CN103617351B - The method and system of search reactor core crucial component - Google Patents

Abstract

Disclose a kind of method and system searching for reactor core crucial component.In the method, according to initial search parameters value and search slope determination eigenwert index, burnup index and/or convergence index; Carry out iterative computation based on initial search parameters value, obtain up-to-date reactor core characteristic value; When calculated reactor core characteristic value does not meet convergence index, the value of the crucial component search multiplication factor using eigenwert index, burnup index and/or convergence index determination next iteration used; And use the value of the crucial component search multiplication factor determined to carry out next iteration search, until determine reactor core crucial component.Utilize the scheme of above-described embodiment, in search procedure, employ critical search multiplication factor, make the search accelerating convergence of crucial component, decrease the computing time of program.

Description

The method and system of search reactor core crucial component

Technical field

The application relates to reactor physics numerical simulation field, is specifically related to Accelerated Convergence Method and the system thereof of the search of a kind of reactor core crucial component.

Background technology

In the calculating of reactor critical problem, after given reactor core effective multiplication factor, reactor crucial component calculates and refers to: under given reactor size condition, the quantity of boron concentration, control rod or absorber (burnable poison rod etc.) in the enrichment of computing fuel composition or water and position etc., i.e. crucial component search.The search of reactor core crucial component belongs to the category that critical (eigenwert) searches for.

Critical (eigenwert) search (Criticality (Eigenvalue) Search) technology refers to that certain parameter of search makes reactor core reach critical, namely makes reactor core characteristic value reach the technology of certain desired value (usually getting 1).This method is widely adopted in traditional core physics routine analyzer, and the parameter that can be used for searching for has: the parameters such as boron concentration, relative power level, reactor core temperature in, core buckling, reactor core pressure and control rod position.

For certain above-mentioned specific search parameter x ^(k), the differential of the kth time search of its correspondence is worth (search slope) ρ ^(k)for:

${\mathrm{\ρ}}^{\left(k\right)}=\frac{k_{\mathrm{eff}}^{\left(k\right)}-k_{\mathrm{eff}}^{(k-1)}}{x^{\left(k\right)}-x^{(k-1)}}---\left(1\right)$

Wherein, x ^(k), x ^(K-1)that kth is secondary, the search parameter value of kth-1 iteration, it is the reactor core characteristic value of two corresponding convergences.

User is needed to input initial slope in advance or adopt default value when starting to search for.Because slope will constantly be recalculated in an iterative process, initial value does not affect result of calculation.

On the basis of slope, current data and current eigenwert, the search parameter of kth+1 iteration can represent with following formula:

$x^{(k+1)}=x^{\left(k\right)}+\frac{k_{\mathrm{eff}}^{t\arg \mathrm{et}}-k_{\mathrm{eff}}^{\left(k\right)}}{{\mathrm{\ρ}}^{\left(k\right)}}---\left(2\right)$

When the reactor core characteristic value searched out meets the following conditions, think that search iteration restrains, stop search, now corresponding search parameter value is exactly required critical search parameter value:

$|k_{\mathrm{eff}}^{\left(k\right)}-k_{\mathrm{eff}}^{t\arg \mathrm{et}}|<{\mathrm{\&epsiv;}}^{\mathrm{search}}---\left(3\right)$

Wherein ε ^searchfor critical (eigenwert) searches for convergence criterion.

Over-relaxation iterative method (SuccessiveOver-Relaxation) is a kind of most popular method of separating large linear systems at present, is a kind of accelerated method of Gauss-Sai repeatedly your (Gauss-Seidel) alternative manner.

For system of linear equations:

Ax=b(4)

Wherein A is nonsingular matrix, and α _ii≠ 0 (i=1,2 ..., n), if obtained the secondary iteration amount x of kth ^(k)and the iteration amount x of kth+1 time ^(k-1)front i-1 component:

$(x_1^{(k+1)},x_2^{(k+1)},\&CenterDot;\&CenterDot;\&CenterDot;x_{i-1}^{(k+1)})---\left(5\right)$

In calculating time, first with Gauss-Sai repeatedly your iteration obtain:

${\tilde{x}}_i^{(k+1)}=\frac{1}{{\mathrm{\&alpha;}}_{\mathrm{ii}}}[b_i-\underset{j=1}{\overset{i-1}{\mathrm{\&Sigma;}}}{\mathrm{\&alpha;}}_{\mathrm{ii}}{x}_j^{(k+1)}-\underset{j=i}{\overset{n}{\mathrm{\&Sigma;}}}{\mathrm{\&alpha;}}_{\mathrm{ij}}{x}_j^{\left(k\right)}]---\left(6\right)$

Selecting All Parameters ω, gets

$x_i^{(k+1)}=(1-\mathrm{\&omega;})x_i^{\left(k\right)}+\mathrm{\&omega;}{\tilde{x}}_i^{(k+1)}---\left(7\right)$

So have

$\left\{\begin{array}{c}{x}_i^{(k+1)}=(1-\mathrm{\&omega;})x_i^{\left(k\right)}+\frac{\mathrm{\&omega;}}{{\mathrm{\&alpha;}}_{\mathrm{ii}}}[b_i-\underset{j-1}{\overset{i-1}{\mathrm{\&Sigma;}}}{\mathrm{\&alpha;}}_{\mathrm{ij}}{x}_j^{(k+1)}-\underset{j=i}{\overset{n}{\mathrm{\&Sigma;}}}{\mathrm{\&alpha;}}_{\mathrm{ij}}{x}_j^{\left(k\right)}],(i=\mathrm{1,2},\&CenterDot;\&CenterDot;\&CenterDot;n,k=\mathrm{1,2},\&CenterDot;\&CenterDot;\&CenterDot;)\\ x^{\left(0\right)}=(x_1^{\left(0\right)},x_2^{\left(0\right)},\&CenterDot;\&CenterDot;\&CenterDot;x_n^{\left(0\right)})\end{array}\right.---\left(8\right)$

Wherein, parameter ω is called relaxation factor.When ω=1, namely over-relaxation iterative method is equivalent to Gauss-Sai repeatedly that iteration; It is overrelaxation iteration during ω >1; It is underrelaxation iteration during ω <1.

The matrix form of overrelaxation iteration:

B _ω=(D-ωL) ^-1[(1-ω)D+ωU](9)

Wherein: D is diagonal matrix, L is unit lower triangular matrix, and U is upper triangular matrix.

According to convergence theorem, the sufficient and necessary condition of overrelaxation iteration convergence is ρ (B _ω) <1, adequate condition is || B _ω|| <1, the convergence necessary condition can releasing over-relaxation iterative method is thus 0< ω <2.

Summary of the invention

The object of the application is to provide a kind of reactor core crucial component searching method and system thereof, and it can make the search accelerating convergence of crucial component, decreases the computing time of program.

In one of application, propose a kind of method of searching for reactor core crucial component, comprise step: according to initial search parameters value and search slope determination eigenwert index I _keff, burnup index I _bU, and/or convergence index I _conv; Carry out iterative computation based on initial search parameters value, obtain up-to-date reactor core characteristic value; When calculated reactor core characteristic value does not meet convergence index, use eigenwert index I _keff, burnup index I _bU, and/or convergence index I _convdetermine the value of the crucial component search multiplication factor that next iteration is used; And use the value of the crucial component search multiplication factor determined to carry out secondary iterative search next time, until determine reactor core crucial component.

Preferably, determine that the step of the value of the crucial component search multiplication factor that next iteration is used comprises: for reactor beginning of life operating mode, determine the value of the critical search multiplication factor of kth time search as follows:

Wherein, b ₁, b ₂, b ₃for coefficient, according to eigenwert index I _keffsize and different.

Preferably, the span of the value of critical search multiplication factor is: b ₁∈ [2.0,2.5], b ₂∈ [1.5,2.0], b ₃∈ [1.0,1.5], with eigenwert index I _keffincrease and increase.

Preferably, determine that the step of the value of the crucial component search multiplication factor that next iteration is used comprises:

For other operating modes except reactor beginning of life operating mode, determine the value of the critical search multiplication factor of kth time search as follows:

$\left\{\begin{array}{c}{f}^{\left(k\right)}=f^{(k-1)}-c_1[1n\left(I_{\mathrm{conv}}\right)+1]\\ f^{\left(0\right)}=c_2[1n\left(I_{\mathrm{conv}}\right)+1]\end{array}\right.$

Wherein, c ₁, c ₂for coefficient, according to burnup index I _bUsize and different.

Preferably, only at I _convcritical search multiplication factor is used to accelerate, when iterations is greater than I before secondary _convtime, do not re-use critical search multiplication factor.

The application another in, propose a kind of system of searching for reactor core crucial component, comprising: according to initial search parameters value and search slope determination eigenwert index I _keff, burnup index I _bU, and/or convergence index I _convdevice; Carry out iterative computation based on initial search parameters value, obtain the device of up-to-date reactor core characteristic value; When calculated reactor core characteristic value does not meet convergence index, use eigenwert index I _keff, burnup index I _bU, and/or convergence index I _convdetermine the device of the value of the crucial component search multiplication factor that next iteration is used; And use the value of the crucial component search multiplication factor determined to carry out next iteration search until determine the device of reactor core crucial component.

Utilize the scheme of above-described embodiment, in search procedure, employ critical search multiplication factor, make the search accelerating convergence of crucial component, decrease the computing time of program.

Accompanying drawing explanation

In order to be illustrated more clearly in the embodiment of the present application or technical scheme of the prior art, be briefly described to the accompanying drawing used required in embodiment or description of the prior art below, apparently, for those of ordinary skills, under the prerequisite not paying creative work, other accompanying drawing can also be obtained according to these accompanying drawings.

Fig. 1 is the indicative flowchart that critical (eigenwert) searches for;

Fig. 2 calculates eigenwert index I _keff, burnup index I _bU, convergence index I _convisoparametric indicative flowchart;

Fig. 3 is the indicative flowchart that the critical search multiplication factor of application upgrades search parameter.

Embodiment

To specific embodiments of the invention be described in detail below, it should be noted that the embodiments described herein is only for illustrating, is not limited to the present invention.In the following description, in order to provide thorough understanding of the present invention, a large amount of specific detail has been set forth.But, those of ordinary skill in the art be it is evident that: these specific detail need not be adopted to carry out the present invention.In other instances, in order to avoid obscuring the present invention, do not specifically describe known structure, circuit, material or method.

In whole instructions, " embodiment ", " embodiment ", " example " or mentioning of " example " are meaned: the special characteristic, structure or the characteristic that describe in conjunction with this embodiment or example are at least one embodiment of the invention involved.Therefore, the phrase " in one embodiment " occurred in each place of whole instructions, " in an embodiment ", " example " or " example " differ to establish a capital and refer to same embodiment or example.In addition, can with any suitable combination and/or sub-portfolio by specific feature, structure or property combination in one or more embodiment or example.In addition, it should be understood by one skilled in the art that term "and/or" used herein comprises any and all combinations of one or more relevant project listed.

Critical (eigenwert) search is the part that reactor core critical problem calculates, and include thermal technology's iteration, group constant calculates, three-dimensional diffusion/transport the steps such as calculating, the time therefore required for an iteration is longer.Simultaneously when reactor core state from away from critical time, need the number of times of search more, so just extend the overall calculation time.

In order to meet growing software computing velocity demand, the present invention is under the prerequisite meeting computational accuracy requirement, effectively can reduce the number of times that critical (eigenwert) searches under certain constraint condition, thus reduce the computing time of program, promote Consumer's Experience.

1. critical search multiplication factor key concept

The search parameter expression formula that the kth of critical (eigenwert) being searched for is+1 time is rewritten into:

x ^(k+1)=x ^(k)+Δx ^(k)(10)

Wherein

$\mathrm{\&Delta;}{x}^{\left(k\right)}=\frac{k_{\mathrm{eff}}^{t\arg \mathrm{et}}-k_{\mathrm{eff}}^{\left(k\right)}}{{\mathrm{\&rho;}}^{\left(k\right)}}---\left(11\right)$

For search parameter increment.

In order to accelerating convergence, make reactor core object feature value approach object feature value sooner, according to the basic thought of over-relaxation iterative method, introduce critical search multiplication factor f, make the search parameter of kth+1 time to be:

x ^(k+1)=x ^(k)+f×Δx ^(k)(13)

2. affect the factor of critical search speed

The object that critical (eigenwert) searches for searches for special parameter exactly, forces to make reactor core arrive critical conditions, and the factor therefore affecting critical search speed mainly current reactor core departs from the degree of critical conditions and the convergence criterion of critical search.

Characterizing the parameter that reactor core departs from of the degree of critical conditions the most frequently used is reactor core effective multiplication factor k ^eff, i.e. reactor core characteristic value.Work as k _effwhen=1, then reactor core is in critical conditions; Another relevant parameter is burnup.If burn-up level difference (Δ BU) of the burn-up level of current state point and Last status point is comparatively large, then reactor core more easily offsets critical conditions.

The impact of convergence criterion on critical searching times of critical search is apparent.When convergence criterion is higher, iteration result is more difficult approaches desired value, and searching times is more; Vice versa.Common engineering requires that convergence criterion is 10 ^-4the order of magnitude.Great many of experiments calculates and shows, as convergence criterion ε ^search<10 ^-4time, computational accuracy does not significantly promote, and counting yield then declines a lot.

3. the determination of critical search multiplication factor value

According to the factor of the critical search speed of above-mentioned impact, for determining critical search multiplication factor value, first introduce several auxiliary quantity.In order to simplify, omit iterations subscript.

(1) eigenwert index I _keff

Represent current reactor core characteristic value k _effwith object feature value the magnitude of difference:

$I_{\mathrm{keff}}=\frac{|k_{\mathrm{eff}}-k_{\mathrm{eff}}^{t\arg \mathrm{et}}|}{10{\mathrm{\&epsiv;}}^{\mathrm{keff}}}---\left(14\right)$

Wherein: ε ^kefffor eigenwert convergence criterion in diffusion calculating.

(2) burnup index I _bU

Represent the tolerance of the size of current burnup increment:

$I_{\mathrm{BU}}=\left\{\begin{array}{cc}1,& \mathrm{\&Delta;BU}<500(\mathrm{MWD}/\mathrm{TU})\\ 2,& 500<\mathrm{\&Delta;BU}<1000(\mathrm{MWD}/\mathrm{TU})\\ 3,& \mathrm{\&Delta;BU}>1000(\mathrm{MWD}/\mathrm{TU})\end{array}\right.---\left(15\right)$

(3) index I is restrained _conv

Characterize the tolerance of current critical search convergence criterion size:

$I_{\mathrm{conv}}=\left\{\begin{array}{c}1,{\mathrm{\&epsiv;}}^{\mathrm{search}}<{10}^{-4}\\ {10}^{-4}/{\mathrm{\&epsiv;}}^{\mathrm{search}}\end{array}\right.---\left(16\right)$

These three auxiliary parameters are to determining that the size of critical search multiplication factor value plays effect of contraction.

Initial core charging is not containing burnable poison, and owing to playing the cumulative effect of the rear burnable poison of heap, the value under the multiplication factor value and rest working conditions of beginning of life is distinguished to some extent.For reactor beginning of life (BOL) operating mode, because search parameter change is comparatively violent, the critical search multiplication factor of kth time search also can be relatively loose:

Wherein: b ₁, b ₂, b ₃for coefficient, according to I _keffsize and different.The span of recommending is: b ₁∈ [2.0,2.5], b ₂∈ [1.5,2.0], b ₃∈ [1.0,1.5], with I _keffincrease and increase.

For other operating modes, the critical search multiplication factor of kth time search is:

$\left\{\begin{array}{c}{f}^{\left(k\right)}=f^{(k-1)}-c_1[1n\left(I_{\mathrm{conv}}\right)+1]\\ f^{\left(0\right)}=c_2[1n\left(I_{\mathrm{conv}}\right)+1]\end{array}\right.---\left(18\right)$

Wherein: c ₁, c ₂for coefficient, according to I _bUsize and different.The span of recommending is: c ₁∈ [0.005,0.02], c ₂∈ [0.1,0.3], with I _bUincrease and increase.

It should be noted that, c ₁be a less numerical value, be equivalent to the small sample perturbations to last iterative value, the object done like this is to prevent iterative repetition from shaking in same value.

When critical search starts, when first time starts iterative computation, must be used as search parameter value with initial value, iterative computation reactor core characteristic value, checks whether convergence.If convergence, exits, otherwise upgrade search parameter value, until eigenwert convergence.

When upgrading search parameter, applying critical search accelerated method and making parameter value approach to criticality parameter value.But in order to numerical stability, only at I _convcritical search multiplication factor is used to accelerate, when iterations is greater than I before secondary _convtime, do not re-use critical search multiplication factor.

The effect that existing critical (eigenwert) search technique is not accelerated, the number of times of required iteration is more, thus makes the overall calculation time longer.The present invention can remarkable accelerating convergence under the prerequisite not affecting computational accuracy, and the overall calculation time can reduce about 37%, and critical search can reduce about 60% computing time.

Below with the one group of qualitative explanation of test result effect of the present invention.Test certain power plant to calculate presurized water reactor circulation full phase in longevity, get 3 groups of different critical search convergence criterions respectively, test employs and does not use critical searching times of the present invention.Comparison result is as shown in the table:

Note: A is for employing critical (eigenwert) of the present invention searching times, and B is not for employ critical (eigenwert) of the present invention searching times.

As can be seen from the comparison of upper example, employ critical (eigenwert) of the present invention searching times and be less than and do not employ critical (eigenwert) of the present invention searching times.

Provided below is a kind of critical search embodiment with reactor core critical search Accelerated Convergence Method.

Technical scheme in the embodiment of the present application is understood better in order to make those skilled in the art person, and enable the above-mentioned purpose of the embodiment of the present application, feature and advantage become apparent more, below in conjunction with accompanying drawing, technical scheme in the embodiment of the present application is described in further detail.

Fig. 1 is the simple flow chart that critical (eigenwert) searches for:

Step 101: to the parameter pre-service required for critical search, and calculate eigenwert index I _keff, burnup index I _bU, convergence index I _convetc. parameter, Fig. 2 is the process flow diagram calculating these parameters:

Step 201: initialization of variable:

Need to judge that user requires the parameter of searching for, compose initial value for required parameter after determining, these initial values comprise initial search parameters value and search slope.If user does not fill in corresponding initial value in input file, then adopt the default value that program is built-in;

Step 202: calculate iterative search parameter value first:

Calculating the search parameter value of first time iteration according to initial search parameters value and search slope value, preparing for entering search iteration circulation.

Step 203: judge current burnup step-length:

When user selects to adopt the critical search Accelerated Convergence Method described in the application, needs judge the burnup step-length corresponding to current burnup node according to the variable importing this module into;

Step 204: according to burnup step-length determination burnup index;

After determining current burnup step-length, according to previously mentioned computation process, according to current burnup step-length determination burnup index I _bUparameter;

Step 205: calculate convergence index I according to previously mentioned computation process and critical search convergence criterion _convparameter:

Step 102: after completing initialization of variable, enters the circulation of critical search iteration.In iterative loop, owing to changing search parameter value, namely change reactor core material composition, need to recalculate reactor core hot-working hydraulic characteristic, and then upgrade few group constant, calculate up-to-date reactor core characteristic value.This step comprises thermal-hydraulic iteration, few group constant upgrades, three-dimensional diffusion/transport the series of steps such as calculating, these modules are all comparatively familiar with for nuclear engineering and designer, and not within scope involved in the present invention, therefore repeat no more;

Step 103: after calculating new reactor core characteristic value, needs to judge whether to meet convergence criterion, if meet, exits search, otherwise perform step 104, continues search until meet convergence criterion;

Step 104: need when not restraining to continue to upgrade search parameter, Fig. 3 is the process flow diagram that parameter upgrades:

Step 301: according to previously mentioned slope computing formula, calculates next iteration search parameter slope;

Step 302: according to previously mentioned search parameter incremental computations formula, calculates next iteration search parameter increment;

It is pointed out that because slope may be less, according to previously mentioned search parameter incremental computations formula, cause increment comparatively greatly, if be so directly increased in the search parameter value of previous step, can cause the concussion of iteration, negative consequence is produced to program.For anti-phenomenon here occurs, certain restrictive condition is set in a program usually, avoids the instability that excessive increment causes.The different program of these restrictive conditions has different schemes, not within scope involved in the present invention, therefore also repeats no more;

Step 303: judge whether be first iteration simultaneously current working be beginning of life;

Step 304: the value determining critical search multiplication factor according to above-mentioned judgement and index parameter good before and previously mentioned computation process;

Step 305: judge that current working is beginning of life;

Step 306: the value determining critical search multiplication factor according to above-mentioned judgement and index parameter good before and previously mentioned computation process;

Step 307: the value determining critical search multiplication factor according to above-mentioned judgement and index parameter good before and previously mentioned computation process;

Step 308: the search parameter value upgrading next iteration.

Above detailed description, by using schematic diagram and/or example, has set forth numerous embodiments of the method and system of search reactor core crucial component.When this schematic diagram and/or example comprise one or more function and/or operation, it will be understood by those skilled in the art that each function in this example and/or operation can by various hardware, software, firmware or in fact their combination in any come to realize separately and/or jointly.In one embodiment, some parts of theme described in embodiments of the invention can be realized by special IC (ASIC), field programmable gate array (FPGA), digital signal processor (DSP) or other integrated forms.But, those skilled in the art will recognize that, some aspects of embodiment disclosed herein can realize in integrated circuits on the whole or partly equally, be embodied as one or more computer programs of running on one or more computing machine (such as, be embodied as the one or more programs run in one or more computer system), be embodied as one or more programs of running on the one or more processors (such as, be embodied as the one or more programs run on one or more microprocessor), be embodied as firmware, or be embodied as in fact the combination in any of aforesaid way, and those skilled in the art are according to the disclosure, the ability of design circuit and/or write software and/or firmware code will be possessed.In addition, those skilled in the art will recognize that, the mechanism of theme described in the disclosure can be distributed as the program product of various ways, and regardless of the actual particular type of signal bearing medium being used for performing distribution, the exemplary embodiment of theme described in the disclosure is all applicable.The example of signal bearing medium includes but not limited to: recordable-type media, as floppy disk, hard disk drive, compact-disc (CD), digital universal disc (DVD), numerical tape, computer memory etc.; And transmission type media, as numeral and/or analogue communication medium (such as, optical fiber cable, waveguide, wired communications links, wireless communication link etc.).

Although exemplary embodiment describe the present invention with reference to several, should be appreciated that term used illustrates and exemplary and nonrestrictive term.Spirit or the essence of invention is not departed from because the present invention can specifically implement in a variety of forms, so be to be understood that, above-described embodiment is not limited to any aforesaid details, and explain widely in the spirit and scope that should limit in claim of enclosing, therefore fall into whole change in claim or its equivalent scope and remodeling and all should be claim of enclosing and contained.

Claims (3)

1. search for a method for reactor core crucial component, comprise step:

According to initial search parameters value and search slope determination eigenwert index I _keff, burnup index I _bU, and/or convergence index I _conv;

Carry out iterative computation based on initial search parameters value, obtain up-to-date reactor core characteristic value;

When calculated reactor core characteristic value does not meet convergence index, use eigenwert index I _keff, burnup index I _bU, and/or convergence index I _convdetermine the value of the crucial component search multiplication factor that next iteration is used; And

The value of the crucial component search multiplication factor determined is used to carry out secondary iterative search next time, until determine reactor core crucial component,

Wherein determine that the step of the value of the crucial component search multiplication factor that next iteration is used comprises:

For reactor beginning of life operating mode, determine the value of the critical search multiplication factor of kth time search as follows:

Wherein, b ₁, b ₂, b ₃for coefficient, according to eigenwert index I _keffsize and different,

The span of the value of critical search multiplication factor is: b ₁∈ [2.0,2.5], b ₂∈ [1.5,2.0], b ₃∈ [1.0,1.5], with eigenwert index I _keffincrease and increase, and

Determine that the step of the value of the crucial component search multiplication factor that next iteration is used comprises:

For other operating modes except reactor beginning of life operating mode, determine the value of the critical search multiplication factor of kth time search as follows:

$\left\{\begin{array}{c}{f}^{\left(k\right)}=f^{(k-1)}-c_1\&lsqb;ln\left(I_{conv}\right)+1\&rsqb;\\ f^{\left(0\right)}=c_2\&lsqb;1n\left(I_{conv}\right)+1\&rsqb;\end{array}\right.$

Wherein, c ₁, c ₂for coefficient, according to burnup index I _bUsize and different.

2. the method for claim 1, wherein only at I _convcritical search multiplication factor is used to accelerate, when iterations is greater than I before secondary _convtime, do not re-use critical search multiplication factor.

3. search for a system for reactor core crucial component, comprising:

According to initial search parameters value and search slope determination eigenwert index I _keff, burnup index I _bU, and/or convergence index I _convdevice;

Carry out iterative computation based on initial search parameters value, obtain the device of up-to-date reactor core characteristic value;

When calculated reactor core characteristic value does not meet convergence index, use eigenwert index I _keff, burnup index I _bU, and/or convergence index I _convdetermine the device of the value of the crucial component search multiplication factor that next iteration is used; And

Use determine crucial component search multiplication factor value carry out next time secondary iterative search until determine the device of reactor core crucial component,

Wherein determine that the device of the value of the crucial component search multiplication factor that next iteration is used comprises:

For reactor beginning of life operating mode, determine the device of the value of the critical search multiplication factor of kth time search as follows:

Wherein, b ₁, b ₂, b ₃for coefficient, according to eigenwert index I _keffsize and different,

The span of the value of critical search multiplication factor is: b ₁∈ [2.0,2.5], b ₂∈ [1.5,2.0], b ₃∈ [1.0,1.5], with eigenwert index I _keffincrease and increase, and

Determine that the device of the value of the crucial component search multiplication factor that next iteration is used comprises:

For other operating modes except reactor beginning of life operating mode, determine the device of the value of the critical search multiplication factor of kth time search as follows:

$\left\{\begin{array}{c}{f}^{\left(k\right)}=f^{(k-1)}-c_1\&lsqb;ln\left(I_{conv}\right)+1\&rsqb;\\ f^{\left(0\right)}=c_2\&lsqb;\ln \left(I_{conv}\right)+1\&rsqb;\end{array}\right.$

Wherein, c ₁, c ₂for coefficient, according to burnup index I _bUsize and different.