JPH0519676B2 - - Google Patents
Info
- Publication number
- JPH0519676B2 JPH0519676B2 JP58233738A JP23373883A JPH0519676B2 JP H0519676 B2 JPH0519676 B2 JP H0519676B2 JP 58233738 A JP58233738 A JP 58233738A JP 23373883 A JP23373883 A JP 23373883A JP H0519676 B2 JPH0519676 B2 JP H0519676B2
- Authority
- JP
- Japan
- Prior art keywords
- neutron
- shielding material
- filled
- absorbing material
- shielding
- 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.)
- Expired - Lifetime
Links
- 239000000463 material Substances 0.000 claims description 29
- 239000011358 absorbing material Substances 0.000 claims description 15
- 229910052751 metal Inorganic materials 0.000 claims description 4
- 239000002184 metal Substances 0.000 claims description 4
- 229910052782 aluminium Inorganic materials 0.000 description 9
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 9
- 239000004698 Polyethylene Substances 0.000 description 8
- -1 polyethylene Polymers 0.000 description 8
- 229920000573 polyethylene Polymers 0.000 description 8
- 230000005855 radiation Effects 0.000 description 6
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical compound [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 description 5
- 229910052796 boron Inorganic materials 0.000 description 4
- 239000006096 absorbing agent Substances 0.000 description 3
- 239000007789 gas Substances 0.000 description 3
- 239000000843 powder Substances 0.000 description 3
- 239000000126 substance Substances 0.000 description 3
- 238000010521 absorption reaction Methods 0.000 description 2
- 238000009835 boiling Methods 0.000 description 2
- JKWMSGQKBLHBQQ-UHFFFAOYSA-N diboron trioxide Chemical compound O=BOB=O JKWMSGQKBLHBQQ-UHFFFAOYSA-N 0.000 description 2
- 239000001307 helium Substances 0.000 description 2
- 229910052734 helium Inorganic materials 0.000 description 2
- SWQJXJOGLNCZEY-UHFFFAOYSA-N helium atom Chemical compound [He] SWQJXJOGLNCZEY-UHFFFAOYSA-N 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- 229910052688 Gadolinium Inorganic materials 0.000 description 1
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 description 1
- INAHAJYZKVIDIZ-UHFFFAOYSA-N boron carbide Chemical compound B12B3B4C32B41 INAHAJYZKVIDIZ-UHFFFAOYSA-N 0.000 description 1
- 125000004432 carbon atom Chemical group C* 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 230000008602 contraction Effects 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- UIWYJDYFSGRHKR-UHFFFAOYSA-N gadolinium atom Chemical compound [Gd] UIWYJDYFSGRHKR-UHFFFAOYSA-N 0.000 description 1
- CMIHHWBVHJVIGI-UHFFFAOYSA-N gadolinium(iii) oxide Chemical compound [O-2].[O-2].[O-2].[Gd+3].[Gd+3] CMIHHWBVHJVIGI-UHFFFAOYSA-N 0.000 description 1
- 229910002804 graphite Inorganic materials 0.000 description 1
- 239000010439 graphite Substances 0.000 description 1
- 229910052735 hafnium Inorganic materials 0.000 description 1
- VBJZVLUMGGDVMO-UHFFFAOYSA-N hafnium atom Chemical compound [Hf] VBJZVLUMGGDVMO-UHFFFAOYSA-N 0.000 description 1
- 125000004435 hydrogen atom Chemical group [H]* 0.000 description 1
- 229910052744 lithium Inorganic materials 0.000 description 1
- 238000003754 machining Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 239000004033 plastic Substances 0.000 description 1
- 229920003023 plastic Polymers 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 230000003014 reinforcing effect Effects 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E30/00—Energy generation of nuclear origin
- Y02E30/30—Nuclear fission reactors
Landscapes
- Particle Accelerators (AREA)
- Absorbent Articles And Supports Therefor (AREA)
- Analysing Materials By The Use Of Radiation (AREA)
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は、放射線、特に中性子線を遮蔽するた
めの中性子遮蔽材に関する。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a neutron shielding material for shielding radiation, particularly neutron beams.
沸騰水型原子力発電所では、炉心の配置された
原子炉圧力容器から加熱された蒸気をとり出し、
主蒸気管を通じてこれをタービンに送り発電を行
つている。第１図は原子炉圧力容器１に接続され
た主蒸気管２の一部を表わしたものである。原子
炉内で発生した放射線を遮蔽するために、原子炉
圧力容器１の周囲はコンクリート壁３で覆われて
いる。コンクリート壁３にはこの主蒸気管２やそ
の他の図示しない管を通すために孔４が開けられ
ている。孔４は主蒸気管２等の管の振動や熱によ
る伸縮を考慮して、多少余裕をもつた大きさとな
つている。このためこの孔４を通じて中性子線が
外部へ漏洩する危険性が生じてくる。そこで孔４
のまわりには、中性子遮蔽材５が配置されてお
り、原子炉設備の安全性が確保されている。
In boiling water nuclear power plants, heated steam is extracted from the reactor pressure vessel in which the reactor core is located.
The steam is sent to the turbine through the main steam pipe to generate electricity. FIG. 1 shows a part of a main steam pipe 2 connected to a reactor pressure vessel 1. As shown in FIG. In order to shield radiation generated within the reactor, the reactor pressure vessel 1 is surrounded by a concrete wall 3. A hole 4 is made in the concrete wall 3 for passing this main steam pipe 2 and other pipes (not shown). The hole 4 is sized with some allowance in consideration of the expansion and contraction of pipes such as the main steam pipe 2 due to vibration and heat. Therefore, there is a risk that the neutron beam will leak to the outside through this hole 4. So hole 4
A neutron shielding material 5 is placed around the reactor to ensure the safety of the reactor equipment.
以上一例として説明した中性子遮蔽材には、従
来から中性子減速材が用いられている。中性子減
速材としては減速能力の大きな水素原子Ｈ、炭素
原子Ｃ等を含む材料が有効である。前記した沸騰
水型原子力発電所では、中性子遮蔽材として例え
ばポリエチレンを所定の形状に成型し、使用して
いる。ところがこのような中性子遮蔽材では、そ
の厚さを十数cm程度にまで厚くしなければ放射線
の十分な遮蔽を行うことができず、遮蔽用の設備
が大型化してしまう。 A neutron moderator has conventionally been used as the neutron shielding material described above as an example. As a neutron moderator, a material containing hydrogen atoms H, carbon atoms C, etc., which have a large moderating ability, is effective. In the boiling water nuclear power plant described above, polyethylene, for example, is molded into a predetermined shape and used as a neutron shielding material. However, such neutron shielding materials cannot provide sufficient radiation shielding unless the thickness is increased to about 10-odd centimeters, and the shielding equipment becomes large.
そこで原料のポリエチレンに中性子吸収材とし
て数パーセントのボロン粉末を混合した中性子遮
蔽材が提案されている。この中性子遮蔽材では、
中性子減速材によつて減速された中性子をボロン
Ｂによつて吸収し、材料の厚さを相対的に減少さ
せることができる。 Therefore, a neutron shielding material has been proposed in which a few percent of boron powder is mixed as a neutron absorbing material into the raw material polyethylene. With this neutron shielding material,
Neutrons moderated by the neutron moderator can be absorbed by boron B, and the thickness of the material can be relatively reduced.
ところがこの中性子遮蔽材では、ボロンの含量
を数％以上に増やすと、機械加工精度が著しく劣
化してしまう。またB10（ｎ、α）Li7反応（ｎは
熱中性子、αはヘリウムガス）によりヘリウムガ
スが材料内部で発生するため、放射線の吸収と共
に材料の損傷劣化が生じる。 However, in this neutron shielding material, when the boron content is increased to more than a few percent, the machining accuracy deteriorates significantly. Furthermore, since helium gas is generated inside the material due to the B 10 (n, α) Li 7 reaction (n is a thermal neutron and α is helium gas), damage and deterioration of the material occur as well as absorption of radiation.
本発明はこのような事情に鑑み、機械加工が容
易でしかも長期間使用することのできる中性子遮
蔽材を提供することをその目的とする。
In view of these circumstances, an object of the present invention is to provide a neutron shielding material that is easy to machine and can be used for a long period of time.
本発明では、ポリエチレン等の固体状の中性子
減速材内に複数の孔を設け、これらにボロン等の
中性子吸収材を充填する。これらの孔の一端を閉
塞し、他端にピンホールの開けられた栓をしても
よい。また中性子遮蔽材を補強するためにこれら
の孔にアルミニウム等から成る中空金属パイプを
装填してもよい。
In the present invention, a plurality of holes are provided in a solid neutron moderator such as polyethylene, and these holes are filled with a neutron absorbing material such as boron. One end of these holes may be closed and the other end may be plugged with a pinhole. Furthermore, hollow metal pipes made of aluminum or the like may be loaded into these holes to reinforce the neutron shielding material.
以下実施例につき本発明を詳細に説明する。 The present invention will be explained in detail with reference to Examples below.
第２図は本実施例の中性子遮蔽材を表わしたも
のである。中性子遮蔽材７の中性子減速材として
のポリエチレン材のブロツク８には、直径１cm程
度の孔９が所定の間隔を置いて多数穿設されてい
る。ブロツク８の底部には、孔９を閉塞するため
のポリエチレン板１１が接着されている。孔９の
内部には、低速中性子吸収断面積の大きな物質
（中性子吸収材）１２が充填されている。 FIG. 2 shows the neutron shielding material of this example. A polyethylene block 8 serving as a neutron moderator of the neutron shielding material 7 is provided with a large number of holes 9 having a diameter of about 1 cm at predetermined intervals. A polyethylene plate 11 for closing the hole 9 is glued to the bottom of the block 8. The inside of the hole 9 is filled with a substance (neutron absorbing material) 12 having a large slow neutron absorption cross section.
中性子吸収材１２としては、例えばボロン、リ
チウム（Li）、ハフニウム（Hf）、ガドリニウム
（Gd）等の純粋物質、あるいはそれらの酸化物等
の化合物が用いられる。例えば次のような物質が
好適である。 As the neutron absorbing material 12, for example, pure substances such as boron, lithium (Li), hafnium (Hf), and gadolinium (Gd), or compounds such as oxides thereof are used. For example, the following substances are suitable.
(i) 三酸化二ホウ素（B2O3）の粉末。(i) Diboron trioxide (B 2 O 3 ) powder.
(ii) 黒鉛と炭化ホウ素（B4C）の粉末との混合
物。(ii) A mixture of graphite and boron carbide (B 4 C) powder.
(iii)酸化ガドリニウム（Gd2O3）の粉末。(iii) Gadolinium oxide (Gd 2 O 3 ) powder.
中性子吸収材１２を充填した中性子遮蔽材７は
必要によりそれらの各孔９に栓をした後、放射線
の遮蔽部に配置される。第３図は栓の一例を表わ
したものである。栓１５は中性子減速材としての
ポリエチレンで成型されており、中性子吸収材１
２から発生されるガスを逃がすためのピンホール
１６が開けられている。中性子吸収材１２が燃焼
して中性子の遮蔽能力が劣化してきたら、栓１５
を取り外し、新しい中性子吸収材と交換すること
ができる。栓１５の代わりにピンホールを多数設
けたポリエチレン板を用意し、これをブロツク８
の上部に着脱自在に取り付けてもよい。 The neutron shielding material 7 filled with the neutron absorbing material 12 is placed in the radiation shielding portion after each hole 9 is plugged if necessary. FIG. 3 shows an example of a stopper. The plug 15 is made of polyethylene as a neutron moderator, and the neutron absorber 1
A pinhole 16 is opened to allow the gas generated from 2 to escape. When the neutron absorbing material 12 burns and its neutron shielding ability deteriorates, the plug 15
can be removed and replaced with a new neutron absorber. Prepare a polyethylene plate with many pinholes in place of plug 15, and connect it to block 8.
It may be removably attached to the top of the
第４図は本発明の変形例として、孔１２にアル
ミニウムパイプ１７を装填した例を表わしたもの
である。この中性子遮蔽材では、アルミニウムパ
イプ１７の中空部に中性子吸収材を充填する。ア
ルミニウムパイプ１７は孔１２の補強部材として
用いられ、中性子遮蔽材の強化および中性子吸収
材の増量化を可能とする。しかもアルミニウムパ
イプは切断が容易なので、このパイプを装填した
中性子遮蔽材の加工性能が劣化することもない。
またアルミニウムパイプ１７の下端を予め閉塞し
ておき、これに中性子吸収材を充填しておけば、
パイプ自体の交換により中性子吸収材の交換が可
能となる。すなわち中性子遮蔽材を放射線遮蔽部
に存置したままで中性子吸収材の交換作業を行う
ことができる。アルミニウムパイプ１７は他の金
属パイプあるいはプラスチツクパイプに置き換え
ることも可能である。
FIG. 4 shows an example in which an aluminum pipe 17 is loaded into the hole 12 as a modification of the present invention. In this neutron shielding material, the hollow portion of the aluminum pipe 17 is filled with a neutron absorbing material. The aluminum pipe 17 is used as a reinforcing member for the hole 12, making it possible to strengthen the neutron shielding material and increase the amount of the neutron absorbing material. Moreover, since aluminum pipes are easy to cut, the processing performance of the neutron shielding material loaded with this pipe will not deteriorate.
Also, if the lower end of the aluminum pipe 17 is closed in advance and filled with a neutron absorbing material,
The neutron absorber can be replaced by replacing the pipe itself. That is, the neutron absorbing material can be replaced while the neutron shielding material remains in the radiation shielding section. The aluminum pipe 17 can also be replaced with other metal pipes or plastic pipes.
以上説明したように本発明によれば中性子減速
材中に設けられた孔に中性子吸収材を充填するこ
ととしたので、これらの比率や遮蔽材内における
中性子吸収材の分布を自由に設定することがで
き、中性子の遮蔽効率をより一層高めることがで
きる。
As explained above, according to the present invention, since the holes provided in the neutron moderator are filled with the neutron absorbing material, these ratios and the distribution of the neutron absorbing material within the shielding material can be freely set. This makes it possible to further improve the neutron shielding efficiency.
第１図は原子炉圧力容器の周辺を表わした一部
断面図、第２図は中性子遮蔽材の一実施例を表わ
した斜視図、第３図は栓の外観図、第４図は孔に
充填されるアルミニウムパイプの斜視図である。
８……ポリエチレン材（中性子減速材）のブロ
ツク、９……孔、１２……中性子吸収材、１５…
…栓、１６……ピンホール、１７……アルミニウ
ムパイプ。
Figure 1 is a partial cross-sectional view showing the surrounding area of the reactor pressure vessel, Figure 2 is a perspective view showing an example of the neutron shielding material, Figure 3 is an external view of the plug, and Figure 4 is a view of the hole. FIG. 2 is a perspective view of an aluminum pipe to be filled. 8... Block of polyethylene material (neutron moderator), 9... Hole, 12... Neutron absorbing material, 15...
...Bung, 16...Pinhole, 17...Aluminum pipe.
Claims (1)
の中性子減速材内に配設された複数の孔と、これ
らの孔に充填された中性子吸収材とから成ること
を特徴とする中性子遮蔽材。 ２ 中性子減速材内に配設された複数の孔のそれ
ぞれ一端が閉塞されており、他端にピンホールの
開けられた栓が嵌合されていることを特徴とする
特許請求の範囲第１項記載の中性子遮蔽材。 ３ 中性子減速材内に配置された複数の孔に中空
金属パイプが装填されており、これらの金属パイ
プに中性子吸収材が充填されていることを特徴と
する特許請求の範囲第１項記載の中性子遮蔽材。[Claims] 1. A neutron moderating material processed into a predetermined shape, a plurality of holes arranged in the neutron moderating material, and a neutron absorbing material filled in these holes. Neutron shielding material. 2. Claim 1, characterized in that one end of each of the plurality of holes arranged in the neutron moderator is closed, and a stopper with a pinhole is fitted to the other end. Neutron shielding material as described. 3. The neutron according to claim 1, characterized in that a plurality of holes arranged in the neutron moderator are filled with hollow metal pipes, and these metal pipes are filled with a neutron absorbing material. Shielding material.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP58233738A JPS60127498A (en) | 1983-12-13 | 1983-12-13 | Neutron shielding material |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP58233738A JPS60127498A (en) | 1983-12-13 | 1983-12-13 | Neutron shielding material |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS60127498A JPS60127498A (en) | 1985-07-08 |
| JPH0519676B2 true JPH0519676B2 (en) | 1993-03-17 |
Family
ID=16959800
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP58233738A Granted JPS60127498A (en) | 1983-12-13 | 1983-12-13 | Neutron shielding material |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS60127498A (en) |
-
1983
- 1983-12-13 JP JP58233738A patent/JPS60127498A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS60127498A (en) | 1985-07-08 |
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