CN115359935A

CN115359935A - Internal circulation tracing method for spherical element of high-temperature gas-cooled reactor

Info

Publication number: CN115359935A
Application number: CN202211176410.2A
Authority: CN
Inventors: 张兴田; 张涛; 吕华权; 张冀兰; 罗勇; 魏文斌; 洪伟; 王苗苗
Original assignee: Huaneng Nuclear Energy Technology Research Institute Co Ltd
Current assignee: Huaneng Nuclear Energy Technology Research Institute Co Ltd
Priority date: 2022-09-26
Filing date: 2022-09-26
Publication date: 2022-11-18

Abstract

The invention relates to a high-temperature gas cooled reactor spherical element in-reactor circulation tracing method, which comprises the following steps: the identification target is added in the spherical element, so that the identification coding of the spherical element is realized; the identification target comprises a target nucleic acid element of ⁵⁹ Co、 ¹⁹¹ Ir、 ¹⁶⁹ One, two or three combinations of Tm, and at least ⁵⁹ Co, different types and/or proportions of target nucleic acid elements contained in different identification targets are different, and the spherical elements comprise fuel elements and/or graphite spheres. The in-reactor circulation tracing method for the spherical element of the high-temperature gas cooled reactor can acquire the circulation tracing data of the spherical element on line and without damage. The method provided by the embodiment of the invention can accurately identify the identification code of the spherical element by using a high-purity germanium gamma spectrometer of the existing fuel consumption measuring system of the high-temperature gas cooled reactor, does not need to add an additional measuring system, and saves the cost.

Description

Internal circulation tracing method for spherical element of high-temperature gas-cooled reactor

Technical Field

The invention relates to the technical field of nuclear reactor internal circulation testing, in particular to an internal circulation tracing method for a spherical element of a high-temperature gas cooled reactor.

Background

The high-temperature gas cooled reactor is a fourth-generation advanced nuclear reactor which takes graphite as a moderator and helium as a coolant and adopts a ceramic core structure, has inherent safety characteristic and high heat energy conversion efficiency.

The reactor core of the high-temperature gas cooled reactor nuclear power station in the initial reactor operation stage and the transition cycle operation stage is a fuel element and a graphite sphere, and the reactor core in the equilibrium cycle operation stage after the transition cycle operation stage is finished is a fuel element which is a sphere.

The high-temperature gas cooled reactor adopts spherical fuel elements, which are composed of an inner spherical fuel area and an outer shell fuel-free area, wherein the cladding fuel particles are dispersed in a graphite matrix of the spherical fuel area, and the outer shell fuel-free area is made of the same material as the graphite matrix of the spherical fuel area, and the cladding fuel particles are not contained in the cladding fuel particles. The reactor power and the uniformity of fuel consumption distribution are obtained to a certain degree through the in-reactor fuel circulation operation mode of repeatedly filling and discharging the high-temperature gas cooled reactor core.

However, the spherical flow motion of the spherical fuel element in the high-temperature gas cooled reactor has randomness, and the distribution of the spherical flow streamline and the flow velocity is relatively complex. If the actual fuel cycle number of the spherical fuel element deviates from the relevant design value of the high-temperature gas-cooled reactor fuel or the residence time of the reactor core is too long, the influence on the safe operation of the high-temperature gas-cooled reactor and the service life of the ceramic core structure is generated, so that the acquisition of the fuel cycle tracing data of the spherical fuel element is the problem which needs to be solved in the high-temperature gas-cooled reactor sphere flow modeling and fuel partition modeling.

The identification encoding of spherical fuel elements to obtain fuel cycle trace data for multiple core fills and discharges through a fuel handling system is a straightforward method. The conventional identification coding method is to mechanically carve an identification code on the surface of a spherical fuel element and then visually recognize the identification code. However, the identification code mechanically depicted on the surface of the spherical fuel element is damaged due to friction, collision, fluid flushing and the like in the process of spherical flow, the time when the spherical fuel element with the identification code is unloaded from the reactor core cannot be detected online and losslessly in the fuel circulation process, and the visual identification of the identification code needs to be carried out in a radioactive shielding lead chamber, so that the conventional identification coding method and the visual identification method are not suitable for the fuel circulation tracing of the spherical fuel element of the high-temperature gas cooled reactor.

Disclosure of Invention

The present invention is directed to solving, at least to some extent, one of the technical problems in the related art. Therefore, the embodiment of the invention provides an in-reactor circulation tracing method for a spherical element of a high-temperature gas-cooled reactor.

The embodiment of the invention provides an in-reactor circulation tracing method for a spherical element of a high-temperature gas cooled reactor, which comprises the following steps: the identification target is added into the spherical element to realize the identification coding of the spherical element; the identification target comprises a target nucleic acid element of ⁵⁹ Co、 ¹⁹¹ Ir、 ¹⁶⁹ One, two or three combinations of Tm, and at least ⁵⁹ Co, different types and/or proportions of target nucleic acid elements contained in different identification targets are different, and the spherical elements comprise fuel elements and/or graphite spheres.

The in-pile circulation tracing method for the spherical element of the high-temperature gas-cooled reactor can acquire the circulation tracing data of the spherical element on line and without damage. The method provided by the embodiment of the invention can accurately identify the identification code of the spherical element by using a high-purity germanium gamma spectrometer of the existing fuel consumption measuring system of the high-temperature gas cooled reactor, does not need to add an additional measuring system, and saves the cost.

Selection of embodiments of the invention ⁵⁹ Co、 ¹⁹¹ Ir、 ¹⁶⁹ One, two or three combinations of Tm are used as identification target to carry out identification coding on the spherical element, and the nuclear reaction formulas are respectively ⁵⁹ Co(n,γ) ⁶⁰ Co、 ¹⁹¹ Ir(n,γ) ¹⁹² Ir and ¹⁶⁹ Tm(n,γ) ¹⁷⁰ tm, which avoids the radionuclide contained in the fission product of the fuel element, and ⁶⁰ Co、 ¹⁹² Ir、 ¹⁷⁰ the gamma ray energy peak and emission intensity of Tm have enough discrimination. In particular, in the case of a system, ⁶⁰ the two main gamma-ray energy peaks of Co are 1173.228keV and 1332.492keV respectively, ¹⁹² the gamma ray energy peak of Ir is 316.506keV, ¹⁷⁰ the gamma ray energy peak of Tm is 84.255keV, and high, medium and low energy gamma ray radioactive nuclides are respectively formed. The resolution of the high-purity germanium gamma spectrometer is generally better than 1.85keV, so the high-purity germanium gamma spectrometer pair ⁶⁰ Co、 ¹⁹² Ir and ¹⁷⁰ the gamma ray energy peak of the Tm has enough discrimination, thereby ensuring the accuracy of the measurement result.

In some embodiments, the amount of the target nucleic acid element in the labeled target part is in parts as follows: ⁵⁹ co is 1-N portion, ¹⁹¹ 0 to 2 portions of Ir, ¹⁶⁹ Tm is 0-3 parts, and N is an integer between 2-41.

The embodiment of the invention realizes the identification and coding of the spherical element by combining the types and the contents of target nucleic elements in the identification target part and utilizing the combination of different characteristic gamma energy peaks and relative intensities of corresponding radionuclides generated by the reaction of the target nucleic elements in a reactor (n, gamma). The target nucleic acid element species and/or ratio of the identification target is designed according to the number of spherical elements of the identification code required by the in-pile circulation tracing.

In some embodiments, the spherical elements of each of the spherical elements, ⁵⁹ the content of Co is 0.1-N/10 mg, ¹⁹¹ The content of Ir is 0 mg-0.2 mg, ¹⁶⁹ The Tm content is 0 mg-0.3mg, and N is an integer between 2-41.

In the embodiment of the invention, by controlling the position of each spherical element ⁵⁹ Co、 ¹⁹¹ Ir、 ¹⁶⁹ The Tm content is within the above range, thereby ensuring that the target nucleic acid element for identifying the target is passed through the reactorn, gamma) reaction and the radioactivity range of the standard calibration source and the calibration source of the high-temperature gas cooled reactor burnup measuring system is 7.0 multiplied by 10 ⁵ ～1.0×10 ¹⁰ Bq is matched, and meanwhile, the marking target piece is ensured not to have obvious influence on the mechanical integrity of the spherical element and the radiation protection of the operation of the burnup measuring system of the high-temperature gas cooled reactor.

In some embodiments, the identification target is ⁵⁹ The raw material of Co is selected from one of simple substance of cobalt and electroplated cobalt ¹⁹¹ The raw material of Ir is selected from one of iridium simple substance and iridium-10% gold alloy, and the raw material is ¹⁶⁹ The raw material of Tm is selected from thulium simple substance and Tm ₂ O ₃ To (3) is provided.

The highest central temperature (balance reactor core) of the fuel element reaches 900 ℃ under the rated power of the high-temperature gas cooled reactor, and the melting points of cobalt, iridium and thulium are 1495 ℃, 2443 ℃ and 1545 ℃ respectively, so that the target in the identification target ⁵⁹ The raw material of Co can be selected from one of simple cobalt and electroplated cobalt ¹⁹¹ The raw material of Ir may be selected from one of elementary iridium, iridium-10% gold alloy, and the like ¹⁶⁹ The raw material of Tm can be selected from thulium simple substance and Tm ₂ O ₃ One kind of (1).

In some embodiments, the identification target is in the form of a pellet, wire, sheet, metal plating, glass with a carrier material, or graphite powder pellet. Preferably, the marking target is granular.

In some embodiments, the fuel elements are of a plurality of types, each loaded with a different enrichment ²³⁵ U。

In some embodiments, the fuel element includes an inner spherical fuel region and an outer fuel free region, and the identification target is added to the outer fuel free region of the fuel element.

In some embodiments, the inner spherical fuel zone has a diameter of 50mm and the outer shell fuel-free zone has a thickness of 2.5 to 7.5mm, preferably 5mm.

In some embodiments, the inner spherical fuel region comprises a graphite matrix and cladding fuel particles dispersed in the graphite matrix, the cladding fuel particles comprising uranium; the shell fuel-free area comprises a graphite substrate and an identification target, the identification target is added into the graphite substrate of the shell fuel-free area, and the inner layer spherical fuel area is made of the same material as the graphite substrate of the shell fuel-free area.

In some embodiments, the marking target is coated with a coating material that is the same matrix graphite powder as the graphite matrix material of the fuel free region of the housing and then added in particulate form to the graphite matrix of the fuel free region of the fuel element.

In some embodiments, the marking target is clad with a cladding material and then pressed into the fuel free region of the fuel element housing using a quasi-isostatic pressing process.

In some embodiments, the identification target is coated with a coating material that is a matrix graphite powder that is the same material as the graphite nodules and then added to the graphite nodules.

In some embodiments, the base graphite powder is prepared from 64% natural crystalline flake graphite, 16% synthetic graphite, and 20% phenolic resin by a process including kneading, extruding, crushing, and sieving.

In some embodiments, the method further comprises: and identifying the identification code of the spherical element by measuring the combination of corresponding gamma ray emission intensities of the spherical elements discharged from the high-temperature gas cooled reactor pebble bed reactor core, wherein the energy peaks are characterized by 1173.228keV, 1332.492keV, 316.506keV and 84.255 keV.

In some embodiments, the measurement is performed by a high purity germanium gamma spectrometer of a burnup measurement system.

In some embodiments, the method of identifying comprises:

acquiring the type and the amount of the radionuclide for marking the target in the spherical element and the activity of each radionuclide;

calculating preset values of corresponding gamma ray emission intensity combinations of the spherical elements with characteristic energy peaks of 1173.228keV, 1332.492keV, 316.506keV and 84.255 keV;

and comparing corresponding gamma ray emission intensity combinations of the spherical elements discharged from the high-temperature gas cooled reactor pebble bed reactor core and taking 1173.228keV, 1332.492keV, 316.506keV and 84.255keV as characteristic energy peaks with preset values, and identifying the identification codes of the spherical elements.

The embodiment of the invention also provides a spherical element for the high-temperature gas cooled reactor, wherein the spherical element is added with a marking target, and the marking target comprises a target nucleic element of ⁵⁹ Co、 ¹⁹¹ Ir、 ¹⁶⁹ One, two or three combinations of Tm, and at least ⁵⁹ Co, different mark target parts comprise different kinds and/or proportions of target nucleic elements, and the spherical elements are fuel elements or graphite spheres.

In some embodiments, each of the spherical elements comprises, in each of the spherical elements, ⁵⁹ the content of Co is 0.1-N/10 mg, ¹⁹¹ The content of Ir is 0 mg-0.2 mg, ¹⁶⁹ The Tm content is 0 mg-0.3mg, and N is an integer between 2-41.

In some embodiments, the identification target is ⁵⁹ The raw material of Co is selected from one of simple substance of cobalt and electroplated cobalt ¹⁹¹ The raw material of Ir is selected from one of iridium simple substance and iridium-10% gold alloy, and the Ir ¹⁶⁹ The raw material of Tm is selected from thulium simple substance and Tm ₂ O ₃ One kind of (1).

In some embodiments, the marking target is in the form of a particle, wire, sheet, metal plating, vitreous or graphite powder pellet with a carrier material; preferably in the form of granules.

In some embodiments, the inner spherical fuel region comprises a graphite matrix and coated fuel particles dispersed in the graphite matrix, wherein the coated fuel particles comprise uranium; the shell fuel-free zone comprises a graphite substrate and an identification target, the identification target is added into the graphite substrate of the shell fuel-free zone, and the inner layer spherical fuel zone is made of the same material as the graphite substrate of the shell fuel-free zone.

The features and advantages described above with respect to the target are equally applicable to spherical elements with target identification and are not described in detail herein.

The embodiment of the invention also provides a high-temperature gas cooled reactor system which comprises the spherical element for the high-temperature gas cooled reactor.

The features and advantages described above with respect to the labeled target are equally applicable to a high temperature gas cooled reactor system including a spherical element with a labeled target and will not be described in detail herein.

The invention has the following advantages and beneficial effects:

(1) The embodiment of the invention provides an in-reactor circulation tracing method for a spherical element of a high-temperature gas-cooled reactor, which can acquire circulation tracing data of the spherical element on line without damage. The high-temperature gas cooled reactor sphere flow model and/or the fuel partition model are/is improved, the accuracy of physical thermal calculation analysis is improved, and the safe operation of the high-temperature gas cooled reactor is guaranteed.

(2) The method provided by the embodiment of the invention can accurately identify the identification code of the spherical element by using a high-purity germanium gamma spectrometer of the existing fuel consumption measuring system of the high-temperature gas cooled reactor, does not need to add an additional measuring system, and saves the cost.

(3) The invention is realized by adopting a mature radiation measurement method, the measurement process is stable, and the measurement result is accurate.

Drawings

FIG. 1 is a schematic diagram of a high temperature gas cooled reactor fuel element.

FIG. 2 is a schematic diagram of a high temperature gas cooled reactor fuel handling system.

FIG. 3 is a drawing of an embodiment of the present invention including ⁵⁹ 25 portions of Co, ¹⁹¹ Ir 2 parts and ¹⁶⁹ tm 3 parts (metal mass per part about 0.1 mg) of the radioactivity curve of the labeled target.

Reference numerals:

101 is a fuel element, 102 is a hemisphere, 103 is a shell fuel-free zone, and 104 is an inner sphere fuel zone.

201 is a reactor pressure vessel, 202 is a reactor core unloading device, 203 is a fuel consumption measuring system, 204 is an unloading temporary storage device, and 205 is a fresh fuel tank.

Detailed Description

The following detailed description of the embodiments of the invention, which is intended to be illustrative and not to be construed as limiting the invention.

The embodiment of the invention provides an in-reactor circulation tracing method for a spherical element of a high-temperature gas cooled reactor, which comprises the following steps: the identification target is added in the spherical element, so that the identification coding of the spherical element is realized; mark target bagThe target nucleic acid element is ⁵⁹ Co、 ¹⁹¹ Ir、 ¹⁶⁹ One, two or three combinations of Tm, and at least ⁵⁹ Co, different types and/or proportions of target nucleic acid elements contained in different labeled targets are different, and the spherical elements comprise fuel elements and/or graphite spheres.

Embodiment selection of the invention ⁵⁹ Co、 ¹⁹¹ Ir、 ¹⁶⁹ One, two or three combinations of Tm are used as identification target to carry out identification coding on the spherical element, and the nuclear reaction formulas are respectively ⁵⁹ Co(n,γ) ⁶⁰ Co、 ¹⁹¹ Ir(n,γ) ¹⁹² Ir and ¹⁶⁹ Tm(n,γ) ¹⁷⁰ tm, which avoids the radionuclide contained in the fission product of the fuel element, and ⁶⁰ Co、 ¹⁹² Ir、 ¹⁷⁰ the gamma ray energy peak and emission intensity of Tm have enough discrimination. In particular, in the case of a system, ⁶⁰ the two main gamma-ray energy peaks of Co are 1173.228keV and 1332.492keV respectively, ¹⁹² the gamma ray energy peak of Ir is 316.506keV, ¹⁷⁰ the gamma ray energy peak of Tm is 84.255keV, and high, medium and low energy gamma ray radioactive nuclides are respectively formed. The resolution of the high-purity germanium gamma spectrometer is generally better than 1.85keV, so the high-purity germanium gamma spectrometer pair ⁶⁰ Co、 ¹⁹² Ir and ¹⁷⁰ the gamma ray energy peak of Tm has enough discrimination, thereby ensuring the accuracy of the measurement result.

In some embodiments, the target nucleic acid elements in the target article are identified in parts by weight: ⁵⁹ co is 1-N portion, ¹⁹¹ 0 to 2 portions of Ir, ¹⁶⁹ Tm is 0-3 parts, and N is an integer between 2-41.

The embodiment of the invention realizes the identification and coding of the spherical element by combining the types and the contents of target nucleic elements in the identification target part and utilizing the combination of different characteristic gamma energy peaks and relative intensities of corresponding radionuclides generated by the reaction of the target nucleic elements in a reactor (n, gamma). And designing the target nucleic element type and/or ratio of the identification target part according to the number of the spherical elements of the identification codes required by the in-pile circulation tracing.

It can be understood that: by combining the type and content of target nucleic acid elements in the target, i.e. ⁵⁹ Co can be 1, 2, 8230, N portions (N selections), ¹⁹¹ ir is 0, 1, 2 parts (3 choices), ¹⁶⁹ tm is 0, 1, 2, 3 parts (4 choices); n is 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, or 41; and then the target nucleic element type and/or ratio of the labeled target is designed according to the number of spherical elements of the labeled codes required by the in-pile cycle tracing.

Non-limiting examples are:

in one specific example, when the number of spherical elements required for the cyclic tracking of the identification code in the stack is 300, the number can be determined according to the number of spherical elements required for the cyclic tracking of the identification code in the stack ⁵⁹ 1 to 25 portions of Co, ¹⁹¹ 0 to 2 portions of Ir, ¹⁶⁹ Tm is 0 to 3 parts, and 300 combinations are obtained.

In one specific example, when the number of identification-coded spherical elements required for in-core cyclic tracking is 270, the number can be determined according to the number ⁵⁹ 1 to 30 portions of Co, ¹⁹¹ 0 to 2 portions of Ir, ¹⁶⁹ Tm is 0 to 2 parts, yielding 270 combinations.

In one specific example, when the number of identification-coded spherical elements required for in-core cyclic tracking is 240, the number can be determined according to the number ⁵⁹ 1 to 30 portions of Co, ¹⁹¹ 0 to 1 portion of Ir, ¹⁶⁹ Tm is 0 to 3 parts, and 240 combinations are obtained.

In one specific example, when the number of identification-coded spherical elements required for in-stack loop tracking is 360, the spherical elements can be identified according to ⁵⁹ 1 to 40 portions of Co, ¹⁹¹ 0 to 2 portions of Ir, ¹⁶⁹ Tm is 0 to 2 parts, yielding 360 combinations.

In one specific example, when in-core cyclic tracing is requiredThe number of the identification-coded spherical elements of (2) is 270, which can be in accordance with ⁵⁹ 1 to 35 portions of Co, ¹⁹¹ 0 to 2 portions of Ir, ¹⁶⁹ Tm is 0 to 3 parts, yielding 420 combinations.

⁶⁰ Co、 ¹⁹² Ir and ¹⁷⁰ the specific activity of Tm is calculated as follows:

cobalt, iridium and thulium as target material are irradiated by neutrons in reactor ⁵⁹ Co(n,γ) ⁶⁰ Co、 ¹⁹¹ Ir(n,γ) ¹⁹² Ir and ¹⁶⁹ Tm(n,γ) ¹⁷⁰ tm nuclear reaction, wherein the nuclear reaction formula is as follows:

theoretical specific activity calculation formula:

in the formula:

A _CO ： ⁶⁰ specific activity of Co, bq/g;

A _Ir ： ¹⁹² ir specific activity, bq/g;

A _Tm ： ¹⁷⁰ tm specific activity, bq/g;

N ₀ :1g number of target nuclei of target nucleic acid element (abundance of target nucleic acid element has been considered)

σ： ⁵⁹ Co、 ¹⁹¹ Ir、 ¹⁶⁹ Thermal neutron capture cross section, cm, of Tm ²

σ′： ¹⁹² Ir、 ¹⁷⁰ Thermal neutron capture cross section, cm, of Tm ²

λ： ⁶⁰ Co、 ¹⁹² Ir、 ¹⁷⁰ Decay constant of Tm

Phi: thermal neutron fluence rate, cm ^-2 ·s ^-1

t: irradiation time, s

In order to make the method of the embodiment of the invention perform measurement through a high-purity germanium gamma spectrometer of the existing burnup measuring system of the high-temperature gas cooled reactor, the radioactivity generated by the reaction of target elements in the reactor (n, gamma) and the radioactivity range of the standard calibration source and the calibration source of the burnup measuring system of the high-temperature gas cooled reactor are 7.0 x 10 ⁵ ～1.0×10 ¹⁰ Bq are matched, and meanwhile, the marking target piece is ensured not to have obvious influence on the mechanical integrity of the spherical elements and the radiation protection of the operation and operation of the fuel consumption measuring system of the high-temperature gas cooled reactor, and the calculation and deduction are carried out through the formula, so that 1 part of matched target nucleic acid elements in each spherical element is about 0.1mg, and the maximum value of the natural number N is 41.

In some embodiments, the spherical elements may be, in each spherical element, ⁵⁹ the content of Co is 0.1-N/10 mg, ¹⁹¹ The content of Ir is 0 mg-0.2 mg, ¹⁶⁹ The Tm content is 0 mg-0.3mg, and N is an integer between 2-41.

In some embodiments, in the target is identified ⁵⁹ The raw material of Co is selected from one of simple substance of cobalt and electroplating cobalt, ¹⁹¹ the raw material of Ir is selected from one of iridium simple substance and iridium-10% gold alloy, ¹⁶⁹ the raw material of Tm is selected from thulium simple substance and Tm ₂ O ₃ To (3) is provided.

The center highest temperature (balance reactor core) of the fuel element reaches 900 ℃ under the rated power of the high-temperature gas cooled reactor, and the cobalt, the iridium and the thuliumThe melting points of the metals are 1495 deg.C, 2443 deg.C and 1545 deg.C, respectively, thereby identifying the target ⁵⁹ The raw material of Co can be selected from one of simple substance of cobalt and electroplated cobalt, ¹⁹¹ the raw material of Ir may be selected from one of elementary iridium, iridium-10% gold alloy, ¹⁶⁹ the raw material of Tm can be selected from thulium simple substance and Tm ₂ O ₃ One kind of (1).

In some embodiments, the marking target is in the form of a pellet, wire, sheet, metal plating, glass with a carrier material, or graphite powder pellet. Preferably, the marking target is granular.

In some embodiments, the fuel elements are divided into a plurality, each loaded with a different enrichment ²³⁵ U。

In some embodiments, the fuel element includes an inner spherical fuel region and an outer shell fuel free region, the outer shell fuel free region where the identification target is added to the fuel element.

In some embodiments, the inner spherical fuel region comprises a graphite matrix and coated fuel particles, the coated fuel particles are dispersed in the graphite matrix, and the coated fuel particles contain uranium; the housing fuel-free zone comprises a graphite substrate and an identification target, the identification target is added into the graphite substrate of the housing fuel-free zone, and the inner layer spherical fuel zone is made of the same material as the graphite substrate of the housing fuel-free zone.

In some embodiments, the marking target is coated with a coating material in the form of particles that are added to the graphite matrix of the fuel element in the fuel-free region of the housing, the coating material being a matrix graphite powder that is the same as the graphite matrix material of the fuel-free region of the housing.

It will be appreciated that the process of manufacturing and testing fuel elements with the identification target is the same as the process of manufacturing and testing conventional fuel elements (fuel elements without identification targets) except that the identification target is added.

In some embodiments, the base graphite powder is prepared from 64% natural flake graphite, 16% synthetic graphite, and 20% phenolic resin by a process including kneading, extruding, crushing, and sieving.

It will be appreciated that the process of manufacturing and testing graphite nodules with identification targets is the same as that of manufacturing and testing conventional graphite nodules (graphite nodules without identification targets) except that identification targets are added.

In some embodiments, the method further comprises: the identification code of the spherical elements is identified by measuring the combination of the corresponding gamma ray emission intensities of the spherical elements discharged from the high-temperature gas cooled reactor pebble bed reactor core, wherein the energy peaks are characterized by 1173.228keV, 1332.492keV, 316.506keV and 84.255 keV.

In some embodiments, the measurements are performed by a high purity germanium gamma spectrometer of a burnup measurement system.

In some embodiments, the method of identifying comprises:

The tracing method for fuel circulation of the spherical element in the high-temperature gas-cooled reactor provided by the embodiment of the invention can acquire circulation data of multiple different periods in the fuel element reactor on line without damage, and the actual measurement data reflecting the randomness of the movement of the spherical flow in the reactor and the spherical flow path is utilized to carry out iterative calculation on the spherical flow model of the high-temperature gas-cooled reactor physical thermal calculation software so as to improve and verify the reactor core radial flow passage partition and axial fuel layering model, so that the accuracy of the physical thermal calculation analysis of the high-temperature gas-cooled reactor can be improved, the problem of spherical flow modeling of the high-temperature gas-cooled reactor in the world can be solved to a certain extent, and the safe operation of the high-temperature gas-cooled reactor can be guaranteed.

The embodiment of the invention also provides a spherical element for the high-temperature gas cooled reactor, the spherical element is a fuel element or a graphite sphere, a marking target part is added in the spherical element, and the marking target part comprises a target nucleic element ⁵⁹ Co、 ¹⁹¹ Ir、 ¹⁶⁹ One, two or three combinations of Tm, and at least ⁵⁹ Co, different types and/or proportions of target nucleic acid elements contained in different labeled targets are different.

In some embodiments, the target nucleic acid elements in the target article are identified in parts by weight: ⁵⁹ 1 to N portions of Co, ¹⁹¹ 0 to 2 portions of Ir, ¹⁶⁹ Tm is 0-3 parts, and N is an integer between 2-41.

In some embodiments, the first and second spherical elements, in each spherical element, ⁵⁹ the content of Co is 0.1-N/10 mg, ¹⁹¹ The content of Ir is 0 mg-0.2 mg, ¹⁶⁹ The Tm content is 0 mg-0.3mg, and N is an integer between 2-41.

In some embodiments, among the identification targets ⁵⁹ The raw material of Co is selected from one of simple substance of cobalt and electroplated cobalt, ¹⁹¹ the raw material of Ir is selected from one of iridium simple substance and iridium-10% gold alloy, ¹⁶⁹ the raw material of Tm is selected from thulium simple substance and Tm ₂ O ₃ One kind of (1).

In some embodiments, the marking target is in the form of a pellet, wire, sheet, metal plating, glass with a carrier material, or graphite powder pellet; preferably in the form of granules.

In some embodiments, the marking target is coated with a coating material, which is the same matrix graphite powder as the graphite matrix material of the fuel free region of the housing, and then added in the form of particles to the graphite matrix of the fuel free region of the fuel element.

In some embodiments, the target is clad with a cladding material and then pressed into the fuel free region of the housing of the fuel element using a quasi-isostatic pressing process.

In some embodiments, the marking target is coated with a coating material that is the same base graphite powder as the graphite nodules and then added to the graphite nodules.

The embodiment of the invention also provides a high-temperature gas-cooled reactor system which comprises the spherical element with the identification target piece for the high-temperature gas-cooled reactor.

FIG. 1 is a schematic diagram of a fuel element structure of a high temperature gas cooled reactor. The fuel element 101 includes an inner spherical fuel region 104 and a shell fuel free region 103, and a target (not shown) for identification is added to the shell fuel free region 103 of the fuel element 101.

Fig. 2 is a schematic diagram of a conventional high temperature gas cooled reactor fuel handling system. The high-temperature gas cooled reactor fuel loading and unloading system comprises a reactor pressure vessel 201, a reactor core unloading device 202, a fuel consumption measuring system 203, an unloading temporary storage device 204 and a fresh fuel tank 205, wherein a bottom outlet of the reactor pressure vessel 201 is communicated with the reactor core unloading device 202, an outlet of the reactor core unloading device 202 is connected with the fuel consumption measuring system 203, the fuel consumption measuring system 203 comprises a first outlet and a second outlet, the first outlet is connected with an inlet of the reactor pressure vessel 201 through a main circulation lifting ball circuit, the second outlet is connected with the unloading temporary storage device 204 through a spent fuel unloading loop, and an outlet of the fresh fuel tank 205 is connected with an inlet of the reactor pressure vessel 201 through a main circulation lifting ball circuit.

FIG. 3 shows an embodiment of the present application ⁵⁹ 25 portions of Co, ¹⁹¹ Ir 2 parts and ¹⁶⁹ tm 3 parts (metal mass per part about 0.1 mg) of the radioactivity curve of the labeled target.

Example 1

The embodiment provides a fuel circulation tracing method in a high-temperature gas cooled reactor fuel element stack, which comprises the following steps:

s1, selecting target nucleic acid elements for marking the target ⁵⁹ Co、 ¹⁹¹ Ir、 ¹⁶⁹ Combinations of three Tm's;

selecting a target nucleic acid element that identifies the target ⁵⁹ Co、 ¹⁹¹ Ir and ¹⁶⁹ tm, in a high temperature gas cooled reactor ⁵⁹ Co(n,γ) ⁶⁰ Co、 ¹⁹¹ Ir(n,γ) ¹⁹² Ir and ¹⁶⁹ Tm(n,γ) ¹⁷⁰ nuclear reaction within Tm (n, gamma) to produce corresponding radionuclide ⁶⁰ Co、 ¹⁹² Ir and ¹⁷⁰ Tm。 ⁶⁰ Co、 ¹⁹² ir and ¹⁷⁰ the Tm is not a radionuclide contained in the fission product of the fuel element, ⁶⁰ the two main gamma-ray energy peaks of Co are 1173.228keV and 133 respectively2.492keV， ¹⁹² The gamma ray energy peak of Ir is 316.506keV, ¹⁷⁰ the gamma ray energy peak of Tm is 84.255keV, and high, medium and low energy gamma ray radioactive nuclides are respectively formed. The energy peak resolution of a high-purity germanium gamma spectrometer of a high-temperature gas cooled reactor burnup measurement system is generally better than 1.85keV, so that the high-purity germanium gamma spectrometer is suitable for ⁶⁰ Co、 ¹⁹² Ir and ¹⁷⁰ the gamma ray energy peak of Tm has sufficient discrimination of measurement.

S2, preparation of marking target

When the core of the high-temperature gas-cooled reactor is filled with new conventional fuel elements (fuel elements without added identification targets) every day by the fuel loading and unloading system during the normal operation of the high-temperature gas-cooled reactor, 10 fuel elements (namely, characteristic gamma fuel balls) with added identification codes are filled at certain time intervals every day for 30 days continuously. Based on the quantity requirement of the gamma fuel balls with the characteristics, the target is marked ⁵⁹ Co contains 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25 parts, ¹⁹¹ Ir in 0, 1, 2 portions, ¹⁶⁹ The Tm contains 0, 1, 2 and 3 parts, and 300 combinations are obtained in total, so that the requirement of the code number of the characteristic gamma fuel spheres is met. The radioactivity range of standard calibration source and verification source for marking target and high-temperature gas cooled reactor burnup measuring system is 7.0 x 10 ⁵ ～1.0×10 ¹⁰ Bq was matched and calculated to give a mass of about 0.1mg for 1 target nucleic acid element. The maximum activity of the marking target part only accounts for 0.154 per mill of the total activity of the fuel element activity, and the radiation protection of the operation of the high-temperature gas cooled reactor burnup measuring system cannot be obviously influenced.

In marking targets ⁵⁹ The raw material of Co is a simple substance of cobalt, ¹⁹¹ the raw material of Ir is an iridium simple substance, ¹⁶⁹ the raw material of Tm is thulium simple substance. The physical form of the marking target is granular.

S3, preparation of characteristic gamma fuel ball

The gamma fuel sphere comprises an inner layer spherical fuel area and an outer shell fuel-free area, wherein the inner layer spherical fuel area comprises a graphite matrix and coated fuel particles, the coated fuel particles are dispersed in the graphite matrix, and the coated fuel particles contain uranium; the shell fuel-free area comprises a graphite substrate and an identification target piece, the material of the inner layer spherical fuel area is the same as that of the graphite substrate of the shell fuel-free area, the identification target piece is coated by a coating material and then added into the graphite substrate of the shell fuel-free area in a particle form, the coating material is matrix graphite powder which is the same as that of the graphite substrate of the shell fuel-free area, the diameter of the inner layer spherical fuel area of the prepared gamma fuel sphere is 50mm, and the thickness of the shell fuel-free area is 5mm.

The matrix graphite powder is prepared from 64 mass percent of natural crystalline flake graphite, 16 mass percent of artificial graphite and 20 mass percent of phenolic resin through the processes of mixing kneading, extruding, crushing and screening.

The marking target is coated by the coating material and then pressed in a fuel-free area of the shell by adopting a quasi-isostatic pressing process.

The manufacturing and testing process of the characteristic gamma fuel ball is the same as that of the conventional fuel element (the fuel element without the added identification target) except that the identification target is added.

S4, on-line identification of characteristic gamma fuel ball identification codes

The fuel circulation of the high-temperature gas cooled reactor adopts a multi-cycle operation mode of fuel elements (including fuel elements without added identification targets and characteristic gamma fuel balls), and the cycle number is 15; and performing burnup measurement on fuel elements (including fuel elements without the added identification target and the characteristic gamma fuel spheres) discharged from the high-temperature gas cooled reactor by using a high-purity germanium gamma spectrometer, and refilling the fuel elements (including the fuel elements without the added identification target and the characteristic gamma fuel spheres) which do not reach the designed burnup value into the core for recycling operation. When the specified burnup limit is reached, the refilling stack is not reused.

The characteristic gamma fuel ball and the conventional fuel element (fuel element without added identification target) have the same fuel circulation operation mode and fuel consumption value measurement mode, and the high-purity germanium gamma spectrometer measures and records the fuel consumption of the characteristic gamma fuel ball while measuring the fuel consumption on line ⁶⁰ Co、 ¹⁹² Ir and ¹⁷⁰ the specific identification code of the characteristic gamma fuel ball is identified on line and without loss by combining the characteristic gamma energy peak and the emission intensity of the Tm. Identification stepThe method comprises the following steps:

performing source item analysis and calculation on the characteristic gamma fuel spheres to obtain the types and the use amounts of the radionuclides which identify the target parts in the characteristic gamma fuel spheres and the activity of each radionuclide;

calculating preset values of corresponding gamma ray emission intensity combinations of the characteristic energy peaks of the corresponding characteristic gamma fuel spheres, wherein the corresponding characteristic gamma fuel spheres take 1173.228keV, 1332.492keV, 316.506keV and 84.255keV as the characteristic energy peaks;

and comparing corresponding gamma ray emission intensity combinations of characteristic gamma fuel spheres discharged from the high-temperature gas cooled reactor pebble bed reactor core and taking 1173.228keV, 1332.492keV, 316.506keV and 84.255keV as characteristic energy peaks with preset values, and identifying the identification codes of the characteristic gamma fuel spheres.

Example 2

s1, selecting a target nucleic acid element for identifying a target ⁵⁹ Co、 ¹⁹¹ A combination of two of Ir;

s2, when a high-temperature gas-cooled reactor is in normal operation, a fuel loading and unloading system loads new conventional fuel elements into a reactor core of the high-temperature gas-cooled reactor every day, wherein 4 fuel elements (namely characteristic gamma fuel balls) added with identification codes are loaded at certain time intervals every day for 30 days continuously. Based on the quantity requirement of the gamma fuel balls with the characteristics, the target is marked ⁵⁹ Co contains 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40 parts, ¹⁹¹ Ir contains 0, 1 and 2 parts, and 120 combinations are obtained in total, so that the requirement of the code number of the characteristic gamma fuel spheres is met. The mass of 1 part of the target nucleic acid element was about 0.1mg.

S3, preparing a characteristic gamma fuel ball: the procedure is as in example 1.

The characteristic gamma fuel spheres and the conventional fuel elements (fuel elements without added identification targets) have the same fuel cycle operating mode and burnup value measurement,the high-purity germanium gamma spectrometer measures and records the characteristic gamma fuel spheres while the fuel consumption is measured on line ⁶⁰ Co and ¹⁹² and combining the characteristic gamma energy peak and the emission intensity of Ir to identify the specific identification code of the characteristic gamma fuel ball on line and in a lossless manner. The identification step comprises:

performing source item analysis and calculation on the characteristic gamma fuel spheres to obtain the types and the use amounts of the radioactive nuclides which identify the target parts in the characteristic gamma fuel spheres and the activity of each radioactive nuclide;

calculating preset values of corresponding gamma ray emission intensity combinations of the corresponding characteristic gamma fuel spheres with 1173.228keV, 1332.492keV and 316.506keV as characteristic energy peaks;

and comparing the corresponding gamma ray emission intensity combinations of the characteristic gamma fuel spheres discharged from the high-temperature gas cooled reactor pebble bed reactor core by using 1173.228keV, 1332.492keV and 316.506keV as characteristic energy peaks with a preset value, and identifying the identification codes of the characteristic gamma fuel spheres.

Example 3

s1, selecting target nucleic acid elements for marking the target ⁵⁹ Co、 ¹⁶⁹ A combination of two Tm;

s2, when a high-temperature gas-cooled reactor is in normal operation, a fuel loading and unloading system loads new conventional fuel elements into a reactor core of the high-temperature gas-cooled reactor every day, wherein 4 fuel elements (namely characteristic gamma fuel balls) added with identification codes are loaded at certain time intervals every day for 30 days continuously. Based on the quantity requirement of the gamma fuel balls with the characteristics, the target is marked ⁵⁹ Co contains 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30 parts, ¹⁶⁹ The Tm contains 0, 1, 2 and 3 parts, and 120 combinations are obtained in total, so that the requirement of the code number of the characteristic gamma fuel spheres is met. The mass of 1 part of the target nucleic acid element was about 0.1mg.

The characteristic gamma fuel ball and the conventional fuel element (fuel element without added identification target) have the same fuel circulation operation mode and fuel consumption value measurement mode, and the high-purity germanium gamma spectrometer measures and records the fuel consumption of the characteristic gamma fuel ball while measuring the fuel consumption on line ⁶⁰ Co and ¹⁷⁰ the specific identification code of the characteristic gamma fuel ball is identified on line and without loss by combining the characteristic gamma energy peak and the emission intensity of the Tm. The identification step comprises:

calculating preset values of corresponding gamma ray emission intensity combinations of the corresponding characteristic gamma fuel spheres with characteristic energy peaks of 1173.228keV, 1332.492keV and 84.255 keV;

and comparing the corresponding gamma ray emission intensity combinations of the characteristic gamma fuel spheres discharged from the high-temperature gas cooled reactor pebble bed reactor core and taking 1173.228keV, 1332.492keV and 84.255keV as characteristic energy peaks with a preset value, and identifying the identification codes of the characteristic gamma fuel spheres.

Example 4

s2, preparation of marking target

When the core of the high-temperature gas-cooled reactor is filled with new conventional fuel elements (fuel elements without the added identification targets) every day by the fuel loading and unloading system during the normal operation of the high-temperature gas-cooled reactor, 9 fuel elements with the added identification codes (namely, characteristic gamma fuel balls) are filled for 30 days continuously at certain time intervals every day for 270 total addition identification codes. Based on the quantity requirement of the gamma fuel balls with the characteristics, the target is marked ⁵⁹ Co contains 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30 parts, ¹⁹¹ Ir in 0, 1, 2 portions, ¹⁶⁹ The Tm contains 0, 1 and 2 parts, and 270 combinations are obtained in total, so that the requirement of the code number of the characteristic gamma fuel spheres is met. The mass of 1 part of the target nucleic acid element was about 0.1mg.

In marking targets ⁵⁹ The raw material of Co is a simple substance of cobalt, ¹⁹¹ the raw material of Ir is an iridium simple substance, ¹⁶⁹ tm is prepared from thulium simple substance. The physical form of the marking target is granular.

S4, on-line identification of the characteristic gamma fuel ball identification code: the procedure is as in example 1.

Example 5

s1, selecting a target nucleic acid element for identifying a target ⁵⁹ Co、 ¹⁹¹ Ir、 ¹⁶⁹ Combinations of three Tm;

s2, preparation of marking target

When the core of the high-temperature gas-cooled reactor is filled with new conventional fuel elements (fuel elements without added identification targets) every day by the fuel loading and unloading system during the normal operation of the high-temperature gas-cooled reactor, 12 fuel elements (namely, characteristic gamma fuel balls) with added identification codes are filled for 30 days continuously at certain time intervals every day. Based on the quantity requirement of the gamma fuel balls with the characteristics, the target is marked ⁵⁹ Co contains 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39 and 40 parts, ¹⁹¹ ir in 0, 1, 2 portions, ¹⁶⁹ The Tm contains 0, 1 and 2 parts, and 360 combinations are obtained in total, so that the requirement of the code number of the characteristic gamma fuel spheres is met. The mass of 1 part of the target nucleic acid element was about 0.1mg.

In marking targets ⁵⁹ The raw material of the Co is electroplated cobalt, ¹⁹¹ the raw material of Ir is an iridium simple substance, ¹⁶⁹ tm is as raw material Tm ₂ O ₃ . The physical form of the marking target is granular.

Example 6

The embodiment provides a fuel circulation tracing method in a high temperature gas cooled reactor spherical element stack, wherein the spherical element comprises a fuel element and graphite spheres, and the method comprises the following steps:

s2, preparation of marking target

During the normal operation of the high-temperature gas cooled reactor, when a core of the high-temperature gas cooled reactor is filled with new conventional fuel elements (fuel elements without added identification targets) through a fuel loading and unloading system every day, 10 spherical elements with added identification codes (the fuel elements with added identification codes are called characteristic gamma fuel spheres, and the graphite spheres with added identification codes are called characteristic gamma graphite spheres) are filled for 30 consecutive days every day; 290 characteristic gamma fuel spheres and 10 characteristic gamma graphite spheres; based on the quantity requirement of the characteristic gamma fuel spheres and the characteristic gamma graphite spheres, marking the target ⁵⁹ Co contains 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25 parts, ¹⁹¹ Ir in 0, 1, 2 portions, ¹⁶⁹ The Tm contains 0, 1, 2 and 3 parts, and 300 combinations are obtained in total, so that the requirement of the coding number of the characteristic gamma fuel spheres and the characteristic gamma graphite spheres is met.

S3, preparation of characteristic gamma fuel spheres and characteristic gamma graphite spheres

(1) The gamma fuel sphere comprises an inner layer spherical fuel area and an outer shell fuel-free area, wherein the inner layer spherical fuel area comprises a graphite matrix and coated fuel particles, the coated fuel particles are dispersed in the graphite matrix, and the coated fuel particles contain uranium; the shell fuel-free area comprises a graphite substrate and an identification target piece, the inner layer spherical fuel area is made of the same material as the graphite substrate of the shell fuel-free area, the identification target piece is coated by a coating material and then added into the graphite substrate of the shell fuel-free area in a particle form, the coating material is matrix graphite powder which is the same as the graphite substrate of the shell fuel-free area, the diameter of the inner layer spherical fuel area of the prepared gamma fuel sphere is 50mm, and the thickness of the shell fuel-free area is 5mm.

The matrix graphite powder is prepared from raw materials of 64% of natural crystalline flake graphite, 16% of artificial graphite and 20% of phenolic resin by mixing, kneading, extruding, crushing and screening.

The marking target is coated by the coating material and then is pressed in a fuel-free area of the shell by adopting a quasi-isostatic pressing process.

The manufacturing and testing process of the characteristic gamma fuel spheres is the same as that of the conventional fuel elements (the fuel elements without the added identification target) except that the identification target is added.

(2) Characteristic gamma graphite nodule

The identification target is added into the graphite nodules after being coated by a coating material, and the coating material is matrix graphite powder which is the same as the material of the graphite nodules. The matrix graphite powder is prepared from 64 mass percent of natural crystalline flake graphite, 16 mass percent of artificial graphite and 20 mass percent of phenolic resin through the processes of mixing, kneading, extruding, crushing and screening. The diameter of the prepared gamma graphite nodules is 60mm.

The manufacturing and detecting process of the characteristic gamma graphite nodules is the same as that of the conventional graphite nodules (the graphite nodules without the marking targets are added) except that the marking targets are added.

S4, identifying and coding on line by characteristic gamma fuel spheres and characteristic gamma graphite spheres

And performing fuel consumption measurement on spherical elements (including fuel elements without added identification targets, characteristic gamma fuel spheres and characteristic gamma graphite spheres) discharged from the high-temperature gas cooled reactor by using a high-purity germanium gamma spectrometer, and refilling the fuel elements (including the fuel elements without added identification targets and the characteristic gamma fuel spheres) which do not reach the designed fuel consumption value into the reactor core for recycling. When the specified burnup limit is reached, the refilling stack is not reused.

The high-purity germanium gamma spectrometer measures and records the characteristic gamma fuel spheres and the characteristic gamma graphite spheres while measuring the fuel consumption on line ⁶⁰ Co、 ¹⁹² Ir and ¹⁷⁰ the combination of the characteristic gamma energy peak and the emission intensity of Tm can identify the specific identification codes of the characteristic gamma fuel spheres and the characteristic gamma graphite spheres on line and in a lossless manner. The identification step comprises:

performing source item analysis and calculation on the characteristic gamma fuel spheres and the characteristic gamma graphite spheres to obtain the types and the dosage of the radioactive nuclides which identify the target parts in the characteristic gamma fuel spheres and the characteristic gamma graphite spheres and the activity of each radioactive nuclide;

calculating preset values of corresponding gamma ray emission intensity combinations of the characteristic gamma fuel spheres and the characteristic gamma graphite spheres with characteristic energy peaks of 1173.228keV, 1332.492keV, 316.506keV and 84.255 keV;

and comparing the corresponding gamma ray emission intensity combinations of the characteristic gamma fuel spheres and the characteristic gamma graphite spheres discharged from the high-temperature gas cooled reactor pebble bed reactor core, which take 1173.228keV, 1332.492keV, 316.506keV and 84.255keV as characteristic energy peaks, with preset values, and identifying the identification codes of the characteristic gamma fuel spheres and the characteristic gamma graphite spheres.

The tracing method for fuel circulation of the fuel element in the high-temperature gas-cooled reactor provided by the embodiment of the invention can acquire circulation data of multiple different periods in the fuel element reactor on line without damage, and the actual measurement data reflecting the randomness of the movement of the spherical flow in the reactor and the spherical flow path are utilized to carry out iterative calculation on the spherical flow model of the high-temperature gas-cooled reactor physical thermal calculation software so as to improve and verify the reactor core radial flow passage partition and axial fuel layering model, so that the accuracy of the physical thermal calculation analysis of the high-temperature gas-cooled reactor can be improved, the problem of spherical flow modeling of the high-temperature gas-cooled reactor in the world can be solved to a certain extent, and the safe operation of the high-temperature gas-cooled reactor can be guaranteed.

In the description of the present invention, it is to be understood that the terms "first", "second" and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implying any number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally formed; may be mechanically coupled, may be electrically coupled or may be in communication with each other; they may be directly connected or indirectly connected through intervening media, or they may be interconnected within two elements or in a relationship where two elements interact with each other unless otherwise specifically limited. The specific meanings of the above terms in the present invention can be understood according to specific situations by those of ordinary skill in the art.

In the present disclosure, the terms "one embodiment," "some embodiments," "an example," "a specific example," or "some examples" and the like mean that a specific feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present disclosure. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.

Although embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are exemplary and not to be construed as limiting the present invention, and that changes, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art within the scope of the present invention.

Claims

1. The internal circulation tracing method for spherical element in high temperature gas cooled reactor is characterized in that the methodThe method comprises the following steps: the identification target is added in the spherical element, so that the identification coding of the spherical element is realized; the identification target comprises a target nucleic acid element of ⁵⁹ Co、 ¹⁹¹ Ir、 ¹⁶⁹ One, two or three combinations of Tm, and at least ⁵⁹ Co, different target targets comprise different target nucleic elements in different types and/or proportions, and the spherical elements comprise fuel elements and/or graphite spheres.

2. The method according to claim 1, wherein the parts of the target nucleic acid element in the identification target are as follows: ⁵⁹ 1 to N portions of Co, ¹⁹¹ 0 to 2 portions of Ir, ¹⁶⁹ Tm is 0-3 parts, and N is an integer between 2-41.

3. The method according to claim 1, wherein in each spherical element, ⁵⁹ the content of Co is 0.1-N/10 mg, ¹⁹¹ Ir content of 0-0.2 mg, ¹⁶⁹ The Tm content is 0 mg-0.3mg, and N is an integer between 2-41.

4. The method as claimed in claim 1, wherein the identification target is a spherical element in-reactor circulation tracer ⁵⁹ The raw material of Co is selected from one of simple substance of cobalt and electroplating cobalt ¹⁹¹ The raw material of Ir is selected from one of iridium simple substance and iridium-10% gold alloy, and the raw material is ¹⁶⁹ The raw material of Tm is selected from thulium simple substance and Tm ₂ O ₃ To (3) is provided.

5. The method as claimed in claim 1, wherein the marking target is a granular, wire-like, sheet-like, metal-plated, glass-loaded or graphite powder tablet.

6. The in-reactor circulation tracing method for spherical elements of a high temperature gas cooled reactor according to any one of claims 1 to 5, wherein the fuel elements comprise an inner spherical fuel area and an outer shell fuel-free area, and the identification target is added to the outer shell fuel-free area of the fuel elements.

7. The method as claimed in claim 6, wherein the diameter of the spherical fuel region of the inner layer is 50mm, and the thickness of the fuel-free region of the outer shell is 2.5-7.5 mm.

8. The in-reactor circulation tracing method for spherical elements of the high temperature gas cooled reactor according to claim 6, wherein the inner spherical fuel zone comprises a graphite matrix and coated fuel particles, the coated fuel particles are dispersed in the graphite matrix, and the coated fuel particles contain uranium; the shell fuel-free zone comprises a graphite substrate and an identification target, the identification target is added into the graphite substrate of the shell fuel-free zone, and the inner layer spherical fuel zone is made of the same material as the graphite substrate of the shell fuel-free zone.

9. The method as claimed in claim 8, wherein the marking target is coated with a coating material, and is added to the graphite matrix of the shell non-fuel region of the fuel element in the form of particles, and the coating material is a matrix graphite powder identical to the graphite matrix of the shell non-fuel region.

10. The method according to claim 9, wherein the identification target is coated with a coating material and then pressed in a fuel-free area of a housing of the fuel element by a quasi-isostatic pressing process.

11. The in-reactor circulation tracing method for spherical elements in a high temperature gas cooled reactor according to any one of claims 1 to 5, characterized in that the identification target is added into graphite nodules after being coated with a coating material, and the coating material is a matrix graphite powder which is the same as the material of the graphite nodules.

12. The method for internally circulating and tracing the spherical element of the high temperature gas cooled reactor according to claim 1, further comprising: the identification code of the spherical elements is identified by measuring the combination of the corresponding gamma ray emission intensities of the spherical elements discharged from the high-temperature gas cooled reactor pebble bed reactor core, wherein the energy peaks are characterized by 1173.228keV, 1332.492keV, 316.506keV and 84.255 keV.

13. The method according to claim 12, wherein the measurement is performed by a high purity germanium gamma spectrometer of a burnup measurement system.

14. The method for tracing the internal circulation of the spherical element of the high-temperature gas-cooled reactor according to claim 12 or 13, wherein the identification method comprises the following steps:

acquiring the type and the dosage of the radionuclide for marking the target piece in the spherical element and the activity of each radionuclide;

15. A spherical element for a high-temperature gas-cooled reactor is characterized in that a marking target is added in the spherical element, and the marking target comprises a target nucleic element ⁵⁹ Co、 ¹⁹¹ Ir、 ¹⁶⁹ One, two or three combinations of Tm, and at least ⁵⁹ Co, different target nucleic elements with different kinds and/or ratios, and the spherical shapeThe elements are fuel elements or graphite spheres.

16. The spherical element for a high temperature gas cooled reactor according to claim 15, wherein the amount of the target core element in the identification target is: ⁵⁹ 1 to N portions of Co, ¹⁹¹ 0 to 2 portions of Ir, ¹⁶⁹ Tm is 0-3 parts, and N is an integer between 2-41.

17. Spherical element for a high temperature gas cooled reactor according to claim 15, wherein in each of said spherical elements, ⁵⁹ the content of Co is 0.1-N/10 mg, ¹⁹¹ The content of Ir is 0 mg-0.2 mg, ¹⁶⁹ The Tm content is 0 mg-0.3mg, and N is an integer between 2-41.

18. Spherical element for high temperature gas cooled reactor according to claim 15, characterized in that in the marking target ⁵⁹ The raw material of Co is selected from one of simple substance of cobalt and electroplated cobalt ¹⁹¹ The raw material of Ir is selected from one of iridium simple substance and iridium-10% gold alloy, and the raw material is ¹⁶⁹ The raw material of Tm is selected from thulium simple substance and Tm ₂ O ₃ To (3) is provided.

19. The spherical element for a high temperature gas-cooled reactor according to claim 15, wherein the marking target is in the form of a pellet, wire, sheet, metal plating, glass with a carrier substance, or graphite powder pellet.

20. The spherical element for a high temperature gas cooled reactor as claimed in any one of claims 15 to 19, wherein the fuel element comprises an inner spherical fuel region and an outer fuel-free region, and the identification target is added to the outer fuel-free region of the fuel element.

21. The spherical element for a high temperature gas cooled reactor as claimed in claim 20, wherein the inner spherical fuel zone has a diameter of 50mm and the outer shell fuel-free zone has a thickness of 2.5-7.5 mm.

22. The spherical element for a high temperature gas-cooled reactor according to claim 20, wherein the inner spherical fuel zone comprises a graphite matrix and coated fuel particles, the coated fuel particles are dispersed in the graphite matrix, and the coated fuel particles contain uranium; the shell fuel-free area comprises a graphite substrate and an identification target, the identification target is added into the graphite substrate of the shell fuel-free area, and the inner layer spherical fuel area is made of the same material as the graphite substrate of the shell fuel-free area.

23. The spherical element for a high temperature gas-cooled reactor as claimed in claim 22, wherein the marking target is coated with a coating material in the form of particles and added to the graphite matrix of the shell fuel-free zone of the fuel element, and the coating material is a matrix graphite powder identical to the graphite matrix material of the shell fuel-free zone.

24. The spherical element for a high temperature gas cooled reactor as claimed in claim 23, wherein the identification target is coated with a coating material and then pressed in the fuel-free zone of the outer shell of the fuel element by a quasi-isostatic pressing process.

25. A spherical element for a high temperature gas cooled reactor according to any of claims 15 to 19 wherein the identification target is coated with a coating material added to the graphite nodules, the coating material being the same base graphite powder as the material of the graphite nodules.

26. A high temperature gas cooled reactor system, comprising: comprising a spherical element according to any one of claims 15 to 25 for a high temperature gas cooled reactor.