippers of a movable gripper assembly are passed 
between rows of the exposed end portions of the array of fuel rods to 
simultaneously grip the fuel rods. The gripper assembly is reciprocated 
along a rectilinear path between a fuel rod gripping position at the 
exposed end of the fuel assembly and a remote fuel rod release position 
which is adjacent an entry end of a fuel rod directing chamber such as a 
transition funnel which has fuel rod receiving openings corresponding to 
the array of fuel rods in the fuel rod assembly. The operation of the 
reciprocating gripper serves to withdraw an increment of length of all the 
fuel rods in unison from the fuel assembly in one axial direction for 
entry and passage in the fuel rod directing chamber. The transition funnel 
at its fuel rod discharge end has a relatively narrow cross section which 
corresponds to the cross section of the desired compacted bundle of fuel 
rods presented to the storage container. For each individual fuel rod, 
there can be a separate guide within the transition funnel for directing a 
fuel rod from the fuel rod assembly through the transition funnel into a 
permanent storage container. The fuel rod consolidation process is thus 
carried out by positioning the transition funnel between the fuel rod 
assembly and a permanent storage container in a tandem arrangement so that 
the spent fuel rods pass in only one direction directly from the fuel rod 
assembly through the transition funnel into the storage container. This 
tandem arrangement of components can be provided in a hot cell or it can 
be provided beneath the water surface in a water pool. In the either 
event, the spent fuel rods move along a generally horizontal path or a 
generally vertical path. In the latter event, the fuel storage container 
can be located either above or below the transition funnel. Thus, the 
storage container can be positioned so that the spent fuel rods either 
move upwardly into the storage container or downwardly into the storage 
container. The passageways through the transition funnel direct the spent 
fuel rods into pre-established storage positions in a compacted array of 
fuel rods within the container. 
A second gripper is arranged to reciprocate along a rectilinear path in a 
gap established between the discharge end of the transition funnel where 
the fuel rod bundle is gripped and the entry end of a storage canister 
where the fuel rod bundle is released. The second gripper can embody a 
construction for gripping the entire bundle of fuel rods since they are in 
a compacted array. The fuel rods are advanced into the storage container 
by reciprocating the second gripper in the same manner as the 
reciprocating motion of the first gripper. When the fuel rods are advanced 
in a generally horizontal plane from a fuel assembly through a transition 
funnel into a storage container as well as the aforesaid arrangement 
wherein the fuel rods are advanced upwardly from the fuel assembly through 
a funnel into a storage container, it is preferable and, in some 
instances, it may be desirable to provide additional retention means to 
support the fuel rods during the return movement of each of the first and 
second grippers. Such retention means can be located at the entry side of 
the transition funnel and/or storage container. The retention means may, 
when desired, include the use of conventional grids provided in the fuel 
assembly to support the fuel rods at various spaced-apart locations along 
the length of the fuel assembly. In this regard, such grids conventionally 
provide resilient spring clips to apply a spring tension force against the 
outer cylindrical surface of the fuel rod. The spring forces can be 
utilized to prevent unwanted axial movement of the fuel rods while the 
grippers are returned from a release position to a gripping position as 
described hereinbefore. When desired, a gripper at the entry and or exit 
end of the transition funnel can be attached to the funnel and the funnel 
with one or both grippers attached thereto can be reciprocated along a 
rectilinear path between gripping and release positions to move the fuel 
rods from the fuel rod assembly. 
Preferably, the individual fuel rods are withdrawn concurrently from a fuel 
rod assembly so that the leading ends of all of the fuel rods enter into 
the container at about the same level to facilitate stacking within the 
container. Preferably, within the container, the array of spent fuel rods 
is a triangular array which provides maximum fuel rod density in the 
container. Preferably, the fuel rod density in the container is 
approximately twice that of the fuel rod density in the fuel rod assembly. 
The transition funnel is so arranged that the guide tubes therein merge 
toward one another. As a consequence, the fuel rods, in passing from the 
fuel rod assembly into the fuel rod container, do not move apart so that 
critical distances between fuel rods cannot occur. 
By providing fuel rod containers of the same cross-sectional dimensions as 
the fuel rod assemblies, the containers can be stored in the same 
underwater fuel rod storage racks which have been employed for the fuel 
rod assemblies. In addition, it is possible to transform the consolidated 
rods to other geometries, i.e., rhombic, to maximize storage in a 
cylindrical container which can be used for transporting and/or permanent 
storage at a local or remote storage site. When the present invention is 
practiced, the capacity of the fuel rod storage pools for spent nuclear 
fuel rods can be approximately doubled. The structural components of the 
empty fuel rod assembly are collected and stored for appropriate disposal. 
Accordingly, it is an object of this invention to provide a method and 
apparatus for moving spent fuel rods from a fuel rod assembly directly 
into a fuel rod container for compact storage of the spent fuel rods. 
It is a further object of this invention to carry out the described method 
and apparatus including reciprocating grippers that move a distance 
corresponding to only a small increment of the fuel rod lengths which 
minimizes the space required to consolidate the fuel rods while causing 
the fuel rods to move unidirectionally from a fuel rod assembly and into a 
storage container.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Referring to FIG. 1, a typical fuel rod assembly 10 includes individual 
fuel rods 11 (64 rods are shown in FIG. 1), support grids 12, guide rods 
13 and a handle member 14. The individual fuel rods 11 (sometimes also 
called fuel pins) are about 0.4-0.6 inch in diameter and about 8 feet long 
in one type of nuclear reactor installation and the fuel rods are about 15 
feet long in another type of nuclear reactor installation. The support 
grids 12 are spaced apart at pre-established distances along the fuel rod 
assembly to position and support the fuel rods. The typical form of 
support grid will be described in greater detail hereinafter. The fuel rod 
assembly 10 is withdrawn from a nuclear reactor after the nuclear fuel 
within the fuel rods 11 has been spent. Thereafter, the fuel rod assembly 
10 is stored in appropriate storage racks under water in storage pools 
until its activity is dissipated. 
The purpose of the present invention is to compact the fuel rods 11 after 
their activity has dissipated and to store the fuel rods in a new and 
different container wherein the fuel rod spacing is altered. The fuel rods 
as presented in a fuel rod assembly for use in a nuclear reactor are 
intended to be active in the presence of slow neutrons. The fuel rods in 
operation are spaced apart by predetermined distances so that released 
neutrons can be slowed to an effective velocity for atomic reactions. 
Water is an effective moderator for this purpose. As the fuel rods are 
brought closer together, there is insufficient water between fuel rods to 
retard the velocity of the neutrons. Hence, the reactivity of the fuel rod 
assembly is reduced because the high velocity neutrons pass through the 
installation without sufficient retardation to cause any significant 
atomic collisions. Thus, the reactivity is reduced as the fuel rods are 
brought together. 
In the embodiment of the present invention shown in FIG. 2, the fuel rod 
assembly 10 is supported by a vertically-arranged structure which can be a 
so-called "strong back" beneath the water surface in a water pool. Beneath 
the fuel assembly in a spaced-apart tandem arrangement is a transition 
funnel 20 and therebelow a storage container 30. Initially, the fuel 
assembly has its lower end removed so that the lower ends 15 of the 
individual fuel rods 11 are exposed. The lower end of the fuel assembly is 
removed by cutting or otherwise. One way of removing the lower end is to 
cut the lower end of the fuel assemblies with an air-powered underwater 
band saw. In some fuel rod assemblies, the lower end may be dismantled by 
removing the bolts or other fastening devices which connect it to the main 
frame. After the lower end of the assembly is removed, the lower ends 15 
of the individual fuel rods 11 are exposed as shown in FIG. 2. 
FIG. 3 illustrates the spaced-apart pattern of fuel rods forming a 
rectangular array of fuel rods within the fuel rod assembly. The 
transition funnel 20 has an upper end 21 and a lower end 22. The upper end 
21 as shown in FIG. 4 has a generally square grid corresponding to the 
array of the fuel rods 11 as shown in FIG. 3. At the upper end 21 is a 
grid 23 having openings for individual tubes 24 corresponding in number 
and array with the exposed lower ends 15 of the fuel rods. The transition 
funnel tapers from its upper end 21 toward its lower end 22. At the lower 
end 22, the transition funnel 20 as shown in FIG. 5 has a grid 25 with 
openings for receiving the ends of the tubes 24 in a desired array. It 
will be observed that the array of the tube openings 24 in the grid 25 is 
an equilateral triangle--the preferred array. 
Below the transition funnel 20 is the container 30 having outer dimensions 
corresponding to the outer dimensions of the fuel rod assembly 10. The 
container 30 preferably is a metal rectangular box having a length 
slightly greater than the length of the fuel rods 11 and having sufficient 
cross-sectional area to receive the compacted fuel rods from the fuel rod 
assembly 10 in approximately half of its cross-sectional area. In one 
embodiment, a vertical baffle is provided to divide the container 30 into 
parallel chambers 32, 34. All of the fuel rods 11 from the fuel rod 
assembly 10 can be confined in the chamber 32 as shown in FIG. 2. All of 
the fuel rods from another fuel rod assembly can be confined in the 
chamber 34. 
In FIG. 2, there is schematically illustrated a spaced-apart relation 
between the tandem arrangement of the fuel assembly 10 and the transition 
funnel 20 as well as the transition funnel 20 and the container 30. 
According to the present invention, there is provided movable grippers 
which can reciprocate between gripping and releasing positions to advance 
fuel rods in a steplike manner from the fuel assembly. Typically, it is 
sufficient to reciprocate each of the grippers through a distance of 2 to 
4 inches. In the space between the fuel assembly and the transition 
funnel, there is provided a gripper 35 which is supported and guided for 
reciprocating movement by the same support structure which supports the 
fuel assembly and the transition funnel. An arm 36 extends from the 
gripper and the rod end of a piston and cylinder assembly 37 is secured to 
the arm 36. The piston and cylinder assembly is supported by a bracket 38. 
It is preferred to provide the same arrangement of a piston and cylinder 
assembly at the opposite lateral side of the gripper 35. The piston and 
assembly 37 forms an actuator which displaces the gripper along a 
rectilinear path from the position shown in FIG. 2 to a position shown by 
phantom lines and identified by the reference numeral 35'. In a similar 
manner, there is provided a movable gripper 39 for gripping fuel rods at 
the discharge end of the transition funnel. The gripper is guided for 
rectilinear movement and supported by the same support structure which 
supports the container 30 and the transition funnel 20. Extending from one 
lateral side of the gripper 39 is an arm 41 to which the rod end of a 
piston and cylinder assembly 42 is secured. The piston and cylinder 
assembly is, in turn, supported by a bracket 43 extending from the support 
structure. The gripper 39 is reciprocated from the position shown in FIG. 
2 by the piston and cylinder assembly 42 to a position shown by phantom 
lines and identified by the reference numeral 39'. During the time while 
the fuel rods are advanced downwardly from the fuel assembly 10 by the 
gripper 35, means are utilized to avoid unrestrained displacement of the 
fuel rods in the direction of their length. 
In the embodiment of the present invention shown in FIG. 2, the means 
utilized for this purpose comprises the fuel assembly support grids 12 
which are illustrated in greater detail in FIGS. 6-8. In this regard, the 
fuel rods need only be restrained against uncontrolled axial movement 
during displacement of the leading ends of the fuel rod from the position 
in which they reside when the lower end of the fuel assembly is removed 
until the array of fuel rods enters the upper end 21 of the transition 
funnel. Thereafter, movement of the fuel rods is constrained due 
frictional resistance in the transition funnel to repositioning of the 
fuel rods from a spaced-apart, rectangular array to a triangular array as 
described hereinbefore and shown in FIGS. 4 and 5, respectively. A typical 
support grid 12 is shown in FIGS. 6-8 and takes the form of spaced-apart, 
parallel plates 45 between which there is welded or otherwise secured 
spaced-apart, parallel plate sections 46 which form a square-shaped array 
of openings into which, inter alia, the fuel rods pass. 
As best shown in FIGS. 7 and 8, the plates 45 and plate sections 46 each 
has a central web section 47 formed by punching or otherwise upsetting the 
metal along a major face area of the plates 45 and plate sections 46. At 
opposite ends of the web section 47, there are smaller dimensioned upset 
web sections 48. Sections 47 and 48 protrude into the open spaces of the 
array for frictional engagement with the outer face surfaces of the fuel 
rods. The resistance against axial movement by the fuel rod assembly 
afforded by frictional engagement with the sections 47 and 48 is 
sufficient to prevent random and uncontrolled movement of one or more fuel 
rods. Even if, however, a fuel rod breaks loose from supporting engagement 
with the support grids, the moving fuel rod will merely enter the 
transition funnel where the required path of movement to undergo the 
consolidation process exerts sufficient frictional force on the rod to 
prevent substantial advancement of the rod through the transition funnel. 
The inhibition against axial movement provided by the support grids 
assures an orderly movement of the entire array of fuel rods from the fuel 
assembly into the transition funnel while at the same time, the 
arrangement of parts is such that the fuel rods of the array cannot 
separate from one another by distances greater than the spacing between 
the fuel rods in the fuel assembly. 
The gripper 35 may embody a construction of parts shown in FIGS. 9 and 10 
wherein the gripper includes spaced-apart plates 51 and 52 interconnected 
by spacer plates 53 which are arranged to extend about outer peripheral 
portions of the plates 51 and 52. The interconnection between these plates 
forms a fluid impervious internal pocket 54 which can be pressurized by a 
fluid medium introduced by a conduit 55 into the pocket through an opening 
in one of the spacer plates 53. The fluid medium is delivered from a pump 
through an adjustable control valve 55A which can be adjusted to vary the 
fluid pressure delivered to conduit 55. Extending through the internal 
pocket 54 and adhered to aligned openings in the plates 51 and 52 is an 
array of elastic tubes 56 each of which has an internal diameter closely 
approximating the outside diameter of a fuel rod. Preferably, the diameter 
of each tube 56 is such that a fuel rod can pass freely. The array of 
tubes 56 corresponds to the array of fuel rods in the fuel assembly as 
typically illustrated in FIG. 3 and described hereinbefore. The tubes 56 
each comprises material such as rubber which has sufficient resiliency so 
that when a fluid medium in chamber 54 is pressurized, the wall of the 
tubes in the chamber can be elastically deformed and pressed into 
frictional engagement with the outer surface of the fuel rods. The 
gripping force which can be applied to the fuel rods in this manner is 
adjustably controlled by valve 55A so that the gripping force is 
sufficient to hold the fuel rods as a group for movement with the gripper 
along a rectilinear path which is parallel to the longitudinal axes of the 
fuel rods. As described previously, the gripper is displaced by piston and 
cylinder assembly 37 for this purpose. When the gripper is moved to the 
position identified by reference numeral 35', the pressure of the fluid 
medium in chamber 54 is reduced by operation of the control valve 55A so 
that the fuel rods are no longer gripped by the tubes. Thereafter, the 
piston and cylinder assembly 37 is operated to return the gripper to a 
starting position during which the tubes 56 slide along a relatively short 
incremental length of the fuel rods. When the gripper is returned to a 
start position which is adjacent the fuel assembly, valve 55A is again 
operated so that the fluid medium in chamber 54 is pressurized to again 
grip the fuel rods for displacement of a further increment of length in a 
direction toward the transition funnel. The reciprocatory motion of the 
gripper pulls the fuel rods from the fuel assembly and introduce the 
leading ends into the passageways in the transition funnel. The leading 
ends of the fuel rods are advanced through and emerge from the funnel by 
operation of the gripper. The emerging fuel rods have a bundle 
configuration as shown in FIG. 5. The length of the paths of travel by the 
fuel rods through the funnel is relatively short as compared to the length 
of the fuel rods so that the fuel rod bundle emerging from the funnel can 
be continually advanced by the gripper to the point where they protrude 
from end 22 of the funnel by a sufficient distance so that the fuel rod 
bundle can be engaged collectively by gripper 39. 
An embodiment of gripper 39 is shown in FIGS. 16 and 17 and includes a 
plate member 57 having a rectangular opening therein which is dimensioned 
so as to receive within the opening the compacted array of fuel rods when 
emerging from the end 22 of the transition funnel. The opening is 
identified by reference numeral 59. Surrounding the opening at one side of 
plate 58 is a manifold 60 having a peripheral recess 61 communicating with 
a conduit 62. The manifold 60 is secured to plate 58 in a fluid-tight 
manner and spanning a recess forming chamber 61 is a resilient membrane 
63. Typically, the membrane is comprised of a strip of elastomeric 
material such as rubber which is adhered as by vulcanizing to the manifold 
60 and plate 58. A fluid medium introduced by conduit 62 into chamber 61 
is pressurized by a pump, not shown, and adjustably controlled by a valve 
64 so that the membrane is pressed into gripping engagement with those 
fuel rods which are situated about the outer periphery of the bundle of 
fuel rods in the opening 59. The fuel rods are in contact with one another 
in the triangular array as typically illustrated in FIG. 5 and described 
hereinbefore. After the fuel rods are gripped in this manner, piston and 
cylinder assembly 42 is actuated to displace the gripper 39 along a 
rectilinear path which is generally parallel to the longitudinal axis of 
the fuel rods. The bundle of fuel rods is advanced from the transition 
funnel in a direction toward the container 30 as shown in FIG. 2 until the 
gripper reaches the position identified by reference numeral 39'. At this 
point, valve 64 is operated so that the pressure of the fluidized medium 
in chamber 61 is reduced to such an extent that the bundle of fuel rods is 
no longer gripped and the gripper can be returned to a start position by 
operation of piston and cylinder assembly 42. After this occurs, the 
gripper is again supplied with a pressurized fluid medium so that the fuel 
rod bundle is again gripped whereupon the gripper is again advanced toward 
the container to displace the fuel rod bundle from the transition funnel. 
The bundle of fuel rods is drawn from the funnel and passed into the 
container through operation of the gripper 39 until the lengths of the 
fuel rods have undergone consolidation in the funnel. As the trailing end 
of the fuel rod bundle emerges from the funnel the gripper 39 operates to 
push a final length of the bundle in the container. 
A further embodiment of the gripper 35 is illustrated in FIGS. 11-13. In 
this embodiment, a frame having a rectangular configuration, is comprised 
of side rails 65 and 66 and end rails 67 and 68. Spanning the distance 
between side rails 65 and 66 is an alternating arrangement of spaced-apart 
active and passive grippers 69 and 70, respectively. The space between the 
grippers is sufficient so that the fuel rods can pass in the direction of 
their length when the active grippers are deenergized. The active and 
passive grippers preferably each includes arcuate recesses 71 and 72, 
respectively, at spaced-apart locations along the length of each gripper 
corresponding to the spacing between rows of fuel rods in the array. The 
arcuate recesses provide an increased gripping area for engagement with 
the fuel rods. In the form of the gripper shown in FIGS. 11-13, the 
passive gripper elements each comprise a rectangular bar which is welded 
or otherwise secured to the side rails. The active grippers 79 each 
comprise a tube 69 preferably comprised of metal such as stainless steel. 
The ends of each tube 69 have a cylindrical configuration which extends to 
transition sections 72. Between the transition sections, the gripper has 
an oval configuration which can be produced by a partial flattening of a 
tube into the oval configuration as shown in FIG. 13. A passageway 74 
extends along the interior of side rails 66 and communicates with an end 
portion of each active gripper. A conduit 75 is connected to a suitable 
supply of a pressurized fluid medium for delivery to the interior of each 
active gripper. The pressure of the fluid medium is sufficient to produce 
a bulging of the elliptical configuration of the tube in the direction of 
the minor axis of the ellipse which forces the corresponding segment of 
the wall of the tube against fuel rods in the gap at either side thereof 
formed with a passive gripper. 
The gripper 35 may embody a further construction shown in FIGS. 14 and 15 
in which fuel rods in the array are received in spaces between 
spaced-apart and parallel gripper elements 76. Opposite ends of the 
gripper elements are provided with arbors 77 and 78 which are rotatably 
supported in annular openings provided in side rails 79 and 80. The 
openings in side rails 79 extend partway through the thickness of the side 
rail; whereas the openings in side rail 30 extend through the entire 
thickness of the rail so that end portions comprise trunnions protruding 
from the side rail. Secured to each trunnion is one end of links 81. The 
free ends of links 81 are connected by a shaft to an actuator bar 82. An 
actuator, such as a piston and cylinder assembly, is operably connected to 
an extended end portion of one of the links which is identified by 
reference numeral 81A. The motion imparted by the actuator to link 81A 
moves the link in a direction to displace the actuator bar 82 and thereby 
rotate each of the grippers 76 about their longitudinal axes in the same 
direction so that edges of the grippers due to their rectangular 
cross-sectional configuration are brought into engagement with the side 
walls of the fuel rods. Operation of the actuator in the opposite 
direction brings about rotation of the grippers to the position which is 
shown in FIG. 15 where a gap exists between the fuel rods and the gripper 
so that the gripper can be moved relative to the fuel rods. 
The gripper 39 used to move the bundle of fuel rods may embody a 
construction shown in FIGS. 18 and 19 in which spaced-apart plates 85 and 
86 are joined together by spacer plates 87, 88 and 89. Plates 85 and 86 
each includes a rectangular opening 90 which is dimensioned to correspond 
to the compacted array of fuel rods emerging from the end 22 of transition 
funnel 20. Plates 88 and 89 extend in a generally parallel relation and 
arranged therebetween is a gripper plate 91 which can be forced into 
compressive engagement with the bundle of fuel rods by operation of a 
piston and cylinder assembly 92 that is supported in a cavity formed 
between anchor plates 93. As shown in FIG. 19, chambers within the piston 
and cylinder assembly 94 at opposite sides of the piston 94A are connected 
by conduits to a valve 95 to adjustably control the flow of pressurized 
fluid to the piston and cylinder assembly so that the gripper plate 91 can 
be pressed into engagement with a bundle of fuel rods to insure gripping 
of the fuel rod bundle. 
In FIG. 20, there is illustrated a further arrangement of apparatus to 
carry out the method of the present invention. Spaced below the surface of 
water identified by reference numeral 100 in a water pool there is 
tandemly arranged a canister 101 and therebelow in a spaced-apart relation 
is the discharge end 22 of the transition funnel 20. The upper end of the 
fuel assembly 10 is located below the entry end of the transition funnel. 
In the space between the transition funnel and the fuel assembly, there is 
arranged two grippers 103 and 104. Gripper 103 is supported in a 
stationary manner by the structure, e.g., a strong back, which also 
supports the fuel assembly, transition funnel and canister. Gripper 104 is 
supported by the structure to reciprocate in the space between the fixed 
gripper 103 and the fuel rod assembly. In the space between the canister 
101 and the transition funnel 20, there is arranged two bundle grippers 
105 and 106. Gripper 105 is supported in a stationary manner by the strong 
back and gripper 106 is supported by this structure to reciprocate in the 
space between the fixed gripper 105 and the transition funnel 20. Each of 
the grippers 103 and 104 may embody a construction according to any one of 
the embodiments described hereinbefore with respect to gripper 35 and each 
of the grippers 105 and 106 may be constructed according to any one of the 
embodiments described hereinbefore for gripper 39. 
A further embodiment of the present invention is shown in FIG. 21 which 
essentially differs from the embodiments hereinbefore described by the 
fact that grippers 35 and 39 are secured by brackets 108 and 109, 
respectively, to the transition funnel 20. The funnel is in turn provided 
with a support bracket 110 which extends to a support structure such as a 
strong back on which there is provided an elongated guide to slideably 
support the funnel for rectilinear reciprocating movement. A piston and 
cylinder assembly 111 is supported by the strong back so that the rod end 
of the piston and cylinder assembly is connected to a bracket or other 
structure extending from the funnel. By this arrangement of parts, the 
grippers at opposite ends of the funnel reciprocate between a rod gripping 
position and a rod release position. During return movement of the 
grippers and funnel, the fuel rods are supported against unwanted axial 
movement by support grids 12 and/or stationary grippers. The use of 
stationary grippers for this purpose is preferred and these grippers are 
identified by reference numerals 112 and 113. The stationary grippers like 
grippers 35 and 39 may embody a construction of parts according to any one 
of the embodiments hereinbefore described. 
As described hereinbefore, it is preferred to utilize the fuel rod 
compacting method and apparatus of the present invention to transfer fuel 
rods from two fuel assemblies into a single canister which can be placed 
in a storage rack for long-term storage. The present invention is not 
limited thereto and can be utilized to transfer, for example, all the fuel 
rods from a fuel assembly into a single container having a square, 
rectangular, or other geometry to permit transportation or permanent 
storage at a local or remote storage site. In this regard, the triangular 
configuration of the array of fuel rods in the compacted bundle emerging 
from the transition funnel can be conveniently placed in a container 
having a rhombic cross-sectional configuration. In FIG. 22, three storage 
containers 115, 116, and 117 are illustrated each having a rhombic 
configuration for receiving a bundle of fuel rods. The rhombic 
configuration of the storage containers is particularly suitable for 
placement in a container having a cylindrical cross-sectional 
configuration. The cylindrical container is identified by reference 
numeral 118 and can be used for transporting fuel rods to a remote storage 
site for permanent storage of the fuel rods. 
The spaced-apart tandem relationship between a fuel assembly, transition 
funnel and canister can, when desired, be provided in a hot cell wherein 
the components are arranged so that the fuel rods preferably move 
unidirectionally along a generally horizontal path. However, if the hot 
cell embodies a size sufficient to accommodate a vertical arrangement of 
components so that the fuel rods move unidirectionally along a vertical 
path, then the fuel consolidating procedure can be carried out by movement 
of the fuel rods along a path of travel which can be either upwardly or 
downwardly from the fuel assembly through the consolidating funnel and 
into the storage canister. 
Although the invention has been shown in connection with a certain specific 
embodiment, it will be readily apparent to those skilled in the art that 
various changes in form and arrangement of parts may be made to suit 
requirements without departing from the spirit and scope of the invention.