CN1866408A - Online measuring method for burn-up level of fuel element of sphere type modular high-temperature gas-cooling reactor - Google Patents
Online measuring method for burn-up level of fuel element of sphere type modular high-temperature gas-cooling reactor Download PDFInfo
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Abstract
The related testing technique for nuclear reactor comprises: the upper machine starts up burn-up level measuring program; the fuel element is radiated and cooled; the PLC controls to send the element to lift position with same axis as the collimator and then notify the upper machine for measurement; the high-pure gamma-spectrometer measures the count of 0.661642MeV gamma radioactive ray emitted by 137Cs during decay, and calculates counting rate for the ray to determine whether takes out the core or returns to original core for work, and it sends the measured result to the main control system through a PLC. This invention is not to contact.
Description
Technical field
The present invention is used for the burn-up level metering system of spherical-bed MHTR fuel element, relates in particular to the line Measurement Technique field.
Background technology
MHTR (MHTGR) is the good heap type of international nuclear energy circle generally recognized as safe, and its R﹠D work starts from the seventies in 20th century, and is different with gas-cooled reactor, and MHTR adopts ceramic coated particle fuel, and helium is as cooling medium.Helium is an inert gas, and chemical stability is good, can not undergo phase transition, and cooling performance is good simultaneously, so the outlet temperature of MHTGR cooling medium can be very high.
Spherical-bed MHTR (PBMHTGR) adopts not shutdown to load and unload the fuel management mode of material continuously, this is characteristics of having utilized spheric fuel element to roll, form one and have mobile pebble bed core, make the supply of fresh fuel element and drawing off of spent fuel element under the situation of not shutdown, to carry out continuously.The fuel element of PBMHTGR repeatedly reaches discharge burn-up by reactor core through fuel handling (FCA) system and just draws off as spent fuel element, and multipass fuel management mode can realize the burn-up level equalization of spent fuel element.
World's seat of honour spherical-bed high temperature gas cooled reactor (PBHTGR) is the AVR reactor of Germany, and it is the spherical graphite fuel element of 6cm that AVR has adopted the diameter made from coated particle fuel, constitutes the spherical-bed reactor core by 100000 spheric fuel elements.The AVR heat output of reactor is 46MW, and electric power is 15MW, reaches critical first in August, 1966, and on Dec 17th, 1967 began to generate electricity by way of merging two or more grid systems.The former design helium outlet temperature of AVR is 850 ℃, and in February, 1974, helium outlet temperature rose to 950 ℃, until close in Dec, 1988, has moved 21 years altogether.
The seventies in 20th century and the beginning of the eighties in the world the design of the commercial power plant of high temperature gas cooled reactor mainly develop towards the direction that maximizes.After three miles islands and Chernobyl nuclear power plant accident, the U.S. has released the development plan of advanced heap type, makes MHTR become the main developing direction of high temperature gas cooled reactor.The basic characteristics of MHTR are that the residual heating of reactor core under anything event condition can carry out by the mode of non-active (promptly relying on the natural laws such as gravity, Natural Circulation), and the temperature of reactor core coated particle fuel can not surpass the limit value that allows.So just can avoid taking place the possibility of core meltdown, the radioactive dosage under the condition of major accident takes place outside the factory of nuclear power plant and need not adopt crash programme outside the factory still within limits.Therefore, MHTR is a kind of advanced person's heap type with non-passive safety.
It by the HTR-Module of the 80MW electric power of Siemens Interatom development the design concept of the low capacity MHTR that proposes at first in the world, has non-active security feature, the residual heating that is reactor core is derived by natural mechanisms such as heat conduction, heat radiations, the maximum temperature that guarantees reactor fuel element under the condition of any accident is no more than temperature limit, avoids taking place the possibility of core meltdown.The graphite spheric fuel element of the 6cm diameter that HTR-Module employing coated particle fuel is made becomes pebble bed core by 360,000 spheric fuel element heap-shaped.Active carry in order to realize that the reactor core residual heating is non-, the diameter of reactor core is restricted, otherwise the maximum temperature of reactor fuel might surpass 1600 ℃ limit value.
From the seventies in 20th century, China carried out a lot of relevant work in the high temperature gas cooled reactor technical field, and certain technology and experience accumulation are arranged.Consider excellent security feature and advanced feature that high temperature gas cooled reactor has, China as advanced reactor type, has listed them in national 863 high-tech research development plans to the correlation technique development.With the main body exploiting entity of Institute of Nuclear and New Energy Technology, Tsing University as project, built a reactor experiment (HTR-10) that thermal power is 10MW in Changping of this institute institute, its basic structure is as shown in Figure 2.The principle of design of PBMHTGR has been followed in the design of HTR-10, and following major technique and safety feature have embodied the principal feature of PBMHTGR substantially:
(1) the HTR-10 reactor core is made up of 27000 graphite spheric fuel elements, and fuel element is made of coated particle fuel.Coating fuel particle is the miniature bead that diameter has only 0.9mm, and its nuclear core is uranium dioxide (UO
2) particle, diameter is 0.5mm.UO
2The particle outsourcing one deck low-density pyrolysis carbon, two-layer high density RESEARCH OF PYROCARBON and one deck silit.Clad is with UO
2The fission product that produces in particle detention fully and can bear the internal pressure that gas fission product produces in coated particle.
The coated particle fuel even dispersion is at the internal layer of graphite spheroid, and diameter is 5cm.Its skin is the graphite housing, is not mechanically damaged in order to the protection coated particle fuel.The fuel element external diameter is 6cm, and average packet contains 8000 coated particle fuels in each fuel element.
What (2) the spherical-bed high temperature gas cooled reactor was unique is fuel handling (FCA) system, and its structure as shown in Figure 1.HTR-10 has adopted and has loaded and unloaded fuel in the reactor operation process continuously, and the excess reactivity of reactor (built-in reactivity of the clean reactor core of cold conditions) is little.The initial state reactor core is made up of 57% fuel element and 43% pure graphite nodule, adopts in the operational process repeatedly by the fuel management mode of reactor core, and the graphite nodule that draws off in the reactor core is discharged out-pile gradually; The average discharge burn-up degree of depth of fuel element (being the average burn-up degree of depth that spent fuel element is reached when reactor core draws off) is 80GWD/tU (1GWD/tU=10
9Watt sky/ton uranium), surpass 72GWD/tU, then discharge, continued circulation in the reactor core and send back to less than the fuel element of this value as spent fuel element if fuel element is measured burnup.Therefore each fuel element on average needs just to be discharged from reactor core through 5 circulations, is realizing that higher burn-up level guarantees that simultaneously the distribute power in the reactor core is more even, also makes the deviation of the burnup distribution that draws off spent fuel element littler.
By above-mentioned analysis, can sum up the functional requirement of PBMHTGR to its FCA system to PBMHTGR:
(1) under the various operating modes of reactor, can carry out the fuel handling operation of not shutdown;
(2) the fuel handling circulation realizes following function:
I) to the new fuel element of reactor core supply;
Ii) fuel element draws off from reactor core, by special " single-row device " device, makes fuel element be changed to the arrangement of simplification from piling up shape, should prevent in this process and form the situation of putting up a bridge and stopping up and can not flow between the fuel element;
Iii) the integrality to fuel element is detected, and filters out to clash into fuel element and the fragment that causes damage in cargo handling process;
Iv) fuel element is carried out burnup measurement one by one, the spent fuel element that will reach discharge burn-up is discharged in the spent fuel storage jar, and the element that does not reach discharge burn-up is carried back reactor core again;
V) from the initial state reactor core to the process of equilibrium state reactor core transition, the graphite nodule that loads in mixture in the reactor core or the graphite nodule that is mixed with neutron poison distinguished identified, and got rid of out-pile one by one;
(3) conveying of fuel element can also adopt aerodynamic force to carry in pipeline except the rolling that relies on gravity, and conveying pipeline inner wall should be smooth, and the gradient of pipeline rout can guarantee that ball type device relies on gravity to roll freely;
(4) supply fresh fuel element in heap, or spent fuel element discharged out-pile, need pile the isolation and the switching of inside and outside atmosphere, reduce the leakage of cooling medium in this process (helium) or sneaking into of air as far as possible;
(5) have very strong radioactivity through irradiated fuel element, in cargo handling process, should prevent to cause radiation effect, during as the generation equipment failure, should have shield facility can approaching to overhaul with the assurance personnel to operating personnel;
The failed fuel element of the fresh fuel element of (6) packing into, the spent fuel element that draws off, discharge, the graphite nodule of discharge and the fuel element that loops back reactor core be precise counting in addition.
In sum, the technical characterstic inevitable requirement deviser of HTR-10 proposes to satisfy the burn-up level of the fuel element accurately and reliably measuring method of on-line operation, and this method must satisfy following requirement:
(1) measurement result must directly reflect the burn-up level value;
(2) must not destroy fuel element in the measuring process;
(3) allow reactor to move by any way, allow fuel element to circulate by any way;
(4) measurement range of burn-up level is 100～105MWD/tU (1MWD/tU=10
6Watt sky/ton uranium);
(5) measuring relative errors be not more than ± 2%, when burn-up level was low, allowing measuring relative errors was ± 10%;
(6) Measuring Time is approximately 60 seconds;
(7) can move continuously for a long time;
(8) measurement result must be sent FCA system and reactor control system in real time, has higher transfer rate and transmission range far away.
The burnup unit of fuel element has two kinds: (1) fima (luxuriant and rich with fragrance horse); (2) MWD/tU.
Wherein, fima is the ratio of the total heavy metal atom number of the atomicity of having fissioned and initial when filling with substance, dimensionless:
In the formula: C
5For
235The enrichment of U (nuclear fuel purity);
Φ is thermal neutron flux (entering in the unit interval with the space point is that center suitable spherular pined for subnumber);
T is the exposure time of fuel element at reactor core;
σ
fFor
235The microscopic fission cross section of U (probability of a particle generation of incident nuclear fission when unit area has an atomic nucleus);
∑
fFor
235Macroscopic fission cross section (the σ of U
fProduct with nuclear number in the U unit volume);
V
BallVolume for fuel element;
5 is the gram number of the contained U of each fuel element.
N
UBe contained atomicity among every gram U:
For explanation basic physical notion directly perceived, suppose C
5, Φ, T be constant, then obtains the burn-up level expression formula:
In the formula: E
fBe each energy of fissioning and emitting:
E
f＝197MeV＝0.365×10
-21MWD。
Therefore, can obtain the relation of fima and MWD/tU:
Hence one can see that, to specific fuel (σ
f, C
5Be known constant), burn-up level is in fact directly related with fuel element integrates flux phi T, and also direct and fission product interrelates.Therefore, by measurement, can estimate the burn-up level of fuel element to some fission product in the fuel element.See generally from measuring method and can be divided into two classes: destroy method is measured and the measurement of non-destroy method.
The destroy method measurement is that spent fuel element is carried out chemical dissolution, and some fission nuclide in the lysate is carried out radiochemicak analysis or spectrometer analysis is determined burn-up level.The destroy method measurement has direct characteristics, data accurately and reliably, but the suffered exposure of staff is big in this method measuring process, process of measurement is complicated, work difficulty is big, analytical cycle is long, to environmental requirement height, analysis cost height, complementary means of measuring as spent fuel element usually.
Certain nucleic gamma-rays relevant with burn-up level that non-destroyed measurement is normally directly measured in the fission product with gamma ray spectrometer determined burn-up level.The non-destroyed measurement principle is clear, easy to operate, reliable results, has obtained using widely.It does not destroy the characteristics of fuel assembly, obviously is fit to the requirement of HTR-10.
The burn-up level measuring method of domestic and international exploitation, major part all is that burnup and fission product are connected.But be put at present the method used, neitherly can have satisfied the basic demand that HTR-10 measures burn-up level comprehensively, for example:
(1) measures the method for short-lived fission product with gamma ray spectrometer.Be seen in having of document: measure
140La,
154The decay rate of Eu (the decay number of times that takes place in the unit interval) etc.Because the above-mentioned nucleic life-span is short, cause its decay rate not only with the concrete history of radiation (as the power fluctuation of heap, when reactor core is passed through in each time of fuel element at different radial portions etc.) relevant, but also depend on cool time strongly, the relation of feasible amount of measuring and burnup is complicated, can not directly express the burn-up level value;
(2) assay method of chemistry (isolating specific fission product) class.These class methods need be carried out the destructiveness measurement to fuel element usually, do not satisfy non-destroyed measurement and online, real-time requirement;
(3) method of neutron measurement.These class methods maybe need to add
252Cf neutron source, or fission product
244The neutron quantity that Cm launched is few; In addition, under the lower situation of single fuel element institute uranium enrichment, also can introduce excessive error; Simultaneously, only when cool time greater than 1.5 years after,
244Cm just becomes main neutron emitter.Therefore, these class methods be difficult to satisfy in time, basic demand accurately.
Summary of the invention
For satisfying HTR-10 to the burn-up level Testing requirement, the present invention proposes the non-destructive method that a kind of suitable PBMHTGR fuel element burn-up level is measured.The present invention solves the scheme that its technical matters adopts: with HpGe gamma energy spectrometer, tungsten collimator, Programmable Logic Controller (OMRON C200HS) is core system equipment, forms burn-up level and measures and control system basic structure, as shown in Figure 3; Adopt the REXX script to work out automatic Survey Software simultaneously, with this as control and the on-line automatic measurement flow process of Survey Software Environment Design; Above-mentioned hardware and software systems is cooperated to realize burn-up level on-line measurement process.
On the principle, this method adopts high resolution gamma-ray spectrometer to measure in the fission product
137The gamma-ray method of the 0.661642MeV that Cs is launched in decay process is come computing fuel element burn-up level.In the fission product
137The total amount of Cs is:
In the formula: t
1Be the cool time after the irradiation end;
Y
7For
137Cs shared share in gross-fission-product;
λ
7For
137The disintegration constant of Cs.
By formula (1) as can be known, formula (2) is represented
137The Cs total amount is proportional to burn-up level, and its scale-up factor is known constant.And
137The total amount of Cs can be by measuring
137The speed of the gamma-rays that Cs emits (for example energy is the gamma-rays of 0.661642MeV) is determined, and is promptly right
137The detectivity of Cs is:
In the formula: f is the self-absorption modifying factor in the spherical source;
Ω is by behind the tungsten collimator, the solid angle that the energy spectrometer detector is opened radioactive source;
ε is that the energy spectrometer detector is the gamma-ray detection efficiency of 0.661642MeV to energy;
RI
7For energy is that the gamma-rays of 0.661642MeV accounts for
137The relative share of Cs decay.
The invention is characterized in that described method contains following steps successively:
Step (1). initialization
Genie 2000 frequency spectrum processing softwares are installed in host computer, and are started the automatic measure R EKX program of burn-up level;
Step (2). fuel element passes through irradiation in reactor core after, in single-row device flow to the discharge duct of reactor core bottom, through about 40 days cooling;
Step (3). programmable logic controller (PLC) confirm to finish once promote operation after, send instruction and start broken bulb spacer, current fuel element is delivered to the lifter position of receiving after broken ball sorting;
Step (4). this programmable logic controller (PLC) controls control lifter is delivered to fuel element and is promoted the position from the position of receiving, fuel element and collimating apparatus are on the same axis;
Step (5). programmable logic controller (PLC) sends the counting sign on to host computer, under this PC control, finish following measurement flow process: the solid angle that the gamma-rays that the nucleic that produces owing to fission in the current fuel element sends limits through collimating apparatus in decay process, arrive the HpGe crystal in the energy spectrometer, produce ionisation effect; Under the effect of biasing high-voltage power supply, be gathered into charge pulse by the input end of the prime amplifier of energy spectrometer, after amplifying, become potential pulse, and have low output impedance; Continue to be enlarged into the positive pulse signal of about 10V to the main amplifier of energy spectrometer through long cable; Enter the multichannel pulse scope-analyzer of energy spectrometer, divide into groups according to pulse height; Pulse amplitude spectrum after degree of the leaping high grouping of feeling the pulse is delivered to the processing that host computer comprises that the dead time is revised, deducts background, finally obtain
137The counting rate of the gamma-rays of the 0.661642MeV that Cs is launched in decay process in 60s used R
7Expression; R
7Calculate by following formula with the relation of burnup (being proportional to exposure time T):
Wherein, f is the self-absorption modifying factor in the spherical source;
Ω is by behind the tungsten collimator, the solid angle that the energy spectrometer detector is opened radioactive source;
ε is that the energy spectrometer detector is the gamma-ray detection efficiency of 0.661642MeV to energy;
RI
7For energy is that the gamma-rays of 0.661642MeV accounts for
137The relative share of Cs decay;
Y
7For
137Cs shared share in gross-fission-product;
V
BallVolume for fuel element;
Φ is a thermal neutron flux, and equaling to enter in the unit interval with the space point is that center suitable spherular pined for subnumber;
λ
7For
137The disintegration constant of Cs;
T is the exposure time of fuel element at reactor core;
t
1Be the cool time after the irradiation end;
∑
fFor
235The macroscopic fission cross section of U equals σ
fWith the product of nuclear number in the uranium unit volume, this σ
fFor
235The microscopic fission cross section of U, the probability of a particle generation of incident nuclear fission when equaling unit area an atomic nucleus being arranged;
Step (6). above-mentioned measurement flow process obtains after finishing
137The counting rate R of the gamma-rays of the 0.661642MeV that Cs is launched in decay process in 60s
7, with R
7With according to setting counting rate threshold ratio that burnup calculates, determining whether needs to discharge reactor core or returns reactor core and continue circulation;
Step (7). measurement result is deposited in local historical data base in real time and generates report, simultaneously the burnup measurement result is sent programmable logic controller (PLC) and master control system DCS.
Choose this method, following advantage arranged:
(1) observes nondestructive measurement principle;
(2)
137The half life period of Cs reaches 30.2, can ignore the influence of cool time, helps simultaneously further and the separating of other nucleic;
(3)
137The neutron cross section of Cs (free area that atomic nucleus and neutron are had an effect) is little, can not consumed by neutron field significantly in reactor core, so the recycle design of the method for operation of reactor and fuel element is unaffected;
(4) there is single valued relation between measurement result and the burn-up level.
Description of drawings
Fig. 1 .HTR-10 fuel handling system synoptic diagram; The 1-reactor core; The 2-single-row device; The 3-glove box; The broken ball sorter of 4-; The 5-Impulsive tank; The broken tanks of 6-; The 7-lifter; 8-burn-up level measurement mechanism; The 9-divider; 10-cover pressing machine structure; 11-spentnuclear fuel shipment jar; 12-graphite component container; The 13-position of receiving; 14-promotes the position; 15-draws off the position; The electronic isolation valve of 51-; The 52-solenoid valve; The 53-sensor for countering; The 54-magnetic slide valve;-6-06-fresh fuel charging chamber;-6-09-reactor cabin;-10-03-operation air valve cabin;-15-01-spent fuel storage storehouse;-15-07-burnup measurement chamber;-15-08-fuel handling chamber;
Fig. 2 .HTR-10 reactor structure; The 16-control rod drive; 17-absorbs the ball storage tank; The 18-helium circulator; The 19-heat shielding; 20-pushes up the reflection horizon; The cold helium header of 21-; The 22-steam generator heat-transfer pipe; The 23-pebble bed core; The 24-Intermediate Heat Exchanger; 25-lateral reflection layer; 26-reactor core shell; The 27-reactor vessel; 28-steam generator pressure vessel; Reflection horizon at the bottom of the 29-; The 30-hot gas conduit; The hot helium header of 31-; 32-in-pile component supporting structure; The 33-device for discharging; 34-hot gas conduit pressure vessel;
Fig. 3. fuel handling system burn-up level measuring system synoptic diagram; The 35-lifter; 36-promotes the position; The 37-baffle plate; The 38-fuel element; The 39-tungsten collimator; 40-HpGe crystal; The 41-calibration source; The 42-multichannel pulse scope-analyzer; The 43-gateway; The 44-Ethernet card; The 45-Ethernet card; The 46-host computer; The 47-RS-232C interface; The 48-RS-232C interface; 49-OMRON C200HS; The 50-concrete walls;
Fig. 4. fuel handling system control system structured flowchart;
Fig. 5 .Genie 2000 software system architectures;
Fig. 6. burn-up level On-line Measuring Method process flow diagram;
The built-in processing environment synoptic diagram of Fig. 7 .Windows operating system;
Fig. 8 .REXX binding processing environment synoptic diagram.
Embodiment
For realizing above-mentioned burn-up level measurement flow process, this method is equipped with HpGe gamma energy spectrometer, tungsten collimator, three kinds of core system equipment of Programmable Logic Controller (OMRON C200HS) in the FCA of HTR-10 system:
(1) HpGe gamma energy spectrometer: fission product sends
137The strong gamma-rays nearly a hundred times of Cs, its composition is very complicated, and some gamma-ray energy with
137The Cs spectral line is very close, so this method adopts high-resolution HpGe gamma energy spectrometer to separate
137The gamma line of Cs.Relevant parameter designing is as follows:
I) detector
P type high purity germanium detector, the vertical placement, the permissive temperature circulation, detection efficiency 19～20% is surveyed gamma-ray energy range and is: 40KeV～10MeV;
Energy resolution: the γ to 1.33MeV is 1.8KeV～1.75KeV;
Gauss's wave mode: FW0.1M/FWHM=1.85～1.9, FW0.02M/FWHM=2.40～2.65, peak-Kombi is 50.
Ii) multiple tracks impact damper
Amplifier gain: 4～1000 times, gain temperature coefficient＜± 0.005%/℃.Noises etc. are input＜4.5 μ VRMS effectively, integral nonlinearity≤± 0.025%, and pile-up rejection (integration) curring time is 1 μ s.
ADC processing time＜5 μ s, counting rate＞10
5/ s.
Digital spectrum-stabilizing, long-time degree of stability≤± 0.018%, road/24 hour promptly＜1, the road number is 16384, the road is wide～0.5KeV, and the adjustable threshold that low energy is screened is arranged.High-voltage power supply ± 5000V, the protection of input field effect transistor.
Parameter regulation such as amplifier gain, analog-to-digital gain, amplifier curring time, digital voltage stabilizer setting, zero utmost point adjustment are by PC control.
Iii) host computer and process software
Host computer CPU adopts Pentium 4 3.0GHz, and operating system is Microsoft Windows 2000 ProfessionalSP4.Process software is Genie 2000 frequency spectrum software systems, and function comprises: spectrum unscrambling, background match, dead time are revised, are calculated peak area, open the energy window arbitrarily.
Iv) cooling
Use 30 liters Dewar flask or electric cooler.
(2) tungsten collimator
The effect of collimating apparatus is the solid angle that restriction energy spectrometer detector is opened the source, only allows the direct projection ray pass through in the chamber within it on the one hand, i.e. " transparent ", and on the arrival energy spectrometer detector (sensitive volume); On the other hand, then " all " block (promptly " deceiving ") any ray that does not enter inner chamber, prevent that it from arriving the energy spectrometer detector.For realizing " transparent ", collimating apparatus adopts the double cone geometric profile; For guaranteeing " deceiving ", collimating apparatus adopts heavy alloy material WNiFe cut to finish.
(3) Programmable Logic Controller (OMRON C200HS)
The HTR-10 overall design to burn-up level measuring system requirement head and shoulders above to the requirement of instrument in the laboratory, more strict to the requirement of its control system:
I) continous-stable operation;
Ii) polygonal communication, control and interlocking: " polygonal " is meant and comprises reactor master control system DCS---FCA system programmable logic controller---host computer---HpGe gamma energy spectrometer;
Iii) higher on-site signal transfer rate;
On-site signal transmission range iv) far away.
FCA system control sytsem structure as shown in Figure 4.This method is with burn-up level measuring system access to LAN, LAN (Local Area Network) is used the baseband digital signal transmission of CSMA/CD (carrier sense multiple access and collision detection) technology, transmission range reaches 1000M, and transfer rate reaches 10 megabit per seconds, connects with concentric cable RG62A/U.
In this method, control system adopts Japan OMRON PLC products C 200HS, and C200HS is the new type PLC product that OMRON company develops on its small PLC products C 200H basis.C200H has modularization, bus type, high performance characteristics, takes the compact one-piece construction.CPU element is its core, and CPU element comprises system power supply, microprocessor, storage system, steering logic, bus interface and other interface circuit etc.The I/O system of C200H adopts modular construction, and all I/O modules all are connected with CPU element by the bus SYSBUS of standard.It is 480 points that maximum I/O counts, and supports the remote I/O system, its I/O can be counted and extend to 1792 points, has the highest I/O density in identical size.C200H adaptability is strong, applying flexible.Though belong to small PLC, provided the function of many Large PLC configurations, especially outstanding performance is arranged at aspects such as processing speed, I/O system, connected network communication ability and antijamming capabilities.The performance of C200HS has been compared a lot of improvement with C200H, but still is consistent with C200H at aspects such as structure, working method and order set, I/O unit, makes C200HS and C200H have good compatibility feature.
The basic composition of C200HS and this method apolegamy module:
The installation frame (motherboard) of system bus and module slot is provided;
CPU element;
The user memory unit;
The hand-held programmable device;
Basic I/O unit;
Position control unit NC111: position control unit is one of specific function I/O unit of C200HS PLC, is the intelligent cell that is exclusively used in position control.Control unit, position is applicable to the servomotor driver of stepping motor or pulse input, can carry out pulse output on the one hand independently and drive the controlled point motion with control step motor or servomotor, can accept steering order and controlled variable that PLC sends on the other hand, finish the control corresponding action, and result and status information are returned to PLC.Wherein NC111 is used for single coordinate control, and this method adopts NC111 as the lifter position control unit.
Communication module
Finish on measuring system and the control system framework basis, according to FCA system design principle among the HTR-10 and subsystem operating standard, this method is made optimization to FCA system operation logic relation, the on-line automatic Survey Software of the design burn-up degree of depth, that realizes the automatic operation of burn-up level measuring process and measurement result builds the storehouse automatically.Reduce because human factor causes the possibility of maloperation on the one hand, improved running efficiency of system and reliability on the other hand.
The automatic Survey Software of burn-up level runs on host computer, and the development kit that this software system provides based on Genie 2000 frequency spectrum software systems adopts the REXX script to develop on host computer and finishes.Genie 2000 be exclusively used in multi-channel spectral collection and analysis (Multichannel Analyzers, synthetic nucleus MCA) are surveyed tool set, its system architecture is as shown in Figure 5.Except that possessing MCA control, spectral line demonstration and standard features such as adjusting, conventional analysis and report, Genie 2000 also provides comprehensive spectrum analysis, the quality guarantee to α and gamma ray spectrometer to reach the integral body of special professional application is supported scheme.
The core of Genie 2000 software systems be the virtual data manager (Virtual Data Manager, VDM) module, the task of VDM be management should be intrasystem full detail flow, finish with data file and MCA equipment between communicate by letter.The client layer application software is by inter-process (Inter Process Communication, IPC) layer is realized communicating by letter with VDM, IPC provides the support to the unit and the network user, the user can analyze by built-in processing environment of operating system or binding processing environment respectively in conjunction with the needs of oneself, and two kinds of processing environments are based on identical computing module.
IBM Britain scientific center be born in the REXX language, be used for IBM Corporation's general purpose virtual machine (Virtual Machine at first, VM) the dialog mode supervisory system of operating system (Conversation Monitor System, CMS) parts, its design motivation is to wish to go out than its more easy-to-use interpreted language with reference to the PL/I language development, to overcome the deficiency that IBM command language at that time exists.The related MS-DOS of MS Windows operating system is the elementary instruction processing environment, as shown in Figure 7.Undeniable, DOS can not show satisfactory performance at aspects such as interactivity, computing power, logical process, branches.As " instruction filter ", REXX directly gives the system directive processor with the instruction that Windows self can move, REXX grammer instruction then is interpreted as the instruction that Windows can move by the REXX instruction processing unit and passes to the operating system processing again down, as shown in Figure 8.S561 (Genie 2000 binding program support modules) is as the optional part in the huge application software package of Genie 2000 software systems, for senior automatic flow exploitation provides REXX script command processor.Therefore, this method adopts REXX script establishment ASCII command file customization burn-up level to measure flow process automatically.
Burn-up level is measured flow process as shown in Figure 6 automatically:
(1) burn-up level is measured process (hereinafter to be referred as " measurement process ") initialization;
(2) measurement process enters listening state, waits for programmable logic controller (PLC) burn-up level measurement instruction (hereinafter to be referred as " instruction is surveyed in combustion ");
(3) lifter is delivered to the lifting position with fuel element after the position of receiving connects fuel element;
(4) after lifter reached the position of receiving, the current running status of programmable logic controller (PLC) prompting operations staff was " allowing burn-up level to measure ", and surveyed instruction by communication interface to measurement process transmission combustion;
(5) receive instruction after, the measurement process is according to collection, analytical algorithm and the parameter of initialization presets, computational rules is in the time
137The gamma-ray counting rate of the 0.661642MeV that is launched in the Cs decay process, and show measuring process in real time;
(6) after the Measurement and analysis process finished, the measurement process was preserved the measurement result of current fuel element automatically in this locality, and document format data is the .cnf file;
(7) according to measurement result, the measurement process transmits measurement result by communication interface to programmable logic controller (PLC);
(8) after programmable logic controller (PLC) receives measurement result, point out the current measuring sensor type of operations staff (fuel element, spent fuel element, graphite nodule), and carry out corresponding operating (rise to reactor core, draw off) according to the processing command of dissimilar elements;
(9) after programmable logic controller (PLC) was confirmed the lifting of current element sphere or drawn off operation and finish, replacement burn-up level measurement signals was an original state, and process is returned step (2) and continued to monitor the programmable logic controller (PLC) instruction, prepares burnup measurement next time.
Claims (1)
1. spherical-bed MHTR fuel element burn-up level On-line Measuring Method is characterized in that, described method contains following steps successively:
Step (1). initialization
Genie 2000 frequency spectrum processing softwares are installed in host computer, and are started the automatic measure R EXX program of burn-up level;
Step (2). fuel element passes through irradiation in reactor core after, in single-row device flow to the discharge duct of reactor core bottom, through about 40 days cooling;
Step (3). programmable logic controller (PLC) confirm to finish once promote operation after, send instruction and start broken bulb spacer, current fuel element is delivered to the lifter position of receiving after broken ball sorting;
Step (4). this programmable logic controller (PLC) controls lifter is delivered to fuel element and is promoted the position from the position of receiving, fuel element and collimating apparatus are on the same axis;
Step (5). this programmable logic controller (PLC) sends the counting sign on to host computer, under this PC control, finish following measurement flow process: the solid angle that the gamma-rays that the nucleic that produces owing to fission in the current fuel element sends limits through collimating apparatus in decay process, arrive the HpGe crystal in the energy spectrometer, produce ionisation effect; Under the effect of biasing high-voltage power supply, be gathered into charge pulse by the input end of the prime amplifier of energy spectrometer, after amplifying, become potential pulse, and have low output impedance; Continue to be enlarged into the positive pulse signal of about 10V to the main amplifier of energy spectrometer through long cable; Enter the multichannel pulse scope-analyzer of energy spectrometer, divide into groups according to pulse height; Pulse amplitude spectrum after degree of the leaping high grouping of feeling the pulse is delivered to the processing that host computer comprises that the dead time is revised, deducts background, finally obtain
137The counting rate of the gamma-rays of the 0.661642MeV that Cs is launched in decay process in 60s used R
7Expression; R
7Calculated by following formula with the relation of burnup, burnup is proportional to exposure time T:
Wherein, f is the self-absorption modifying factor in the spherical source;
Ω is by behind the tungsten collimator, the solid angle that the energy spectrometer detector is opened radioactive source;
ε is that the energy spectrometer detector is the gamma-ray detection efficiency of 0.661642MeV to energy;
RI
7For energy is that the gamma-rays of 0.661642MeV accounts for
137The relative share of Cs decay;
Y
7For
137Cs shared share in gross-fission-product;
V
BallVolume for fuel element;
Φ is a thermal neutron flux, and equaling to enter in the unit interval with the space point is that center suitable spherular pined for subnumber;
λ
7For
137The disintegration constant of Cs;
T is the exposure time of fuel element at reactor core;
t
1Be the cool time after the irradiation end;
∑
fFor
235The macroscopic fission cross section of U equals σ
fWith the product of nuclear number in the uranium unit volume, this σ
fFor
235The microscopic fission cross section of U, the probability of a particle generation of incident nuclear fission when equaling unit area an atomic nucleus being arranged;
Step (6). above-mentioned measurement flow process obtains after finishing
137The counting rate R of the gamma-rays of the 0.661642MeV that Cs is launched in decay process in 60s
7, with R
7With according to setting counting rate threshold ratio that burnup calculates, determining whether needs to discharge reactor core or returns reactor core and continue circulation;
Step (7). measurement result is deposited in local historical data base in real time and generates report, simultaneously the burnup measurement result is sent programmable logic controller (PLC) and master control system DCS.
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| JPS54155392A (en) * | 1978-05-30 | 1979-12-07 | Nippon Atom Ind Group Co Ltd | Device for prenotifying maximum permissible power changing time of nuclear reactor fuel element |
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| CN102543227A (en) * | 2010-12-15 | 2012-07-04 | 中国核动力研究设计院 | High temperature foaming test device for radioactive shielding hot cell fuel elements |
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