Self-powered nuclear radiation detector and method for correcting temperature-related changes in the output signal of a self-powered nuclear radiation detector

Abstract

A self-powered nuclear radiation detector. The self-powered nuclear radiation detector includes a cable assembly, a temperature compensation assembly, and a metallic outer sheath. The cable assembly includes a metallic signal lead, an insulating material surrounding the metallic signal lead, and a metallic sheath surrounding the insulating material. The temperature compensation assembly includes a second metallic signal lead, a second insulating material surrounding the second metallic signal lead, and a second metallic sheath surrounding the second insulating material. The metallic outer sheath surrounds the cable assembly and the temperature compensation assembly.

Description

[Background technology]

[0001] (CROSS-REFERENCE TO RELATED APPLICATIONS) This application claims the benefit under 35 U.S.C. §119(e) of earlier-filed U.S. Provisional Patent Application No. 63 / 048,476, filed July 6, 2020, entitled "SELF-POWERED NUCLEAR RADIATION DETECTOR AND METHOD OF CORRECTING A TEMPERATURE-RELATED CHANGE OF AN OUTPUT SIGNAL OF SAME," the contents of which are incorporated herein by reference in their entirety.

[0002] Some nuclear reactors utilize self-powered nuclear radiation detectors (SPNRDs) to measure nuclear radiation levels near or within the reactor core. The measured levels can then be used to indicate reactor power levels and reactor power distribution, and the measured levels can be monitored to assist in reactor control.

[0003] FIG. 1 shows a cross-section of a prior art self-powered nuclear radiation detector 10. The self-powered nuclear radiation detector 10 includes a conductive element 12, an insulating material 14, such as highly compressed magnesium oxide, surrounding the conductive element 12, and a metallic sheath 16 surrounding the insulating material 14 and, in turn, the conductive element 12. In various applications, the conductive element 12 may be referred to as an emitter, and the metallic sheath 16 may be referred to as a current collector. The self-powered nuclear radiation detector 10 also includes a cable assembly 20 configured to carry an output signal current of the self-powered nuclear radiation detector 10. The cable assembly 20 includes a metallic signal lead 22, an insulating material 24 surrounding the metallic signal lead 22, and a metallic sheath 26 surrounding the insulating material 24 and, in turn, the metallic signal lead 22. The metallic signal lead 22 is electrically coupled to the conductive element 12, and the composition of the metallic signal lead 22 may be similar to or the same as the composition of the conductive element 12. The composition of insulating material 24 may be similar to or the same as the composition of insulating material 14. Metal sheath 26 is in contact with metal sheath 16, and the composition of metal sheath 26 may be similar to or the same as the composition of metal sheath 16. Because of the composition and arrangement of cable assembly 20, cable assembly 20 may be referred to as a mineral insulated cable assembly.

[0004] The detector 10 is considered "self-powered" because it does not require an electrical potential to be applied across the conductive element 12 and the metallic sheath 16. Rather, the output signal of the detector 10 is generated as a function of the different radiation response characteristics of the materials of the conductive element 12 and the metallic sheath 16. Generally, the material of the conductive element 12 is selected as the more radiation-responsive material, and may be selected as a neutron-responsive or gamma-responsive material depending on the particular type of application and nuclear reactor. During operation, radiation from the reactor passes through the metallic sheath 16, through the insulating material 14, and through the conductive element 12. Due to the different radiation responses of the different materials, an output signal (i.e., a current) is induced that is applied to and carried by the metallic signal lead 22 of the cable assembly 20. The output signal is a function of the radiation level and the reactor core. The output signal can be measured and used to indicate the reactor power level and the reactor power distribution.

[0005] Changes in the temperature of the environment surrounding insulating material 14 and insulating material 24, which may be quite high, can change the magnitude of the output signal applied to and carried by metallic signal lead 22. Such changes in the magnitude of the output signal caused by changes in the temperature surrounding insulating material 14 and insulating material 24 can appear to change the relationship between the output signal and the reactor power level and / or reactor power distribution. If this "temperature effect" is not properly accounted for, it can cause the output signal carried by metallic signal lead 22 to reflect inaccurate values ​​of the reactor power level and / or reactor power distribution. Such inaccuracies can lead to unsafe operation of the nuclear reactor. The above-mentioned "temperature effect" is of particular concern in nuclear reactors with high coolant / moderator temperatures, such as high-temperature gas reactors and liquid metal reactors (including liquid metal fast reactors). The above-mentioned "temperature effect" is also of concern in nuclear reactor designs operating at relatively low power levels, where the output signal level of the associated detector 10 is also relatively low. [Brief explanation of the drawings]

[0006] The novel features of the aspects described herein are set forth with particularity in the appended claims. The aspects, however, both as to organization and method of operation, may be better understood by reference to the following description taken in conjunction with the accompanying drawings, in which:

[0007] [Figure 1] 1 shows a cross section of a prior art self-powered nuclear radiation detector.

[0008] [Figure 2] 1 illustrates a cross section of a self-powered nuclear radiation detector according to at least one embodiment of the present disclosure.

[0009] [Figure 3] 3 illustrates a cross section of a temperature compensation assembly of the self-powered nuclear radiation detector of FIG. 2 in accordance with at least one embodiment of the present disclosure.

[0010] [Figure 4] 4 illustrates a measurement device electrically coupled to the temperature compensation assembly of FIG. 3 in accordance with at least one embodiment of the present disclosure.

[0011] [Figure 5] 3 illustrates a method of applying temperature change correction to the electrical output signal of the self-powered nuclear radiation detector of FIG. 2 in accordance with at least one embodiment of the present disclosure.

[0012] [Figure 6] 3 illustrates another method of applying temperature change correction to the electrical output signal of the self-powered nuclear radiation detector of FIG. 2 in accordance with at least one embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0013] It will be appreciated that at least some of the drawings and descriptions of the present invention have been simplified to show elements relevant to a clear understanding of the present invention, but for clarity, the exclusion of other elements that those skilled in the art will understand may comprise part of the present invention. However, because such elements are well known in the art and do not facilitate a better understanding of the present invention, descriptions of such elements are not provided herein.

[0014] In the following detailed description, reference is made to the accompanying drawings, which form a part hereof. In the drawings, like symbols and reference characters typically identify like components throughout the several views, unless the context dictates otherwise. The illustrative embodiments described in the detailed description, drawings, and claims are not intended to be limiting. Other embodiments may be utilized, and other changes may be made, without departing from the scope of the technology described herein.

[0015] The following description of specific examples of the technology should not be used to limit its scope. Other examples, features, aspects, embodiments, and advantages of the technology will become apparent to those skilled in the art from the following description. This is by way of example and one of the best modes contemplated for carrying out the technology. As will be realized, the technology described herein is capable of other different and obvious aspects without departing from the technology. Accordingly, the drawings and description should be regarded as illustrative in nature, and not restrictive.

[0016] It is further understood that any one or more of the teachings, expressions, aspects, embodiments, examples, etc. described herein can be combined with any one or more of the other teachings, expressions, aspects, embodiments, examples, etc. described herein. Accordingly, the teachings, expressions, aspects, embodiments, examples, etc. described below should not be viewed in isolation from one another. Various suitable ways in which the teachings herein can be combined will be readily apparent to those of skill in the art in light of the teachings herein. Such modifications and variations are intended to be included within the scope of the claims.

[0017] Before describing various aspects of the self-powered nuclear radiation detector in detail, it should be noted that the various aspects disclosed herein are not limited in their application or use to the details of construction and arrangement of parts illustrated in the accompanying drawings and description. Rather, the disclosed aspects may be situated in or incorporated into other aspects, embodiments, variations, and modifications thereof, and may be practiced or carried out in various ways. Accordingly, the aspects of the self-powered nuclear radiation detector disclosed herein are exemplary in nature and are not intended to limit their scope or application. Furthermore, unless otherwise indicated, the terms and phrases used herein have been chosen for the purpose of describing the aspects for the convenience of the reader and are not intended to limit their scope. In addition, it should be understood that any one or more of the disclosed aspects, aspect expressions, and / or example embodiments of these aspects can be combined, without limitation, with any one or more of the other disclosed aspects, aspect expressions, and / or example embodiments of these aspects.

[0018] It should also be understood that in the following description, terms such as inward, outward, upward, downward, above, top, bottom, left, right, side, interior, exterior, etc., are terms of convenience and should not be construed as limiting. The terms used herein are not intended to be limiting, inasmuch as the devices described herein, or portions thereof, may be mounted or utilized in other orientations. Various aspects are described in more detail with reference to the drawings.

[0019] 2 illustrates a cross section of a self-powered nuclear radiation detector 30 according to at least one embodiment of the present disclosure. The self-powered nuclear radiation detector 30 is configured to generate an output signal (i.e., current) that provides an accurate indication of the power level and power distribution of a nuclear reactor, regardless of the temperature proximate to various components of the self-powered nuclear radiation detector 30. The self-powered nuclear radiation detector 30 is similar to, but different from, the self-powered nuclear radiation detector 10. The self-powered nuclear radiation detector 30 is similar to the self-powered nuclear radiation detector 10 in that the self-powered nuclear radiation detector 30 includes a conductive element 32, an insulating material 34 (e.g., highly compressed magnesium oxide) surrounding the conductive element 32, and a metal sheath 36 that surrounds the insulating material 34 and, in turn, the conductive element 32.

[0020] The self-powered nuclear radiation detector 30 is also similar to the self-powered nuclear radiation detector 10 in that the self-powered nuclear radiation detector 30 also includes a cable assembly 40, which includes a metal signal lead 42, an insulating material 44 (e.g., highly compressed magnesium oxide) surrounding the metal signal lead 42, and a metal sheath 46 surrounding the insulating material 44 and, in turn, the metal signal lead 42. According to various embodiments, the metal signal lead 42 is configured as a cylindrically shaped wire having a longitudinal axis, a radius, a diameter, and an associated length. The metal signal lead 42 is electrically coupled to the conductive element 32, and the composition of the metal signal lead 42 may be similar to or the same as the composition of the conductive element 32. According to various embodiments, the metal signal lead 42 includes cobalt, cadmium, rhodium, vanadium, and / or combinations thereof. The composition of the insulating material 44 may be similar to or the same as the composition of the insulating material 34. The metallic sheath 46 is in contact with the metallic sheath 36, and the composition of the metallic sheath 46 may be similar or the same as the composition of the metallic sheath 36. Due to the composition and arrangement of the cable assembly 40, the cable assembly 40 may be referred to as a mineral-insulated cable assembly. During operation, radiation from the reactor passes through the metallic sheath 36, through the insulating material 34, and through the metallic signal lead 32. Due to the different radiation responses of different materials, an output signal (i.e., current) is induced. The induced current is applied to and carried by the metallic signal lead 42 of the cable assembly 40.

[0021] The self-powered nuclear radiation detector 30 differs from the self-powered nuclear radiation detector 10 in that the self-powered nuclear radiation detector 30 further includes a temperature compensation assembly 50 and a metallic outer sheath 52. The metallic outer sheath 52 surrounds the temperature compensation assembly 50, the metallic sheath 36, and the metallic sheath 46, and thus surrounds all of the other above-described components of the self-powered nuclear radiation detector 30. The composition of the metallic outer sheath 52 may be similar to or the same as the composition of the metallic sheath 36 and / or the composition of the metallic sheath 46. The temperature compensation assembly 50 is described in detail below. Also, as shown in FIG. 2 , according to various embodiments, the self-powered nuclear radiation detector 30 may also include a material 59 positioned between the temperature compensation assembly 50 and the cable assembly 40 and between the temperature compensation assembly 50 and the metallic sheath 36 (and thus between the temperature compensation assembly 50 and the conductive element 32 and between the temperature compensation assembly 50 and the insulating material 34). According to various embodiments, material 59 may include aluminum oxide (Al2O3), helium, or another suitable material.

[0022] 3 illustrates a cross-section of a temperature-compensating assembly 50 according to at least one embodiment of the present disclosure. The temperature-compensating assembly 50 includes a metallic signal lead 54, an insulating material 56 surrounding the metallic signal lead 54, and a metallic sheath 58 surrounding the insulating material 56 and, in turn, the metallic signal lead 54. According to various embodiments, the metallic signal lead 54 is configured as a cylindrically shaped wire having a longitudinal axis, a radius, a diameter, and an associated length. The composition of the metallic signal lead 54 is the same as the composition of the metallic signal lead 42, the composition of the insulating material 56 is the same as the composition of the insulating material 44, and the composition of the metallic sheath 58 is the same as the composition of the metallic sheath 46. Due to the composition and arrangement of the temperature-compensating assembly 50, the temperature-compensating assembly 50 may be referred to as a mineral-insulated cable assembly. During operation, radiation from the reactor passes through the metal sheath 58, through the insulating material 56, and through the metal signal lead 54, and the different radiation responses to different materials result in an induced output signal (i.e., current) that is carried by the metal signal lead 54 of the temperature compensation assembly 50.

[0023] As shown in FIG. 2 , the temperature compensation assembly 50 is positioned adjacent to and parallel to the cable assembly 40. The size and configuration of the temperature compensation assembly 50 is similar to or the same (e.g., equal to) the size and configuration of the cable assembly 40. Although the overall length of the temperature compensation assembly 50 is shown in FIG. 2 as being slightly smaller than the overall length of the cable assembly 40 (the slight difference in length can be a few microns), it will be understood that the self-powered nuclear radiation detector 30 can be configured such that the overall length of the temperature compensation assembly 50 is the same (e.g., equal to) the overall length of the cable assembly 40. Thus, the radial dimensions of the temperature compensation assembly 50 are similar to or the same (e.g., equal to) the corresponding radial dimensions of the cable assembly 40. Additionally, the radial dimensions of each component of the temperature-compensation assembly 50 (i.e., the metal signal lead 54, the insulating material 56, and the metal sheath 58) are similar to or the same (e.g., equal to) the corresponding radial dimensions of each component of the cable assembly 40 (i.e., the metal signal lead 42, the insulating material 44, and the metal sheath 46). For example, the radius or diameter of the metal signal lead 54 may be the same (e.g., equal to) the radius or diameter of the metal signal lead 42, respectively. Furthermore, the overall length of the temperature-compensation assembly 50 is similar to or the same (e.g., equal to) the overall length of the cable assembly 40. Furthermore, the overall length of each component of the temperature-compensation assembly 50 (i.e., the metal signal lead 54, the insulating material 56, and the metal sheath 58) are similar to or the same (e.g., equal to) the corresponding overall length of each component of the cable assembly 40 (i.e., the metal signal lead 42, the insulating material 44, and the metal sheath 46). In view of the above, it will be appreciated that, according to various embodiments, the temperature compensation assembly 50 and the cable assembly are matched to one another.

[0024] Each component of the temperature compensation assembly 50 and each component of the cable assembly 40 are subjected to the same radiation and the same temperature environment. In other words, each component of the temperature compensation assembly 50 will experience the same radiation and associated temperature environment as each component of the cable assembly 40. Also, because both the metal sheath 58 of the temperature compensation assembly 50 and the metal sheath 46 of the cable assembly 40 are in electrical contact with the metal outer sheath 52, a common ground is maintained between the two.

[0025] Considering the above, for embodiments in which the radial dimensions and overall length of the temperature compensation assembly 50 and the cable assembly 40 are the same, the leakage resistance of the temperature compensation assembly 50 (i.e., the electrical resistance between the metal signal lead 54 and ground) varies in the same way as the leakage resistance of the cable assembly 40 (i.e., the electrical resistance between the metal signal lead 42 and ground). (1) The change in resistance (ΔR TCA ), and (2) the change in temperature of the insulating material 56 and / or the temperature compensation assembly 50 from a reference temperature (ΔT TCA ) can be measured at different temperatures using standard measurement methods known by those skilled in the art. TCA ), where the different temperatures encompass the expected operating temperature range of the self-powered nuclear radiation detector 30.

[0026] Furthermore, (1) the change in the output signal / current of the cable assembly 40 at a constant radiation level (ΔI CA ) and (2) the insulation resistance (ΔR CA ) can be determined by (a) exposing the cable assembly 40 to suitable nuclear radiation (e.g., neutron radiation, gamma radiation) from a stationary source, and (b) (i) exposing the electrical output signal / current (ΔI CA ), and (ii) the insulation resistance (R CA) can be determined by measuring both the

[0027] Next, the temperature compensation current (I TC ) is (1) the output current (I CA ), and (2)(a) the insulation resistance (ΔR TCA ) and (b)(i) the change in the output current of the cable assembly 40 (ΔI CA ) and (ii) the measured change in leakage resistance (ΔR CA ) and the product of the slope of the calibration relationship between σ and σ, which can be expressed as a function of time using the following equation:

number

[0028] Additionally, the induced current (I) in the metal signal lead 54 of the temperature compensation assembly 50 resulting from gamma radiation TCA ) is a cable assembly 40 (I CA ) from the current measured at the metallic signal lead 42 of the temperature compensation assembly 50 to obtain the gamma radiation induced current (I TCA ) can be used to filter the gamma-induced portion of the current in the metal signal lead 42 of the cable assembly 40. This is an important capability if the "corrected" output signal of the self-powered nuclear radiation detector 30 is one that reflects neutron interactions. The total corrected current from the neutron sensitive self-powered nuclear radiation detector 30 can be expressed by the following equation:

number

[0029] FIG. 4 illustrates a measurement device 60 electrically coupled to the temperature compensation assembly 50 of FIG. 3 in accordance with at least one embodiment of the present disclosure. The measurement device 60 may be implemented, for example, as a digital multimeter or a megohmmeter device and may be utilized to measure and monitor the leakage resistance of the temperature compensation assembly 50 in real time and / or continuously. Generally, a megohmmeter device is utilized when the input voltage is relatively high. By positioning one probe 62 of the measurement device 60 on the metal signal lead 54 of the temperature compensation assembly 50 and another probe 64 of the measurement device 60 at various locations on the metal sheath 58 of the temperature compensation assembly 50 (e.g., the locations labeled R1, R2, R3, etc. in FIG. 4 ), the total leakage resistance of the temperature compensation assembly 50 may be determined based on the following equation:

number

[0030] 5 illustrates a method 70 for correcting for changes in output current of a self-powered nuclear radiation detector 30, according to at least one embodiment of the present disclosure. The changes in output current may be caused by changes in temperature proximate to the self-powered nuclear radiation detector 30, which can cause changes in the insulation value of the cable assembly 40 of the self-powered nuclear radiation detector 30, changes in the leakage resistance of the cable assembly 40 of the self-powered nuclear radiation detector 30, etc.

[0031] For method 70, the insulation resistance of the temperature compensation assembly 50 is measured 72 at a plurality of different temperatures. The temperature of the insulating material 56 of the temperature compensation assembly 50 is also measured 74 at a plurality of different temperatures. According to various embodiments, each measurement 72, 74 may be performed simultaneously and / or together. Once the insulation resistance and temperature are measured, a relationship between the two may be determined 76. The determined relationship may then be used to determine a “temperature correction” value 78 of the output current of the self-powered nuclear radiation detector 30 to account for changes in the value of the output current of the self-powered nuclear radiation detector 30 caused only by the temperature proximate to the self-powered nuclear radiation detector 30. The corrected output current may then be used to determine a reactor power level and a reactor power distribution 80. According to various embodiments, the determination of the “temperature correction” value 78 of the output current of the self-powered nuclear radiation detector 30 and the determination of the reactor power level and the reactor power distribution 80 may be implemented by control circuitry (not shown) associated with the nuclear reactor. Utilizing a corrected output current reduces temperature related errors associated with determining reactor power levels and reactor power distribution.

[0032] 6 illustrates a method 100 for correcting for changes in output current of a self-powered nuclear radiation detector 30, according to at least one embodiment of the present disclosure. The changes in output current may be caused by changes in temperature proximate to the self-powered nuclear radiation detector 30, which may cause changes in the insulation value of the cable assembly 40 of the self-powered nuclear radiation detector 30, changes in the leakage resistance of the cable assembly 40 of the self-powered nuclear radiation detector 30, etc.

[0033] For method 100, cable assembly 40 is exposed 102 to suitable nuclear radiation (e.g., neutron radiation, gamma radiation) from a stationary source (e.g., a nuclear reactor). CA The output current of the cable assembly 40 (R CA The insulation resistance of the temperature compensation assembly 50 (R TCA ) is measured at multiple different temperatures 108. According to various embodiments, one or more of the respective measurements 104, 106, 108 may be performed simultaneously and / or together.

[0034] The measured change in output current of the cable assembly 40 (ΔI CA ) and the measured change in insulation resistance of the cable assembly 40 (ΔR CA ) is determined 110. The product of the slope and the measured change in insulation resistance (ΔR TCA ) is determined 112. The product is then multiplied by the output current (I CA ), a "temperature correction" value for the output current of the self-powered nuclear radiation detector 30 is determined 114. The "temperature correction" value for the output current of the self-powered nuclear radiation detector 30 accounts for changes in the value of the output current of the self-powered nuclear radiation detector 30 caused only by the temperature proximate to the self-powered nuclear radiation detector 30. The temperature corrected output current may then be utilized to determine the reactor power level and the reactor power distribution 116. According to various aspects, the determination of the "temperature correction" value for the output current of the self-powered nuclear radiation detector 30 114 and the determination of the reactor power level and the reactor power distribution 116 may be implemented by control circuitry (not shown) associated with the nuclear reactor. By utilizing the temperature corrected output current, temperature related errors associated with determining the reactor power level and the reactor power distribution are mitigated.

[0035] In view of the above, it will be appreciated that the configuration of the self-powered nuclear radiation detector 30 incorporates the basic configuration of existing types of self-powered nuclear radiation detectors (e.g., the self-powered nuclear radiation detector 10), thereby enabling the use of the self-powered nuclear radiation detector 30 as an in-core detector in reactor designs having very high operating temperatures without losing radiation measurement accuracy. The configuration of the self-powered nuclear radiation detector 30 allows the self-powered nuclear radiation detector 30 to be accurately used as an in-core detector in relatively low nuclear radiation reactor environments at very high temperatures. The configuration of the self-powered nuclear radiation detector 30 also allows for continuous compensation of the gamma radiation-induced portion of the output signal of the self-powered nuclear radiation detector 30 when the metal signal lead 42 is made of a neutron-sensitive material such as rhodium or vanadium.

[0036] Example

[0037] Example 1 - A self-powered nuclear radiation detector is provided. The self-powered nuclear radiation detector includes a cable assembly, a temperature compensation assembly, and a metallic outer sheath. The cable assembly includes a metallic signal lead, an insulating material surrounding the metallic signal lead, and a metallic sheath surrounding the insulating material. The temperature compensation assembly includes a second metallic signal lead, a second insulating material surrounding the second metallic signal lead, and a second metallic sheath surrounding the second insulating material. The metallic outer sheath surrounds the cable assembly and the temperature compensation assembly.

[0038] Example 2 - A self-powered nuclear radiation detector as described in Example 1, wherein the temperature compensation assembly is adjacent to and parallel to the cable assembly.

[0039] Example 3 - A self-powered nuclear radiation detector as described in example 1 or 2, wherein the overall length of the temperature compensation assembly is equal to the overall length of the cable assembly.

[0040] Example 4 - The self-powered nuclear radiation detector of Examples 1, 2, or 3, wherein the overall length of the second metallic signal lead is equal to the overall length of the metallic signal lead.

[0041] Example 5 - The self-powered nuclear radiation detector of Examples 1, 2, 3, or 4, wherein the total length of the second insulating material is equal to the total length of the insulating material.

[0042] Example 6 - The self-powered nuclear radiation detector of Examples 1, 2, 3, 4, or 5, wherein the total length of the second metal sheath is equal to the total length of the metal sheath.

[0043] Example 7 - The self-powered nuclear radiation detector of Examples 1, 2, 3, 4, 5, or 6, wherein a radial dimension of the temperature compensation assembly is equal to a corresponding radial dimension of the cable assembly.

[0044] Example 8 - The self-powered nuclear radiation detector of Examples 1, 2, 3, 4, 5, 6, or 7, wherein the radial dimension of the second metallic signal lead is equal to the corresponding radial dimension of the metallic signal lead.

[0045] Example 9 - The self-powered nuclear radiation detector of Examples 1, 2, 3, 4, 5, 6, 7, or 8, wherein a radial dimension of the second insulating material is equal to a corresponding radial dimension of the insulating material.

[0046] Example 10 - The self-powered nuclear radiation detector of Examples 1, 2, 3, 4, 5, 6, 7, 8, or 9, wherein the radial dimension of the second metal sheath is equal to the corresponding radial dimension of the metal sheath.

[0047] Example 11 - The self-powered nuclear radiation detector of Examples 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10, wherein the temperature compensation assembly is mated with the cable assembly.

[0048] Example 12 - The self-powered nuclear radiation detector of Example 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or 11, wherein the metal signal lead comprises at least one of (1) cobalt, (2) cadmium, (3) rhodium, and (4) vanadium.

[0049] Example 13 - A method of correcting for temperature-related changes in an output current of a self-powered nuclear radiation detector is provided. The method comprises exposing a self-powered nuclear radiation detector to nuclear radiation from a fixed source, measuring the output current of the self-powered nuclear radiation detector at a plurality of different temperatures, measuring the insulation resistance of the self-powered nuclear radiation detector at the plurality of different temperatures, measuring the insulation resistance of a temperature compensation assembly of the self-powered nuclear radiation detector at the plurality of different temperatures, determining a slope of a relationship between (1) the measured change in the output current of the self-powered nuclear radiation detector and (2) the measured change in the insulation resistance of the self-powered nuclear radiation detector, determining a product of (1) the determined slope and (2) the measured change in the insulation resistance of the temperature compensation assembly of the self-powered nuclear radiation detector, and adding the determined product to the measured output current of the self-powered nuclear radiation detector to determine a temperature correction value for the output current of the self-powered nuclear radiation detector.

[0050] Example 14 - The method of example 13, wherein the nuclear radiation comprises neutron radiation.

[0051] Example 15 - The method of example 14, wherein the nuclear radiation further comprises gamma radiation.

[0052] Example 16 - The method described in Example 13, 14, or 15, further comprising measuring a gamma induced current in a temperature compensation assembly of the self-powered nuclear radiation detector, and subtracting the measured gamma induced current in the temperature compensation assembly of the self-powered nuclear radiation detector from the temperature corrected value of the output current of the self-powered nuclear radiation detector.

[0053] Example 17 - The method of Example 13, 14, 15, or 16, further comprising utilizing at least one of (1) a multimeter and (2) a megohmmeter device to measure the insulation resistance of the self-powered nuclear radiation detector.

[0054] Example 18 - The method of Example 13, 14, 15, 16, or 17, further comprising utilizing at least one of (1) a multimeter and (2) a megohmmeter device to measure the insulation resistance of the temperature compensation assembly.

[0055] Example 19 - The method of example 13, 14, 15, 16, 17, or 18, further comprising determining a power level of the reactor based on a temperature-corrected value of the output current of the self-powered nuclear radiation detector.

[0056] Example 20 - The method of example 13, 14, 15, 16, 17, 18, or 19, further comprising determining a distribution of reactor power based on a temperature-corrected value of the output current of the self-powered nuclear radiation detector.

[0057] Although various aspects of self-powered nuclear radiation detectors have been described herein with reference to certain disclosed aspects, many modifications and variations on those aspects may be implemented. Also, where materials are disclosed for particular components, other materials may be used. Furthermore, according to various aspects, a single component may be replaced with multiple components, and multiple components may be replaced with a single component to perform a given function(s). The foregoing description and the appended claims are intended to cover all such modifications and variations that are within the scope of the aspects of the present disclosure.

[0058] While the present invention has been described as having an exemplary design, the described invention may be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. For example, while the present invention has been described in the context of a self-powered nuclear radiation detector, the general principles of the invention are equally applicable to other types of detectors.

[0059] All or a portion of any patent, patent application, publication, or other disclosure material referred to herein as being incorporated by reference is incorporated herein to the extent that the incorporated material does not contradict existing definitions, descriptions, or other disclosure material set forth in this disclosure. Accordingly, and to the extent necessary, the present disclosure as expressly set forth herein supersedes any conflicting material incorporated herein by reference. All material referred to herein as being incorporated by reference, or portions thereof, that contradicts existing definitions, descriptions, or other disclosure material set forth herein, will be incorporated only to the extent that there is no contradiction between the incorporated material and the existing disclosure material.

Claims

1. 1. A self-powered nuclear radiation detector comprising:

1. A cable assembly comprising: a metal signal lead for generating a first induced current; an insulating material surrounding the metal signal leads; a metal sheath surrounding the insulating material. the cable assembly; 1. A temperature compensation assembly comprising: a second metallic signal lead for generating a second induced current to compensate for the first induced current; a second insulating material surrounding the second metal signal lead; a second metal sheath surrounding the second insulating material; the temperature compensation assembly; a metallic outer sheath surrounding the cable assembly and the temperature compensation assembly; Equipped with the overall length of the temperature compensation assembly is equal to the overall length of the cable assembly; Self-powered nuclear radiation detector.

2. 1. A self-powered nuclear radiation detector comprising:

1. A cable assembly comprising: a metal signal lead for generating a first induced current; an insulating material surrounding the metal signal leads; a metal sheath surrounding the insulating material. the cable assembly; 1. A temperature compensation assembly comprising: a second metallic signal lead for generating a second induced current to compensate for the first induced current; a second insulating material surrounding the second metal signal lead; a second metal sheath surrounding the second insulating material; the temperature compensation assembly; a metallic outer sheath surrounding the cable assembly and the temperature compensation assembly; Equipped with the total length of the second metal signal lead is equal to the total length of the metal signal lead; Self-powered nuclear radiation detector.

3. 1. A self-powered nuclear radiation detector comprising:

1. A cable assembly comprising: a metal signal lead for generating a first induced current; an insulating material surrounding the metal signal leads; a metal sheath surrounding the insulating material. the cable assembly; 1. A temperature compensation assembly comprising: a second metallic signal lead for generating a second induced current to compensate for the first induced current; a second insulating material surrounding the second metal signal lead; a second metal sheath surrounding the second insulating material; the temperature compensation assembly; a metallic outer sheath surrounding the cable assembly and the temperature compensation assembly; Equipped with the total length of the second insulating material is equal to the total length of the insulating material; Self-powered nuclear radiation detector.

4. 1. A self-powered nuclear radiation detector comprising:

1. A cable assembly comprising: a metal signal lead for generating a first induced current; an insulating material surrounding the metal signal leads; a metal sheath surrounding the insulating material. the cable assembly; 1. A temperature compensation assembly comprising: a second metallic signal lead for generating a second induced current to compensate for the first induced current; a second insulating material surrounding the second metal signal lead; a second metal sheath surrounding the second insulating material; the temperature compensation assembly; a metallic outer sheath surrounding the cable assembly and the temperature compensation assembly; Equipped with The total length of the second metal sheath is equal to the total length of the metal sheath. Self-powered nuclear radiation detector.

5. 5. The self-powered nuclear radiation detector of claim 1, wherein the temperature compensation assembly is adjacent to and parallel to the cable assembly.

6. 6. A self-powered nuclear radiation detector according to claim 1, wherein a radial dimension of the temperature compensation assembly is equal to a corresponding radial dimension of the cable assembly.

7. 7. The self-powered nuclear radiation detector of claim 1, wherein a radial dimension of the second metallic signal lead is equal to a corresponding radial dimension of the metallic signal lead.

8. 8. A self-powered nuclear radiation detector according to claim 1, wherein a radial dimension of the second insulating material is equal to a corresponding radial dimension of the insulating material.

9. 9. A self-powered nuclear radiation detector according to claim 1, wherein a radial dimension of the second metal sheath is equal to a corresponding radial dimension of the metal sheath.

10. The metal signal lead cobalt, cadmium, Rhodium, and 10. A self-powered nuclear radiation detector according to any one of claims 1 to 9, comprising at least one of: vanadium.

11. 1. A method of correcting for temperature-related changes in output current of a self-powered nuclear radiation detector, comprising: The method comprises: exposing the self-powered nuclear radiation detector to nuclear radiation from a fixed source; measuring the output current of the self-powered nuclear radiation detector at a plurality of different temperatures; measuring the insulation resistance of the self-powered nuclear radiation detector at the plurality of different temperatures; measuring the insulation resistance of the temperature compensation assembly of the self-powered nuclear radiation detector at the plurality of different temperatures; (1) determining a slope of a relationship between the measured change in the output current of the self-powered nuclear radiation detector and (2) the measured change in the insulation resistance of the self-powered nuclear radiation detector; Determining the product of (1) the determined slope and (2) the measured change in insulation resistance of the temperature compensation assembly of the self-powered nuclear radiation detector; adding the determined product to the measured output current of the self-powered nuclear radiation detector to determine a temperature correction value for the output current of the self-powered nuclear radiation detector; A method comprising:

12. The method of claim 11 , wherein the nuclear radiation comprises neutron radiation.

13. The method of claim 12 , wherein the nuclear radiation further comprises gamma radiation.

14. measuring a gamma induced current in the temperature compensation assembly of the self-powered nuclear radiation detector; 14. The method of claim 13, further comprising: subtracting the measured gamma induced current in the temperature compensation assembly of the self-powered nuclear radiation detector from the temperature corrected value of the output current of the self-powered nuclear radiation detector.

15. 15. The method of any one of claims 11 to 14, further comprising utilizing at least one of a multimeter and a megohmmeter device to measure the insulation resistance of the self-powered nuclear radiation detector.

16. 16. The method of claim 11, further comprising utilizing at least one of a multimeter and a megohmmeter device to measure the insulation resistance of the temperature compensation assembly.

17. 17. The method of any one of claims 11 to 16, further comprising determining a power level for a reactor based on the temperature corrected value of the output current of the self-powered nuclear radiation detector.

18. 18. The method of any one of claims 11 to 17, further comprising determining a distribution of reactor power based on the temperature corrected values ​​of the output currents of the self-powered nuclear radiation detectors.

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