CN117238542A - Aging state evaluation method for spent fuel neutron absorption material and storage grillwork thereof - Google Patents
Aging state evaluation method for spent fuel neutron absorption material and storage grillwork thereof Download PDFInfo
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- CN117238542A CN117238542A CN202311014141.4A CN202311014141A CN117238542A CN 117238542 A CN117238542 A CN 117238542A CN 202311014141 A CN202311014141 A CN 202311014141A CN 117238542 A CN117238542 A CN 117238542A
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- 239000002915 spent fuel radioactive waste Substances 0.000 title claims abstract description 61
- 238000003860 storage Methods 0.000 title claims abstract description 53
- 230000032683 aging Effects 0.000 title claims abstract description 26
- 238000011156 evaluation Methods 0.000 title claims abstract description 23
- 239000000463 material Substances 0.000 title claims description 39
- 238000010521 absorption reaction Methods 0.000 title claims description 13
- 238000001514 detection method Methods 0.000 claims abstract description 53
- 239000011358 absorbing material Substances 0.000 claims abstract description 44
- 238000000034 method Methods 0.000 claims abstract description 32
- 230000015556 catabolic process Effects 0.000 claims abstract description 30
- 238000006731 degradation reaction Methods 0.000 claims abstract description 30
- 230000008859 change Effects 0.000 claims abstract description 15
- 230000007246 mechanism Effects 0.000 claims description 32
- 238000001125 extrusion Methods 0.000 claims description 14
- 238000007789 sealing Methods 0.000 claims description 13
- 238000004458 analytical method Methods 0.000 claims description 10
- 238000005259 measurement Methods 0.000 claims description 9
- 238000007689 inspection Methods 0.000 claims description 6
- 238000011179 visual inspection Methods 0.000 claims description 6
- 230000005587 bubbling Effects 0.000 claims description 4
- 238000005260 corrosion Methods 0.000 claims description 4
- 230000007797 corrosion Effects 0.000 claims description 4
- 230000008961 swelling Effects 0.000 claims description 4
- 230000009467 reduction Effects 0.000 claims description 3
- 238000005070 sampling Methods 0.000 claims description 3
- 239000000126 substance Substances 0.000 claims description 3
- 230000001186 cumulative effect Effects 0.000 claims description 2
- 238000005516 engineering process Methods 0.000 claims description 2
- 238000002474 experimental method Methods 0.000 claims description 2
- 230000000737 periodic effect Effects 0.000 claims description 2
- 238000009434 installation Methods 0.000 claims 5
- 238000012360 testing method Methods 0.000 description 5
- 238000012986 modification Methods 0.000 description 4
- 230000004048 modification Effects 0.000 description 4
- 230000008569 process Effects 0.000 description 4
- 230000008901 benefit Effects 0.000 description 3
- 238000013461 design Methods 0.000 description 3
- 239000006096 absorbing agent Substances 0.000 description 2
- 230000000712 assembly Effects 0.000 description 2
- 238000000429 assembly Methods 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 2
- 238000011161 development Methods 0.000 description 2
- 230000018109 developmental process Effects 0.000 description 2
- 230000000670 limiting effect Effects 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 238000005299 abrasion Methods 0.000 description 1
- 230000001174 ascending effect Effects 0.000 description 1
- 239000003086 colorant Substances 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000003780 insertion Methods 0.000 description 1
- 230000037431 insertion Effects 0.000 description 1
- 239000003758 nuclear fuel Substances 0.000 description 1
- 238000003825 pressing Methods 0.000 description 1
- 230000002265 prevention Effects 0.000 description 1
- 238000012552 review Methods 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
Classifications
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E30/00—Energy generation of nuclear origin
- Y02E30/30—Nuclear fission reactors
Abstract
The application belongs to the technical field of aging management of nuclear power plants, in particular to a method for evaluating the aging state of a spent fuel neutron absorbing material, which comprises the steps of making a supervision plan and placing a sufficient number of samples in a sample tree; taking out the sample according to a supervision plan for detection; selecting part of standby samples, periodically taking out the samples, detecting the samples by adopting a nondestructive method, and putting the samples back into a sample tree after the detection is finished; judging the degradation condition of the neutron absorbing material according to the acceptance criterion; the sample tree is stored through the storage grid, and the application monitors the degradation condition and the change trend of the neutron absorbing material in a mode of regularly taking out samples for detection and evaluation by arranging a sufficient number of samples in advance aiming at the risk that the degradation of the neutron absorbing material of the spent fuel possibly occurs to cause the failure to maintain the spent fuel pool in a subcritical state, thereby achieving the aim of maintaining the subcritical state of the spent fuel pool and effectively ensuring the safe storage of the spent fuel.
Description
Technical Field
The application belongs to the technical field of aging management of nuclear power plants, and particularly relates to a method for evaluating aging states of spent fuel neutron absorbing materials and a storage grid thereof.
Background
The nuclear fuel assembly becomes a spent fuel assembly after irradiation in the reactor, and the spent fuel assembly needs to be discharged from the reactor core after reaching a certain burnup depth and stored in a spent fuel storage grid in the nuclear power plant. To increase the storage capacity of spent fuel assemblies, dense storage is currently common in nuclear power plants. However, when the spent fuel assemblies are in close proximity to each other, neutrons released from the spent fuel may reach concentrations that cause critical accidents to the spent fuel, and therefore neutron absorbers must be placed in the spent fuel storage shelves to prevent the spent fuel from being critical.
Neutron attenuation is the main function of neutron absorber, which is the basis for maintaining the critical state of spent fuel Chi Ya, wherein 10 B-side sealDegree variation is the most important consideration. And B can possibly happen when neutron absorbing materials are affected by mechanisms such as mechanical abrasion, corrosion and the like during the service life of the nuclear power unit 4 Loss and redistribution of C, thereby resulting in 10 The B-plane density varies. The foreign nuclear power operation experience also shows that part of nuclear power stations have swelling, bubbling, and other phenomena of neutron absorbing materials, 10 The degradation of the B-plane density, which is small, creates challenges in maintaining the subcritical state of the spent fuel pool. Therefore, measures are needed to monitor the state of neutron absorbing materials in the spent fuel storage grillwork, the critical degradation risk possibly causing the spent fuel pool is found in time, the safety of materials is ensured in the material taking process, and leakage of the materials is avoided, so that the storage grillwork is designed.
Disclosure of Invention
This section is intended to outline some aspects of embodiments of the application and to briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section as well as in the description of the application and in the title of the application, which may not be used to limit the scope of the application.
The application is provided in view of the above or the problems in the prior art that measures are taken to monitor the state of neutron absorbing materials in the spent fuel storage grillwork and discover the risk of critical degradation of the spent fuel pool in time.
Therefore, the application aims to provide a method for evaluating the aging state of a spent fuel neutron absorbing material.
In order to solve the technical problems, the application provides the following technical scheme: a method for evaluating the ageing state of neutron absorbing material of spent fuel includes such steps as providing a test sample,
making a supervision plan, and placing a sufficient number of samples in a sample tree;
taking out the sample according to a supervision plan for detection;
selecting part of standby samples, periodically taking out the samples, detecting the samples by adopting a nondestructive method, and putting the samples back into a sample tree after the detection is finished;
judging the degradation condition of the neutron absorbing material according to the acceptance criterion;
the sample tree is stored by a storage grid.
As a preferable scheme of the aging state evaluation method of the spent fuel neutron absorbing material, the application comprises the following steps:
the supervision plan is established, wherein the supervision plan is used for determining the detection interval of the taken sample;
and determining the detection interval of the taken sample, wherein the initial interval time is 4-5 years, and the subsequent interval time is 8-10 years.
As a preferable scheme of the aging state evaluation method of the spent fuel neutron absorbing material, the application comprises the following steps: placing a sufficient number of samples in a sample tree, wherein the sufficient number of samples is the number of samples required for sampling detection according to a supervision plan in a supervision period, and comprises more than two standby samples; loading the sample into a frame for fixing and supporting the sample, and placing the frame loaded with the sample at a designated storage position on a spent fuel storage rack, close to the newly discharged spent fuel assembly, so as to accelerate cumulative exposure to parameters which may influence ageing degradation of the neutron absorbing material, and simulate the worst case; each sample is marked and distinguished;
the sample is taken out according to a supervision plan for detection, wherein the detection comprises the following steps: visual inspection, dimensional inspection, gravimetric measurement, neutron absorption capability detection; neutron absorption capacity detection as a chemical measurement experiment sample 10 B-plane density.
As a preferable scheme of the aging state evaluation method of the spent fuel neutron absorbing material, the application comprises the following steps: the periodically taken samples are detected by adopting a nondestructive method, wherein the nondestructive detection comprises the steps of selecting at least two standby samples for periodic detection according to a supervision plan, and the steps of: visual inspection, dimensional inspection, gravimetric measurement, neutron absorption capability detection; the neutron absorption capacity detection needs to be carried out by adopting a proper nondestructive detection method, for example, a temporary detection technology without proper detection can be used for temporary detection; after the relevant detection is completed, the sample is put back into the frame and put back into the spent fuel pool so as to continuously monitor the change trend of the degradation condition.
As a preferable scheme of the aging state evaluation method of the spent fuel neutron absorbing material, the application comprises the following steps: and judging the degradation condition of the neutron absorbing material according to an acceptance criterion, wherein the acceptance criterion is as follows:
(1) recording appearance change conditions of the sample, if obvious uniform/local corrosion phenomenon is found, the criterion of (3) is required to be met;
(2) recording the weight and size change conditions of the sample, and if the thickness reduction, swelling and bubbling phenomena are found, meeting the criterion of item (3);
③ 10 the B-plane density needs to be greater than the values used in the critical analysis of spent fuel pool.
As a preferable scheme of the aging state evaluation method of the spent fuel neutron absorbing material, the application comprises the following steps: judging the degradation condition of the neutron absorbing material according to the acceptance criterion, wherein the judgment of the degradation condition of the neutron absorbing material is to compare the detection result with the acceptance criterion to obtain an evaluation conclusion, and judging according to the evaluation conclusion;
the evaluation conclusion is obtained, wherein the evaluation conclusion is that:
(a) Confirming that degradation does not occur;
(b) Confirming that expected degradation changes are occurring, the strip being suitable for neutron absorbing materials that have long been experienced and found to be degraded;
(c) An ongoing unintended degradation variation is identified.
As a preferable scheme of the aging state evaluation method of the spent fuel neutron absorbing material, the application comprises the following steps: judging according to the comment conclusion, wherein the judging result is as follows:
if the conclusion is (a) or (b), the state of the neutron absorbing material can still continuously meet the requirements in the critical analysis of the spent fuel pool; if the conclusion is (c), the attention needs to be paid, and the evaluation of the influence of the related change on the critical analysis result of the spent fuel pool is carried out.
The aging state evaluation method for the spent fuel neutron absorption material has the beneficial effects that: according to the application, aiming at the risk that the subcritical state of the spent fuel pool cannot be maintained due to the fact that the degradation of the neutron absorbing material of the spent fuel is likely to occur, the degradation condition and the change trend of the neutron absorbing material are supervised in a mode of arranging a sufficient number of samples in advance and taking out the samples periodically for detection and evaluation, so that the aim of maintaining the subcritical state of the spent fuel pool is fulfilled, and the safe storage of the spent fuel is effectively ensured.
In order to solve the technical problem of material taking leakage prevention, the application provides the following technical scheme: the storage grid comprises a storage grid body, wherein the storage grid body comprises a containing mechanism, a material taking switching mechanism arranged in the containing mechanism and a sample storage mechanism arranged at the top of the containing mechanism.
As a preferred embodiment of the storage grid according to the application, wherein: the accommodating mechanism comprises a base, an installing sleeve arranged on the base, an accommodating sleeve arranged on the installing sleeve, a plurality of accommodating boxes arranged inside the accommodating sleeve, a slot arranged on one side of the accommodating boxes, and a material taking switching mechanism comprising a lifting part arranged inside the installing sleeve, an adjusting part arranged on the lifting part, a positioning part arranged on the adjusting part, wherein the lifting part comprises an electric telescopic rod arranged on the installing sleeve, a lifting rod arranged on the electric telescopic rod, and an installing groove arranged inside the lifting rod.
As a preferred embodiment of the storage grid according to the application, wherein: the adjusting part comprises a driving assembly arranged in the mounting groove and a rotating frame arranged on the driving assembly;
the driving assembly comprises a rotating column arranged in the mounting groove, an extrusion piece and a positioning piece which are arranged on the rotating column, and the rotating column is connected with the rotating frame;
the extrusion piece comprises a rectangular box arranged on the rotary column, a connecting spring arranged on the rectangular box, a sliding frame arranged on the connecting spring and an extrusion wheel arranged on the sliding frame;
the positioning piece comprises a stop groove arranged on the rotary column, a stop block arranged on the stop groove, a positioning spring arranged on the stop block and a positioning frame arranged between the positioning spring and the mounting sleeve;
the positioning component comprises a side groove for adapting to the extrusion piece, a sliding sleeve arranged between the side groove and the lifting rod, two clamping plates arranged on the sliding sleeve, a sealing plate arranged in the sliding sleeve, a rod body arranged on one side of the sealing plate, a plugboard arranged on one side of the rod body, a reset spring arranged between the sealing plate and the sliding sleeve, an air bag arranged on one side of the sliding sleeve, a bracket arranged on one side of the air bag, and an arc groove arranged on the bracket;
the side groove is formed in the mounting sleeve, the air bag is communicated with the sliding sleeve, and the positioning component further comprises a positioning plugboard arranged on the mounting sleeve;
the sample storage mechanism comprises a top cover arranged on the accommodating sleeve, and a sample box arranged at the bottom of the top cover.
The storage grid has the beneficial effects that: the setting of sample storage mechanism can be effectual carry out spacing and storage to the material, can guarantee the state of material, and the setting of getting material switching mechanism can take out corresponding material as required, can only take out the material in the single box at every turn, avoids the material to take place to leak.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the description of the embodiments will be briefly described below, it being obvious that the drawings in the following description are only some embodiments of the present application, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
FIG. 1 is a flow chart of a method for evaluating the aging state of a spent fuel neutron absorbing material.
Fig. 2 is a schematic view of the overall structure of the storage grid.
Fig. 3 is a split schematic view of the overall structure of the storage grid.
Fig. 4 is a schematic view of a part of the structure of the storage grid.
Fig. 5 is an enlarged view at a in fig. 4.
Fig. 6 is a schematic structural view of a material taking and switching mechanism of the storage grillwork.
Fig. 7 is an enlarged view at B in fig. 6.
Fig. 8 is a schematic view of the extrusion configuration of the storage grid.
Fig. 9 is a schematic view of the positioning member structure of the storage grid.
Fig. 10 is a schematic cross-sectional view of a storage grid positioning member.
Detailed Description
In order that the above-recited objects, features and advantages of the present application will become more readily apparent, a more particular description of the application will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings.
In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application, but the present application may be practiced in other ways other than those described herein, and persons skilled in the art will readily appreciate that the present application is not limited to the specific embodiments disclosed below.
Further, reference herein to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic can be included in at least one implementation of the application. The appearances of the phrase "in one embodiment" in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments.
Embodiment 1, referring to fig. 1, is a first embodiment of the present application, and the embodiment provides a method for evaluating aging state of a neutron absorbing material of spent fuel, which includes the following steps:
making a supervision plan, and placing a sufficient number of samples in a sample tree:
and (5) setting the detection interval of the taken samples. The initial interval was 5 years and the subsequent interval was 10 years. The supervision cycle considers the lifetime of the nuclear power plant (including the license extending 20 years) plus a margin of 5 years, i.e. 85 years.
The number of samples required to meet the supervisory schedule for sampling test was made and contained 2 spare samples. The sample is then loaded into a frame for holding, supporting the sample and the frame loaded with the sample is placed in a designated storage location on the spent fuel storage rack. In addition, each sample needs to be distinguished by a position identification number.
Taking out the sample according to the plan for detection: periodically taking out the sample for detection according to a supervision plan, including: visual inspection, dimensional inspection, gravimetric measurement, neutron absorption capacity detection (chemical measurement of test pieces 10 B areal density). The detection result is recorded after detection and compared with the previous case.
Selecting part of standby samples, periodically taking out the samples, detecting the samples by adopting a nondestructive method, and replacing the samples with the sample tree after the detection is finished:
selecting two standby samples to perform detection regularly according to a supervision plan, wherein the method comprises the following steps: visual inspection, dimensional inspection, weight measurement. The detection result is recorded after detection and compared with the previous case. After the relevant test is completed, the sample is replaced in the frame and returned to the pool.
Judging the degradation condition of the neutron absorbing material according to the acceptance criterion:
analyzing the detection result according to the following acceptance criteria:
1. recording appearance change conditions of the sample, if obvious uniform/local corrosion phenomenon is found, the 3 rd criterion is required to be met;
2. recording the weight and size change conditions of the sample, and if the thickness reduction, swelling and bubbling phenomena are found, meeting the 3 rd criterion;
3. 10 the B-plane density needs to be greater than the values used in the critical analysis of spent fuel pool.
And (5) determining an evaluation conclusion by comprehensive detection analysis results.
Conclusions fall into three categories: a, confirming that degradation and change do not occur; b confirming that the expected degradation change is occurring (applicable to neutron absorbing materials that have long been experienced and found to be degraded); c identifying the unexpected degradation changes that are occurring.
If the conclusion is a or b, the state of the neutron absorbing material can still continuously meet the requirements in the critical analysis of the spent fuel pool; if the conclusion is c, the attention needs to be enhanced, and the evaluation of the influence of the related change on the critical analysis result of the spent fuel pool is carried out.
Embodiment 2 referring to fig. 2 to 10, a storage rack according to a second embodiment of the present application is different from the previous embodiment in that the storage rack includes a storage rack including a receiving mechanism 100, a material taking and switching mechanism 200 provided inside the receiving mechanism 100, and a sample storage mechanism 300 provided on top of the receiving mechanism 100. The housing mechanism 100 includes a base 101, a mounting sleeve 102 provided on the base 101, a housing sleeve 103 provided on the mounting sleeve 102, a plurality of housing boxes 104 provided inside the housing sleeve 103, and a slot 105 provided on one side of the housing boxes 104. The sample storage mechanism 300 includes a top cover 301 provided on the receiving sleeve 103, and a sample box 302 provided at the bottom of the top cover 301.
Specifically, the setting of sample storage mechanism 300 can be effectual to carry out spacing and storage to the material, can guarantee the state of material, and the setting of getting material switching mechanism 200 can take out corresponding material as required, can only take out the material in the single box at a time, avoids the material to take out to leak.
The material taking and switching mechanism 200 comprises a lifting component 201 arranged in the mounting sleeve 102, an adjusting component 202 arranged on the lifting component 201, and a positioning component 203 arranged on the adjusting component 202. The lifting member 201 includes an electric telescopic rod 201a provided to the mounting sleeve 102, a lifting rod 201b provided to the electric telescopic rod 201a, and a mounting groove 201c provided inside the lifting rod 201 b.
Further, the lifting component 201 can effectively drive the accommodating box 104 to lift, so as to achieve the effect of taking out materials, and the positioning component 203 can effectively limit the accommodating box 104, so as to cooperate with the lifting component 201 to lift the accommodating box 104.
The rest of the structure is the same as in embodiment 1.
When the device is used, if only sample materials are taken out, only the top cover 301 is required to be lifted, the sample box 302 is lifted in the lifting process of the top cover 301, the materials in the test box are taken out at the moment, when the materials in the accommodating box 104 are required to be taken out, the material taking switching mechanism 200 is rotated, so that the materials required to be taken out are determined, the electric telescopic rod 201a drives the selected accommodating box 104 to lift after the selection is completed, and the materials required to be taken out again are required to be selected by resetting the last accommodating box 104 and then rotating the material taking switching mechanism 200.
Embodiment 3 referring to fig. 2 to 10, which is a third embodiment of the present application, unlike the previous embodiment, the adjustment member 202 includes a driving assembly 202a disposed in a mounting groove 201c, and a rotating frame 202b disposed on the driving assembly 202 a; the drive assembly 202a includes a rotor post 202a-1 disposed in a mounting groove 201c, an extrusion 202a-2 disposed on the rotor post 202a-1 and a positioning member 202a-3, the rotor post 202a-1 being coupled to a rotor frame 202b; the extrusion 202a-2 includes a rectangular box 202a-2a provided on the rotary column 202a-1, a connection spring 202a-2b provided on the rectangular box 202a-2a, a carriage 202a-2c provided on the connection spring 202a-2b, and an extrusion wheel 202a-2d provided on the carriage 202a-2 c; the positioning member 202a-3 includes a stop groove 202a-3a provided on the rotary post 202a-1, a stop block 202a-3b provided on the stop groove 202a-3a, a positioning spring 202a-3c provided on the stop block 202a-3b, and a positioning bracket 202a-3d provided between the positioning spring 202a-3c and the mounting sleeve 102.
Specifically, the rotating column 202a-1 is formed by splicing a cylinder body and a round rod, the sections of the cylinder body and the round rod are rectangular, the rotating column 202a-1 is arranged to prevent the electric telescopic rod 201a from driving the rotating frame 202b to move in the ascending and descending processes, so that the accommodating box 104 can be effectively jacked, the one-way movement of the rotating column 202a-1 can be ensured by arranging the stop groove 202a-3a and the stop block 202a-3b, the positioning springs 202a-3c can be effectively limited by arranging the positioning frames 202a-3d, and the number of the accommodating boxes 104 is four.
The positioning member 203 includes a side groove 203a adapted to the pressing member 202a-2, a sliding sleeve 203b provided between the side groove 203a and the lifting rod 201b, two holding plates 203c provided on the sliding sleeve 203b, a sealing plate 203d provided inside the sliding sleeve 203b, a rod body 203e provided on one side of the sealing plate 203d, a plug board 203f provided on one side of the rod body 203e, a return spring 203g provided between the sealing plate 203d and the sliding sleeve 203b, an air bag 203h provided on one side of the sliding sleeve 203b, a bracket 203i provided on one side of the air bag 203h, and an arc groove 203j provided on the bracket 203 i; the side groove 203a is formed in the mounting sleeve 102, the air bag 203h is communicated with the sliding sleeve 203b, and the positioning member 203 further comprises a positioning insertion plate 203k arranged on the mounting sleeve 102.
Further, the setting of limit groove 203a can be effectual carries out spacingly to sliding sleeve 203b, newspaper sliding sleeve 203b is only inside limit groove 203a at the in-process that removes, sealing plate 203 d's setting can be effectual to the storage gas, guarantee to form a sealed space between gasbag 203h and sliding sleeve 203b, the sealing plate 203d, be equipped with gas in this space, when gasbag 203h is extruded, atmospheric pressure can effectual promotion sealing plate 203d remove, thereby drive location picture peg 203k and remove, thereby guarantee that location picture peg 203k gets into slot 105, after entering slot 105, location picture peg 203k can effectual drive holding case 104 rise after the electric telescopic handle 201a stretches.
The rest of the structure is the same as in embodiment 2.
When the rotary frame 202b is rotated, when the rotary frame 202b rotates, the extrusion wheels 202a-2d extrude the air bags 203h, when the air bags 203h are extruded, air pressure can effectively push the sealing plate 203d to move so as to drive the positioning inserting plate 203k to move, thereby ensuring that the positioning inserting plate 203k enters the slot 105, the lifting part 201 at the moment is connected with one of the four accommodating boxes 104 after the positioning inserting plate 203k enters the slot 105, the electric telescopic rod 201a is started, and the positioning inserting plate 203k can effectively drive the accommodating boxes 104 to rise after the electric telescopic rod 201a stretches so as to take materials;
after the material is taken out, the reset can be completed by reversing the operation, when the material in the next accommodating box 104 needs to be taken out, the rotating frame 202b is continuously rotated, and the extrusion wheels 202a-2d pass through the support 203i and enter the next air bag 203h under the limiting action of the arc groove 203 j.
It is important to note that the construction and arrangement of the application as shown in the various exemplary embodiments is illustrative only. Although only a few embodiments have been described in detail in this disclosure, those skilled in the art who review this disclosure will readily appreciate that many modifications are possible (e.g., variations in sizes, dimensions, structures, shapes and proportions of the various elements, values of parameters (e.g., temperature, pressure, etc.), mounting arrangements, use of materials, colors, orientations, etc.) without materially departing from the novel teachings and advantages of the subject matter described in this application. For example, elements shown as integrally formed may be constructed of multiple parts or elements, the position of elements may be reversed or otherwise varied, and the nature or number of discrete elements or positions may be altered or varied. Accordingly, all such modifications are intended to be included within the scope of present application. The order or sequence of any process or method steps may be varied or re-sequenced according to alternative embodiments. In the claims, any means-plus-function clause is intended to cover the structures described herein as performing the recited function and not only structural equivalents but also equivalent structures. Other substitutions, modifications, changes and omissions may be made in the design, operating conditions and arrangement of the exemplary embodiments without departing from the scope of the present applications. Therefore, the application is not limited to the specific embodiments, but extends to various modifications that nevertheless fall within the scope of the appended claims.
Furthermore, in order to provide a concise description of the exemplary embodiments, all features of an actual implementation may not be described (i.e., those not associated with the best mode presently contemplated for carrying out the application, or those not associated with practicing the application).
It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions may be made. Such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure.
It should be noted that the above embodiments are only for illustrating the technical solution of the present application and not for limiting the same, and although the present application has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that the technical solution of the present application may be modified or substituted without departing from the spirit and scope of the technical solution of the present application, which is intended to be covered in the scope of the claims of the present application.
Claims (10)
1. A method for evaluating the aging state of a spent fuel neutron absorption material is characterized by comprising the following steps of: comprising the steps of (a) a step of,
making a supervision plan, and placing a sufficient number of samples in a sample tree;
taking out the sample according to a supervision plan for detection;
selecting part of standby samples, periodically taking out the samples, detecting the samples by adopting a nondestructive method, and putting the samples back into a sample tree after the detection is finished;
judging the degradation condition of the neutron absorbing material according to the acceptance criterion;
the sample tree is stored by a storage grid (M).
2. The method for evaluating the aging state of the spent fuel neutron absorbing material according to claim 1, wherein the method comprises the following steps: the supervision plan is established, wherein the supervision plan is used for determining the interval of sample taking detection ；
And determining the detection interval of the taken sample, wherein the initial interval time is 4-5 years, and the subsequent interval time is 8-10 years.
3. The method for evaluating the aging state of the spent fuel neutron absorbing material according to claim 2, wherein the method comprises the following steps of: placing a sufficient number of samples in a sample tree, wherein the sufficient number of samples is the number of samples required for sampling detection according to a supervision plan in a supervision period, and comprises more than two standby samples; loading the sample into a frame for fixing and supporting the sample, and placing the frame loaded with the sample at a designated storage position on a spent fuel storage rack, close to the newly discharged spent fuel assembly, so as to accelerate cumulative exposure to parameters which may influence ageing degradation of the neutron absorbing material, and simulate the worst case; each sample is marked and distinguished;
the sample is taken out according to a supervision plan for detection, wherein the detection comprises the following steps: visual inspection, dimensional inspection, gravimetric measurement, neutron absorption capability detectionThe method comprises the steps of carrying out a first treatment on the surface of the Neutron absorption capacity detection as a chemical measurement experiment sample 10 B-plane density.
4. The method for evaluating the aging state of the spent fuel neutron absorbing material according to claim 3, wherein the method comprises the following steps of: the periodically taken samples are detected by adopting a nondestructive method, wherein the nondestructive detection comprises the steps of selecting at least two standby samples for periodic detection according to a supervision plan, and the steps of: visual inspection, dimensional inspection, gravimetric measurement, neutron absorption capability detection; the neutron absorption capacity detection needs to be carried out by adopting a proper nondestructive detection method, for example, a temporary detection technology without proper detection can be used for temporary detection; after the relevant detection is completed, the sample is put back into the frame and put back into the spent fuel pool so as to continuously monitor the change trend of the degradation condition.
5. The method for evaluating the aging state of the spent fuel neutron absorbing material according to claim 4, which is characterized in that: and judging the degradation condition of the neutron absorbing material according to an acceptance criterion, wherein the acceptance criterion is as follows:
(1) recording appearance change conditions of the sample, if obvious uniform/local corrosion phenomenon is found, the criterion of (3) is required to be met;
(2) recording the weight and size change conditions of the sample, and if the thickness reduction, swelling and bubbling phenomena are found, meeting the criterion of item (3);
③ 10 the B-plane density needs to be greater than the values used in the critical analysis of spent fuel pool.
6. The method for evaluating the aging state of the spent fuel neutron absorbing material according to claim 5, wherein the method comprises the following steps of: judging the degradation condition of the neutron absorbing material according to the acceptance criterion, wherein the judgment of the degradation condition of the neutron absorbing material is to compare the detection result with the acceptance criterion to obtain an evaluation conclusion, and judging according to the evaluation conclusion;
the evaluation conclusion is obtained, wherein the evaluation conclusion is that:
(a) Confirming that degradation does not occur;
(b) Confirming that expected degradation changes are occurring, the strip being suitable for neutron absorbing materials that have long been experienced and found to be degraded;
(c) An ongoing unintended degradation variation is identified.
7. The method for evaluating the aging state of the spent fuel neutron absorbing material according to claim 6, wherein the method comprises the following steps: judging according to the comment conclusion, wherein the judging result is as follows:
if the conclusion is (a) or (b), the state of the neutron absorbing material can still continuously meet the requirements in the critical analysis of the spent fuel pool; if the conclusion is (c), the attention needs to be paid, and the evaluation of the influence of the related change on the critical analysis result of the spent fuel pool is carried out.
8. A storage grid, characterized by: the storage rack (M) according to claim 1, wherein the storage rack (M) comprises a receiving mechanism (100), a material taking switching mechanism (200) disposed inside the receiving mechanism (100), and a sample storage mechanism (300) disposed on top of the receiving mechanism (100).
9. The storage grid of claim 8, wherein: the accommodating mechanism (100) comprises a base (101), an installation sleeve (102) arranged on the base (101), an accommodating sleeve (103) arranged on the installation sleeve (102), a plurality of accommodating boxes (104) arranged inside the accommodating sleeve (103), a slot (105) arranged on one side of the accommodating boxes (104), the material taking switching mechanism (200) comprises a lifting component (201) arranged inside the installation sleeve (102), an adjusting component (202) arranged on the lifting component (201), a positioning component (203) arranged on the adjusting component (202), the lifting component (201) comprises an electric telescopic rod (201 a) arranged on the installation sleeve (102), a lifting rod (201 b) arranged on the electric telescopic rod (201 a), and an installation groove (201 c) arranged inside the lifting rod (201 b).
10. The storage grid of claim 9, wherein: the adjusting component (202) comprises a driving assembly (202 a) arranged in the mounting groove (201 c), and a rotating frame (202 b) arranged on the driving assembly (202 a);
the driving assembly (202 a) comprises a rotating column (202 a-1) arranged in the mounting groove (201 c), an extrusion piece (202 a-2) arranged on the rotating column (202 a-1) is connected with a positioning piece (202 a-3), and the rotating column (202 a-1) is connected with a rotating frame (202 b);
the extrusion (202 a-2) comprises a rectangular box (202 a-2 a) arranged on the rotary column (202 a-1), a connecting spring (202 a-2 b) arranged on the rectangular box (202 a-2 a), a sliding frame (202 a-2 c) arranged on the connecting spring (202 a-2 b) and an extrusion wheel (202 a-2 d) arranged on the sliding frame (202 a-2 c);
the positioning piece (202 a-3) comprises a stop groove (202 a-3 a) arranged on the rotary column (202 a-1), a stop block (202 a-3 b) arranged on the stop groove (202 a-3 a), a positioning spring (202 a-3 c) arranged on the stop block (202 a-3 b), and a positioning frame (202 a-3 d) arranged between the positioning spring (202 a-3 c) and the mounting sleeve (102);
the positioning component (203) comprises a side groove (203 a) which is matched with the extrusion piece (202 a-2), a sliding sleeve (203 b) which is arranged between the side groove (203 a) and the lifting rod (201 b), two clamping plates (203 c) which are arranged on the sliding sleeve (203 b), a sealing plate (203 d) which is arranged in the sliding sleeve (203 b), a rod body (203 e) which is arranged on one side of the sealing plate (203 d), a plugboard (203 f) which is arranged on one side of the rod body (203 e), a reset spring (203 g) which is arranged between the sealing plate (203 d) and the sliding sleeve (203 b), an air bag (203 h) which is arranged on one side of the sliding sleeve (203 b), a bracket (203 i) which is arranged on one side of the air bag (203 h), and an arc groove (203 j) which is arranged on the bracket (203 i);
the side groove (203 a) is formed in the mounting sleeve (102), the air bag (203 h) is communicated with the sliding sleeve (203 b), and the positioning component (203) further comprises a positioning plugboard (203 k) arranged on the mounting sleeve (102);
the sample storage mechanism (300) comprises a top cover (301) arranged on the accommodating sleeve (103), and a sample box (302) arranged at the bottom of the top cover (301).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311014141.4A CN117238542A (en) | 2023-08-11 | 2023-08-11 | Aging state evaluation method for spent fuel neutron absorption material and storage grillwork thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311014141.4A CN117238542A (en) | 2023-08-11 | 2023-08-11 | Aging state evaluation method for spent fuel neutron absorption material and storage grillwork thereof |
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| Publication Number | Publication Date |
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| CN117238542A true CN117238542A (en) | 2023-12-15 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202311014141.4A Pending CN117238542A (en) | 2023-08-11 | 2023-08-11 | Aging state evaluation method for spent fuel neutron absorption material and storage grillwork thereof |
Country Status (1)
| Country | Link |
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| CN (1) | CN117238542A (en) |
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- 2023-08-11 CN CN202311014141.4A patent/CN117238542A/en active Pending
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