System for sensing UF6 gas leak in nuclear fuel manufacturing process

Abstract

Disclosed is a system for sensing a UF.sub.6 gas leak in a nuclear fuel manufacturing process. The system is configured to sense whether or not there is a UF.sub.6 gas leak by optically detecting UO.sub.2F.sub.2 in a solid state generated due to a reaction with outside air. This allows prevention of damage to a detection apparatus by means of sensing in a non-contact manner whether or not there is a UF.sub.6 gas leak. Further, the system extends the mechanical life of and reduces the maintenance and repair costs for the detection apparatus.

Claims

1. A system for sensing a UF6 gas leak in a nuclear fuel manufacturing process, the system comprising: an autoclave connected to a nitrogen supply pipe installed on one side of the autoclave and to a nitrogen discharge pipe installed on an opposite side of the autoclave, nitrogen inflow and nitrogen discharge being provided through the nitrogen supply pipe and the nitrogen discharge pipe, respectively, a cylinder charged with uranium hexafluoride (UF.sub.6) in a solid state, the cylinder being disposed in the autoclave, wherein the autoclave vaporizes the UF.sub.6 inside the cylinder through heating the nitrogen inside the autoclave; and a detection unit, the detection unit configured to sense whether the UF.sub.6 is mixed with the nitrogen discharged after circulating inside the autoclave, thereby sensing whether the UF.sub.6 leaks inside the autoclave, and the detection unit configured to generate UO.sub.2F.sub.2 particles and HF by allowing the UF.sub.6 to react with outside air; wherein the detection unit comprises an outside air injection pipe for injecting the outside air into the detection unit and a measuring instrument for optically sensing the UO.sub.2F.sub.2 particles in a solid state generated by reacting the outside air with the UF.sub.6, thereby allowing non-contact UF.sub.6 leak detection to be made.

2. The system of claim 1, wherein the nitrogen discharge pipe is provided with a filter configured to filter out the UO.sub.2F.sub.2 particles generated in the detection unit.

3. The system of claim 1, wherein the nitrogen discharge pipe is provided with an HF sensor configured to sense the HF having generated in the detection unit.

4. The system of claim 1, wherein the measuring instrument is a device configured to optically sense particles floating in the air in the detection unit.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) FIG. 1 is a view showing a configuration of a UF.sub.6 vaporization process in a nuclear fuel manufacturing process.

(2) FIG. 2 is a view of a main part showing a detector for sensing whether UF.sub.6 leaks in a UF.sub.6 vaporization process in a nuclear fuel manufacturing process according to a related art.

(3) FIG. 3 is a view showing a main part of a system for sensing a UF.sub.6 gas leak in a nuclear fuel manufacturing process according to an exemplary embodiment of the present disclosure.

(4) FIG. 4 is a view showing a configuration of the system for sensing a UF.sub.6 gas leak in the nuclear fuel manufacturing process according to the exemplary embodiment of the present disclosure.

(5) FIG. 5 is a flow chart showing a process in which detection of UF.sub.6, generated during the nuclear fuel manufacturing process according to the exemplary embodiment of the present disclosure, is accomplished through the system for sensing a UF.sub.6 gas leak.

DETAILED DESCRIPTION

(6) Terms and words used in present specification and claims are not limited to a conventional or dictionary meaning and should be interpreted as having a meaning and concept consistent with the technical idea of the present disclosure on the basis of the principle that an inventor may appropriately define a concept of terms in order to describe the disclosure in the best way.

(7) Hereinafter, a system for sensing a UF.sub.6 gas leak in a nuclear fuel manufacturing process according to an exemplary embodiment of the present disclosure will be described with reference to FIGS. 3 and 4.

(8) Prior to the description, since a configuration and an operation of an autoclave 20 is a well-known technology, a detailed illustration and description will be omitted.

(9) The system for sensing a UF.sub.6 gas leak in the nuclear fuel manufacturing process is configured, as shown in FIGS. 3 and 4, to include a detection unit 100 and a filter 200 and may include an HF sensor 300.

(10) The detection unit 100 serves to sense in a non-contact manner whether UF.sub.6 is contained in nitrogen discharged from the autoclave 20 and is installed at a nitrogen discharge pipe 50.

(11) The detection unit 100 may be installed at a main pipe of the nitrogen discharge pipe 50 as shown in FIG. 4.

(12) As the detection unit 100 is installed at the nitrogen discharge pipe 50, nitrogen discharged through the nitrogen discharge pipe 50 is discharged via the detection unit 100.

(13) The detection unit 100 may allow the nitrogen discharged from the autoclave 20 to react with the outside air, thereby sensing whether or not UF.sub.6 leaks.

(14) That is, when UF.sub.6 is contained in the gas discharged through the nitrogen discharge pipe 50, the UF.sub.6 generates UO.sub.2F.sub.2 and HF while reacting with outside air in the detection unit 100.

(15) To this end, the detection unit 100 includes a reaction unit 110 providing a reaction space, an outside air injection pipe 120, which is a conduit through which injection of the outside air into the reaction unit 110 is accomplished, and a measuring instrument 130 for measuring UO.sub.2F.sub.2 reacted in the reaction unit 110.

(16) The reaction unit 110 provides a space in which reaction of nitrogen and the outside air is accomplished in the process of discharging the high-temperature nitrogen discharged from the autoclave 20 through the nitrogen discharge pipe 50 as described above and is installed at the nitrogen discharge pipe 50.

(17) In this case, an outside air injection pipe 120 is installed at the reaction unit 110 so as to allow the outside air to be injected into the reaction unit 110 for the reaction of UF.sub.6.

(18) In addition, the measuring instrument 130 serves to measure the UO.sub.2F.sub.2 generated while the reaction is accomplished in the reaction unit 110.

(19) For the leakage of UF.sub.6 gas, while the sensor 61 electronically senses HF that is in a gaseous state conventionally, the present disclosure provides a technical configuration for optically measuring UO.sub.2F.sub.2 that is in a solid state.

(20) That is, in the reaction unit 110, UO.sub.2F.sub.2, which is solid particles in a form of fumes, and liquid HF are generated through the reaction of UF.sub.6 with outside air. At this time, by optically measuring the solid UO.sub.2F.sub.2, it is possible to sense whether UF.sub.6 gas leaks.

(21) In this case, the reaction unit 110 is provided of a transparent material so that an inside of the reaction unit 110 may be seen, and the measuring instrument 130 may be installed outside the reaction unit 110.

(22) Accordingly, the measuring instrument 130 may sense whether the UF.sub.6 leaks from the outside of the reaction unit 110 without contacting the material generated in the reaction unit 110.

(23) The measuring instrument 130 may be provided as a device for optically sensing particles floating in the air.

(24) For example, the measuring instrument 130 may be provided as a floating particle counter or a photosensor.

(25) Next, the filter 200 serves to filter out the UO.sub.2F.sub.2 discharged through the nitrogen discharge pipe 50, thereby preventing the conduit of the nitrogen discharge pipe 50 from being blocked.

(26) That is, when UF.sub.6 is contained in the nitrogen discharged through the nitrogen discharge pipe 50, the conduit of the nitrogen discharge pipe 50 may be blocked by the UO.sub.2F.sub.2 due to the generation of UO.sub.2F.sub.2, so UO.sub.2F.sub.2 is filtered through the filter 200, whereby the conduit of the nitrogen discharge pipe 50 is prevented from being blocked.

(27) Accordingly, even when there is a leak of UF.sub.6, UO.sub.2F.sub.2 particles pass through the detection unit 100 and are filtered by the filter 200, and only nitrogen and HF are discharged passing through the filter 200.

(28) Next, the HF sensor 300 serves to sense the HF passing through the filter 200.

(29) The HF sensor 300 plays an auxiliary role in sensing whether UF.sub.6 leaks.

(30) That is, the present disclosure optically senses UO.sub.2F.sub.2 particles through the measuring instrument 130, but when installation of the HF sensor 300 is parallelly established, even when a malfunction or failure of the measuring instrument 130 occurs, it may sense whether UF.sub.6 leaks through the HF sensor 300.

(31) Hereinafter, a process of sensing a UF.sub.6 leak is accomplished by the system for sensing a UF.sub.6 gas leak in the nuclear fuel manufacturing process configured as described above will be described with reference to FIG. 5.

(32) The vaporization process is performed in S100 through the autoclave 20 of the nuclear fuel reconversion process.

(33) Nitrogen is introduced into the autoclave 20, and the nitrogen heated by the heater 30 heats the cylinder 10 filled with solid UF.sub.6 to vaporize UF.sub.6.

(34) Thereafter, the gas vaporized in the cylinder 10 is transferred to a subsequent process.

(35) Next, the nitrogen that heated the cylinder 10 while circulating in the autoclave 20 is discharged in S200 through the nitrogen discharge pipe 50.

(36) At this time, the nitrogen is discharged through the reaction unit 110 of the detection unit 100 whereas the outside air is introduced into the reaction unit 110 in S300 through the outside air inlet pipe 120.

(37) Accordingly, the outside air and nitrogen are mixed in the reaction unit 110.

(38) At this time, when UF.sub.6 leaks and being discharged with nitrogen together, UO.sub.2F.sub.2 and HF are generated in S400 through the above-described reaction equations.

(39) At this time, UO.sub.2F.sub.2 is a particle in a solid state and is sensed in S500 through the measuring instrument 130 installed outside the reaction unit 110.

(40) In this way, when UO.sub.2F.sub.2 is sensed through the measuring instrument 130, the administrator is able to quickly recognize it through an alarm or light emission of warning light to perform a series of post-processing.

(41) Meanwhile, the UO.sub.2F.sub.2 and HF reacted in the reaction unit 110 are continuously discharged along the nitrogen discharge pipe 50.

(42) At this time, UO.sub.2F.sub.2 is filtered out in S600 through the filter 200, and nitrogen and HF are discharged through the filter 200.

(43) At this time, the HF sensor 300 senses in S700 the HF transferred through the nitrogen discharge pipe 50 and let the manager recognize it.

(44) When the UO.sub.2F.sub.2 is detected through the measuring instrument 130, the HF will be detected also through the HF sensor 300.

(45) Even when the UO.sub.2F.sub.2 is not detected due to the failure of the measuring instrument 130, the UF.sub.6 detection error does not occur as the HF sensor 300 senses the HF.

(46) Hereby, the process of sensing the UF.sub.6 leak is completed.

(47) As described so far, the system for sensing a UF.sub.6 gas leak according to the present disclosure may sense whether UF.sub.6 leaks through the optical detection of the UO.sub.2F.sub.2 by generating the UO.sub.2F.sub.2 particles in a solid state through the reaction with the outside air.

(48) As the UF.sub.6 leak detection is performed through such a non-contact method, damage to the detection apparatus may be prevented, and the maintenance cost of the detection apparatus may be reduced.

(49) In the above, the present disclosure has been described in detail with respect to the described embodiments, but it is obvious to those skilled in the art that various alterations and modifications are possible within the scope of the technical idea of the present disclosure. In addition, it is natural that such alterations and modifications are included in the appended claims.

(50) TABLE-US-00001 <Description of the Reference Numerals in the Drawings> 100: detection unit 110: reaction unit 120: outside air injection pipe 130: measuring instrument 200: filter 300: HF sensor

(51) All references, including publications, patent applications, and patents cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein.

(52) The use of the terms “a” and “an” and “the” and similar referents in the context of describing the invention (especially in the context of the following claims) is to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The terms “comprising,” “having,” “including,” and “containing” are to be construed as open-ended terms (i.e., meaning “including, but not limited to,”) unless otherwise noted. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention.

(53) Preferred embodiments of this invention are described herein, including the best mode known to the inventors for carrying out the invention. Variations of those preferred embodiments may become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventors expect skilled artisans to employ such variations as appropriate, and the inventors intend for the invention to be practiced otherwise than as specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context.