JP2020051916A - METHOD FOR PRODUCING RADIOISOTOPE Mo-99, AND TARGET MATERIAL - Google Patents
METHOD FOR PRODUCING RADIOISOTOPE Mo-99, AND TARGET MATERIAL Download PDFInfo
- Publication number
- JP2020051916A JP2020051916A JP2018182149A JP2018182149A JP2020051916A JP 2020051916 A JP2020051916 A JP 2020051916A JP 2018182149 A JP2018182149 A JP 2018182149A JP 2018182149 A JP2018182149 A JP 2018182149A JP 2020051916 A JP2020051916 A JP 2020051916A
- Authority
- JP
- Japan
- Prior art keywords
- water
- moo
- target
- molybdenum oxide
- relative density
- 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.)
- Granted
Links
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 6
- 239000013077 target material Substances 0.000 title claims description 11
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 52
- 238000000034 method Methods 0.000 claims abstract description 14
- 229910000476 molybdenum oxide Inorganic materials 0.000 claims description 25
- PQQKPALAQIIWST-UHFFFAOYSA-N oxomolybdenum Chemical compound [Mo]=O PQQKPALAQIIWST-UHFFFAOYSA-N 0.000 claims description 25
- 230000001678 irradiating effect Effects 0.000 claims description 10
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 abstract description 14
- 239000000243 solution Substances 0.000 abstract description 7
- 239000007864 aqueous solution Substances 0.000 abstract description 3
- 230000035515 penetration Effects 0.000 abstract 1
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 10
- 239000000843 powder Substances 0.000 description 7
- 238000006243 chemical reaction Methods 0.000 description 6
- 239000011148 porous material Substances 0.000 description 6
- 238000000605 extraction Methods 0.000 description 5
- 238000005245 sintering Methods 0.000 description 5
- 239000011780 sodium chloride Substances 0.000 description 5
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 4
- 229910052751 metal Inorganic materials 0.000 description 4
- 239000002184 metal Substances 0.000 description 4
- 239000002105 nanoparticle Substances 0.000 description 4
- 239000002245 particle Substances 0.000 description 4
- 238000000634 powder X-ray diffraction Methods 0.000 description 4
- 238000005119 centrifugation Methods 0.000 description 3
- 239000007789 gas Substances 0.000 description 3
- 238000007088 Archimedes method Methods 0.000 description 2
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 2
- 238000010521 absorption reaction Methods 0.000 description 2
- AIYUHDOJVYHVIT-UHFFFAOYSA-M caesium chloride Chemical compound [Cl-].[Cs+] AIYUHDOJVYHVIT-UHFFFAOYSA-M 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000000084 gamma-ray spectrum Methods 0.000 description 2
- 229910002804 graphite Inorganic materials 0.000 description 2
- 239000010439 graphite Substances 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 150000002500 ions Chemical class 0.000 description 2
- 238000002156 mixing Methods 0.000 description 2
- 239000007787 solid Substances 0.000 description 2
- YZCKVEUIGOORGS-OUBTZVSYSA-N Deuterium Chemical compound [2H] YZCKVEUIGOORGS-OUBTZVSYSA-N 0.000 description 1
- 229910017299 Mo—O Inorganic materials 0.000 description 1
- YZCKVEUIGOORGS-NJFSPNSNSA-N Tritium Chemical compound [3H] YZCKVEUIGOORGS-NJFSPNSNSA-N 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 238000002048 anodisation reaction Methods 0.000 description 1
- 239000003054 catalyst Substances 0.000 description 1
- 239000000919 ceramic Substances 0.000 description 1
- 229910052878 cordierite Inorganic materials 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 238000003795 desorption Methods 0.000 description 1
- 229910052805 deuterium Inorganic materials 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- JSKIRARMQDRGJZ-UHFFFAOYSA-N dimagnesium dioxido-bis[(1-oxido-3-oxo-2,4,6,8,9-pentaoxa-1,3-disila-5,7-dialuminabicyclo[3.3.1]nonan-7-yl)oxy]silane Chemical compound [Mg++].[Mg++].[O-][Si]([O-])(O[Al]1O[Al]2O[Si](=O)O[Si]([O-])(O1)O2)O[Al]1O[Al]2O[Si](=O)O[Si]([O-])(O1)O2 JSKIRARMQDRGJZ-UHFFFAOYSA-N 0.000 description 1
- 238000004090 dissolution Methods 0.000 description 1
- 239000000835 fiber Substances 0.000 description 1
- 239000010419 fine particle Substances 0.000 description 1
- 230000004992 fission Effects 0.000 description 1
- 239000012530 fluid Substances 0.000 description 1
- 230000004907 flux Effects 0.000 description 1
- 230000005251 gamma ray Effects 0.000 description 1
- 239000001307 helium Substances 0.000 description 1
- 229910052734 helium Inorganic materials 0.000 description 1
- SWQJXJOGLNCZEY-UHFFFAOYSA-N helium atom Chemical compound [He] SWQJXJOGLNCZEY-UHFFFAOYSA-N 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 238000001000 micrograph Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 238000007747 plating Methods 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 238000003825 pressing Methods 0.000 description 1
- 239000010453 quartz Substances 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 238000001878 scanning electron micrograph Methods 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 239000000741 silica gel Substances 0.000 description 1
- 229910002027 silica gel Inorganic materials 0.000 description 1
- 239000002915 spent fuel radioactive waste Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 239000000758 substrate Substances 0.000 description 1
- 239000010409 thin film Substances 0.000 description 1
- 229910052722 tritium Inorganic materials 0.000 description 1
- 238000007740 vapor deposition Methods 0.000 description 1
Landscapes
- Particle Accelerators (AREA)
Abstract
Description
本発明は、中性子による核反応を利用した放射性同位元素Mo-99の製造方法およびそれ
に使用されるターゲット材料に関する。
The present invention relates to a method for producing a radioisotope Mo-99 using a neutron nuclear reaction and a target material used for the method.
Mo-99はMoの同位体であり、これが崩壊して医療用放射性同位体Tc-99mが生成する。こ
れまで、Mo-99の生産は、高濃縮U-235を使った原子炉の使用済み核燃料中の核分裂生成物を原料（特許文献１：特開2016-180760）とし、これを溶液にして抽出（特許文献２：特
開2018-91708）する核分裂法で行われてきたが、核セキュリティーの観点から日本では実施できなかった。
Mo-99 is an isotope of Mo, which breaks down to produce the medical radioisotope Tc-99m. Until now, production of Mo-99 has been based on the use of fission products in spent nuclear fuel of a nuclear reactor using highly concentrated U-235 as a raw material (Patent Document 1: JP-A-2016-180760), and extracting it as a solution (Patent Document 2: Japanese Unexamined Patent Application Publication No. 2018-91708), which has not been implemented in Japan from the viewpoint of nuclear security.
これに代わって、Mo-98同位体を研究用原子炉で中性子照射することによりMo-99を生産する核反応法が研究されてきた。この際、Mo-98同位体を濃縮したMo酸化物焼結体やMo金
属微粒子ターゲットに中性子照射した後、NaOH水溶液で全量溶解後Mo-99を抽出し、未反
応のMo-98を再利用する方法が検討されている（非特許文献１：木村ら、JAEA-Technology
2013-048）。一方、未反応のMo-98が大量に含まれているNaOH水溶液からMo-99同位体の
みを抽出することは容易ではなかった。さらに、この溶解・再利用の過程をホットセルとマニピュレーターを使用して行わなければならず、作業性と安全性に問題を抱えていた。
Instead, nuclear reactions have been studied to produce Mo-99 by neutron irradiation of Mo-98 isotopes in a research reactor. At this time, after irradiating neutrons to the Mo oxide sintered body or Mo metal fine particle target enriched with Mo-98 isotope, Mo-99 is extracted after dissolving the whole amount with NaOH aqueous solution, and unreacted Mo-98 is reused (Non-Patent Document 1: Kimura et al., JAEA-Technology)
2013-048). On the other hand, it was not easy to extract only the Mo-99 isotope from an aqueous NaOH solution containing a large amount of unreacted Mo-98. Furthermore, this melting and reusing process had to be performed using a hot cell and a manipulator, and there was a problem in workability and safety.
本発明は中性子照射したMoターゲットをNaOH水溶液に溶解せずにMo-99を抽出すること
ができる方法を提供することを課題とする。
An object of the present invention is to provide a method capable of extracting Mo-99 without dissolving a neutron-irradiated Mo target in an aqueous NaOH solution.
本発明者らは、上記課題を解決すべく、検討を行った。
まず、背景技術として、Mo-98(n, γ)Mo-99の核反応の場合、Mo-99が得る運動エネルギーは190eVしかなく、価数は変化する可能性があるもののMo-O固体中を3nmしか透過できない。このため、単にMoを含むターゲットを中性子照射しただけでは、生成したMo-99のほ
とんどはターゲットから脱出・溶液中に抽出できないことが予想された。固体中をMo-99
ホットアトムに拡散させて抽出のためにターゲット表面に出すためには、高いγ線エネルギーを発生するMo-100(n,2n)Mo-99を利用する加速器由来の中性子照射（初川、科学研究
費基盤研究（C）、25420913）や、拡散しなければならないターゲット直径を小さくした
金属Moナノ粒子（Ilyinら、Physics Proc., 72 (2015) 548）を用いる必要があったが、
前者は照射施設が限られ、後者はMo-99抽出のための金属Moナノ粒子を遠心分離する必要
があった。このため、単なるMoを含んだターゲットでは、原子炉での中性子照射後に水に接するだけでは、生成したMo-99の大部分を水に抽出することができないことが分かって
いた。
The present inventors have studied to solve the above problems.
First, as a background art, in the case of a nuclear reaction of Mo-98 (n, γ) Mo-99, the kinetic energy obtained by Mo-99 is only 190 eV, and although the valence may change, the Can be transmitted only 3 nm. For this reason, it was expected that most of the generated Mo-99 would not be able to escape from the target and be extracted into the solution simply by irradiating the target containing Mo with neutrons. Mo-99 in solid
Neutron irradiation from an accelerator using Mo-100 (n, 2n) Mo-99, which generates high γ-ray energy, to diffuse the hot atoms to the target surface for extraction (Hatsukawa, Scientific Research Fundamental Research (C), 25420913) and the need to use metal Mo nanoparticles with a reduced target diameter that must diffuse (Ilyin et al., Physics Proc., 72 (2015) 548)
The former had limited irradiation facilities, and the latter required centrifugation of metallic Mo nanoparticles for Mo-99 extraction. For this reason, it was found that with a simple Mo-containing target, most of the generated Mo-99 could not be extracted into water simply by contact with water after neutron irradiation in a nuclear reactor.
一方、Mo酸化物への水の浸透はアモルファス状態のMoO3薄膜でのみ観察されており、結晶質MoO3のみならず、MoO2では不明であった。そして、水によるMo-99ホットアトム抽出
を行った実験結果は存在せず、実現できるかは全く不明であった。特に、Mo-98(n, γ)Mo-99反応で、Mo-99が異なる価数のイオンとなったとしても、それが水へ移動するかどうかは全く不明であった。実際、Mo+4価のMoO2や+6価のMoO3は水にほぼ不溶であることが知られており、さらに、前述の通り、ホットアトムになったとしてもMo-99はMo-O固体ターゲ
ット中を3nmしか移動せず、水と接する生成核種はごく一部と予想されたので、水に不溶
のターゲットに水を接するだけで目的の核種を分離することができるかま全く不明でであった。
On the other hand, permeation of water into the Mo oxide was observed only in the amorphous MoO 3 thin film, and was unknown not only in the crystalline MoO 3 but also in the MoO 2 . And there was no experimental result of Mo-99 hot atom extraction with water, and it was not completely clear whether it could be realized. In particular, even if Mo-99 became an ion of a different valence in the Mo-98 (n, γ) Mo-99 reaction, it was completely unknown whether it would migrate to water. In fact, Mo + 4 valent MoO 2 and +6 valent MoO 3 are known to be almost insoluble in water.Moreover, as described above, Mo-99 is Mo-O Since only 3 nm of the generated nuclides migrated in the solid target and contacted with water was expected to be only a small part, it was not completely clear whether the target nuclide could be separated simply by contacting the water with a water-insoluble target. there were.
このような状況下、発明者らは、水に不溶であるが吸水特性を有するMoO3やMoO2多孔体ターゲットを開発できれば、ホットアトムを利用し、原子炉での中性子照射後のターゲットに水を接するだけで、ターゲット全量を溶解せずに、Mo-99のみを抽出できるのではな
いかと着想した。
ホットアトムは、核反応後に発生するγ線の反跳により、生成した核種が高い運動エネルギーを有し、異なる価数のイオンになる現象であるが、これにより、生成した核種がターゲットから飛び出したり、ターゲットに対して不溶な溶液、特に水に選択的に溶解したりするため、同位体の抽出に好適である。
ここで、MoO3は、6配位のMoO3八面体が層状に並んだ結晶であり、その層間は弱く結合
しているのみである。よって、MoO3の多孔体を用意し、それをターゲットに利用すれば、ホットアトムによって価数が変わったMo-99がターゲット中に浸透した水に接し、多孔体MoO3中および外への水の拡散に伴いターゲットから抽出可能になる可能性があると考えた
。
Under these circumstances, if the inventors can develop a MoO 3 or MoO 2 porous target that is insoluble in water but has water absorption properties, it will use a hot atom to add water to the target after neutron irradiation in a nuclear reactor. The idea was that it would be possible to extract only Mo-99 without dissolving the entire target simply by contacting with.
Hot atom is a phenomenon in which generated nuclides have high kinetic energy due to recoil of γ-rays generated after a nuclear reaction and become ions of different valences. It is suitable for isotope extraction because it selectively dissolves in a solution insoluble in a target, particularly water.
Here, MoO 3 is a crystal in which six-coordinated MoO 3 octahedrons are arranged in layers, and the layers are only weakly bonded. Therefore, if a porous body of MoO 3 is prepared and used as a target, Mo-99, whose valence has changed due to the hot atom, comes into contact with water that has penetrated into the target, and water that enters and exits the porous body MoO 3 It is thought that it may be possible to extract from the target with the diffusion of
そして、鋭意検討した結果、相対密度が２０〜７０％の多孔体モリブデン酸化物ターゲット材料の作製に成功した。得られた多孔体モリブデン酸化物ターゲット材料は、Mo-98(n, γ)Mo-99の核反応により生成するMo-99ホットアトムの飛程（3nm）よりはるかに大き
な粒子からなるが、これに中性子照射し、水を接触させることで、効率よくMo-99を得る
ことができることを見出し、本発明を完成させた。
As a result of intensive studies, a porous molybdenum oxide target material having a relative density of 20 to 70% was successfully produced. The resulting porous molybdenum oxide target material consists of particles much larger than the range (3 nm) of the Mo-99 hot atom generated by the nuclear reaction of Mo-98 (n, γ) Mo-99. It has been found that Mo-99 can be obtained efficiently by irradiating neutrons with water and bringing it into contact with water, thus completing the present invention.
すなわち、本発明は、相対密度20〜70%のモリブデン酸化物ターゲット材料に中性子照
射してMo-99を生成させる工程、および、前記モリブデン酸化物ターゲット材料に水を接
触させてMo-99を回収する工程を含む、Mo-99の製造方法、に係るものである。
また、モリブデン酸化物がMoO3であることを特徴とする前記方法に係るものである。
本発明はまた、相対密度20〜70%のMoO3からなる、Mo-99製造用ターゲット材料、に係るものである。
That is, the present invention provides a step of irradiating neutrons to a molybdenum oxide target material having a relative density of 20 to 70% to generate Mo-99, and recovering Mo-99 by contacting water with the molybdenum oxide target material. And a method for producing Mo-99.
The present invention also relates to the above method, wherein the molybdenum oxide is MoO 3 .
The present invention also relates to a target material for producing Mo-99, comprising MoO 3 having a relative density of 20 to 70%.
本発明によれば、モリブデン酸化物の多孔体に中性子照射することにより、Moターゲットを溶解せずに、水に接触するだけでMo-99を抽出することができ、簡便にMo-99を得ることができる。モリブデン酸化物の多孔体を用いることで、水との接触面積が増えるうえ、取扱が容易なため、遠心分離等の手段を用いることなく、高速にMo-99を抽出可能になる
。
According to the present invention, by irradiating neutrons to the porous body of molybdenum oxide, Mo-99 can be extracted by simply contacting water without dissolving the Mo target, and Mo-99 is easily obtained. be able to. By using a porous body of molybdenum oxide, the contact area with water increases, and handling is easy, so that Mo-99 can be extracted at high speed without using means such as centrifugation.
以下、本発明について説明する。 Hereinafter, the present invention will be described.
ターゲット材料として用いるモリブデン酸化物としては、Mo-98を含むモリブデン酸化
物であればよいが、Mo-98を含むMoO2やMoO3の多孔体が好ましく、Mo-98を含むMoO3の多孔体がより好ましい。モリブデン酸化物多孔体のサイズは中性子を照射し、水を通水できるサイズであれば特に制限されないが、例えば、0.1〜25mmである。なお、モリブデン酸化
物はMo-99の生成および抽出が可能である限り、他のMo同位体や他の元素を含んでもよい
。
The molybdenum oxide used as the target material may be a molybdenum oxide containing Mo-98, but is preferably a porous body of MoO 2 or MoO 3 containing Mo-98, and a porous body of MoO 3 containing Mo-98. Is more preferred. The size of the molybdenum oxide porous body is not particularly limited as long as it can be irradiated with neutrons and water can pass therethrough, but is, for example, 0.1 to 25 mm. Note that the molybdenum oxide may contain other Mo isotopes and other elements as long as Mo-99 can be generated and extracted.
モリブデン酸化物多孔体は相対密度２０〜７０％の物を用いる。ここで、相対密度は、（アルキメデス法で測定した実際の密度）／（Mo酸化物の組成から計算した理論密度）×１００（％）で表すことができる。モリブデン酸化物多孔体の相対密度は２０〜５０％がより好ましく、２０〜４０％がさらに好ましい。 A molybdenum oxide porous body having a relative density of 20 to 70% is used. Here, the relative density can be expressed by (actual density measured by Archimedes method) / (theoretical density calculated from the composition of Mo oxide) × 100 (%). The relative density of the molybdenum oxide porous body is more preferably from 20 to 50%, further preferably from 20 to 40%.
多孔体に流体を通すコーディエライト自動車用触媒（理論密度2.6g/cm3）では細孔容積0.2cm3/g（すなわち相対密度66%）であり、一方、気体を通して吸着させる活性炭（理論
密度1.5g/cm3）が細孔容積0.2-0.3cm3/g（すなわち相対密度77-69%）であることから、通水してMo-99を回収するためには、モリブデン酸化物多孔体の相対密度の上限は70%が妥当と考えられる。さらに、水分子を無機物中に吸収・脱離する必要があるシリカゲル（理論密度2.65g/cm3）では細孔容積0.4-4.0cm3/g（すなわち相対密度49-9%）である（ファインセラミックスハンドブック、P.635）ことから、モリブデン酸化物多孔体の相対密度の上
限は40%であることがより好ましい。
A cordierite automotive catalyst (theoretical density of 2.6 g / cm 3 ), which allows fluid to pass through a porous material, has a pore volume of 0.2 cm 3 / g (that is, a relative density of 66%), while activated carbon (theoretical density) adsorbed through a gas 1.5 g / cm 3 ) has a pore volume of 0.2-0.3 cm 3 / g (ie, relative density of 77-69%). It is considered appropriate that the upper limit of the relative density of is 70%. Furthermore, the pore volume of silica gel (theoretical density of 2.65 g / cm 3 ), which requires the absorption and desorption of water molecules into inorganic substances, is 0.4-4.0 cm 3 / g (that is, the relative density is 49-9%) (fine density). (Ceramics Handbook, p. 635), the upper limit of the relative density of the molybdenum oxide porous body is more preferably 40%.
モリブデン酸化物多孔体の作製に関しては、以下の実施例に記載の方法が採用できるが、それ以外にも圧粉体、有機物繊維、基板へのMoのメッキ・蒸着・酸化や、Mo金属板の陽極酸化、MoO2やMoO3粉末の加圧、常圧焼結やガス中加圧焼結などでも可能である。 For the preparation of the molybdenum oxide porous body, the method described in the following examples can be adopted, but in addition to the above, green compacts, organic fibers, plating, vapor deposition, oxidation of Mo on a substrate, and Mo metal plate Anodization, pressurization of MoO 2 or MoO 3 powder, normal pressure sintering, and pressure sintering in gas are also possible.
モリブデン酸化物多孔体をターゲットとして中性子照射する工程は、通常の中性子照射の手順に従って行うことができる。
例えば、中性子発生用加速器を用いて、例えば重水素（2Ｈ）ビームを３重水素（3Ｈ）に照射して、高速中性子をヘリウム（4Ｈｅ）とともに生成することができる。
照射する中性子のエネルギーはMo-99を発生させることができる限り特に制限はないが
、例えば、0.001〜0.1eVである。照射時間も適宜設定できるが、例えば、1〜10時間であ
る。
The step of irradiating neutrons with the molybdenum oxide porous body as a target can be performed according to a normal neutron irradiation procedure.
For example, a neutron generating accelerator can be used to irradiate, for example, a deuterium ( 2 H) beam onto tritium ( 3 H) to generate fast neutrons together with helium ( 4 He).
The energy of the neutrons for irradiation is not particularly limited as long as Mo-99 can be generated, but is, for example, 0.001 to 0.1 eV. The irradiation time can be set as appropriate, for example, 1 to 10 hours.
中性子照射後、モリブデン酸化物多孔体ターゲットを水と接触させる。水量はMo-99を
抽出できる十分量であれば特に制限はないが、例えば、モリブデン酸化物多孔体ターゲット 1ｇあたり10ml以上である。水温は例えば25〜90℃である。モリブデン酸化物多孔体
ターゲットへの通水時間は例えば、10分〜20時間であり、短時間でMo-99を抽出できる。
また、水量としては、1gあたり1mlでもよく、10ml以上であればMo-99を抽出することができる。
Mo-99の抽出方法としては、MoO2やMoO3多孔体への中性子照射後に通水するバッチ処理
法の他に、照射中に通水する連続処理法も可能である。
After neutron irradiation, the molybdenum oxide porous target is brought into contact with water. The amount of water is not particularly limited as long as it is a sufficient amount to extract Mo-99. For example, the amount of water is 10 ml or more per 1 g of the molybdenum oxide porous target. The water temperature is, for example, 25 to 90 ° C. The water passage time to the molybdenum oxide porous target is, for example, 10 minutes to 20 hours, and Mo-99 can be extracted in a short time.
The amount of water may be 1 ml per 1 g, and if it is 10 ml or more, Mo-99 can be extracted.
As a method for extracting Mo-99, in addition to a batch treatment method in which water is passed after neutron irradiation on MoO 2 or MoO 3 porous body, a continuous treatment method in which water is passed during irradiation is also possible.
［実施例］
以下、実施例を挙げて本発明を具体的に説明する。ただし、本発明は以下の実施例の態様
には限定されない。
[Example]
Hereinafter, the present invention will be described specifically with reference to examples. However, the present invention is not limited to the following embodiments.
粒径12.6マイクロメートルのMoO3粉末を黒鉛型に充填し、真空中、40MPaの圧力、500-550℃、5分、昇温速度200℃/minでパルス通電加圧焼結を行った。粉末X線回折結果を図１
に示す。すべて単相MoO3であった。アルキメデス法で測定したところ、その相対密度は下記の表１のようであった。よって、500℃で相対密度70％以下の焼結体が得られた。
A graphite mold was filled with MoO 3 powder having a particle size of 12.6 μm, and pulse current pressure sintering was performed in vacuum at a pressure of 40 MPa, at 500-550 ° C. for 5 minutes, and at a heating rate of 200 ° C./min. Figure 1 shows the powder X-ray diffraction results.
Shown in All were single phase MoO 3 . When measured by the Archimedes method, the relative density was as shown in Table 1 below. Therefore, a sintered body having a relative density of 70% or less at 500 ° C. was obtained.
MoO2粉末を黒鉛型で成型し、Arガス中30MPaの圧力にてホットプレスを用いて450-1100
℃、1時間加圧・加熱して焼結を行った。図２に粉末X線回折結果を示す。MoO2単一相であった。また、450℃で焼結した試料の相対密度は60%であった。実施例１と同様な多孔体をMoO2で得られたことが分かった。
MoO 2 powder is molded in a graphite mold and 450-1100 using a hot press at a pressure of 30 MPa in Ar gas.
Sintering was performed by pressing and heating at ℃ for 1 hour. FIG. 2 shows the results of powder X-ray diffraction. MoO 2 single phase. The relative density of the sample sintered at 450 ° C. was 60%. It was found that the same porous body as in Example 1 was obtained with MoO 2 .
MoO3にNaCl、CsCl2、KCl粉末を20、50、70vol.%添加/混合し、大気中500℃で0.5-4時間保持することによりMoO3を80、50、30vol.%含む焼結体を作製した。これを水に浸すこと
により、NaClを溶解させ、MoO3多孔体を作製した。
焼結後の試料外観を図３に示す。試料直径は10mmであった。MoO3とNaCl粉末の混合比は体積比であるから、相対密度80％、50、30％のMoO3試料を作製できたことが分かった。また、MoO3にCaCl2、KCl粉末を添加しても、同様な焼結体が作製できた。この試料の中で、NaCl添加量50vol.％の試料の通水後の走査型電子顕微鏡写真を図４に示す。通水前には、白色のコアの中に灰色の粒子が見られたが、通水後にはコアのみが存在している。多孔体サイズは250μm程度であり、他に0.1〜1mmの多孔体も観察された。このことから、MoO3からなる多孔体が得られた。
NaCl to MoO 3, CsCl 2, KCl powder was 20,50,70vol.% Addition / mixing, the sintered body containing 80,50,30vol.% Of MoO 3 by holding 0.5-4 hours at 500 ° C. in air Was prepared. This was immersed in water to dissolve NaCl, thereby producing a MoO 3 porous body.
FIG. 3 shows the appearance of the sample after sintering. The sample diameter was 10 mm. Since the mixing ratio of MoO 3 and NaCl powder is a volume ratio, it was found that MoO 3 samples with relative densities of 80%, 50, and 30% could be prepared. A similar sintered body could be produced even when CaCl 2 and KCl powder were added to MoO 3 . FIG. 4 shows a scanning electron micrograph of the sample having 50% NaCl added thereto after passing water. Before passing water, gray particles were found in the white core, but after passing water, only the core was present. The size of the porous body was about 250 μm, and a porous body of 0.1 to 1 mm was also observed. From this, a porous body made of MoO 3 was obtained.
粒径700nmのMoO31.0gを、内寸Φ7×26mmの石英管に封入した。この相対密度は21%であ
った。これを2ｘ1013n/cm2sの中性子束、中性子エネルギー0.001-0.1eV（ピーク強度のエネルギーは0.025eV）で7時間照射した。これを水中10mlに投入し、20時間置いた後、水中のMo-99およびTc-99mからのγ線をGeスペクトロメーターで測定し、水中に溶解したMo-99の濃度を算出した。
図５に水からのγ線スペクトルを示す。これから測定したMo-99は29.84MBqであった。
これを溶解度に直すと0.36%であった。一方、MoO3の水への溶解度は0.04％であることか
ら、9倍のMoが水に溶解した。これは、結晶質MoO3水が浸透し、ホットアトムとなったMo-99が溶解した効果と考えられた。この効果は、粉末と同様比表面積が大きく水との接触が容易な他のモリブデン酸化物多孔体、特に結晶質MoO3多孔体でも同様に期待される。よって、本発明により、MoO3多孔体を中性子照射した後水に接するだけでMo-99を抽出可能で
あることが判明した。
1.0 g of MoO 3 having a particle diameter of 700 nm was sealed in a quartz tube having an inner diameter of Φ7 × 26 mm. This relative density was 21%. This was irradiated with a neutron flux of 2 × 10 13 n / cm 2 s and a neutron energy of 0.001-0.1 eV (the energy of the peak intensity was 0.025 eV) for 7 hours. This was put into 10 ml of water and left for 20 hours, and then γ-rays from Mo-99 and Tc-99m in the water were measured with a Ge spectrometer to calculate the concentration of Mo-99 dissolved in the water.
FIG. 5 shows a γ-ray spectrum from water. The Mo-99 measured from this was 29.84 MBq.
This was converted to a solubility of 0.36%. On the other hand, since the solubility of MoO 3 in water was 0.04%, 9 times of Mo was dissolved in water. This is considered to be due to the effect that the crystalline MoO 3 water permeated and Mo-99 which became a hot atom dissolved. This effect is also expected for other molybdenum oxide porous materials having a large specific surface area and easy contact with water, particularly crystalline MoO 3 porous materials like powders. Therefore, according to the present invention, it was found that Mo-99 can be extracted only by contacting water after irradiating the porous MoO 3 with neutrons.
［対照例１］
原子炉中性子を高密度MoO3ターゲットに照射してMo-99を製造した例が文献（木村ら、J
AEA-Technology 2013-048）で報告された。この中で2種類のターゲットが使われ、相対密度は>90%であった。照射後、高密度MoO3ターゲットは6N-NaOH水溶液に溶解され、溶液か
らMo-99を回収した。
これに対し、本発明では、相対密度20-70％のモリブデン酸化物多孔体ターゲットを原
子炉中性子照射後に水に接するだけでMo-99を抽出することができる。
[Control Example 1]
An example of producing Mo-99 by irradiating reactor neutrons on a high-density MoO 3 target is described in the literature (Kimura et al., J.
AEA-Technology 2013-048). Two targets were used, with a relative density of> 90%. After irradiation, the high-density MoO 3 target was dissolved in a 6N-NaOH aqueous solution, and Mo-99 was recovered from the solution.
On the other hand, in the present invention, Mo-99 can be extracted only by bringing the molybdenum oxide porous target having a relative density of 20 to 70% into contact with water after irradiation with reactor neutrons.
［対照例２］
原子炉中性子をMoに照射してMo-99を製造する際、飛程3nmのホットアトムを利用して抽出する方法が文献（Ilyinら、Physics Proc., 72 (2015) 548）で報告された。この中で
は、水中でMo-99を抽出する際Mo-99ホットアトムがターゲット表面まで拡散しなければならないため、ターゲット直径140nmの金属Moナノ粒子を用いる必要があった。Mo-99抽出後、未反応の金属Moナノ粒子を回収・再利用したと記載されている。この方法の記述はないが、遠心分離、フィルターによる分離や酸による溶解が行われたと推定された。
これに対し、本発明では、モリブデン酸化物多孔体ターゲットを利用しているため、水に接するだけでMo-99を水に抽出できる。
[Control Example 2]
A method for extracting Mo-99 by irradiating Mo with reactor neutrons using a hot atom with a range of 3 nm was reported in the literature (Ilyin et al., Physics Proc., 72 (2015) 548). . Among them, when extracting Mo-99 in water, the Mo-99 hot atom had to diffuse to the target surface, so it was necessary to use metal Mo nanoparticles with a target diameter of 140 nm. It is stated that after Mo-99 extraction, unreacted metallic Mo nanoparticles were recovered and reused. Although there is no description of this method, it was presumed that centrifugation, separation by a filter, and dissolution by acid were performed.
On the other hand, in the present invention, since the molybdenum oxide porous target is used, Mo-99 can be extracted into water only by contacting with water.
Claims (3)
収する工程を含む、Mo-99の製造方法。 A step of irradiating neutrons to a molybdenum oxide target material having a relative density of 20 to 70% to generate Mo-99, and including a step of contacting the molybdenum oxide target material with water to recover the Mo-99. Manufacturing method of Mo-99.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2018182149A JP7187750B2 (en) | 2018-09-27 | 2018-09-27 | Production method and target material for radioactive isotope Mo-99 |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2018182149A JP7187750B2 (en) | 2018-09-27 | 2018-09-27 | Production method and target material for radioactive isotope Mo-99 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2020051916A true JP2020051916A (en) | 2020-04-02 |
| JP7187750B2 JP7187750B2 (en) | 2022-12-13 |
Family
ID=69996756
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2018182149A Active JP7187750B2 (en) | 2018-09-27 | 2018-09-27 | Production method and target material for radioactive isotope Mo-99 |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP7187750B2 (en) |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5522102A (en) * | 1978-08-02 | 1980-02-16 | Japan Atomic Energy Res Inst | Method of making molybdenumm99 by using molybdenum trioxide pellet |
| JPH059617A (en) * | 1991-07-04 | 1993-01-19 | Tokyo Tungsten Co Ltd | Method for removing tungsten in molybdenum oxide |
| JPH0730119A (en) * | 1993-07-09 | 1995-01-31 | Toshiba Corp | Manufacture of thin film transistor for liquid crystal display device |
| US20170337998A1 (en) * | 2016-05-18 | 2017-11-23 | The Regents Of The University Of California | High efficiency continuous-flow production of radioisotopes |
| JP2018039133A (en) * | 2016-09-05 | 2018-03-15 | ジオマテック株式会社 | Thin film with substrate |
-
2018
- 2018-09-27 JP JP2018182149A patent/JP7187750B2/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5522102A (en) * | 1978-08-02 | 1980-02-16 | Japan Atomic Energy Res Inst | Method of making molybdenumm99 by using molybdenum trioxide pellet |
| JPH059617A (en) * | 1991-07-04 | 1993-01-19 | Tokyo Tungsten Co Ltd | Method for removing tungsten in molybdenum oxide |
| JPH0730119A (en) * | 1993-07-09 | 1995-01-31 | Toshiba Corp | Manufacture of thin film transistor for liquid crystal display device |
| US20170337998A1 (en) * | 2016-05-18 | 2017-11-23 | The Regents Of The University Of California | High efficiency continuous-flow production of radioisotopes |
| JP2018039133A (en) * | 2016-09-05 | 2018-03-15 | ジオマテック株式会社 | Thin film with substrate |
Also Published As
| Publication number | Publication date |
|---|---|
| JP7187750B2 (en) | 2022-12-13 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP6952151B2 (en) | Method for Producing 99Mo Radioisotope | |
| JP5647273B2 (en) | Radionuclide generation method | |
| US3833469A (en) | Process for the production of technetium-99m from neutron irradiated molybdenum trioxide | |
| WO2020261650A1 (en) | Radionuclide production method and radionuclide production system | |
| UA127266C2 (en) | Method of production of irradiated particles | |
| RU2588594C1 (en) | Method of producing nanostructured target for producing molybdenum-99 radioisotopes | |
| JP7187750B2 (en) | Production method and target material for radioactive isotope Mo-99 | |
| RU2725414C1 (en) | Method of producing actinium-225 | |
| NL2011311B1 (en) | Extracting method of radioactive 99Mo from low-enriched uranium target. | |
| RU2578039C1 (en) | Method of producing nanostructured target for production of molybdenum-99 radioisotope | |
| RU2666552C1 (en) | Method of producing nanostructured target for production of molybdenum-99 | |
| Vandegrift et al. | RERTR progress in Mo-99 production from LEU | |
| RU2339718C2 (en) | Method for receiving actinium-227 and thorium-228 from treated by neutrons in reactor radium-226 | |
| JP2004117106A (en) | Structure for nuclide transmutation and method for forming it | |
| JP2004045254A (en) | Nuclide conversion method | |
| JP5668112B2 (en) | Cesium waste filter ceramic ingot in which radioactive cesium is collected and method for producing the same | |
| RU2735646C1 (en) | Method of producing nanostructured target for production of radionuclide molybdenum-99 | |
| JP2023154459A (en) | Target material for production of molybdenum-99 and method for producing the same | |
| CN110335697B (en) | High abundance98Tc preparation method | |
| US5875220A (en) | Process for production of radiostrontium | |
| KR101590941B1 (en) | The method of adsorption and recovery of gas phase iodine generated in fission molybdenum production process | |
| RU2554653C1 (en) | Method of obtaining radioisotope molybdenum-99 | |
| RU2690692C1 (en) | METHOD OF PRODUCING NANOSTRUCTURED TARGET FOR PRODUCTION OF RADONUCLIDE Mo-99 | |
| CN111733339B (en) | Irradiation enrichment by accelerator100Mo production99mTc method | |
| Dikiy et al. | Photonuclear production of ⁹⁹Mo/⁹⁹ᵐТс-generator with using effect Szilard-Chalmers and electrolysis method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20210915 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20220623 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20220809 |
|
| A601 | Written request for extension of time |
Free format text: JAPANESE INTERMEDIATE CODE: A601 Effective date: 20221011 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20221017 |
|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20221101 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20221109 |
|
| R150 | Certificate of patent or registration of utility model |
Ref document number: 7187750 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| S531 | Written request for registration of change of domicile |
Free format text: JAPANESE INTERMEDIATE CODE: R313531 |
|
| S533 | Written request for registration of change of name |
Free format text: JAPANESE INTERMEDIATE CODE: R313533 |