U.S. patent application number 10/912742 was filed with the patent office on 2005-03-17 for transport/storage container for radioactive elements.
Invention is credited to Diersch, Rudolf, Huggenberg, Roland.
Application Number | 20050056563 10/912742 |
Document ID | / |
Family ID | 33522328 |
Filed Date | 2005-03-17 |
United States Patent
Application |
20050056563 |
Kind Code |
A1 |
Huggenberg, Roland ; et
al. |
March 17, 2005 |
Transport/storage container for radioactive elements
Abstract
A storage/transport container comprises a floor, a side wall,
and a cover fittable with the side wall to form with the floor and
side wall a closed interior having a height between an inner face
of the floor and an inner face of the cover that is greater than an
overall length of the element. A spring is engaged between a lower
end of the rod and the floor and has a spring force smaller than a
weight of the rod so that, when the cover is above the floor, an
upper end of the rod is spaced below the cover and, when the floor
is above the cover, the spring presses the rod upper end against
the cover.
Inventors: |
Huggenberg, Roland; (Bochum,
DE) ; Diersch, Rudolf; (Essen, DE) |
Correspondence
Address: |
THE FIRM OF KARL F ROSS
5676 RIVERDALE AVENUE
PO BOX 900
RIVERDALE (BRONX)
NY
10471-0900
US
|
Family ID: |
33522328 |
Appl. No.: |
10/912742 |
Filed: |
July 30, 2004 |
Current U.S.
Class: |
206/524.6 |
Current CPC
Class: |
G21F 5/08 20130101; G21F
5/008 20130101 |
Class at
Publication: |
206/524.6 |
International
Class: |
B65D 085/30 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 1, 2003 |
EP |
03017417.1 |
Claims
We claim:
1. In combination with a radioactive element, a storage/transport
container comprising: a floor; a side wall; a cover fittable with
the side wall to form with the floor and side wall a closed
interior having a height between an inner face of the floor and an
inner face of the cover, the element having an overall length
shorter by an amount shorter than the height; and a spring engaged
between a lower end of the rod and the 11 floor and having a spring
force smaller than a weight of the rod, whereby when the cover is
above the floor an upper end of the rod is spaced below the cover
and when the floor is above the cover the spring presses the rod
upper end against the cover.
2. The storage/transport container defined in claim 1 wherein the
element is a fuel rod.
3. The storage/transport container defined in claim 1 wherein the
spring is a coil compression spring.
4. The storage/transport container defined in claim 3 wherein the
rod is formed at its lower end with a pocket at least partially
receiving the spring.
5. The storage/transport container defined in claim 4 wherein the
pocket is deep enough to completely contain the spring in
compressed condition.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to a transport and/or storage
container for radioactive elements. More particularly this
invention concerns such a container used to ship fresh or used fuel
rods or high-active-waste glass units.
BACKGROUND OF THE INVENTION
[0002] A typical storage/transport container for radioactive
elements is basically formed as a massive barrel, typically of
reinforced concrete, having a flat circular floor, a cylindrical
side wall extending upward from the floor, and a flat circular
cover that fits on the upper rim of the side wall so as to define a
cylindrical interior. Since the elements placed in such a container
can be of different lengths, since they expand and contract
somewhat because of radioactive-decay heating, and also since the
container is not made to extremely tight tolerances, it is standard
to make the interior somewhat taller than the longest element that
is likely to be stored in the container. This leaves under normal
circumstances, that is when the container is standing on its floor
with its cover up, an empty free space above the elements and below
the cover.
[0003] The problem with this type of construction is that in the
event of an accident when the container is dropped on its cover,
breakage is likely. If, for instance, the container is dropped in
such a manner that it is inverted with its floor up and its cover
down, during the fall the elements inside it will naturally remain
roughly in their starting position, that is engaging the floor and
spaced from the cover. When, however, the container lands on its
cover, the elements inside the container will travel and will, like
massive hammers, strike the inside face of the cover with great
force, transferring all their considerable kinetic energy to the
cover. Thus the cover is struck from the inside, in a direction
that is not really what it was designed to resist, so it can be
popped off and the contents spilled.
OBJECTS OF THE INVENTION
[0004] It is therefore an object of the present invention to
provide an improved transport/storage container for radioactive
elements.
[0005] Another object is the provision of such an improved
transport/storage container for radioactive elements which
overcomes the above-given disadvantages, that is which can better
resist breakage if it is dropped on its cover.
SUMMARY OF THE INVENTION
[0006] These objects are attained by a storage/transport container
comprising a floor, a side wall, and a cover fittable with the side
wall to form with the floor and side wall a closed interior having
a height between an inner face of the floor and an inner face of
the cover that is greater than an overall length of the element.
According to the invention a spring is engaged between a lower end
of the rod and the floor and has a spring force smaller than a
weight of the rod so that when the cover is above the floor an
upper end of the rod is spaced below the cover and when the floor
is above the cover the spring presses the rod upper end against the
cover.
[0007] Thus with this system, as the container is inverted so that
its floor is above its cover, the load will be taken off the spring
and the spring will shift the element toward the cover until it
actually is pressed by the spring against the inner face of the
cover. Thus if the container is inverted and dropped, by the time
it hits the ground the element will be already in contact with the
cover and will not strike it with a delayed hammer action likely to
loosen the cover.
[0008] According to the invention the element is a fuel rod. In
fact the container is designed to hold a plurality of the elements,
each with its own spring so that elements of different length can
be accommodated.
[0009] The spring in accordance with the invention is a simple coil
compression spring. It can be at least partially received in a
pocket formed in a lower end of the rod so that the system of this
invention can be used with a conventional transport/storage
container. Typically the pocket is deep enough to completely
contain the spring in compressed condition so that, under normal
circumstances, the element sits directly on the floor of the
container. Each element is formed with such a pocket for its
spring.
BRIEF DESCRIPTION OF THE DRAWING
[0010] The above and other objects, features, and advantages will
become more readily apparent from the following description,
reference being made to the accompanying drawing in which:
[0011] FIG. 1 is a partial axial section through a container
according to the invention as it is being loaded;
[0012] FIG. 2 is a view like FIG. 1 showing the loaded and closed
container; and
[0013] FIG. 3 is a view like FIG. 2 but showing the container
inverted.
SPECIFIC DESCRIPTION
[0014] As seen in FIGS. 1 and 2, a standard container according to
the invention is centered on a normally vertical axis A and has a
flat horizontal floor 3, a cylindrically tubular side wall 4, and,
when complete, a flat horizontal cover 5 together defining a
cylindrical interior 1 having a height H. Such a container is
typically loaded with radioactive fuel elements, here spent fuel
rods 2 of which one is shown. The rod 2 has an overall length h
which is shorter than the height H by a distance f so that, when
sitting on the floor 3, there is a space between its upper end and
the cover 5 as shown in FIG. 2. The cover 5 here is shown as one
piece although it is often constituted as two separate disks that
may even be separated by a slight spacing.
[0015] According to the invention the lower end of the rod 2 is
formed with a blind cylindrical pocket 7 in which is seated a steel
coil-compression spring 6, although it is within the scope of the
invention to use an elastomeric spring element. With
high-active-waste glass elements the pocket 7 is of rounded
cup-shaped. When unstressed, this spring 6 has an overall length L
that is substantially more than the distance f. The strength of
this spring 6 is, however, such that the weight of the rod 2 is
sufficient to compress it by an amount V until it is completely
contained in the pocket 7 and the rod 2 sits with its lower end
directly on the floor 3. Thus as the rod 2 is lowered into the
container, the spring 6 is prestressed.
[0016] With this system, if the container is inverted as shown in
FIG. 3, the spring 6 will extend and will shift the rod 2 downward
through the distance f such that what is normally its upper end
bears against the inside normally lower face of the cover 5. Thus
if the container is inverted and dropped, by the time the cover 5
and rim of the side wall 4 strike the ground, the rod 2 will
already be in solid contact with the inner face of the cover 4 and
it will not act like a delayed hammer on this inner face. Instead
the cover 5 will merely be subjected to compression and is not
likely to be knocked off the side wall 4.
* * * * *