JPH081294U - Ampoule tube for measuring gas generation - Google Patents

Abstract

(57) [Abstract] [Purpose] To measure radiation resistance of organic materials and polymer materials rapidly, it is used to easily measure decomposed gas generated when the material is irradiated with γ-ray. An ampoule tube for irradiation is provided. [Composition] Small mercury manometer (1) with branch pipe (2)
An ampoule tube for measuring gas generation, characterized in that it is integrated with an ampoule tube (5) provided at the open end (3) with a constricted portion (4) for a sealed tube.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention is intended to measure the amount of decomposed gas generated when an organic material or a polymer material is irradiated with γ-rays in order to quickly measure the radiation resistance or radiation sensitivity of the organic material or the polymer material. The present invention relates to an ampoule tube for γ-ray irradiation used.

[0002]

[Prior art and its problems]

 Regarding radiation resistance, various phenomena and properties have been measured by using the deterioration of materials and changes in physical properties as an index. Among these, the most sensitive measured amount is the amount of decomposed gas generated. When an organic material or a polymer material is exposed to radiation, molecules are excited or cleaved, or electrons are ejected to generate radicals or ions, which causes some decomposition reaction to proceed. At this time, many produce low molecular weight substances, which are detected as the amount of gas generated. Therefore, the ampoule tube for measuring the gas generation amount of the present invention is not limited to the generation amount of the decomposed gas at the time of γ-ray irradiation, but it is not limited to the organic materials and high-grade materials such as α-rays, β-rays, ultraviolet rays, electromagnetic waves, heat, and magnetic fields. It can be applied even when a minute decomposition reaction occurs in the molecular material to generate gas.

With the recent further use of nuclear energy, not only nuclear reactors, but also nuclear fuel reprocessing, radioactive waste treatment facilities, radiation utilization facilities, etc. will be expanded in the future. In order to ensure the safety of these facilities and facilitate maintenance and management, the organic materials and polymer materials used must have high reliability including radiation resistance.

In the facilities and equipment using radiation mentioned above, various organic materials such as insulating materials for electric devices and cables, structural materials such as gaskets, O-rings and spacers, ion exchange resins, filters, lubricating oils, paints, etc. Materials and polymer materials are used. Thus, it is expected that the number of organic materials and polymer materials used in the radiation environment of nuclear facilities will continue to increase. Moreover, it is expected that the environmental conditions required for these organic materials and polymer materials will become more severe, so it is necessary to further develop materials having radiation resistance that can meet these requirements.

[0005] Many practical reports have already been made on researches on how much radiation dose of organic materials and polymer materials can withstand, that is, radiation resistance. However, regarding these radiation resistance examination items, changes in physical properties are emphasized as follows due to the nature of the problem. That is, stress one elongation curve, tensile strength, elongation at break, elastic modulus, shear strength, weight change, specific gravity, water absorption, light transmittance, volume resistivity, arc resistance and the like.

As described above, with respect to radiation deterioration of organic materials and polymer materials, changes in mechanical properties or electrical properties have been generally investigated so far. However, a relatively large dose is required before these mechanical or electrical properties change. Moreover, before changes in practical properties such as mechanical properties and electrical properties appear, chemical changes occur in the fields of organic materials and polymer materials, isomerization, H ₂ -migration, oxidation, crosslinking, cleavage, etc. Since it should be, it is natural that a method to detect this initial radiation irradiation effect is required.

On the other hand, when sterilizing or sterilizing a packaging material that irradiates food with radiation for long-term storage or a disposable medical device such as a plastic syringe, even if it cannot withstand a large amount of irradiation dose, A material with less decomposition products by irradiation with 10 Mrad is required. However, it is normal for practical substances such as mechanical strength to change little at this level of dose.

When chemical changes such as decomposition, isomerization, H ₂ -transfer, acidification, crosslinking, and cleavage occur before the change of mechanical properties and electrical properties appear, generally, decomposition products are generated along with the chemical changes. A low-molecular gas is generated as a substance. Conventionally, in order to measure this gas generation amount, a method was used in which a sample was placed in an ampoule tube equipped with a breakable joint, irradiated with radiation, and then the breakable joint was opened and measurement was performed with a mass spectrometer. .

[0009]

[Problems to be solved by the device]

 The conventional methods using mass spectrometers can measure only the gas generation amount for one radiation dose at a time, and to measure the change in irradiation dose, the gas generation amount for several irradiation doses must be measured. It had to be measured several times, which was very time-consuming and troublesome. In addition, mass spectrometry, which is a high-level analytical instrument, must be used for the measurement, and there is a restriction in that point as well, and radiation resistance of organic materials and polymer materials could not be easily measured. The present invention has been made in view of these problems of the conventional technology.

[0010]

[Means for Solving the Problems]

 In order to solve the above problems, the ampule tube for measuring the amount of gas generated in the present invention is made entirely of Pyrex glass, and has a certain thickness (0.8 mm or more) to cope with radiation deterioration of glass. is necessary. As shown in FIG. 1, the present invention is an ampoule tube (5) provided with a throttle part (4) for a sealed tube, and a small mercury manometer (1) attached as a branch tube (2). Even though it is small, mercury with a high specific gravity enters the mercury manometer, so it is preferable to process the root portion (2) of the branch pipe to be particularly thick (1 mm or more). The dotted line (6) of the constricted portion (4) for the sealed tube in FIG. 1 shows the appearance of the ampoule tube after fusion sealing.

[0011]

[Action]

To measure the radiation resistance of organic materials and polymer materials using the ampoule tube for measuring gas generation of the present invention, first put a sample (preferably about 50 mg) into the ampoule tube and degas the gas. It is evacuated under high vacuum (<10 ⁻⁵ mmHg) for several days until the generation completely disappears, and then the narrowed portion (4) for the sealed tube is sealed by glass work. This is irradiated at a constant dose rate in the radiation irradiation facility of the γ-ray source, the ampoule tube is taken out of the case at each required dose irradiation, the room temperature is kept constant, and then a reading microscope with 1/100 mm accuracy is used. Accurately read the movement (Δh) of the mercury column of the small mercury manometer and convert it to the amount of gas generated. At this time, with irradiation of doses up to several tens of Mrad, no mercury vapor was generated that could be detected by a scanning microscope with an accuracy of 1/100 mm, and the movement (Δh) of the mercury column of the small water silver manometer was all generated from the sample. Interpreted as a product.

[0012]

【Example】

 An embodiment of the present invention will be described with reference to FIG. The ampoule tube for measuring the amount of generated gas in the present invention was entirely made of Pyrex glass and had a wall thickness of about 0.8 mm. As shown in FIG. 1, a small mercury manometer (1) is attached as a branch pipe (2) to an ampoule pipe (5) provided with a narrowed portion (4) for sealing a pipe.

[0013]

[Effect of device]

 Since the present invention is configured as described above, it has the following effects. The gas generation amount measuring ampoule tube according to the present invention is small in size and convenient to carry, and has the advantage of being able to irradiate a large number of γ-ray irradiating ampoule tubes with data inserted. In addition, when a certain dose is irradiated at the radiation irradiation facility, it is taken out each time and the movement of the small mercury manometer is measured, so that one sample is used to measure the gas generation amount or the G value of the gas generation amount at various irradiation doses. Can be asked.

Table 1 shows an example of the results of measuring the gas generation amount by irradiating a polymer material having good radiation resistance with γ-rays using the gas generation amount measuring ampoule tube of the present invention. This is the result of irradiating γ-rays from the Kovardo 60 source under vacuum at a total dose of 6.5 Mrad under the condition of a dose rate of 1 Mrad / h at room temperature. The unit is μmol / g Is very few. If the ampule tube for measuring the amount of generated gas of the present invention is used, it is possible to measure up to an amount of 0.1 μmol / g.

[0015]

[Table 1]

Next, surface chlorinated polyethylene was used as a sample, and in the same manner as described above, the irradiation dose and the gas generation amount when γ-ray irradiation from cobalt 60 was performed at room temperature under vacuum. Table 2 shows the relationship.

[0017]

[Table 2]

[Brief description of drawings]

FIG. 1 is a front view showing an embodiment of the present invention.

[Explanation of Codes] 1 Small mercury manometer 2 Branch pipe 3 Open end 4 Restriction part for sealing pipe 5 Ampoule pipe 6 Melt cutting part 7 Sample 8 Mercury

Claims (1)

[Scope of utility model registration request] 1. A compact mercury manometer (1) is provided on a branch pipe (2) and is integrated with an ampoule pipe (5) having a constricted portion (4) for a sealed pipe at an open end (3). An ampoule tube for measuring the amount of gas generated.