Radiant energy – Radiant energy generation and sources – With container for radioactive source and radiation...
Reexamination Certificate
2000-06-26
2003-09-30
Lee, John R. (Department: 2881)
Radiant energy
Radiant energy generation and sources
With container for radioactive source and radiation...
C250S493100, C250S308000, C378S119000, C378S120000, C378S065000, C252S644000, C252S645000
Reexamination Certificate
active
06627908
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates, in general, to a radiation source assembly used in a nondestructive inspection process and a connector press used in producing such assemblies and, more particularly, to an Ir-192 radiation source assembly, with a source capsule having double-sealed radiation source discs and two connectors, or a cap connector and a female connector being respectively coupled to both ends of a pigtail, and to a connector press used for compression-connecting the two connectors to both ends of such a pigtail so as to form a desired radiation source assembly.
2. Description of the Prior Art
In order to produce a radiation source used in a nondestructive inspection, a plurality of Ir-radiation source discs have been conventionally used. Some countries import radiation source disc targets from foreign countries. Such disc targets are primarily processed products, and so they must be pre-processed and finally processed before they are exposed to neutrons within a nuclear reactor. A conventional pre-process and a conventional final process for the disc targets will be described as follows.
Primarily, both diameter and thickness of such a disc target are measured prior to inspecting any external defect of the disc target with the naked eye. Sometimes, such a naked eye inspection may discover a defect on one surface of a disc target.
Thereafter, the flatness of the disc target is measured. Since conventional radiation source disc targets are typically produced through a punching process, the disc targets fail to have a desired flatness. Therefore, it is necessary to flatten the radiation source disc target with a nonmetal hammer while interposing the disc target between two flat metal discs. When the radiation source disc target fails to accomplish a desired flatness, it is almost impossible for the disc target to perform a desired operational performance of a point source or to provide a high quality nondestructive inspection image.
It is also necessary to completely remove micro debris from the surface of the radiation source disc target since such micro debris may cause a radioactive contamination.
After the pre-process, the radiation source disc target is washed using neutral detergent and distilled water, and is finally ultrasonically washed prior to being dried, thus completely preparing a desired radiation source disc target. The dimension of the disc target is measured and is compared with calculated values. The prepared disc target is an Ir-metal type disc having a diameter of 2.5 mm, a thickness of 0.25 mm, a weight of 27.6 mg/disc, a nuclidic purity of 99.9%, and a specific weight of 22.5 g/cm
3
.
After preparing the radiation source disc targets and manufacturing a radiation source capsule, a desired radiation source is produced. In order to produce a desired radiation source, a plurality of disc targets, enclosed within an aluminum irradiation container, are exposed to neutrons within a neutron irradiation hole of a multi-purpose nuclear reactor for a predetermined period of time. After the neutron irradiation process, the irradiation container is removed from the neutron irradiation hole of the nuclear reactor and is received within a carrier vessel, and is moved to a concrete hot cell along with the vessel. Within the concrete hot cell, the irradiation container is removed from the carrier vessel by a manipulator. The irradiation container is, thereafter, set in automatic classifying and measuring equipment. When a control unit of the equipment is turned on, the container is automatically processed through a container cutting process, a radioactivity measuring process, and a classified radiation source capsuling process in accordance with a program of the control unit. In such a case, the Ir-disc targets from the radioactivity measuring process are received within a stainless capsule in a way such that 5 to 10 disc targets are received within each capsule. The stainless capsule is, thereafter, closed by a lid prior to being welded into a single structure at the junction between the capsule and the lid through a plasma arc welding process, thus forming a sealed radiation source.
When such a radiation source capsule is completely produced, a desired radiation source assembly is produced. An example of conventional radiation source assemblies is shown in the accompanying drawing, FIG.
1
.
As shown in the drawing, the radiation source assembly
1
comprises a source capsule
3
, a female connector
5
and a pigtail
7
. In such a case, the source capsule
3
is made of SUS 316L, and consists of a cap connector
9
, an outside cap
11
and an inside capsule
13
. As best seen in
FIG. 2
, the cap connector
9
receives one end of the pigtail
7
, while the outside cap
11
is welded to the cap connector
9
through a TIG welding process. The inside capsule
13
is set within the outside cap
11
.
In order to receive the inside capsule
13
, the outside cap
11
has a cavity. The above cap
11
also has an arcuate cross-section, with the tip of the cap
11
being rounded. The object of such a rounded tip of the cap
11
is to minimize a kinetic resistance generated at the tip when the radiation source assembly passes through guide tube of a nondestructive inspection apparatus. The inside cap
11
is fitted over a connecting projection
31
of the cap connector
9
at its fitting opening prior to being integrated with the connector
9
into a single structure through a TIG welding process.
The cap connector
9
, connected to the pigtail
7
, is a cylindrical member provided with a pigtail fitting hole
15
. The connecting projection
31
is provided on an end of the cap connector
9
opposite to the pigtail fitting hole
15
.
As shown in
FIG. 3
, the inside capsule
13
, set within the outside cap
11
, consists of a cylindrical outside case
14
, a sealing cover
16
and a filler
17
. The outside case
14
receives a plurality of radiation source disc targets
10
in a way such that the targets
10
are regularly stacked. The sealing cover
16
is fitted into the top open end of the outside case
14
, thus sealing the outside case
14
. The filler
17
is interposed between the sealing cover
16
and the stacked targets
10
so as to press the targets
10
.
As best seen in
FIGS. 4
a
and
4
b
, the pigtail
7
consists of a wire core
23
, a primary coil
25
, a secondary coil
27
, and a large-diameter coil
29
. The wire core
23
is made by twisting a plurality of wires
21
, the primary coil
25
is wound around the wire core
23
. The secondary coil
27
is wound around the primary coil
25
. The large-diameter coil
29
, having a predetermined regular pitch, is wound around the primary coil
25
along with the secondary coil
27
. In such a case, all the wires and coils of the pigtail
7
are made of carbon steel, and so they have a predetermined elasticity. The wires and coils of the pigtail
7
are not undesirably wear-cut or loosened even though the pigtail
7
is used ten thousand or more times. The wires and coils are also free from corrosion even when they are exposed to atmospheric air.
The above radiation source assembly
1
passes through a guide tube under the control of a manipulation handle connected to a male connector engaging with the female connector
5
of the assembly
1
. The assembly
1
is thus finally received within a radiation source carrier. Such an assembly
1
enclosed by the radiation source carrier is used with a nondestructive inspection apparatus. During a nondestructive inspecting operation, the assembly
1
reaches an inspection point by the guide tube. When the radiation source assembly
1
is kept within the radiation source carrier, a stop ball
19
, formed on one end of the female connector
5
positioned at the rear end of the assembly
1
as shown in
FIG. 5
, is locked to an inside wall of the carrier, thus being firmly and precisely positioned within the carrier. This finally completely prevents a radiation leakage, caused by an assembly
1
failing to be pr
Cho Woon Kap
Han Hyon Soo
Hong Soon Buk
Jang Kyeong Deuk
Park Ul Jae
Bachman & LaPointe P.C.
Korea Atomic Energy Research Institute
Lee John R.
Vanore David A.
LandOfFree
Radiation source assembly and connector press used in... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Radiation source assembly and connector press used in..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Radiation source assembly and connector press used in... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3017430