Patent Description:
A nuclear power plant is configured to heat a primary coolant using energy generated during nuclear fission by using nuclear fuel inside a nuclear reactor, to transfer heated energy of the primary coolant to a steam generator, thereby transferring the energy to a secondary coolant and generating steam in the steam generator, to rotate a turbine using the steam, and to convert rotational energy of the turbine into electric power by a generator.

Energy sources for the nuclear fission are provided by the nuclear fuel.

The nuclear fuel arranged inside the nuclear reactor is composed of nuclear fuel assemblies <NUM>, with each nuclear fuel assembly as a unit, as shown in <FIG>, and the nuclear fuel assembly <NUM> includes a framework composed of a top nozzle <NUM>, a bottom nozzle <NUM>, and spacer grid assemblies <NUM>; and nuclear fuel rods <NUM> each inserted into the spacer grid assemblies <NUM> and supported by springs and dimples provided in the spacer grid assemblies <NUM>.

At this time, each of the nuclear fuel rods <NUM> is composed of a plurality of uranium pellets <NUM> and a zirconium alloy cladding tube <NUM> provided in the form of a long bar for protecting the uranium and preventing radiation leakage.

In manufacturing such a nuclear fuel assembly <NUM>, in order to prevent scratches on a surface of the nuclear fuel rod <NUM> and to prevent damage to the spacer grid assemblies <NUM>, lacquer is applied to the surface of the nuclear fuel rod <NUM>. Thereafter, a plurality of the nuclear fuel rods <NUM> is inserted into the framework, followed by attaching and fixing the top and bottom nozzles <NUM> and <NUM>, whereby the assembly of the nuclear fuel assembly <NUM> is completed.

Thereafter, after removing the lacquer of the completed nuclear fuel assembly <NUM>, a process of manufacturing the nuclear fuel assembly <NUM> is completed by inspecting gaps, warpage, full length, dimensions, and the like between the nuclear fuel rods <NUM>.

Meanwhile, the nuclear fuel assembly <NUM>, the manufacturing process of which is completed as described above, is not directly introduced into the nuclear reactor but is inspected to determine whether the nuclear fuel assembly <NUM> is structurally deformed.

This is for preventing a collision between neighboring fuel assemblies <NUM> in a process of arranging a plurality of fuel assemblies <NUM> in the nuclear reactor.

That is, when structural deformation occurs in the nuclear fuel assembly during structural assembling of the nuclear fuel assembly <NUM>, the collision with the neighboring nuclear fuel assemblies <NUM> may occur, and thus the cladding tube <NUM> of the nuclear fuel rod <NUM> may be damaged. When the cladding tube <NUM> of the nuclear fuel rod <NUM> is damaged, radioactivity may be excessively leaked from the nuclear fuel, thereby intensifying contamination of the primary coolant. In the case of severe damage, the nuclear fuel rods <NUM> may be dropped out and moved inside the nuclear reactor, thereby causing a highly risky situation.

Therefore, since the nuclear fuel assembly <NUM> is required to have a high degree of reliability with respect to quality thereof, work of inspecting the structural deformation of the nuclear fuel assembly <NUM> is obviously a very important task.

Accordingly, it is urgent to develop equipment for measuring and inspecting the structural deformation of the nuclear fuel assembly <NUM>.

Naturally, as disclosed in the related art, equipment for measuring a structure of the nuclear fuel assembly <NUM> has been provided but has been limited to measurement of a structure of the spacer grid assemblies <NUM> of the nuclear fuel assembly <NUM>, thereby having a problem of being limited in measuring the nuclear fuel assembly <NUM> as a whole.

In particular, in measuring whether or not the nuclear fuel assembly <NUM> is structurally deformed, because no calibration work has been performed on measuring means and no standard has been provided for the calibration of the measuring means, there has been a problem in that accuracy of measuring the nuclear fuel assembly <NUM> has been difficult to be enhanced.

<CIT> discloses a shipping container for nuclear fuel assemblies. The shipping container has a lid frame.

<CIT> discloses a method of disassembling a nuclear reactor fuel element without destroying the individual fuel pins.

Accordingly, the present invention has been made keeping in mind the above problems occurring in the related art, and an object of the present invention is to provide a standard for mobile equipment for measuring structural deformation of a nuclear fuel assembly, wherein a standard member corresponding to a nuclear fuel assembly standard specification is provided in the measuring equipment in order to allow the calibration work of a scanner to be performed.

In order to accomplish the above object, the present invention provides a standard device for mobile equipment for measuring structural deformation of a nuclear fuel assembly, as defined in claim <NUM>.

Optionally, the fixing frame may include: a protective cover provided with an accommodating groove configured to accommodate the standard member and with a fastening means configured to prevent the standard member accommodated in the accommodating groove from being removed; a lower support provided below the protective cover and fixed to the container; and an upper support installed between the protective cover and the lower support and configured to fix the protective cover to the lower support.

Optionally, a plurality of buffer members may be further provided between both side parts of the upper support and the lower support, in a longitudinal direction of the lower support.

In addition, through holes may be provided on both side portions of one end portion of the protective cover; a shaft hole corresponding to the through holes may be provided on the one end portion of the standard member; and a rotating pin through the through holes and the shaft hole may be provided to allow the standard member to rotate with the one end portion of the protective covers.

As described above, the standard for the mobile equipment for measuring structural deformation of the nuclear fuel assembly according to the present invention has following effects.

Since calibration work of the scanner, which is a measuring means, can be performed accurately, there is an effect that accuracy of measuring the nuclear fuel assembly can be enhanced.

That is, by providing a standard member corresponding to the nuclear fuel assembly standard specification, and by allowing the scanner to be calibrated with the standard member as a reference, the accuracy of measuring the nuclear fuel assembly through the calibrated scanner can be enhanced compared to measured value without the calibration work.

In addition, even when the structural deformation of the column in which the scanner is installed occurs, there is an effect that it is possible to always uniformly maintain the accuracy of measuring the fuel assembly through the calibration work through the standard member.

Terms or words used in the present specification and claims are not to be construed as limiting to usual or dictionary meanings thereof. On the basis of a principle that the inventors may properly define the concept of terms in order to best explain the invention thereof in the best way possible, it should be interpreted as meaning and concept corresponding to the technical idea of the present invention.

Hereinafter, a standard device for mobile equipment for measuring structural deformation of a nuclear fuel assembly (hereinafter referred to as "standard device" according to an exemplary embodiment of the present invention will be described with reference to the accompanying <FIG>.

The standard device has a technical feature provided for scanner calibration for the mobile equipment for measuring the nuclear fuel assembly.

That is, by providing a standard member corresponding to a nuclear fuel assembly standard specification, and by allowing the scanner to be calibrated through the standard member, accuracy of measuring the nuclear fuel assembly through the scanner may be enhanced.

As shown in <FIG>, the standard device includes a fixing frame <NUM> and a standard member <NUM>.

The fixing frame <NUM> is configured to fix the standard member <NUM>, and is installed inside the container protecting the measurement equipment.

The fixing frame <NUM> includes a protective cover <NUM>, a lower support <NUM>, and an upper support <NUM>.

The protective cover <NUM> protects the standard member <NUM> and is a portion to and from which the standard member <NUM> is attached and detached.

The protective cover <NUM> is provided with an accommodating groove <NUM> to accommodate the standard member <NUM>, wherein the accommodating groove <NUM> corresponds to a shape of the standard member <NUM>.

As the standard member <NUM> is provided in a quadrangular shape, the accommodating groove <NUM> also has a quadrangular shape corresponding thereto, wherein a top portion of the accommodating groove <NUM> is open, whereby the standard member <NUM> may enter or exit the accommodating groove <NUM> therethrough.

The protective cover <NUM> configured as described above is provided in a "U" shape consisting of a bottom surface <NUM> and opposite side parts <NUM>, wherein the opposite side portions <NUM> of the protective cover <NUM> may be each provided with through holes 113a so as to reduce production cost and weight.

In addition, both side portions of one end of the protective cover <NUM> may be each composed of extension portions <NUM> provided to extend to the outside.

That is, only the opposite side parts <NUM> except the bottom surface <NUM> are configured to be provided to extend.

At this time, the extension parts <NUM> are provided with a through hole 114a penetrating both sides.

The through hole 114a is configured to allow a rotating pin P to be passed so that the standard member <NUM> is axially coupled thereto.

As such, the standard member <NUM> may be axially coupled to the extension portions <NUM> having no bottom surface <NUM> and thus may not interfere with the bottom surface <NUM> when rotating. Accordingly, rotation of the standard member <NUM> may be smoothly performed.

In addition, a fastening means <NUM> is installed at an opened portion of the protective cover <NUM>.

The fastening means <NUM> is configured to prevent the standard member <NUM> positioned in the accommodating groove <NUM> from being removed from the open portion.

That is, when transporting the measuring equipment, the standard member <NUM> is transported in a state of being laid in the accommodating groove <NUM> as shown in <FIG>. At this time, because the fastening means <NUM> is blocking the opened portion of the protective cover <NUM>, the standard member <NUM> may be prevented in advance from being removed or moved upward.

In a longitudinal direction of the standard member <NUM>, the rotating pin P is coupled to the protective cover <NUM>, so that escape of the standard member <NUM> from the protective cover <NUM> does not occur.

The plurality of the fastening means <NUM> may be provided in the longitudinal direction of the protective cover <NUM>, but not limited to a specific configuration.

As shown in <FIG> and <FIG>, one end of the fastening means <NUM> may be hinged to one side of the protective cover <NUM>, and an opposite end of the fastening means <NUM> may be configured to fold upwardly or to fasten to an opposite side of the protective cover <NUM>, with the one end of the fastening means <NUM> as the center.

In addition, the lower support <NUM> is a configured to fix the protective cover <NUM> to the inside of the container of the measuring equipment and is located under the protective cover <NUM>.

The lower supporter <NUM> is fixed to the inside of the container and, the same as the protective cover <NUM>, may be in the "U" shape consisting of a bottom surface <NUM> and opposite side parts <NUM>.

In addition, the through holes 122a may also be provided at the opposite side parts of the lower support <NUM>.

In addition, the upper support <NUM> serves to support the protective cover <NUM> to the lower support <NUM> and is fixed between the protective cover <NUM> and the lower support <NUM>.

At this time, the upper support <NUM> fixing means is not limited to a specific one and may be provided by a fixing means such as bolts and the like.

At this time, the upper support <NUM> may include a top plate <NUM> corresponding to the bottom surface of the protective cover <NUM> and opposite side parts <NUM> bent downward from both sides of the top plate <NUM>.

At this time, width of the upper support <NUM> is provided smaller than width of the lower support <NUM>, the opposite side parts <NUM> of the upper support <NUM> are located in the space between the opposite side parts <NUM> of the lower support <NUM>.

On the other hand, buffer members <NUM> may be further provided on both side parts <NUM> of the upper support <NUM>, respectively.

This is to attenuate that vibration of the lower support <NUM> fixed to the container is transferred to the protective cover <NUM> in which the standard member <NUM> is installed.

That is, since the lower support <NUM> is located between the container and the standard member <NUM>, as shown in <FIG>, the vibration may be transferred from the container to the standard member <NUM> when transporting the container. At this time, the buffer member <NUM> interposed between the lower support <NUM> and the upper support <NUM> may attenuate the vibration, thereby preventing the standard member <NUM> from being damaged.

Next, the standard member <NUM> is a standard specification member for calibrating a scanner for measuring the nuclear fuel assembly.

Standard member <NUM> is provided in a straight line and may be made of stone.

This is to prevent the standard member <NUM> from being deformed even after a long period of time.

The standard member <NUM> is made in a form corresponding to the accommodating groove <NUM> of the protective cover <NUM>, and the length of the standard member <NUM> is provided to be longer than length of the protective cover <NUM> as shown in <FIG>.

This is to ensure that the rotation of the standard member <NUM> is smoothly accomplished on the protective cover <NUM>.

To this end, a shaft hole <NUM> is provided on both sides of one end of the standard member <NUM>.

Here, the shaft hole <NUM> is provided in a shape corresponding to the through hole 114a of the protective cover <NUM>.

On the other hand, the rotating pin P is provided to provide a rotating reference of the standard member <NUM> by passing through the through hole 114a of the protective cover <NUM> and the shaft hole <NUM> of the standard member <NUM>.

That is, in order to move the standard member <NUM> from the protective cover <NUM>, the standard member <NUM> is to be erected upright. To this end, the rotating pin P is configured to become a shaft when the standard member <NUM> is erected.

In addition, an upper plate <NUM> and a lower plate <NUM> are installed at both end portions of the standard member <NUM>, respectively.

The upper plate <NUM> is a portion to which the transport means provided for erecting the standard member <NUM> is coupled in the process of erecting the standard member <NUM> with the rotating pin P as the center.

To this end, the upper plate <NUM> provides a coupling means <NUM> for coupling with the transport means.

The coupling means <NUM> is provided on the upper plate <NUM> and is good enough, provided the transport means such as a crane and the like is allowed to be hooked and coupled therewith.

The coupling means <NUM> may be provided in a ring shape, as shown in <FIG>, may be provided in a plurality of through holes.

In addition, the lower plate <NUM> is configured to stably erect the standard member <NUM> and is detachably attached to one end of the standard member <NUM>.

The standard member <NUM> is configured to perform the calibration work of the scanner. To this end, the standard member <NUM> should be erected upright by being adjacent to one side of the column as shown in <FIG>. Since the lower plate <NUM> may be fixed to a floor adjacent to the one side of the column, the standard member <NUM> may be stably erected upright.

To this end, the lower plate <NUM> includes an insertion protrusion <NUM>, and an insertion means for inserting the insertion protrusion <NUM> may be provided on the floor adjacent to the one side of the column.

Hereinafter, the use of the standard configured as described above will be examined.

The measuring equipment stored in the container is transported to a measurement site.

In this case, the container may be transported by land, sea, or air.

Meanwhile, the container transported to the measurement site is removed of the cover thereof for measuring the nuclear fuel assembly, whereby the measuring equipment provided on a base is exposed to the outside.

Next, as shown in <FIG>, supports are rotated to and positioned at the outside of a boundary of the base, whereby the base is fixed to the ground without moving.

Next, as shown in <FIG>, the column is erected upright by operating a hydraulic cylinder.

Next, in order to enhance the accuracy of measured values of the nuclear fuel assembly through the scanner, the calibration work of the scanner is performed.

To this end, the standard member provided on one side of the base is fixed to the transport means.

At this time, although not shown, a crane may be provided as the transport means.

Meanwhile, in order to connect the crane to the standard member <NUM>, a transport hanger <NUM> may be provided as a connection medium between the crane and the standard member <NUM>.

That is, after coupling the transport hanger <NUM> to the upper plate <NUM> of the standard member <NUM>, the crane is to lift the transport hanger <NUM>.

When the coupling of the transport hanger <NUM> to the coupling means <NUM> of the upper plate <NUM> is completed, the fastening means <NUM> is released to open the opened portion of the protective cover <NUM>.

Next, when the transport hanger <NUM> is lifted by using a crane, the standard member <NUM> is rotated upward with the rotation pin P as the center.

Subsequently, the standard member <NUM> is erected upright while being rotated between the extension portions <NUM>.

Next, the rotating pin P is separated from the through hole 114a of the protective cover <NUM> and the shaft hole <NUM> of the standard <NUM>.

Accordingly, the standard member <NUM> becomes to be in a state free to move on the protective cover <NUM>.

Next, the standard member <NUM> is fixed to the floor adjacent to the one side of the column by operating the crane.

At this time, the insertion protrusion <NUM> provided on the lower plate <NUM> of the standard member <NUM> is coupled to the floor adjacent to the one side of the column, whereby the standard member <NUM> becomes to be in a state erected upright adjacent to the one side of the column as shown in <FIG>.

Next, the calibration work of the scanner is performed through measuring the standard member <NUM> by operating the scanner.

That is, the calibration work is performed through the standard member <NUM> with respect to standard values such as length, envelope, slope, and the like of the nuclear fuel assembly input to the scanner.

Next, when the calibration work of the scanner has been completed, the standard member <NUM> is laid and seated on the accommodating groove <NUM> of protective cover <NUM> by performing the above-described series of procedures in reverse order.

Then, by fastening the fastening means <NUM>, the calibration work of the scanner using the standard member <NUM> is completed.

As described above, the standard device for the mobile equipment for measuring structural deformation of the nuclear fuel assembly according to the present invention has a technical feature that allows the calibration work of the scanner to be performed in the mobile equipment for measuring structural deformation of the nuclear fuel assembly.

That is, after the calibration work of the scanner is performed through the same standard member as the nuclear fuel assembly standard specification, it is possible to measure whether or not the nuclear fuel assembly structure is deformed, thereby increasing the accuracy of measuring the nuclear fuel assembly.

Therefore, the nuclear fuel assembly may be stably introduced into the nuclear reactor.

Although the present invention has been described in detail with respect to the described embodiments, it will be apparent to those skilled in the art that various modifications and variations are possible within the technical scope of the present invention, which is defined in the appended claims.

Claim 1:
A standard device for mobile equipment, the standard device being provided with a scanner for measuring structural deformation of a nuclear fuel assembly (<NUM>), wherein the standard device further comprises:
a container, a measuring equipment and a fixing frame (<NUM>) for fixing a standard member (<NUM>), wherein the fixing frame is fixed to one side of the measuring equipment accommodated in the container of the equipment; and
the standard member configured to be detachable from the fixing frame, to rotate around one end portion of the fixing frame, and to correspond to a nuclear fuel assembly standard specification,
wherein an upper plate (<NUM>) provided with a coupling means (<NUM>) configured to be coupled with a transport means is coupled on one end portion of the standard member, and
a lower plate (<NUM>) configured to be erected upright on and fixed to one side of the measuring equipment is coupled on an opposite end portion of the standard member,
wherein the standard member is a standard specification member for calibrating the scanner for measuring the nuclear fuel assembly to enhance the accuracy of measuring the nuclear fuel assembly.