Patent Description:
Generally, among nuclear facilities used for nuclear power generation, a pressurized water reactor type of nuclear power plant includes a nuclear reactor pressure vessel, an in-core instrument (ICI) nozzle for measuring the inside of the nuclear reactor pressure vessel through a lower portion of the nuclear reactor pressure vessel, and bio-protective concrete for surrounding the nuclear reactor pressure vessel and the in-core instrument nozzle.

When decommissioning a nuclear facility, in order to easily separate the nuclear reactor pressure vessel from the bio-protective concrete, it is necessary to separate the in-core instrument nozzle from the nuclear reactor pressure vessel and to separate waste inside the nuclear reactor pressure vessel from the nuclear reactor pressure vessel.

<CIT> discloses a device for standardising the emission products for the detection of rupture of the wrappers of fuel elements of a nuclear reactor with an opening in the reactor pressure vessel and an insert.

An embodiment provides an apparatus for treating waste of a nuclear reactor pressure vessel and a method for treating waste of a nuclear reactor pressure vessel that easily treat waste inside a nuclear reactor pressure vessel when decommissioning a nuclear facility.

An embodiment provides an apparatus for treating waste of a nuclear reactor pressure vessel including: a suction unit inserted into the nuclear reactor pressure vessel through a plurality of through-pipes passing through a lower portion of the nuclear reactor pressure vessel to suck waste inside the nuclear reactor pressure vessel; a waste treatment part connected to the suction unit to treat the waste; and a lower collection part connected to the waste treatment part to be positioned under the nuclear reactor pressure vessel with the suction unit therebetween.

The suction unit may include a plurality of inserts inserted into the nuclear reactor pressure vessel through the plurality of through-pipes, and the plurality of inserts are flexible sucking members sucking the waste.

The plurality of inserts may further include a camera, a radiation meter, a manipulator, a chemical injector, a stirrer, an ultrasonic generator, and an air injector.

The lower collection part may collect waste falling through the plurality of through-pipes from the inside of the nuclear reactor pressure vessel.

In addition, another embodiment provides a method for treating waste of a nuclear reactor pressure vessel, including: inserting a suction unit into the nuclear reactor pressure vessel through a plurality of through-pipes passing through a lower portion of the nuclear reactor pressure vessel; sucking waste inside the nuclear reactor pressure vessel by using the suction unit; collecting waste falling from the inside of the nuclear reactor pressure vessel through the plurality of through-pipes into a lower collection part positioned under the nuclear reactor pressure vessel with the suction unit therebetween; and treating the waste and the falling waste by using a waste treatment part connected to the suction unit and the lower collection part.

The inserting of the suction unit may include inserting a plurality of inserts included in the suction unit into the nuclear reactor pressure vessel through the plurality of through-pipes, and the sucking of the waste may include sucking the waste inside the nuclear reactor pressure vessel by using a flexible sucking member included in the plurality of inserts.

The sucking of the waste may further include: identifying a solid contained in the waste inside the nuclear reactor pressure vessel by using a camera included in the plurality of inserts; physically crushing the solid contained in the waste by using a manipulator included in the plurality of inserts; chemically dissolving the solid contained in the waste by using a chemical injector included in the plurality of inserts; and stirring the waste by using a stirrer and an ultrasonic generator included in the plurality of inserts.

According to the embodiment, an apparatus for treating waste of a nuclear reactor pressure vessel and a method for treating waste of a nuclear reactor pressure vessel that easily treat waste inside a nuclear reactor pressure vessel when decommissioning a nuclear facility are provided.

The present invention will be described more fully hereinafter with reference to the accompanying drawings, in which embodiments of the invention are shown. As those skilled in the art would realize, the described embodiment may be modified in various different ways, all without departing from the scope of the present.

Hereinafter, a method for treating waste of a nuclear reactor pressure vessel according to an embodiment will be described with reference to <FIG> and <FIG>.

Hereinafter, a nuclear reactor pressure vessel included in a pressurized water reactor type (PWR) nuclear power plant as a nuclear reactor pressure vessel is described as an example, but is not limited thereto, and the nuclear reactor pressure vessel may be a nuclear reactor pressure vessel included in a boiling water reactor (BWR) type of nuclear power plant.

A pressurized water reactor type of nuclear power plant uses light water as a coolant and a moderator, and uranium <NUM> is concentrated to about <NUM> % to <NUM> % to be used as nuclear fuel. A pressurized light-water reactor type of nuclear power plant is divided into a facility related to a nuclear reactor system that transmits heat generated by nuclear fission within a reactor to a steam generator for heat exchange; and a facility related to a turbine and generator system that turns a turbine with steam generated from the steam generator, returns it to water through a condenser, and then circulates it back to the steam generator.

Generally, a coolant (light water), which is a heat transfer medium of a nuclear reactor system, is heated to about <NUM> in a nuclear reactor and pressurized to about <NUM> atmospheres so that it does not boil. Equipment configuring the system includes a pressurizer that adjusts pressure to maintain constant enthalpy, and a coolant pump that circulates the coolant between the reactor and the steam generator. A system in which the steam generated from the steam generator rotates the turbine to generate power from a generator connected to a turbine shaft may be the same as that of a general thermal power plant.

<FIG> illustrates a schematic view of an apparatus for treating waste of a nuclear reactor pressure vessel according to an embodiment.

Referring to <FIG>, a waste treatment apparatus <NUM> of a nuclear reactor pressure vessel according to an embodiment sucks and treats waste <NUM> inside a nuclear reactor pressure vessel <NUM> through a plurality of through-pipes <NUM> passing through a lower portion of the nuclear reactor pressure vessel <NUM> when a nuclear facility is decommissioned.

Here, the plurality of through-pipes <NUM> passing through the lower portion of the nuclear reactor pressure vessel <NUM> may be through-pipes guiding an in-core instrument (ICI) nozzle that passes through the lower portion of the nuclear reactor pressure vessel <NUM> and measures the inside of the nuclear reactor pressure vessel <NUM>, and the in-core instrument nozzle is in a state of being separated from the nuclear reactor pressure vessel <NUM>. The nuclear reactor pressure vessel <NUM> may be supported on a bio-protective concrete, but is not limited thereto.

The apparatus <NUM> for treating the waste of the nuclear reactor pressure vessel includes a suction unit <NUM>, a waste treatment part <NUM>, and a lower collection part <NUM>.

The suction unit <NUM> is positioned under the nuclear reactor pressure vessel <NUM>. The suction unit <NUM> is inserted into the nuclear reactor pressure vessel <NUM> through the plurality of through-pipes <NUM> passing through the lower portion of the nuclear reactor pressure vessel <NUM> to suck the waste <NUM> inside the nuclear reactor pressure vessel <NUM>. The suction unit <NUM> is connected to the waste treatment part <NUM>, and the waste <NUM> sucked by the suction unit <NUM> is moved to the waste treatment part <NUM> to be treated in the waste treatment part <NUM>.

Here, the treatment in the waste treatment part <NUM> may mean decontamination of the waste <NUM> or storing the waste <NUM> in a waste storage container, but is not limited thereto.

The suction unit <NUM> includes a plurality of inserts <NUM> inserted into the nuclear reactor pressure vessel <NUM> through the plurality of through-pipes <NUM>.

<FIG> illustrates a schematic view of a portion A of <FIG>.

Referring to <FIG>, the plurality of inserts <NUM> include a flexible sucking member <NUM>, a camera <NUM>, a radiation meter (not shown), a manipulator <NUM>, a chemical injector <NUM>, a stirrer <NUM>, an ultrasonic generator <NUM>, and an air injector (not shown).

The flexible sucking member <NUM> is flexible and is inserted into the nuclear reactor pressure vessel <NUM> through the through-pipes <NUM> to suck the waste <NUM> inside the nuclear reactor pressure vessel <NUM>.

Here, the waste <NUM> may be cooling water inside the nuclear reactor pressure vessel <NUM> and a reaction product remaining after reaction in a core of the nuclear reactor pressure vessel <NUM>, and the waste <NUM> includes a solid <NUM> and a liquid <NUM>. The solid <NUM> may have a form such as crud or sludge, but is not limited thereto.

The flexible sucking member <NUM> may be various types of known sucking members as long as it may be inserted into the nuclear reactor pressure vessel <NUM> through the through-pipes <NUM> to be flexibly moved to suck the waste <NUM>.

The camera <NUM> is inserted into the nuclear reactor pressure vessel <NUM> through the through-pipes <NUM> to check the inside of the nuclear reactor pressure vessel <NUM>. The camera <NUM> may check a position of the solid <NUM> contained in the waste <NUM>, but is not limited thereto.

The camera <NUM> may be various types of known cameras as long as it may be inserted into the nuclear reactor pressure vessel <NUM> through the through-pipes <NUM> to check the inside of the nuclear reactor pressure vessel <NUM>.

The radiation meter is inserted into the nuclear reactor pressure vessel <NUM> through the through-pipes <NUM> to measure radiation concentration inside the nuclear reactor pressure vessel <NUM>. The radiation meter may be various types of known radiation meters as long as it may be inserted into the nuclear reactor pressure vessel <NUM> through the through-pipes <NUM> to check radiation concentration inside the nuclear reactor pressure vessel <NUM>.

The manipulator <NUM> is inserted into the nuclear reactor pressure vessel <NUM> through the through-pipes <NUM> to physically crush the solid <NUM> of the waste <NUM> inside the nuclear reactor pressure vessel <NUM>. Various end effectors for crushing the solids <NUM> of the waste <NUM> may be positioned at an end portion of the manipulator <NUM>. For example, the end effector of the manipulator <NUM> may be a rotation saw, but is not limited thereto, and it may be various types of known end effectors as long as it may crush the solid <NUM> of the waste <NUM>.

The manipulator <NUM> may be various types of known manipulators as long as it may be inserted into the nuclear reactor pressure vessel <NUM> through the through-pipes <NUM> to physically crush the solid <NUM> of the waste <NUM> inside the nuclear reactor pressure vessel <NUM>.

The chemical injector <NUM> is inserted into the nuclear reactor pressure vessel <NUM> through the through-pipes <NUM> to chemically dissolve the solid <NUM> of the waste <NUM> inside the nuclear reactor pressure vessel <NUM>. The chemical injector <NUM> may inject various known chemicals that may chemically dissolve the solid <NUM> of the waste <NUM> inside the nuclear reactor pressure vessel <NUM>.

The chemical injector <NUM> may be various types of known chemical injectors as long as it may be inserted into the nuclear reactor pressure vessel <NUM> through the through-pipes <NUM> to chemically dissolve the solid <NUM> of the waste <NUM> inside the nuclear reactor pressure vessel <NUM>.

The stirrer <NUM> is inserted into the nuclear reactor pressure vessel <NUM> through the through-pipes <NUM> to stir the waste <NUM> inside the nuclear reactor pressure vessel <NUM>. The stirrer <NUM> stirs the waste <NUM> and mixes the crushed material or dissolved material of the solid <NUM> contained in the waste <NUM> with the liquid <NUM> contained in the waste <NUM>.

The stirrer <NUM> may be various types of known stirrers as long as it may be inserted into the nuclear reactor pressure vessel <NUM> through the through-pipes <NUM> to stir the waste <NUM> inside the nuclear reactor pressure vessel <NUM>.

The ultrasonic generator <NUM> is inserted into the nuclear reactor pressure vessel <NUM> through the through-pipes <NUM> to generate an ultrasonic wave to the waste <NUM> inside the nuclear reactor pressure vessel <NUM>. The ultrasonic generator <NUM> may generate an ultrasonic wave to the waste <NUM> to mix the crushed material or dissolved material of the solid <NUM> contained in the waste <NUM> with the liquid <NUM> contained in the waste <NUM>. When the crushed material or dissolved material of the solid <NUM> is stirred with the liquid <NUM>, the stirred waste <NUM> may have a form of a slurry, and the stirred waste be sucked by using the flexible sucking member <NUM>.

The ultrasonic generator <NUM> may be various types of known ultrasonic generators as long as it may be inserted into the nuclear reactor pressure vessel <NUM> through the through-pipes <NUM> to generate an ultrasonic wave to the waste <NUM> inside the nuclear reactor pressure vessel <NUM>.

The air injector (not shown) is inserted into the nuclear reactor pressure vessel <NUM> through the through-pipes <NUM> to inject air into the waste <NUM> inside the nuclear reactor pressure vessel <NUM>.

Due to the air injected from the air injector (not shown), the crushed or dissolved material of the solid <NUM> contained in the waste <NUM> may be mixed with the liquid <NUM> contained in the waste <NUM>, and the waste <NUM> remaining at a bottom portion of the nuclear reactor pressure vessel <NUM> may be moved to a predetermined position.

The waste <NUM> that is confirmed by the camera <NUM> and is treated as described above by the manipulator <NUM>, the chemical injector <NUM>, the stirrer <NUM>, the ultrasonic generator <NUM>, and the air injector (not shown) may be sucked by the flexible sucking member <NUM> to be moved to the waste treatment part <NUM>.

Referring back to <FIG>, the waste treatment part <NUM> is connected to the suction unit <NUM> and the lower collection part <NUM>. The waste treatment part <NUM> treats the waste <NUM> sucked by the suction unit <NUM> and the falling waste collected by the lower collection part <NUM>.

For example, the waste treatment part <NUM> may decontaminate the waste <NUM>, or may store the waste <NUM> in a waste storage container.

The lower collection part <NUM> is positioned under the nuclear reactor pressure vessel <NUM> with the suction unit <NUM> interposed therebetween. The lower collection part <NUM> overlaps the nuclear reactor pressure vessel <NUM>, and has a two-dimensionally larger area than the suction unit <NUM>.

When the suction unit <NUM> sucks the waste <NUM> inside the nuclear reactor pressure vessel <NUM>, the lower collection part <NUM> collects the falling waste falling from the inside of the nuclear reactor pressure vessel <NUM> through the plurality of through-pipes <NUM>.

The lower collection part <NUM> is connected to the waste treatment part <NUM>, and the falling waste collected by the lower collection part <NUM> is moved to the waste treatment part <NUM> and treated in the waste treatment part <NUM>.

As described above, according to the apparatus <NUM> for treating the waste of the nuclear reactor pressure vessel according to the embodiment, when the waste <NUM> inside the nuclear reactor pressure vessel <NUM> is treated, without forming a separate hole in the nuclear reactor pressure vessel <NUM>, the waste <NUM> inside the nuclear reactor pressure vessel <NUM> is sucked through the through-pipes <NUM> for guiding the in-core instrument (ICI) nozzle by using the suction unit <NUM> to be treated by the waste treatment part <NUM>, so that a separate additional process and equipment for changing a structure of the nuclear reactor pressure vessel <NUM> is not required.

In addition, when treating the waste <NUM> inside the nuclear reactor pressure vessel <NUM>, the apparatus <NUM> for treating the waste of the nuclear reactor pressure vessel according to the embodiment uses the camera <NUM>, the manipulator <NUM>, the chemical injector <NUM>, the stirrer <NUM>, the ultrasonic generator <NUM>, and the air injector (not shown) included in the inserts <NUM> of the suction unit <NUM> to check the position of the solid <NUM> of the waste <NUM> to physically crush or chemically dissolve it to stir it with the liquid <NUM>, so that the waste <NUM> is easily sucked by using the flexible sucking member <NUM> included in the inserts <NUM> to be transferred to the waste treatment part <NUM>, and thus the waste <NUM> may be easily treated in the waste treatment part <NUM>.

In addition, according to the apparatus <NUM> for treating the waste of the nuclear reactor pressure vessel according to the embodiment, when the waste <NUM> inside the nuclear reactor pressure vessel <NUM> is sucked by using the suction unit <NUM>, since the falling waste falling from the inside of the nuclear reactor pressure vessel <NUM> through the plurality of through-pipes <NUM> is collected by the lower collection part <NUM> and transferred to the waste treatment part <NUM>, when the waste <NUM> inside the nuclear reactor pressure vessel <NUM> is treated, contamination of the vicinity of the nuclear reactor pressure vessel <NUM> due to the falling waste is suppressed.

That is, the apparatus <NUM> for treating the waste of the nuclear reactor pressure vessel that easily treats the waste <NUM> inside the nuclear reactor pressure vessel <NUM> when the nuclear facility is decommissioned is provided.

Hereinafter, a method for treating waste of a nuclear reactor pressure vessel according to another embodiment will be described with reference to <FIG>.

The method for treating the waste of the nuclear reactor pressure vessel according to another embodiment may be performed by using the apparatus for treating the waste of the nuclear reactor pressure vessel according to the embodiment described above, but is not limited thereto.

<FIG> illustrates a flowchart of a method for treating waste of a nuclear reactor pressure vessel according to another embodiment.

Referring to <FIG>, first, the suction unit <NUM> is inserted into the nuclear reactor pressure vessel <NUM> through the plurality of through-pipes <NUM> passing through the lower portion of the nuclear reactor pressure vessel <NUM> (S100).

Specifically, the in-core instrument (ICI) nozzle passing through the through-pipes <NUM> of the lower portion of the nuclear reactor pressure vessel <NUM> is removed, and the through-pipes <NUM> are sealed.

The suction unit <NUM> and the lower collection part <NUM> are positioned under the nuclear reactor pressure vessel <NUM>, and the inserts <NUM> included in the suction unit <NUM> are inserted into the nuclear reactor pressure vessel <NUM> through the through-pipes <NUM>.

Next, the waste <NUM> inside the nuclear reactor pressure vessel <NUM> is sucked by using the suction unit <NUM> (S200).

Specifically, the inserts <NUM> included in the suction unit <NUM> are inserted into the nuclear reactor pressure vessel <NUM> through the through-pipes <NUM> to suck the waste <NUM>.

First, the solid <NUM> contained in the waste <NUM> inside the nuclear reactor pressure vessel <NUM> is checked by using the camera <NUM> included in the plurality of inserts <NUM>.

Next, the solid <NUM> contained in the waste <NUM> is physically crushed by using the manipulator <NUM> included in the plurality of inserts <NUM>.

Then, the solid <NUM> contained in the waste <NUM> is chemically dissolved by using the chemical injector <NUM> included in the plurality of inserts <NUM>.

Next, the waste <NUM> is stirred by using the stirrer <NUM> and the ultrasonic generator <NUM> included in the plurality of inserts <NUM> to mix the crushed material or dissolved material of the solid <NUM> included in the waste <NUM> with the liquid <NUM> included in the waste <NUM>.

Next, the waste <NUM> inside the nuclear reactor pressure vessel <NUM> is sucked by using the flexible sucking member <NUM> included in the plurality of inserts <NUM>.

The stirred waste <NUM> may be sucked by using the flexible sucking member <NUM>, and the cooling water contained in the waste <NUM> may be first sucked before the solid <NUM> contained in the waste <NUM> is treated.

After the waste <NUM> is sucked by using the suction unit <NUM>, the through-pipes <NUM> may be sealed.

Next, the falling waste <NUM> falling from the inside of the nuclear reactor pressure vessel <NUM> through the plurality of through-pipes <NUM> is collected by the lower collection part <NUM> positioned under the nuclear reactor pressure vessel <NUM> with the suction unit <NUM> interposed therebetween (S300).

When the suction unit <NUM> sucks the waste <NUM> inside the nuclear reactor pressure vessel <NUM>, the falling waste falling from the inside of the nuclear reactor pressure vessel <NUM> through the plurality of through-pipes <NUM> is collected by using the lower collection part <NUM>.

Next, the waste <NUM> and the falling waste are treated by using the waste treatment part <NUM> connected to the suction unit <NUM> and to the lower collection part <NUM> (S400).

Specifically, the waste <NUM> sucked by the suction unit <NUM> and the falling waste collected by the lower collection part <NUM> are transferred to the waste treatment part <NUM> connected to the suction unit <NUM> and to the lower collection part <NUM>, so that the waste <NUM> is decontaminated or the waste <NUM> is stored and treated in a waste storage container.

As described above, according to the method for treating the waste of the nuclear reactor pressure vessel according to another embodiment, when the waste <NUM> inside the nuclear reactor pressure vessel <NUM> is treated, without forming a separate hole in the nuclear reactor pressure vessel <NUM>, the waste <NUM> inside the nuclear reactor pressure vessel <NUM> is sucked through the through-pipes <NUM> for guiding the in-core instrument (ICI) nozzle by using the suction unit <NUM> to be treated by the waste treatment part <NUM>, so that a separate additional process for changing a structure of the nuclear reactor pressure vessel <NUM> is not required.

In addition, when treating the waste <NUM> inside the nuclear reactor pressure vessel <NUM>, the method for treating the waste of the nuclear reactor pressure vessel according to another embodiment uses the camera <NUM>, the manipulator <NUM>, the chemical injector <NUM>, the stirrer <NUM>, the ultrasonic generator <NUM>, and the air injector (not shown) included in the inserts <NUM> of the suction unit <NUM> to check the position of the solid <NUM> of the waste <NUM> to physically crush or chemically dissolve it to stir it with the liquid <NUM>, so that the waste <NUM> is easily sucked by using the flexible sucking member <NUM> included in the inserts <NUM> to be transferred to the waste treatment part <NUM>, and thus the waste <NUM> may be easily treated in the waste treatment part <NUM>.

In addition, according to the method for treating the waste of the nuclear reactor pressure vessel according to another embodiment, when the waste <NUM> inside the nuclear reactor pressure vessel <NUM> is sucked by using the suction unit <NUM>, since the falling waste falling from the inside of the nuclear reactor pressure vessel <NUM> through the plurality of through-pipes <NUM> is collected by the lower collection part <NUM> and transferred to the waste treatment part <NUM>, when the waste <NUM> inside the nuclear reactor pressure vessel <NUM> is treated, contamination of the vicinity of the nuclear reactor pressure vessel <NUM> due to the falling waste is suppressed.

That is, the method for treating the waste of the nuclear reactor pressure vessel that easily treats the waste <NUM> inside the nuclear reactor pressure vessel <NUM> when the nuclear facility is decommissioned is provided.

While this invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and arrangements included within the scope of the appended claims.

Claim 1:
An apparatus for treating waste of a nuclear reactor pressure vessel (<NUM>) when decommissioning a nuclear facility, comprising:
a suction unit (<NUM>) suitable to be inserted into the nuclear reactor pressure vessel (<NUM>) through a plurality of through-pipes (<NUM>) passing through a lower portion of the nuclear reactor pressure vessel to suck waste (<NUM>) inside the nuclear reactor pressure vessel
a waste treatment part (<NUM>) connected to the suction unit (<NUM>) to treat the waste:
and a lower collection part (<NUM>) connected to the waste treatment part (<NUM>) the lower collection part (<NUM>) to be positioned under the nuclear reactor pressure vessel (<NUM>) with the suction unit (<NUM>) therebetween.