JPH11242094A - Device for inspecting vibration-packed fuel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To allow nuclear data including the abundance ratio of fissionable products typified by fissile concentration of vibration-packed fuel rods and those about on internal structure such as the packing density of a nuclear fuel and a packing condition in nuclear fuel powder to provide data not only in the axial direction of fuel rods but also in any section of the axial directions. SOLUTION: The purpose mentioned above is accomplished by a device for inspecting a vibration-packed fuel constituted of an X-ray generator emitting X rays with the energy enough to cause the photonuclear reaction of a nuclear fuel substance when a nuclear fuel rod 21 is irradiated with the X rays, a fuel rod support base 10 equipped with a mechanism holding the nuclear fuel rod 21, an X-ray detector 6 measuring the intensity of the X rays that have passed through the nuclear fuel rod 21, and a neutron detector 8 measuring the intensity of neutrons generated through the photonuclear reaction of the unclear fuel substances.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a nuclear fuel rod used in a nuclear reactor, and more particularly, to a technique for inspecting a vibration-filled fuel rod.

[0002]

BACKGROUND OF THE INVENTION Currently used fuels are mostly pellet type fuels. Pellet fuel is formed by compacting nuclear fuel powder into a columnar shape (pellet), burning it at a high temperature, and then, for all pellets, their outer diameter and density, and the concentration of fissionable material (enrichment). Is passed through the test tube and passed into a long metal tube with a diameter of about 5 mm to about 15 mm and a length of about 2 m to about 4 m, which is called a cladding tube. This fuel is manufactured by sealing with a stopper.

[0003] In recent years, plutonium (P
When u) is used, the increase in radiation exposure of workers in the compacting process, sintering process, pellet inspection process, etc. of pellet type fuel, or additional shielding required to reduce radiation exposure is required. The rise in manufacturing costs has become an issue requiring new measures. As one of the measures,
Vibrating charged fuels are receiving attention.

[0004] Vibration-filled fuel is a fuel produced by a method in which nuclear fuel powder is directly supplied to a cladding tube and charged while applying vibration. Since the compacting process, sintering process, and pellet inspection process such as pellet-type fuel are not required, the fuel manufacturing process can be simplified, and remote and easy to automate. It is considered to have an advantage over pellet type fuel.

In the case of vibration-filled fuel, simply filling the cladding tube with the nuclear fuel raw material powder has a lower nuclear fuel packing density of the entire fuel rod than a pellet-type fuel loaded with high-density pellets. This causes a problem that the loading amount of nuclear fuel material is reduced.

On the other hand, in the powder filling theory or the powder filling experiment, powders having different particle sizes such as coarse particles, fine particles, and intermediate particles are mixed at an appropriate ratio, rather than filling a single particle size (particle size) powder. It is suggested that filling with the prepared multi-component powder results in a higher packing density.

[0007] Therefore, these findings are also taken into account in the production of vibration-filled fuels, and the nuclear fuel powder is reduced in particle size from about 1 to about 100.
By classifying several types in the range of 0 μm and using a multi-component nuclear fuel powder in which these are mixed at an appropriate mixing ratio, an attempt is made to solve the problem of low packing density.

On the other hand, since the fuel cladding tube is a long thin tube as described above, there is a possibility that the nuclear fuel powder separates and moves for each particle size during the vibration filling process. In general, it is known that in the vibration filling of a multi-component powder, coarse particles are separated and moved upward while fine particles are separated downward. Such separation and movement of the mixed powder means that the density of the vibration-filled fuel varies in the longitudinal direction (hereinafter, axial direction) and the cross-sectional radial direction (hereinafter, radial direction), that is, a density distribution.

Further, in the case of vibration-filled fuel, as one of the methods for adjusting the average fissile material concentration (the content of fissile isotopes such as U and Pu, hereinafter referred to as fissile concentration) of fuel rods, the fissile concentration is determined for each powder particle size. There is a method of changing the concentration. In this case, the separation and movement of the mixed powder means that the concentration distribution and segregation of the fissile material occur in the axial direction and the radial direction of the fuel rod.

[0010] Such fuel density or distribution or segregation of fissile material may affect the nuclear and thermal performance of the fuel.

Therefore, in the fuel rod inspection of the vibration-filled fuel rod, information on the nuclear fuel material represented by fissile concentration and Pu enrichment (hereinafter referred to as nuclear information), the nuclear fuel filling density and the state of filling of the nuclear fuel powder are given. Is required to be obtained as axial and radial distributions, ie, three-dimensional information. At present, the typical inspection items of fuel rod inspection performed on general pellet type fuel rods are the length of the fuel area (fuel stack length), the soundness of the pellet (presence of cracks and chips), the fuel density , Fissile concentration, Pu enrichment, insertion member confirmation,
And so on.

The representative inspection techniques are as follows. The X-ray transmission method is used for information on the internal structure, such as the measurement of the length of the fuel area (fuel stack length), the confirmation of the integrity of the pellet, and the confirmation of the inserted member. The nuclear information such as the fissile concentration and the enrichment of Pu is The passive method of measuring γ-rays emitted from nuclear fuel material or the active method of irradiating fuel with neutrons using a neutron source and measuring neutrons and γ-rays generated by fission reactions are generally used. I have. The fuel density is measured by the transmission X-ray method or the transmission γ-ray method. However, in the case of pellet-type fuel, only the pellets that have passed the density inspection are basically loaded into the cladding tube, and this inspection may be omitted. .

[0013] For vibration-filled fuels, there is still no universally established technology. There are examples in which an X-ray transmission method and a neutron radiography method are used on an experimental scale.

However, all of these methods only provide average two-dimensional information of the projected cross section regarding the internal structure of the fuel rod to be inspected, and cannot obtain three-dimensional information or nuclear information of nuclear fuel material.

On the other hand, as a method for obtaining three-dimensional information inside an object, there is an X-ray CT method used in medical treatment and the like. However, this method cannot provide nuclear information on nuclear fuel material.

[0016]

SUMMARY OF THE INVENTION In a vibration-filled fuel rod,
Nuclear information typified by fissile concentration and information on internal structure such as nuclear fuel filling density and nuclear fuel powder filling state are not only information on fuel rod axial direction but also information on arbitrary cross section in axial direction, that is, three-dimensional information Need to be obtained as

In order to obtain such information using the conventional technology, it is necessary to combine various inspection devices such as an X-ray transmission device, a passive method or an active method detection device, and the workability is deteriorated, and the inspection equipment is deteriorated. In addition to the increase in size, it is difficult to completely obtain the above-described three-dimensional information even by these methods.

An object of the present invention is to provide a vibration-filled fuel inspection apparatus which solves these problems and problems.

[0019]

A first aspect of the present invention for achieving the above object is as follows.
The present invention is characterized in that when X-rays are irradiated on a nuclear fuel rod, an X-ray generator for generating X-rays having an energy at which a nuclear fuel substance generates a photonuclear reaction, a fuel rod support having a mechanism for holding the nuclear fuel rod, a nuclear fuel rod, This is an inspection device for vibration-filled fuel, comprising an X-ray detector for measuring the intensity of X-rays transmitted through a rod, and a neutron detector for measuring the intensity of neutrons generated by photonuclear reaction of nuclear fuel material.

The reasons and effects are as follows. When X-rays penetrate an object, they are absorbed at an absorption rate unique to the object.
Therefore, X-rays are irradiated from all angles in the circumferential direction of the nuclear fuel rod under a certain geometrical arrangement, the intensity of the transmitted X-rays is measured, and the line absorption coefficient in the object is determined based on the attenuation data. By analyzing the distribution, three-dimensional information on the internal structure of the vibrationally charged fuel, that is, the axial distribution of the fuel rods regarding the nuclear fuel density and the filling state of the nuclear fuel powder, and their distributions and images on the fuel cross section at arbitrary positions in the axial direction, Obtainable.

When a substance is irradiated with high energy γ-rays or X-rays, the photonuclear reaction (X (γ),
n) and emit neutrons. By measuring the intensity of this neutron with a neutron detector and analyzing it based on the data, three-dimensional nuclear information of the vibrationally charged fuel, that is,
It is possible to obtain the axial distribution of the fuel rods such as the fissile concentration and the Pu enrichment, and their distribution in the fuel cross section at an arbitrary position in the axial direction.

A second feature of the present invention to achieve the above object is that the X-ray generator of the above-described inspection apparatus for vibration-filled fuel can generate X-rays having an energy of 6 Mev or more and at least 1 to 6 Mev.
The energy level can be changed arbitrarily within the range of Mev.

The reasons and effects are as follows. The energy of the radiation that triggers a photonuclear reaction is called the photoreaction threshold and depends on the mass number of the substance. U and P which are nuclear fuel materials
The photoreaction threshold such as u is in the range of 5 to 6 Mev, and the threshold of Fe, Cr, Ni, Zr, etc., which is the alloy composition of the cladding tube, is in the range of 8 to 12 Mev. Therefore, by irradiating the fuel rods with X-rays having an energy of 5 to 6 Mev and measuring the neutrons generated, information such as the three-dimensional arrangement of nuclear fuel materials in the fuel rods can be selectively obtained.

Further, since the X-ray energy threshold of the photonuclear reaction depends on the mass number of the substance, the energy of the X-ray is reduced to 5 to 6
It is possible to know the ratio of Pu contained in the nuclear fuel, that is, the Pu enrichment, etc., by gradually changing the Mev range and selectively obtaining Pu information.

A feature of the third invention for achieving the above object is that the X-ray generator of the above-described vibration-filled fuel inspection apparatus includes a collimator, and the slit width or through-hole diameter of the collimator is 300 μm or less. is there.

The reason and effect are as follows. The average particle size of each component powder constituting the multi-component nuclear fuel powder used for the vibration-filled fuel is approximately several μm for fine particles, several tens μm for intermediate particles, and several hundred μm for coarse particles. Therefore,
By narrowing the X-ray beam to 300 μm or less by a collimator, it is possible to obtain an image of the state of filling of at least one component powder of these nuclear fuel powders.

A fourth feature of the present invention that achieves the above object is that the neutron detector of the above-described vibration-filled fuel inspection apparatus is capable of attenuating the energy of neutrons generated by photonuclear reactions to a range of 1 Mev to 1 ev. It is to provide a material.

The reason and effect are as follows. Neutrons generated by the photonuclear reaction and secondary neutrons generated by the nuclear reaction of the neutrons with nuclear matter have a wide band energy. Of these, neutrons can be efficiently measured by slowing down high energy neutrons to the thermal neutron level using a moderator.

A fifth feature of the present invention to achieve the above object is that three or more neutron detectors are arranged around a nuclear fuel rod in the above-mentioned inspection apparatus for vibration-filled fuel.

The reason and effect are as follows. Since neutrons or secondary neutrons generated by the photonuclear reaction are emitted isotropically, measurement accuracy can be improved by arranging a large number of neutron detectors around the nuclear fuel rod.

A feature of a sixth invention for achieving the above object is that the X-ray detector of the vibration-filled fuel inspection apparatus has a collimator, and the collimator has a slit width or through-hole diameter of 50 μm to 300 μm. That is.

The reason and effect are as follows. The provision of the collimator can prevent noise X-rays scattered from the nuclear fuel rods and peripheral devices from entering the detector. However, if the slit width or the diameter of the through hole is too small, the X-ray intensity decreases and the measurement accuracy decreases. The collimator slit width or through diameter is 50μm ~ 300μ
m, the noise signal can be cut sufficiently,
In addition, in terms of measurement accuracy, a sufficient intensity of the measurement signal can be obtained, and furthermore, it is possible to detect the state of filling of at least one component of the multi-component filling powder.

A feature of the seventh invention that achieves the above object is that the fuel rod support of the above-described inspection apparatus for vibration-filled fuel has a mechanism for moving the nuclear fuel rod up and down, translationally, and rotationally.

The reason and effect are as follows. In order to obtain three-dimensional information, it is necessary to irradiate X-rays from various directions around the circumference at each position in the axial direction of the nuclear fuel rod, and to measure the transmitted X-rays and neutrons. As a method of irradiating the X-ray at any position of the subject, there is a method of fixing the subject and moving the X-ray generator, but when the shape of the subject is simple such as a nuclear fuel rod, the subject is exposed. It becomes mechanically easier to drive.

[0035]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An inspection apparatus and a measuring method for a vibration-filled fuel according to an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows the concept of the inspection apparatus for vibration-filled fuel according to the present invention.

As shown in FIG. 1, the inspection apparatus for vibration-filled fuel according to the present invention comprises an X-ray generator 3 having an electron beam accelerator 1 and a collimator 2 for emitting light, and an X-ray generator having a collimator 4 for receiving light.
Ray detector 5, neutron detector 7 with neutron moderator 6,
It comprises an X-ray signal processing device 8, a neutron signal processing device 9, a nuclear fuel rod support 10, a control device 11, an accelerator trigger device 12, a computing device 13, and a display device 14.

The X-ray generator 3 pulsates X-rays obtained by colliding high-energy electrons accelerated by the electron beam accelerator 1 with a target metal from the 200 μm slit-shaped collimator 2 to produce a nuclear fuel rod as an object. Emit toward 21.
The maximum X-ray energy of the X-ray generator 3 is 12 Mev.

The beam X radiated from the X-ray generator 3
When passing through the nuclear fuel rod 21, the ray is attenuated by nuclear material and reaches the X-ray detector 5 having the light-receiving collimator 4 on the opposite side of the X-ray generator 3 across the nuclear fuel rod 21. If the X-ray energy is equal to or higher than the photonuclear reaction threshold,
The nuclear material in the nuclear fuel rod 21 causes a photonuclear reaction and emits neutrons.

The X-ray detector 5 cuts the scattered X-rays by the collimator 4 and captures only the X-rays transmitted through the nuclear fuel rod 21 and measures the intensity. The detection unit is CWO (Cd
Although a high-density scintillation detector such as WO4) can be used, a semiconductor detector and a Si-SSD, which can be further reduced in size and improved in sensitivity, are used in this embodiment. In FIG. 1, a typical X
Although several line detectors 5 are shown, the inspection apparatus for vibration-filled fuel used in the present embodiment has a size of about 40 × 3 × 0.5 mm.
About 20 i-SSDs were used. The collimator material is
The width of the slit in tungsten is about 0.1 × 1 mm.

The X-ray signal processor 8 digitizes the X-ray intensity measured by the X-ray detector 5 and transfers it to the arithmetic unit 13.

The neutron moderator 6 is composed of polyethylene and Cd, and attenuates neutrons in a wide energy band generated by a photonuclear reaction or a fission reaction to a thermal neutron level of 1 eV or less.

The neutron detector 7 measures the neutron intensity reduced by the neutron moderator 6. The neutrons generated in the nuclear fission reaction by neutrons of the X-ray photonuclear reaction or photonuclear reaction are radiated from the nuclear fuel rod 21 isotropically. Deploy. FIG. 1 shows nine neutron detectors with a neutron moderator as a typical example, but the inspection device for vibration-filled fuel used in this embodiment uses a total of 30 neutron detectors with a moderator. did. The detector of the neutron detector 7 is a He-3 detector having a length of about 400 mm.

The neutron signal processor 9, like the X-ray signal processor 8, digitizes the neutron intensity measured by the neutron detector 7 and transfers it to the arithmetic unit 13.

In order to obtain tertiary information, it is necessary to irradiate X-rays at various positions in the axial direction of the nuclear fuel rod from the circumferential direction and measure the transmitted X-rays and neutron rays. The nuclear fuel rod support 10 holds the nuclear fuel rod 21 and moves it up, down, rotates, and translates with high accuracy. FIG. 2 shows the conceptual structure.

The fuel rod supporting base 10 includes a translation driving base 15 and its driving mechanism 18, a vertical driving base 16, and its driving mechanism 19, a rotary driving base 17, and its driving mechanism 2.
0, a fuel rod support mechanism 22 for supporting a fuel rod 21 as an object.

The fuel rod support 10 can hold several tens of rods at a time if it is a typical FBR fuel rod having a length of about 3 m and a diameter of about 5 mm. The minimum value of the movement step is vertical movement,
The translation angle is 1 mm, and the minimum angle of rotation is 1 degree. Their moving speed is 0-4 m / min.

The control device 11 controls the movement of the fuel rod support 10 and, at the same time, transfers information on the X-ray incident direction and position to the arithmetic device 13.

The arithmetic unit 13 comprises an X-ray signal processor 8,
Based on the digital data on the radiation from the neutron signal processor 9 and the position data from the controller 11, information on the internal structure such as the density distribution of the nuclear fuel material inside the nuclear fuel rod and the filling state of the filling powder, and fissile
Calculate core information such as concentration and Pu enrichment.

The analysis on the internal structure of the nuclear fuel rod and the analysis on the nuclear information of the nuclear fuel material performed by the arithmetic unit 13 will be outlined with reference to FIG.

As shown in FIG. 3, when an X-ray having an intensity I ₀ is incident on a nuclear fuel rod along a straight line L, the X-ray is scattered or absorbed by the nuclear fuel material and attenuated. Assuming that the intensity of the transmitted X-ray is I, the following relational expression holds.

[0052]

(Equation 1)

In the equation (1), f (x, y) is defined as a linear absorption coefficient distribution, and is a scalar quantity unique to a nuclear fuel material. Also, ∫f (x, y) dL, that is,
The value obtained by integrating the X-ray absorption coefficient distribution along the path (straight line L) through which X-rays pass is a value referred to as measured X-ray projection data or attenuation data.

Information such as the filling state of the filling powder and the arrangement of the nuclear fuel material basically includes projection data (デ ー タ f (x, y) d
L) to obtain a linear absorption coefficient distribution (f (x, y)) and re-image it. That is, the arithmetic unit 13 calculates a linear absorption coefficient distribution based on a set of attenuation data obtained by uniformly irradiating X-rays from around the nuclear fuel rod. Since the research paper has been published, the calculation method is omitted here.

Regarding the density distribution, which is other internal structural information of a nuclear fuel rod, generally, when the interaction between a substance and radiation is in the Compton scattering region, the density between the linear absorption coefficient and the density of the specimen is Since a proportional relationship is established, a corresponding density distribution is calculated from the obtained linear absorption coefficient distribution f (x, y).

Regarding nuclear information of nuclear fuel material, although there is a difference in using intensity data of neutrons generated by photonuclear reactions instead of the X-ray attenuation data used in the internal structure information, re-imaging is basically performed. The concept similar to the internal structure analysis is used. That is, the amount of neutrons generated by the incidence of X-rays is proportional to the product of the intensity of the X-rays and the amount of the target nuclear material determined by the energy of the X-rays. For example, three-dimensional information on nuclear matter can be obtained from neutron intensity data. And
The intensity distribution along the straight line (L) where the X-rays are incident is given by (Equation 1)
Obtained from the formula.

The fissile density is determined by the concept shown in FIG.

When the nuclear material is composed of non-fissionable nuclear material such as U-238, neutrons generated by the photonuclear reaction (referred to as primary neutrons) are shown in FIG.
Decreases over time as shown by. On the other hand, U
When a fissile material such as -235 is included, a fission reaction occurs between the primary neutron and the fissile material, and neutrons (secondary neutrons) are emitted in proportion to the amount of the fissile material.

This is conceptually shown in the figure as shown in FIG. Therefore, the abundance of fissile material can be obtained by subtracting the number of primary neutrons (including neutrons generated by spontaneous fission of nuclear material) as a background from the total number of neutrons generated within a certain period of time.

The nuclear fuel rod 21 used in this embodiment is a U-2
35 Sintered pellets with a concentration of about 3.5%, a sintered density of about 10.4 g / cm ³ (about 95% theoretical density), a diameter of about 10 mm and a height of about 11 mm, an outer diameter of about 12 mm and a length of about 11 mm This is a single pellet-type short fuel rod in which a 2.5 m 2 zircaloy (Zry-2) cladding tube is filled up to a fuel region length of about 2 m.

The nuclear fuel rod 21 to be inspected is
The lower end of the nuclear fuel rod was fixed to the X-ray beam position on the fuel rod support mechanism 22, and the X-ray irradiation and radiation measurement were started by setting the position to Step 1 and setting the circumferential angle to 0 °. When irradiation and measurement at that position are completed, the nuclear fuel rod is
After rotating each time and performing the same irradiation and measurement up to 360 degrees, the nuclear fuel rod was raised by one step (50 mm) at a moving speed of about 40 mm / sec, and the same irradiation and measurement were performed again.
Thus, the same X-ray irradiation and measurement were repeated up to 50 steps. The energy of X-rays in each irradiation and measurement is 0.1 Mev in a range of 5 to 6 Mev at a maximum of 6 Mev.
Swept every time.

The measurement results are as follows.

Pellet Density: The nuclear fuel used in this embodiment is a material filled with sintered pellets having little variation in density, and therefore has very little variation in density in the fuel rod axial direction and radial direction. 0 °, 90 at each axial position
The measured densities of °, 180 °, and 270 ° are all 95.5.
± 0.1%, which was almost the same as the measured density during pellet production.

Effective fuel length: Regarding the effective fuel length, the fuel length was evaluated from the change in the intensity of transmitted X-rays in the axial direction of the fuel rod.
As a result of the measurement, it was confirmed that measurement was possible with an accuracy of ± 1.6 mm at a reliability of 95% (2σ).

U-235 enrichment: The enrichment of the test fuel rod obtained by the present invention utilizing the (X, n) reaction was 3.5 ± 3.5%.
0.15%, confirming that it has sufficient accuracy as a nondestructive inspection method.

Another embodiment of the present invention will be described with reference to FIG.

As shown schematically in FIG. 5, a sample 23 to be an object was prepared by mixing two types of glass beads 24 and 25 having diameters of 0.1 mm and 1 mm at a weight ratio of 3: 7, respectively. The two-component granules are vibration-filled to a height of about 20 cm in a glass measuring cylinder having a diameter of about 15 mm.

After fixing the sample 23 on the support, X-ray irradiation and measurement were performed. The energy of the X-ray is about 4 Mev, and other operating conditions, measurement conditions, dimensions and shape of the collimator and the like are the same as those in the first embodiment.

As an example of the measurement result, the measurement result at each position in the axial direction of the packing density is shown on the left side of FIG. As shown in the figure, the distribution of the packing density was observed in the axial direction. Particularly, the upper part has a low density. This is considered to be due to the separation phenomenon (seregation) between the coarse grains 24 and the fine grains 25.

This phenomenon occurs as shown on the right side of FIG.
This is supported by the cross-sectional images at each position in the axial direction. That is, the coarse grains 24 and the fine grains 25 are relatively densely packed in the region below the middle part, whereas the coarse grains 2 and fine grains 25
4 are observed, and many voids are observed between the particles.
In a region where the coarse particles 24 and the fine particles 25 are densely packed, segregation of particles is observed in the radial direction.

The present invention is not limited to the above embodiment, and the inspection apparatus for vibration-filled fuel rods of the present invention can be applied to various fuel types such as pellet fuel, hollow pellet fuel, and metal fuel.

Further, uranium (U)
O ₂ ) oxide fuel, mixed oxide (MOX) fuel, nitride fuel, carbide fuel, rock fuel, minor actinide (M
A) The present invention can be applied to a fuel using any nuclear fuel material such as a fuel.

[0073]

According to the present invention, the fiss of the vibrating filled fuel rod is
Nuclear information such as the fissile material abundance represented by the ile concentration, and information about the internal structure such as the nuclear fuel packing density and the packing state of nuclear fuel powder,
It is obtained as information on an arbitrary cross section in the axial direction, that is, three-dimensional information.

[Brief description of the drawings]

FIG. 1 is a plan view showing a configuration of an inspection apparatus for vibration-filled fuel according to a first embodiment for achieving the present invention.

FIG. 2 is a vertical cross-sectional configuration view of a nuclear fuel rod support according to the first embodiment.

FIG. 3 is a diagram schematically illustrating an X-ray beam transmitted through a cross section of a nuclear fuel rod.

FIG. 4 is a characteristic diagram conceptually showing the number of neutrons generated in a photonuclear reaction and a nuclear reaction and how they are attenuated.

FIG. 5 is a view showing a packing density of a vibration packing sample and a packing state of packing particles in each cross section, showing a second embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Electron beam accelerator, 2 ... Emitting part collimator, 3 ... X-ray generator, 4 ... Light receiving part collimator, 5 ... X-ray detector, 6 ...
Neutron moderator, 7: neutron detector, 8: X-ray signal processor, 9: neutron signal processor, 10: nuclear fuel rod support,
DESCRIPTION OF SYMBOLS 11 ... Control device, 12 ... Accelerator trigger device, 13 ... Computing device, 14 ... Display device, 15 ... Translation drive stand, 16 ... Vertical drive stand, 17 ... Rotation drive stand, 18 ... Translation drive mechanism, 1
9: drive mechanism, 20: rotary drive mechanism, 21: nuclear fuel rod,
22: Nuclear fuel rod support mechanism, 23: Vibration filling test specimen,
24: coarse powder, 25: fine powder.

 ──────────────────────────────────────────────────の Continuing from the front page (72) Inventor Katsutoshi Sato 3-1-1, Komachi, Hitachi-shi, Ibaraki Pref. Hitachi, Ltd. Hitachi Plant

Claims (7)

[Claims] 1. An X-ray generator for generating X-rays having an energy at which a nuclear fuel substance causes a photonuclear reaction when a nuclear fuel rod is irradiated with X-rays, a fuel rod support having a mechanism for holding the nuclear fuel rod,
An X-ray detector for measuring the intensity of X-rays transmitted through a nuclear fuel rod, and a neutron detector for measuring the intensity of neutrons generated by a photonuclear reaction of a nuclear fuel substance. . 2. The vibration-filled fuel inspection apparatus according to claim 1, wherein the X-ray generator can generate X-rays having an energy of 6 MeV or more, and can arbitrarily change the energy level within a range of at least 1 to 6 MeV. Inspection device for vibration filling fuel. 3. The vibration-filled fuel according to claim 1, wherein the X-ray generator has a collimator, and the slit width or the through-hole diameter of the collimator is 300 μm or less. Inspection equipment. 4. A vibration-filled fuel according to claim 1, further comprising a neutron moderator capable of attenuating neutron energy generated by photonuclear reaction in the range of 1 Mev to 1 ev for neutron detection. Inspection equipment. 5. An inspection apparatus for vibration-filled fuel according to claim 1, wherein three or more neutron detectors are arranged around the nuclear fuel rod. 6. An inspection apparatus for vibration-filled fuel according to claim 1, wherein the X-ray detector has a collimator, and the slit width or through-hole diameter of the collimator is 50 μm to 300 μm. . 7. The vibration-filled fuel inspection system according to claim 1, wherein the fuel rod support base has a mechanism for moving the nuclear fuel rods up, down, translationally, and rotationally.