CN207232047U - A kind of equipment for spent fuel storage rack boron Tube heating furnace - Google Patents
A kind of equipment for spent fuel storage rack boron Tube heating furnace Download PDFInfo
- Publication number
- CN207232047U CN207232047U CN201721154826.9U CN201721154826U CN207232047U CN 207232047 U CN207232047 U CN 207232047U CN 201721154826 U CN201721154826 U CN 201721154826U CN 207232047 U CN207232047 U CN 207232047U
- Authority
- CN
- China
- Prior art keywords
- boron
- steel pipe
- boron steel
- neutron
- equipment
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Abstract
It the utility model is related to a kind of equipment for spent fuel storage rack boron Tube heating furnace, transmission system and measuring system including boron steel pipe, boron steel pipe moves horizontally in the transmission system, and the measuring system includes corresponding neutron source and neutron detector and γ sources and gamma detector；During boron steel pipe moves horizontally, neutron source and γ sources are passed through from the inside of boron steel pipe, and neutron detector and gamma detector are located at the outside of boron steel pipe；Gamma detector detects the gamma-rays through boron steel tube wall, the thickness of boron steel pipe is measured by the decay of gamma intensity, neutron detector detects the thermal neutron through boron steel tube wall, and neutron absorption rate during by thermal neutron through boron steel tube wall measures content of the boron element in boron steel.The utility model can synchronize measurement to the thickness and Boron contents in six faces of boron steel pipe, can not only obtain the neutron absorption rate in six faces, can also obtain the thickness information of boron steel, the criticality safety for the intensive storage of spentnuclear fuel provides premise guarantee.
Description
Technical field
It the utility model is related to the detection technique of boron steel, and in particular to one kind is used for spent fuel storage rack boron Tube heating furnace
Equipment.
Background technology
In the early 1970s, Siemens start to develop irradiated fuel store high density storage frame, and select boron
Steel is and the neutron-absorbing performance to boron steel, metallurgical performance, mechanical property, anti-neutron irradiation performance, anti-as neutron absorber material
Corrosive nature has carried out research.It is external that various aspects have been carried out with neutron absorber material Boron contents and the detection of boron uniformity to shielding
Research.They are divided into two kinds at main method：Neutron reflection method and neutron transmission method.
Neutron reflection method be using the thermal neutron of detector measurement back scattering by sample when attenuation measure boron
Content.This method can both realize the measurement to thin sample (thickness is less than 2cm), can also realize that (thickness is more than to thick sample
The measurement of Boron contents in 5cm).But such method is only limitted to the Boron contents inspection to the boracic neutron absorber material of tabular or strip
Survey.
The detection principle of neutron transmission method is similar with thermal neutron radiography principle, is to pass through boracic neutron-absorbing according to thermal neutron
The decay of fluence measures Boron contents after material.Current such detection device can only detect Boron contents, to the thickness of boron steel pipe without
Method is realized and detected at the same time.
Utility model content
The purpose of this utility model is to provide a kind of equipment for spent fuel storage rack boron Tube heating furnace, to realize
Measurement is synchronized to the thickness and Boron contents in the multiple faces of boron steel pipe.
The technical solution of the utility model is as follows：A kind of equipment for spent fuel storage rack boron Tube heating furnace, including
The transmission system and measuring system of boron steel pipe, boron steel pipe move horizontally in the transmission system, and the measuring system includes phase
Corresponding neutron source and neutron detector and γ sources and gamma detector；During boron steel pipe moves horizontally, neutron source and
γ sources are passed through from the inside of boron steel pipe, and neutron detector and gamma detector are located at the outside of boron steel pipe；Gamma detector detection through
The gamma-rays of boron steel tube wall, the thickness of boron steel pipe is measured by the decay of gamma intensity, and neutron detector is detected through boron
The thermal neutron of steel pipe walls, neutron absorption rate during by thermal neutron through boron steel tube wall measure boron element containing in boron steel
Amount.
Further, it is used for the equipment of spent fuel storage rack boron Tube heating furnace as described above, wherein, the power train
System includes the mobile platform for being located at measuring system both sides respectively, several live rollers are equipped with each mobile platform, are driven
Being connected by belt between roller and driven by motor and rotated, boron steel pipe is located on live roller, and with live roller
Rotation moves horizontally.
Further, the moving direction and translational speed of boron steel pipe are controlled by control system, and before and after mobile platform
End sets limiter to sense the position of boron steel pipe movement.
Further, it is used for the equipment of spent fuel storage rack boron Tube heating furnace as described above, wherein, the measurement system
System includes horizontally disposed hanging support arm, neutron source and slow body, and γ sources and shield is set on hanging support arm, relatively
The neutron detector and gamma detector answered are arranged on the stent on the outside of hanging support arm, during boron steel pipe moves horizontally,
The hanging support arm is passed through from the inside of boron steel pipe, and the stent is located at the outside of boron steel pipe.
Further, the neutron source is252Cf neutron sources, neutron detector BF3Neutron counter；The γ
Source is133Ba gamma ray radiators, gamma detector are Nal (TI) detector.
Further, it is used for the equipment of spent fuel storage rack boron Tube heating furnace as described above, wherein, the boron steel pipe
For hexagon, there are six measuring surface, each measuring surface is correspondingly arranged a neutron detector and gamma detector.
Further, it is used for the equipment of spent fuel storage rack boron Tube heating furnace as described above, wherein, the neutron detection
Device detects the pulse signal through the thermal neutron formation of boron steel pipe, and pulse signal passes through after pre-amplifier and main amplifier
Signal screening and A/D conversions are sent to data acquisition terminal, and signal data is handled.
Further, it is used for the equipment of spent fuel storage rack boron Tube heating furnace as described above, wherein, the gamma detector
The signal through the gamma-rays formation of boron steel pipe is detected, is sent to after pre-amplifier and main amplifier through signal screening
Data acquisition terminal, handles signal data.
The beneficial effects of the utility model are as follows：The spent fuel storage rack boron steel pipe provided by the utility model that is used for is examined
The equipment of survey at the same time can be detected the neutron absorption rate and pipe thickness of boron steel pipe, different from chemical analysis and spectrum
Analysis method damages detection, and detection of the equipment to Boron contents in boron steel pipe belongs to Non-Destructive Testing；With neutron-radiography phase
Can carry out neutron absorption rate detection comprehensive to boron steel pipe in real time than, the detection device, it is possible to achieve to the boron in six faces
The synchronous detection of content.The utility model adds thickness measuring system, and the thickness and Boron contents in six faces of boron steel pipe can be carried out
Synchro measure, can not only obtain the neutron absorption rate in six faces, can also obtain the thickness information of boron steel, be that spentnuclear fuel is intensive
The criticality safety of storage provides premise guarantee.
Brief description of the drawings
Fig. 1 is the structure diagram for spent fuel storage rack boron steel pipe detection device；
Fig. 2 is the principle schematic that the utility model measures boron steel tube thickness part；
Fig. 3 is the principle schematic that the utility model measures Boron contents part；
Fig. 4 is the data acquisition schematic diagram that the utility model measures boron steel tube thickness part；
Fig. 5 is the data acquisition schematic diagram that the utility model measures Boron contents part；
Fig. 6 is the utility model signal processing flow figure；
Fig. 7 is boron steel tube thickness experiment curv in specific embodiment；
Fig. 8 is boron steel pipe neutron absorption rate experiment curv in specific embodiment.
Embodiment
The utility model is described in detail with reference to the accompanying drawings and examples.
Following embodiments are the equipment being detected for hexagon boron steel pipe Boron contents and thickness, but the utility model is simultaneously
It is not limited only to the detection to hexagon boron steel pipe.
It is bigger in view of the size of sample to be tested, and because being steel material, quality also can be heavier, so detection system
System will have mobile platform to be driven boron steel pipe when being detected to boron steel pipe.And boron steel pipe is hexagon, to accomplish pair
The synchro measure in six faces is, it is necessary to have six sets of thickness measuring systems and Boron contents measuring system.The detection device of the utility model design
By boron steel thickness measurement system, Boron contents measuring system, four part composition of transmission system and control analysis record system.It is overall
Design structure it is as shown in Figure 1.
The measuring system part of boron steel pipe among equipment, including corresponding neutron source 4 and neutron detector 5 and
γ sources 6 and gamma detector 7, both sides are boron steel pipe mobile platforms 1, and boron steel pipe 2 moves horizontally on mobile platform 1, neutron source 4 and
Corresponding slow body, γ sources and corresponding shield are placed on measuring table part by hanging support arm 3, and neutron detector 5 and γ are visited
Survey device 7 to be arranged on the stent 8 on the outside of hanging support arm, during boron steel pipe moves horizontally, the hanging support arm 3 is from boron steel
The inside of pipe 2 passes through, and the stent 8 is located at the outside of boron steel pipe 2.In measurement, boron steel pipe is from left side mobile platform with certain
Speed pass through measuring system, be moved to right side mobile platform, you can realize to the thickness in six faces of boron steel pipe and Boron contents
Measure at the same time.
(1) boron steel thickness measurement system
Principle to boron steel thickness measuring is to measure the thickness of boron steel pipe by measuring the decay of gamma intensity.In view of boron
Steel pipe is hexagon, and one-shot measurement will be carried out at the same time measure to the thickness in six faces, so needing six sets of independent thickness measures
System.The composition of the thickness measurement system in each face includes common133Ba gamma ray radiators, gamma detector and data acquiring section
Point.The position relationship in the γ sources 6 of thickness measuring system, boron steel pipe 2 and gamma detector 7 is as shown in Figure 2.The signal that detector obtains passes through
Before put, it is main put and signal screening collection after be sent to further processing of the data acquisition terminal to signal data, so as to obtain
The thickness information in each face of boron steel pipe.Data acquisition flow chart is as shown in Figure 4.
(2) Boron contents measuring system
10B has thermal neutron very high absorption cross-section, and neutron absorption rate when passing through boron steel by measuring thermal neutron can
Push away10Content of the B element in boron steel.Known sample to be tested is hexagonal boron steel pipe, thus it is similar with thickness measuring system, it is real
Measurement is, it is necessary to six sets of independent Boron contents measuring systems while now to six face Boron contents of boron steel pipe.Often covering system includes public affairs
Neutron source and slow body, detector and data acquiring portion.Survey Boron contents when neutron source 4, slow body 9, boron steel pipe 2 and in
The position relationship of sub- detector 5 is as shown in Figure 3.
From252The neutron that Cf neutron sources are released is absorbed after slow body slowing down by boron steel pipe, and neutron detector, which detects, to be worn
The neutron for crossing boron steel pipe forms pulse signal, and pulse signal is after pre-amplifier and main amplifier by signal screening and A/
Data acquisition terminal is sent to after D conversions, data are further handled, so as to obtain the Boron contents information in each face.This process
As shown in Figure 5.
(3) transmission system
Transmission system includes two independent mobile platforms, motor, frequency converter, front and back end limiter and control system
Composition.As it was previously stated, boron steel pipe range to be measured is 4.3 meters, so the length of each mobile platform is 4.5 meters.On each platform
There are 9 live rollers, as the transmission support of boron steel pipe, connected with belt mutually.The transmission of whole process is by a motor
Driving, the transmission speed of motor is by Frequency Converter Control.The position of steel pipe beginning and end is sensed by limiter.
Measuring system include thickness measuring system and survey Boron contents system, two systems form substantially it is identical, be all by radioactive source,
Detector, signal amplifier and signal processing module composition.Signal flow graph is as shown in Figure 6.
The signal obtained by detector screens signal into LM393P type voltage comparators after amplifier, screens
Useful signal afterwards is counted by 16 digit counters, and then counting is sent to PC by microcontroller per 0.5s, controls analysis software
It is responsible for carrying out analysis of accounts processing to data, and handling result is graphically provided.
In the present embodiment, the γ sources that thickness measuring system uses are133Ba, activity are 60 μ Ci.Nal (TI) detector size isBoron contents system neutron source is surveyed to use252Cf, activity are 4.4 × 107/s.Neutron detector is BF3Neutron
Counter, size areIt is 92% inside to fill purity10BF3Gas, air pressure inside 500mmHg.Due to BF3
Pipe operating voltage higher (2000V or so) is, it is necessary to be equipped with high voltage power supply.
(4) record analysis system is controlled
The debugging and operation of whole equipment are controlled by main control software.Software function mainly has the control to transmission system
System, includes the control of moving direction and translational speed；The detection of measuring system, including to BF3The control of pipe high pressure, each detection
The inspection of the working status of device；The calibration of thickness measuring system；Start the acquisition of data after measuring, processing and real-time display；Measurement
The functions such as printout as a result.
Detection device can be divided into main part and control section in use.Main body includes transmission system, measurement system
System, when use, are placed in measurement；Control section mainly controls analysis record system, be responsible for control to main part with
And the processing analysis of data.
In addition, the equipment can also be to other boron system neutron shielding materials, such as boron aluminium alloy, Al-B4C composite and
AI/B4C ceramics etc. are detected.Using this equipment as prototype, the neutron shielding material for other shapes can also be designed
Detection, is that the development of neutron shielding material Non-Destructive Testing produces positive effect.
The detection process of the utility model is specifically described below by example.
1) before sample to be tested is measured, first have to demarcate the sample of standard thickness, in the hope of boron steel
The attenuation coefficient mu of material, then by passing through the measurement of sample to be tested penetrance to gamma-rays, boron steel can be tried to achieve according to formula
Thickness.Six faces of boron steel pipe point six sets detection systems, since every cover also can be variant between detection system, so often covering detection system
Independently demarcated.
Standard thickness sample intercepts one section from sample to be tested, and standard thickness sample is fabricated to after over mechanical processing.By
This has made the sample of three thickness, is respectively 4mm, 5mm and 8mm standard sample.
Since standard thickness sample length is smaller, it is impossible to be directly placed into thickness measuring system, can only connect to sample to be tested
Both ends carry out calibration measurement.This time experiment is only demarcated with the standard thickness boron steel pipe of two specifications of 4mm and 5mm.It is right
The calibration result in each face is as shown in the table：
1 thickness calibration result of table
(2) preliminary surveying has been carried out to existing seven boron steel pipes sample after thickness calibration, due to lacking Boron contents
The tables of data of calibration, so only being measured thickness and neutron absorption rate, measuring speed 0.25cm/s, measures in figure
What each point represented is the assembly average of every cm, so the timing statistics each put are 4s.
Several measurement result figures is all more similar, and simply thickness value and neutron absorption rate some differences, only provide below
The thickness measure figure and neutron absorption rate figure of No. 0046 boron steel pipe.What Fig. 7 was represented is the thickness of No. 0046 boron steel pipe diverse location
Figure.Six curves expressions are the thickness informations in six faces of boron steel pipe in figure, and abscissa represents the position of boron steel pipe, and unit is
Cm, ordinate represent the thickness value of boron steel pipe, unit mm.It is by 4mm thickness calibrations sample and 5mm thickness calibrations during measurement
What the head and the tail both ends that sample is connected to No. 0046 boron steel pipe measured.
What Fig. 7 was represented is the neutron absorption rate curve of No. 0046 boron steel pipe diverse location, and abscissa represents the position of boron steel pipe
Put, unit cm, ordinate represents the neutron absorption rate of boron steel pipe.Due to being set display threshold, neutron absorption rate is bent
The last period (corresponding 4mm boron steel pipes absorptivity) of line and latter section (corresponding 5mm boron steel pipes absorptivity) are truncated in figure, in figure
Display has just started the neutron absorption rate of boron steel pipe 0.8 or so, corresponding to the neutron absorption rate of the boron steel tube material of 4mm thickness, and
Neutron absorption rate rises to 0.88 or so afterwards, corresponding to the neutron absorption rate of boron steel pipe to be measured.The neutron absorption rate of afterbody is slow
The part to diminish corresponds to 5mm boron steel pipe samples.
As can be seen from Figure 8,0.88 or so, the reduction of neutron absorption rate corresponds to the neutron absorption rate of whole boron steel pipe
In the change of boron steel tube thickness and the change of Boron contents.The thickness near 180cm of face 2 reduces suddenly in figure, a depression occurs.And
Also reduce suddenly in the correspondence position neutron absorption rate of boron steel pipe neutron absorption rate figure, have a corresponding depression, illustrate thickness
Reduction can reduce neutron absorption rate, this is readily appreciated that.Thickness reduces the reduction that correspond to 10B contents, makes to be absorbed
Neutron population decline, cause neutron absorption rate to reduce.
Preliminary surveying has been carried out to existing 7 boron steel pipes, has obtained the data of thickness and neutron absorption rate, and to surveying
Amount result is analyzed and summarized, and is contrasted with analog result, and analysis has been carried out to the statistical error in experiment and has been calculated,
Thickness statistical error is less than 5%, and the statistical error of neutron absorption rate is less than 1%.
2 0046 boron steel pipe testing result of table
Obviously, those skilled in the art can carry out the utility model various modification and variations without departing from this practicality
New spirit and scope.In this way, if the utility model claims are belonged to these modifications and variations of the utility model
And its within the scope of equivalent technology, then the utility model is also intended to comprising including these modification and variations.
Claims (8)
- A kind of 1. equipment for spent fuel storage rack boron Tube heating furnace, it is characterised in that：Include the transmission system of boron steel pipe And measuring system, boron steel pipe (2) move horizontally in the transmission system, the measuring system includes corresponding neutron source (4) and neutron detector (5) and Y sources (6) and Y detectors (7)；During boron steel pipe moves horizontally, neutron source (4) and Y sources (6) are passed through from the inside of boron steel pipe (2), and neutron detector (5) and Y detectors (7) are located at the outside of boron steel pipe (2)；Y is visited Survey device detects the gamma ray through boron steel tube wall, and the thickness of boron steel pipe, neutron detector are measured by the decay of gamma ray intensity The thermal neutron through boron steel tube wall is detected, neutron absorption rate during by thermal neutron through boron steel tube wall measures boron element in boron Content in steel.
- 2. it is used for the equipment of spent fuel storage rack boron Tube heating furnace as claimed in claim 1, it is characterised in that：The biography Dynamic system includes being located at the mobile platform (1) of measuring system both sides respectively, several transmission rollings are equipped with each mobile platform To take turns, connected between live roller by belt and rotation is driven by motor, boron steel pipe (2) is located on live roller, and with The rotation of live roller moves horizontally.
- 3. it is used for the equipment of spent fuel storage rack boron Tube heating furnace as claimed in claim 2, it is characterised in that：Pass through control System controls the moving direction and translational speed of boron steel pipe, and sets limiter to be moved to sense boron steel pipe in mobile platform front and back end Dynamic position.
- 4. it is used for the equipment of spent fuel storage rack boron Tube heating furnace as claimed in claim 1, it is characterised in that：The survey Amount system includes horizontally disposed hanging support arm (3), and neutron source (4) and slow body, and Y sources are set on hanging support arm (3) (6) it is arranged on shield, corresponding neutron detector (5) and Y detectors (7) on the stent on the outside of hanging support arm (8), During boron steel pipe moves horizontally, the hanging support arm (3) is passed through from the inside of boron steel pipe (2), and the stent (8) is located at boron The outside of steel pipe (2).
- 5. the equipment for spent fuel storage rack boron Tube heating furnace as described in claim 1 or 4, it is characterised in that：It is described Neutron source (4) be252Cf neutron sources, neutron detector (5) are BF3Neutron counter；The Y sources (6) are133Ba Y are radiated Source, Y detectors (7) are Nal (TI) detector.
- 6. it is used for the equipment of spent fuel storage rack boron Tube heating furnace as claimed in claim 1, it is characterised in that：The boron Steel pipe (2) is hexagon, has six measuring surface, and each measuring surface is correspondingly arranged a neutron detector and Y detectors.
- 7. it is used for the equipment of spent fuel storage rack boron Tube heating furnace as claimed in claim 1, it is characterised in that：The neutron Detector detects the pulse signal through the thermal neutron formation of boron steel pipe, and pulse signal passes through pre-amplifier and main amplifier Data acquisition terminal is sent to by signal screening and A/D conversions, signal data is handled.
- 8. it is used for the equipment of spent fuel storage rack boron Tube heating furnace as claimed in claim 1, it is characterised in that：The Y is visited Survey device and detect the signal through the gamma ray formation of boron steel pipe, sent out after pre-amplifier and main amplifier through signal screening Data acquisition terminal is given, signal data is handled.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201721154826.9U CN207232047U (en) | 2017-09-08 | 2017-09-08 | A kind of equipment for spent fuel storage rack boron Tube heating furnace |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201721154826.9U CN207232047U (en) | 2017-09-08 | 2017-09-08 | A kind of equipment for spent fuel storage rack boron Tube heating furnace |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN207232047U true CN207232047U (en) | 2018-04-13 |
Family
ID=61861207
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201721154826.9U Active CN207232047U (en) | 2017-09-08 | 2017-09-08 | A kind of equipment for spent fuel storage rack boron Tube heating furnace |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN207232047U (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107561103A (en) * | 2017-09-08 | 2018-01-09 | 中国原子能科学研究院 | A kind of equipment for spent fuel storage rack boron Tube heating furnace |
| CN112179924A (en) * | 2020-10-23 | 2021-01-05 | 中国石油大学(华东) | Downhole casing damage detection method based on boron neutron capture |
| CN107561103B (en) * | 2017-09-08 | 2024-05-14 | 中国原子能科学研究院 | Equipment for detecting spent fuel storage grillage boron steel pipe |
-
2017
- 2017-09-08 CN CN201721154826.9U patent/CN207232047U/en active Active
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107561103A (en) * | 2017-09-08 | 2018-01-09 | 中国原子能科学研究院 | A kind of equipment for spent fuel storage rack boron Tube heating furnace |
| CN107561103B (en) * | 2017-09-08 | 2024-05-14 | 中国原子能科学研究院 | Equipment for detecting spent fuel storage grillage boron steel pipe |
| CN112179924A (en) * | 2020-10-23 | 2021-01-05 | 中国石油大学(华东) | Downhole casing damage detection method based on boron neutron capture |
| CN112179924B (en) * | 2020-10-23 | 2022-07-05 | 中国石油大学(华东) | Downhole casing damage detection method based on boron neutron capture |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN108680943B (en) | Neutron energy spectrum measuring device and method based on prompt gamma ray neutron activation analysis technology | |
| CN107422359A (en) | A kind of measuring method of the neutron gamma dosage based on liquid scintillation bulk detector | |
| CN111913205A (en) | Nuclear emergency multifunctional portable radiation monitoring system and monitoring method | |
| CN207232047U (en) | A kind of equipment for spent fuel storage rack boron Tube heating furnace | |
| CN206710614U (en) | The measuring system of radioactivity inert gas | |
| CN108802792B (en) | Device and method for measuring radioactive inert gas | |
| CN107561103A (en) | A kind of equipment for spent fuel storage rack boron Tube heating furnace | |
| CN204705719U (en) | A kind of portable radioactive contamination meter | |
| US2967937A (en) | Method and apparatus for measuring thickness | |
| CN212515056U (en) | Nuclear emergency multifunctional portable radiation monitoring system | |
| CN107561103B (en) | Equipment for detecting spent fuel storage grillage boron steel pipe | |
| CN107024712A (en) | One kind is determined235The device of U mass | |
| CN111736201B (en) | Nuclear fuel rod active detection system and method | |
| CN113791439A (en) | On-line monitoring method and system for obtaining gadolinium concentration by measuring neutrons | |
| CN206906592U (en) | One kind measure235The device of U mass | |
| CN215678794U (en) | Power measuring device for reactor core of pressurized water reactor | |
| US4270051A (en) | Device for gauging thickness of refractory lining | |
| Rizzo et al. | Virtual point detector: Application to coincidence-summing correction in gamma-ray spectrometry | |
| CN2476814Y (en) | Coal ash content investigating device | |
| CN116184482B (en) | Helium-3-based neutron multiple self-adaptive measurement device and measurement method | |
| CN107561104B (en) | Equipment for detecting neutron absorption performance of boron aluminum alloy material of nuclear power plant | |
| CN219590522U (en) | Underwater measuring device for radioactivity | |
| CN202305438U (en) | Double-neutron-source coal on-line analyzer | |
| JPH0318914Y2 (en) | ||
| Corey et al. | Determination of soil density and water content by fast neutrons and gamma rays |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |