CN115331852B - Subcritical reactor control rod reactivity value measurement method - Google Patents
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Abstract
The invention discloses a method for measuring the reactivity value of a subcritical reactor control rod, which comprises the following steps: acquiring the neutron flux density of the reactor in an initial subcritical state; inserting control rods into the subcritical reactor core section by section, and measuring neutron flux densities corresponding to different positions of the control rods inserted into the subcritical reactor core; calculating space correction factors corresponding to different positions of the core of the subcritical reactor, in which the control rods are inserted; correcting neutron flux density corresponding to different positions of a subcritical reactor core by using space correction factors of control rod insertion positions; and calculating to obtain the subcritical state of the control rod inserted into different positions of the subcritical reactor core. According to the invention, neutron flux densities of the control rods recorded by the reactor neutron detector at different positions in the reactor core are used as raw data input, and the reactivity value of each section of the control rods is calculated through a correlation algorithm, so that the scales of the reactivity value of the subcritical reactor control rods can be rapidly realized in real time.
Description
Technical Field
The invention relates to the technical field of accelerator driving subcritical system (ADS) benchmark test measurement, in particular to a subcritical reactor control rod reactivity value measurement method.
Background
The control rod is one of key equipment of a nuclear reactor system, and changes of the reactivity of the reactor system are realized through neutron absorption, so that functions of reactor power level control, full reactor core power distribution flattening and the like are realized. For a nuclear reactor system, a control rod reactivity value measurement test must be carried out before the nuclear reactor system is operated under power to obtain control rod integral value and differential value information, verify theoretical design and provide data support for safe operation and control of the reactor.
The most common control rod reactivity value measurement means used in the current nuclear power station reactor system is a positive cycle method, namely, the reactor operates in a slightly supercritical state, the power rising periods of the reactors in different control rod insertion states are measured, and the reactivity value of the control rod is determined by combining the relation table lookup between the periods and the reactivity. The accuracy of measuring the reactivity value of the control rod by the positive cycle method is higher, but the method needs to measure the power multiplication cycle of the reactor, so that the measurement of the reactivity value of each section of control rod takes longer time, and the quick calibration of the value of the control rod is not facilitated. In addition, positive cycle methods to measure control rod value require that the reactor be operated in supercritical conditions, increasing safety risks.
For an accelerator driven subcritical system, the reactor is always operated under subcritical working conditions, and the positive cycle method is not applicable any more.
Disclosure of Invention
Therefore, in order to overcome the defects and limitations of the conventional control rod reactivity value measurement technology, the invention provides a subcritical reactor control rod reactivity value measurement method. According to the invention, neutron flux densities of the control rods recorded by the reactor neutron detector at different positions in the reactor core are used as raw data input, and the reactivity value of each section of the control rods is calculated through a correlation algorithm, so that the scales of the reactivity value of the subcritical reactor control rods can be rapidly realized in real time.
The invention is realized by the following technical scheme:
a subcritical reactor control rod reactivity value measurement method, comprising:
acquiring the neutron flux density of the reactor in an initial subcritical state;
inserting control rods into the subcritical reactor core section by section, and measuring neutron flux densities corresponding to different positions of the control rods inserted into the subcritical reactor core;
calculating space correction factors corresponding to different positions of the core of the subcritical reactor, in which the control rods are inserted;
correcting neutron flux density corresponding to different positions of a subcritical reactor core by using space correction factors of control rod insertion positions;
and calculating the subcritical state of the control rod inserted into different positions of the subcritical reactor core according to the initial subcritical state of the reactor, the neutron flux density in the initial subcritical state and the neutron flux densities corresponding to the different positions of the corrected control rod inserted into the subcritical reactor core.
As a preferred embodiment, the method for obtaining the initial subcritical state of the reactor and the neutron flux density in the initial subcritical state of the reactor according to the present invention specifically comprises:
when the control rod is completely positioned outside the reactor, the reactor is in an initial subcritical state, the initial subcritical state is measured through a pulse neutron source test, and the neutron flux density in the initial subcritical state is obtained by taking the neutron flux density recorded by a neutron detector after the reactor stably runs for a preset time.
As a preferred embodiment, the spatial correction factor of the present invention is defined as the ratio of neutron flux density distribution shape functions in two different subcritical states, and the spatial correction factor calculation process includes:
performing physical modeling on the researched subcritical reactor by adopting a Monte Carlo neutron transport program MCNP;
the neutron counting rate measured at the position of the neutron detector is calculated in a simulation mode, and meanwhile the total number of neutrons in the whole space in the simulation calculation process is recorded, so that the value of the neutron flux density distribution shape function at the position of the neutron detector is the ratio of the neutron counting rate measured at the position of the neutron detector to the total number of neutrons in the space;
the neutron flux distribution shape function of the control rod in the initial subcritical state of the reactor and the neutron flux density distribution shape function of the control rod inserted into different positions of the subcritical reactor core can be obtained through the simulation calculation in the space correction factor calculation process, so that the space correction factors of the control rod inserted into different positions of the subcritical reactor core are obtained according to the definition of the space correction factors.
As a preferred embodiment, the correction process of the present invention specifically includes:
and (3) inserting the measured control into neutron flux densities at different positions of the subcritical reactor core to divide the neutron flux densities by corresponding space correction factors, so that the corrected neutron flux densities can be obtained.
As a preferred embodiment, the calculation of the present invention obtains the subcritical state of the control rod inserted into different positions of the subcritical reactor core, specifically:
the subcritical state at a location where the control rod is inserted into the subcritical reactor core is equal to the product of the initial subcritical state of the reactor and the neutron flux density at that initial subcritical state divided by the corrected neutron flux density at that location.
As a preferred embodiment, the neutron flux density of the present invention may be obtained by at least one neutron detector.
As a preferred embodiment, the neutron flux density of the present invention can be obtained by averaging data obtained from multiple neutron detectors arranged at different locations of the subcritical reactor.
As a preferred embodiment, the neutron detector of the present invention for measuring neutron flux density is a galvanic neutron detector or a pulsed neutron detector.
As a preferred embodiment, the measurement system adopted by the method of the invention comprises at least one path of neutron detector, a signal conditioning module and a reactivity calculation module;
and at least one path of neutron detector output signal is sent to the signal conditioning module for filtering and amplifying treatment and then sent to the reactivity calculation module for reactivity calculation.
As a preferred embodiment, the signal conditioning module of the present invention comprises a pre-amplifier and a linear pulse amplifier.
The invention has the following advantages and beneficial effects:
the invention can be used for the control rod reactivity value scale under the deep subcritical condition, and the subcritical depth is k eff The control rod reactivity value can be measured rapidly and accurately when the control rod is in the condition of being=0.8.
According to the invention, the space effect caused by the insertion of the control rod is fully considered in the process of realizing the control rod reactivity value scale, and the influence of the neutron flux density distribution shape change under different subcritical levels is eliminated by combining the correction factor f calculated by MCNP modeling, so that the control rod reactivity value scale precision under the subcritical environment is greatly improved.
Drawings
The accompanying drawings, which are included to provide a further understanding of embodiments of the invention and are incorporated in and constitute a part of this application, illustrate embodiments of the invention. In the drawings:
FIG. 1 is a schematic block diagram of a measurement system according to an embodiment of the present invention.
Fig. 2 is a flowchart of a measurement method according to an embodiment of the present invention.
Fig. 3 is a circuit diagram of a measurement system according to an embodiment of the present invention.
Fig. 4 is a schematic diagram of measurement results according to an embodiment of the present invention.
In the drawings, the reference numerals and corresponding part names:
the system comprises a 1-control rod, a 2-reactor, a 3-reactor outer neutron detector, a 4-reactor core neutron detector, a 5-signal conditioning module, a 51-preamplifier, a 52-linear pulse amplifier, a 6-calculation module, a 7-high voltage power supply module and an 8-low voltage power supply module.
Detailed Description
Hereinafter, the terms "comprises" or "comprising" as may be used in various embodiments of the present invention indicate the presence of inventive functions, operations or elements, and are not limiting of the addition of one or more functions, operations or elements. Furthermore, as used in various embodiments of the invention, the terms "comprises," "comprising," and their cognate terms are intended to refer to a particular feature, number, step, operation, element, component, or combination of the foregoing, and should not be interpreted as first excluding the existence of or increasing likelihood of one or more other features, numbers, steps, operations, elements, components, or combinations of the foregoing.
In various embodiments of the invention, the expression "or" at least one of a or/and B "includes any or all combinations of the words listed simultaneously. For example, the expression "a or B" or "at least one of a or/and B" may include a, may include B or may include both a and B.
Expressions (such as "first", "second", etc.) used in the various embodiments of the invention may modify various constituent elements in the various embodiments, but the respective constituent elements may not be limited. For example, the above description does not limit the order and/or importance of the elements. The above description is only intended to distinguish one element from another element. For example, the first user device and the second user device indicate different user devices, although both are user devices. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element, without departing from the scope of various embodiments of the present invention.
It should be noted that: if it is described to "connect" one component element to another component element, a first component element may be directly connected to a second component element, and a third component element may be "connected" between the first and second component elements. Conversely, when one constituent element is "directly connected" to another constituent element, it is understood that there is no third constituent element between the first constituent element and the second constituent element.
The terminology used in the various embodiments of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the various embodiments of the invention. As used herein, the singular is intended to include the plural as well, unless the context clearly indicates otherwise. Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which various embodiments of the invention belong. The terms (such as those defined in commonly used dictionaries) will be interpreted as having a meaning that is the same as the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein in connection with the various embodiments of the invention.
For the purpose of making apparent the objects, technical solutions and advantages of the present invention, the present invention will be further described in detail with reference to the following examples and the accompanying drawings, wherein the exemplary embodiments of the present invention and the descriptions thereof are for illustrating the present invention only and are not to be construed as limiting the present invention.
Example 1
The embodiment provides a method for measuring the reactivity value of a control rod of a subcritical reactor, which can be used for a control rod reactivity value scale test before power operation of an accelerator driving subcritical system. The subcritical system subcritical degree range suitable for the method is 0.8<k eff <0.999, wherein the upper limit of the reactivity value of the single control rod is-1500 pcm, the error of the reactivity value scale of the control rod is less than 15pcm, and the length of the reactivity value scale of the single control rod is less than 5min.
The measurement system adopted by the measurement method of the present embodiment is shown in fig. 1, and mainly includes a neutron detector, a signal conditioning module 5 and a reactivity calculation module 6. The neutron detectors include an off-reactor neutron detector 3 and a reactor core neutron detector 4. The signal conditioning module 5 amplifies and filters current signals or pulse signals output by the reactor outer neutron detector and the reactor core neutron detector; the reactivity calculation module carries out control rod reactivity value operation on the conditioned current or pulse signals, the control rod reactivity value is rapidly solved, and the measurement system can process 8 paths of neutron detector output signals simultaneously.
The design principle of the measuring method of the embodiment is as follows: the neutron transport equation of the subcritical reactor can be obtained:
AΦ＝PΦ+S (1)
a represents neutron migration and disappearance operators;
p represents a neutron production operator;
s represents an external neutron source;
Φ represents a theoretical value of neutron flux density.
The subcritical core reactivity state expression can be obtained from the expression (1):
ρ represents the reactor subcritical (reactive state);
∑ d represents a macroscopic cross-section of the neutron detector;
<∑ d ，Φ>representing neutron signals measured by the detector.
Formula (2) is rewritable:
c represents neutron flux density.
For two different subcritical conditions ρ of the core 0 And ρ 1 The following formula can be obtained according to formula (3):
from equation (4), if a specific subcritical state ρ is known 0 And neutron flux density C at this subcritical state 0 For another subcritical state, based on the neutron flux density C detected by the neutron detector 1 The subcritical level ρ of the state can be obtained 1 . f is a correction factor term introduced by the difference between the effective neutron source intensity and the neutron detection efficiency of the detector in each of two different subcritical conditions.
As shown in fig. 2, the measurement method of the present embodiment specifically includes the following steps:
step one, obtaining an initial subcritical state of a reactor and neutron flux density in the initial subcritical state.
Step two, inserting control rods into the subcritical reactor core section by section, and measuring neutron flux densities corresponding to different positions of the control rods inserted into the subcritical reactor core.
And thirdly, calculating the space correction factors corresponding to different positions of the control rod inserted into the subcritical reactor core.
And step four, correcting neutron flux density corresponding to different positions of the subcritical reactor core by using the space correction factors corresponding to the positions.
And fifthly, calculating the subcritical state of the control rod inserted into different positions of the subcritical reactor core according to the initial subcritical state of the reactor, the neutron flux density in the initial subcritical state and the neutron flux densities corresponding to different positions of the corrected control rod inserted into the subcritical reactor core.
Further, the control rod is located entirely outside the reactor, while the reactor is in a defined subcritical state ρ 0 Recording neutron flux density C in this subcritical state by neutron detector 0 The method comprises the steps of carrying out a first treatment on the surface of the Initial subcritical state ρ of reactor 0 Measured by a pulse neutron source test, the initial subcritical state measurement error<1％，C 0 And taking the neutron flux density recorded by the neutron detector after the initial subcritical reactor state is stably operated.
Furthermore, in order to overcome the disturbance of the spatial flux distribution caused by the insertion of the control rod and improve the accuracy of the reactivity measurement, the sub-critical reactor control rod reactivity value measurement introduces a spatial correction factor f to correct the influence caused by the introduction of the control rod. According to theoretical deduction, the spatial correction factor is defined as the ratio of neutron flux density distribution shape functions in two different subcritical states:
therefore, the neutron signal measured by the detector in the new subcritical state needs to be corrected by the correction factor f in consideration of the influence of the change in the neutron flux distribution shape:
in the control rod reactivity value measurement process, the measured neutron signal is subjected to correction of the formula (6) and then is used for reactivity calculation:
as shown in fig. 1, a control rod is inserted into the core position a, and the neutron flux density C in this subcritical state is recorded by a neutron detector 1 The neutron flux density distribution shape of the reactor core after the control rod is inserted into the reactor core position A is changed, and the spatial correction factor f when the control rod is inserted into the reactor core position A is calculated according to the (5) by utilizing a Monte Carlo neutron transport program MCNP 1 Determining the reactor subcritical degree ρ of the control rod at the time of insertion into the core position A by the method (7) 1 。ρ 1 And ρ 0 The difference is the reactivity value of the control rod inserted into the core. Continuing to insert the control rod to the position B of the reactor core, and recording the neutron flux density C of the control rod at the moment B by a neutron detector 2 And calculates a spatial correction factor f at that time 2 Thereby obtaining a subcritical level ρ of the control rod insertion core position B 2 ，ρ 2 And ρ 1 The difference is the reactivity value of the control rod corresponding to the insertion of the control rod from position 1 to position B. And repeating the measurement work to measure the reactivity value of each section of control rod, thereby determining the differential value curve of the whole control rod.
The embodiment can process 8 paths of neutron detector signals simultaneously, the detectors are arranged at different positions of the subcritical reactor (comprising a reactor core detector and an off-reactor detector), and 8 paths of neutron signals are measured simultaneously to obtain an average value, so that the measurement accuracy of the reactivity value of the control rod is ensured. In other preferred embodiments, other numbers of neutron detectors may be used, such as 5-way, 9-way neutron detectors, to effect neutron signal measurements.
The spatial correction factor f in the embodiment is obtained by simulation calculation of a neutron transport program MCNP, a physical model is constructed in the calculation process, and the reactor core structure is truly simulated by considering the geometrical structure, the material composition and the type of the detector.
The neutron detector of the present embodiment may employ, but is not limited to, an output signal of a current type neutron detector or a pulse type neutron detector as a data input, and may process a current signal and a pulse count signal at the same time.
Example 2
In this embodiment, the method for measuring the reactivity value of the subcritical reactor control rod in embodiment 1 is described in detail by taking the output signal of the one-path out-of-reactor pulse neutron detector as an example.
Firstly, a measuring system shown in fig. 3 is built, which mainly comprises a neutron detector 4 outside a reactor, a signal conditioning module (a preamplifier 51 and a linear pulse amplifier 52), a calculating module 6, a high-voltage power supply module 7 and a low-voltage power supply module 8, wherein the neutron detector 4, the preamplifier 51, the linear pulse amplifier 52 and the calculating module 6 are sequentially connected, the high-voltage power supply module 7 supplies power to the neutron detector 4, and the low-voltage power supply module 8 supplies power to the preamplifier 51.
The instrumentation and materials used in this example were:
the neutron detector is LND 25190 type 3 He proportional counter tube, diameter 16mm, length 153.9mm;
the preamplifier used was ORTEC charge-sensitive preamplifier 142PC;
the linear pulse amplifier is ORTEC 590amplifier;
the high-voltage power supply module of the detector is ORTEC 556high-voltage power supply;
the pre-amplifier low voltage power supply module used is ORTEC 4002P.
The specific measurement process is as follows:
the first step: determining an initial subcritical state ρ of a reactor 0 Neutron flux density C at this initial subcritical state 0 。
The control rods are all outside the reactor and the reactor is in an inactive state. The measurement system circuit was energized and preheated for ten minutes, and then the neutron detector background count rate was initially measured. Injecting a neutron source into the reactor, keeping the intensity of the neutron source constant, starting to measure the output signal of the neutron detector after the reactor is operated stably (starting to operate for ten minutes), continuously measuring for ten minutes, and taking the average count rate of the detector output minus the background count as a controlInitial neutron flux density C for rod-making reactivity value measurement 0 . Initial subcritical state ρ of reactor 0 Measured by a pulsed neutron source method.
And a second step of: the control rods are inserted into the subcritical reactor core section by section, and neutron flux densities corresponding to different control rod positions are measured.
The control rod is inserted into the subcritical reactor core for 10cm, at this time, the reactor is in a new subcritical state, the neutron count rate measured by the detector in the subcritical state is recorded, and the measurement data is transmitted to the reactivity calculation module 6 in real time. The measurement time of the whole measurement process is two minutes, the data acquisition is stopped after two minutes, and the average neutron flux density C in the subcritical state is obtained by a reactivity calculation module 1 . Completion C 1 After measurement, the control rod is continuously inserted into the reactor core for 10cm, and the neutron flux density C in the subcritical state can be measured by repeating the process 2 . Repeating the above process until the measurement of the whole control rod is completed, and finally obtaining a relation curve of neutron flux density with the insertion depth of the control rod as shown in fig. 3 (a).
And a third step of: calculating spatial correction factors at different positions of control rod insertion subcritical reactor core
First, the subcritical reactor under study is physically modeled using the monte carlo neutron transport program MCNP, and the subcritical reactor geometry, material composition, and fuel loading are described in detail. After the reactor physical modeling is completed, the neutron flux density distribution shape function of the control rod in the state of not being inserted into the reactor core is calculated.
And (3) calculating the neutron counting rate N measured at the position of the neutron detector in a simulation mode, and recording the total number N of neutrons in the whole space in the simulation calculation process, wherein the numerical value of the neutron flux density distribution shape function at the position of the neutron detector can be determined as follows:
the neutron flux density distribution shape function in equation (8) can be regarded as a normalized distribution of neutron flux density throughout space.
Repeating the above steps, and calculating the neutron flux density distribution shape function psi of the control rod inserted into different positions of the subcritical reactor core according to the formula (8) 1 、ψ 2 、ψ 3 ···
The spatial correction factors f at different positions of the control rod inserted into the subcritical reactor core can be calculated by the method (5) 1 、f 2 、f 3 ···
Fourth step: control rod reactivity value calculation
Using the spatial correction factor f calculated in the third step 1 、f 2 、f 3 ···f n And calculating according to formula (6) to obtain neutron flux density C 'of the corrected control rod inserted into different positions of the subcritical reactor core' 1 、C′ 2 、C′ 3 ··C′ n 。
In combination with the subcritical state ρ of the control rods when not inserted into the core 0 Neutron flux density C 0 The subcritical state rho of the control rod inserted into different positions of the reactor core can be obtained by utilizing the method (7) 1 、ρ 2 、ρ 3 ···ρ n 。
ρ 1 And ρ 0 The difference value is the reactivity value corresponding to the first 10cm section of the control rod, ρ 2 And ρ 1 The difference value is the reactivity value corresponding to the second 10cm section of the control rod. By such pushing, the corresponding reactivity value of each section of the whole control rod can be obtained, and one control rod reactivity value scale is realized, as shown in fig. 3 (b).
The foregoing description of the embodiments has been provided for the purpose of illustrating the general principles of the invention, and is not meant to limit the scope of the invention, but to limit the invention to the particular embodiments, and any modifications, equivalents, improvements, etc. that fall within the spirit and principles of the invention are intended to be included within the scope of the invention.
Claims (8)
1. A method for measuring the reactivity value of a subcritical reactor control rod, comprising:
acquiring the neutron flux density of the reactor in an initial subcritical state;
inserting control rods into the subcritical reactor core section by section, and measuring neutron flux densities corresponding to different positions of the control rods inserted into the subcritical reactor core;
calculating space correction factors corresponding to different positions of the core of the subcritical reactor, in which the control rods are inserted;
correcting neutron flux density corresponding to different positions of a subcritical reactor core by using space correction factors of control rod insertion positions;
calculating to obtain the subcritical state of the control rod inserted into different positions of the subcritical reactor core according to the initial subcritical state of the reactor, the neutron flux density in the initial subcritical state and the neutron flux densities corresponding to different positions of the corrected control rod inserted into the subcritical reactor core; the method comprises the steps of obtaining an initial subcritical state of a reactor and neutron flux density in the initial subcritical state, wherein the method specifically comprises the following steps:
when the control rod is completely positioned outside the reactor, the reactor is in an initial subcritical state, the initial subcritical state is measured through a pulse neutron source test, and the neutron flux density in the initial subcritical state is obtained by taking the neutron flux density recorded by a neutron detector after the reactor stably runs for a preset time; the space correction factor is defined as the ratio of neutron flux density distribution shape functions in two different subcritical states, and the calculation process of the space correction factor comprises the following steps:
performing physical modeling on the researched subcritical reactor by adopting a Monte Carlo neutron transport program MCNP;
the neutron counting rate measured at the position of the neutron detector is calculated in a simulation mode, and meanwhile the total number of neutrons in the whole space in the simulation calculation process is recorded, so that the value of the neutron flux density distribution shape function at the position of the neutron detector is the ratio of the neutron counting rate measured at the position of the neutron detector to the total number of neutrons in the space;
the neutron flux distribution shape function of the control rod in the initial subcritical state of the reactor and the neutron flux density distribution shape function of the control rod inserted into different positions of the subcritical reactor core can be obtained through the simulation calculation in the space correction factor calculation process, so that the space correction factors of the control rod inserted into different positions of the subcritical reactor core are obtained according to the definition of the space correction factors.
2. The method for measuring the reactivity value of a subcritical reactor control rod in accordance with claim 1, wherein the correction process is specifically:
and (3) inserting the measured control into neutron flux densities at different positions of the subcritical reactor core to divide the neutron flux densities by corresponding space correction factors, so that the corrected neutron flux densities can be obtained.
3. The method for measuring the reactivity value of control rods of a subcritical reactor according to claim 1, wherein the subcritical state of the control rods inserted into different positions of the subcritical reactor core is calculated, specifically:
the subcritical state at a location where the control rod is inserted into the subcritical reactor core is equal to the product of the initial critical state of the reactor and the neutron flux density at that initial critical state divided by the corrected neutron flux density at that location.
4. A method of measuring the reactivity value of a subcritical reactor control rod in accordance with any of claims 1-3, wherein the neutron flux density is obtainable by at least one neutron detector.
5. A method of measuring the reactivity value of a subcritical reactor control rod in accordance with any of claims 1-3, wherein the neutron flux density is obtained by averaging data obtained from a plurality of neutron detectors disposed at different positions in the subcritical reactor.
6. A method of measuring the reactivity value of a subcritical reactor control rod in accordance with any of claims 1-3, wherein the neutron detector measuring the neutron flux density is a galvanic neutron detector or a pulsed neutron detector.
7. A method for measuring the reactivity value of a subcritical reactor control rod in accordance with any one of claims 1-3, wherein the measuring system adopted by the method comprises at least one path of neutron detector, a signal conditioning module and a reactivity calculation module;
and at least one path of neutron detector output signal is sent to the signal conditioning module for filtering and amplifying treatment and then sent to the reactivity calculation module for reactivity calculation.
8. The method of claim 7, wherein the signal conditioning module comprises a preamplifier and a linear pulse amplifier.
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Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS62228199A (en) * | 1986-03-29 | 1987-10-07 | 株式会社東芝 | Reactivity monitor device for nuclear reactor |
| CN102947889A (en) * | 2010-03-29 | 2013-02-27 | 嘉科E&C有限公司 | Accelerator-driven nuclear system with control of effective neutron multiplication coefficent |
| CN109273119A (en) * | 2018-09-13 | 2019-01-25 | 中国核动力研究设计院 | Optimize the method for neutron detector position when measuring big reactivity on critical assembly |
| CN110111917A (en) * | 2019-04-17 | 2019-08-09 | 中广核工程有限公司 | Out-pile neutrons in nuclei flux monitoring method, apparatus and readable storage medium storing program for executing after accident |
Family Cites Families (1)
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-
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Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS62228199A (en) * | 1986-03-29 | 1987-10-07 | 株式会社東芝 | Reactivity monitor device for nuclear reactor |
| CN102947889A (en) * | 2010-03-29 | 2013-02-27 | 嘉科E&C有限公司 | Accelerator-driven nuclear system with control of effective neutron multiplication coefficent |
| CN109273119A (en) * | 2018-09-13 | 2019-01-25 | 中国核动力研究设计院 | Optimize the method for neutron detector position when measuring big reactivity on critical assembly |
| CN110111917A (en) * | 2019-04-17 | 2019-08-09 | 中广核工程有限公司 | Out-pile neutrons in nuclei flux monitoring method, apparatus and readable storage medium storing program for executing after accident |
Non-Patent Citations (3)
| Title |
|---|
| 充硼堆芯的临界试验研究;牛江;黄礼渊;代启东;;科技创新导报(第09期);全文 * |
| 压水堆中子脉冲计数率计算与弱源启动分析方法;李同林;周连帮;韩伟实;;核动力工程(第03期);全文 * |
| 次临界反应性测量的空间修正及其应用综述;张瑜;王释伟;徐琳琳;郑正;;核科学与工程(第01期);全文 * |
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