JPS62276492A - Fuel aggregate - Google Patents
Fuel aggregateInfo
- Publication number
- JPS62276492A JPS62276492A JP61119268A JP11926886A JPS62276492A JP S62276492 A JPS62276492 A JP S62276492A JP 61119268 A JP61119268 A JP 61119268A JP 11926886 A JP11926886 A JP 11926886A JP S62276492 A JPS62276492 A JP S62276492A
- Authority
- JP
- Japan
- Prior art keywords
- fuel
- uranium
- enrichment
- axial
- distribution
- 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.)
- Pending
Links
- 239000000446 fuel Substances 0.000 title claims description 62
- 229910052770 Uranium Inorganic materials 0.000 claims description 12
- JFALSRSLKYAFGM-UHFFFAOYSA-N uranium(0) Chemical compound [U] JFALSRSLKYAFGM-UHFFFAOYSA-N 0.000 claims description 12
- 229910052778 Plutonium Inorganic materials 0.000 claims description 6
- OYEHPCDNVJXUIW-UHFFFAOYSA-N plutonium atom Chemical compound [Pu] OYEHPCDNVJXUIW-UHFFFAOYSA-N 0.000 claims description 6
- WZECUPJJEIXUKY-UHFFFAOYSA-N [O-2].[O-2].[O-2].[U+6] Chemical compound [O-2].[O-2].[O-2].[U+6] WZECUPJJEIXUKY-UHFFFAOYSA-N 0.000 claims description 4
- 229910000439 uranium oxide Inorganic materials 0.000 claims description 4
- 238000009826 distribution Methods 0.000 description 22
- 230000009257 reactivity Effects 0.000 description 11
- 238000000034 method Methods 0.000 description 8
- CMIHHWBVHJVIGI-UHFFFAOYSA-N gadolinium(iii) oxide Chemical compound [O-2].[O-2].[O-2].[Gd+3].[Gd+3] CMIHHWBVHJVIGI-UHFFFAOYSA-N 0.000 description 6
- 230000004907 flux Effects 0.000 description 5
- WJWSFWHDKPKKES-UHFFFAOYSA-N plutonium uranium Chemical compound [U].[Pu] WJWSFWHDKPKKES-UHFFFAOYSA-N 0.000 description 5
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 5
- 238000009835 boiling Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- 238000005516 engineering process Methods 0.000 description 2
- 239000008188 pellet Substances 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 230000000712 assembly Effects 0.000 description 1
- 238000000429 assembly Methods 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 238000005253 cladding Methods 0.000 description 1
- 238000002485 combustion reaction Methods 0.000 description 1
- 230000008602 contraction Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000004992 fission Effects 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 231100000614 poison Toxicity 0.000 description 1
- 230000007096 poisonous effect Effects 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 238000005245 sintering Methods 0.000 description 1
- 238000003466 welding Methods 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
Abstract
(57)【要約】本公報は電子出願前の出願データであるた
め要約のデータは記録されません。(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.
Description
【発明の詳細な説明】
３、発明の詳細な説明
［発明の目的］
（産業上の利用分野）
本発明は原子炉の炉心に装荷される燃料集合体、特にウ
ラン・プルトニウム混合酸化物を使用した燃料集合体に
関する。[Detailed Description of the Invention] 3. Detailed Description of the Invention [Object of the Invention] (Industrial Application Field) The present invention is directed to a fuel assembly loaded in the core of a nuclear reactor, in particular, using a uranium-plutonium mixed oxide. related to fuel assemblies.
（従来の技術）
沸騰水型原子炉では主に熱中性子が２３５１Ｊ 、 ２
３９ ＰＬＩ。(Prior art) In a boiling water reactor, mainly thermal neutrons are 2351J, 2
39 PLI.
２４４ ｐ ｕに吸収され、核分裂することによって発
生するエネルギーを利用している。It utilizes the energy generated by nuclear fission that is absorbed by 244 p u.
ところで、沸騰水型原子炉で燃料経済性、炉心熱的特性
の上から重要なことは、熱中性子束分布に応じて適切な
２３５Ｕ濃縮度、Ｐｕ富化度の設計を行い、出力分布の
平坦化を図ることである。By the way, what is important in terms of fuel economy and core thermal characteristics for boiling water reactors is to design appropriate 235U enrichment and Pu enrichment according to the thermal neutron flux distribution, and to achieve a flat power distribution. The goal is to make the world a better place.
第５図は沸騰水型原子炉で用いられている従来のウラン
・プルトニウム混合酸化物入り燃料集合体（以下、ＭＯ
１′Ｆ４集合体という）の断面図である。同図に示すよ
うに、ＭＯＸ燃料集合体はウラン燃料棒１１．１２’
、 １３．１４． Ｇ、ウラン・プルトニウム混合酸化
物入り燃料棒（以下ＭＯＸ燃料棒）Ｐ＋ 、Ｐ２及びウ
ォータロッドＷを８（１８列の正方格子状に配置して構
成される。これら各燃料棒の縦方向構成を第６図の縦断
面図で示している。Figure 5 shows a conventional uranium-plutonium mixed oxide fuel assembly (hereinafter referred to as MO) used in boiling water reactors.
1′F4 aggregate). As shown in the figure, the MOX fuel assembly consists of uranium fuel rods 11.12'
, 13.14. G, fuel rods containing uranium-plutonium mixed oxide (hereinafter referred to as MOX fuel rods) P+, P2, and water rods W are arranged in a square grid of 8 (18 rows). This is shown in the longitudinal cross-sectional view of FIG.
そして、上記第５図及び第６図に示す如く、従来技術で
はウラン燃料棒１１．１２’ 、 １３．１４の２３５
Ｕ濃縮度をそれぞれ３．５ｗｔ％、 ３．２ｗｔ％、
２．６ｗｔ％。As shown in FIGS. 5 and 6 above, in the prior art, uranium fuel rods 11.12', 13.14 and 235
The U enrichment was set to 3.5 wt%, 3.2 wt%, and
2.6wt%.
ｉ、９ｗｔ％とし、ＭＯＸ燃料燃料＋ 、 Ｐ２のＰｕ
富化度をそれぞれ４．７ｗｔ％、 ３．６ｗｔ％とな
るように構成されている。しかして従来技術では熱中性
子束の高いところには反応度の低い燃料棒が配置され、
熱中性子束の低いところには反応度の高い燃料棒が配置
されて燃料集合体内の出力分布は平坦化されている。i, 9wt%, MOX fuel +, Pu of P2
The enrichments are set to 4.7wt% and 3.6wt%, respectively. However, in the conventional technology, fuel rods with low reactivity are placed in areas with high thermal neutron flux.
Highly reactive fuel rods are placed in areas with low thermal neutron flux, and the power distribution within the fuel assembly is flattened.
しかしながら、軸方向については第６図に示すように、
２３５ ＵｙＡ縮度、Ｐｕ富化度は一様であるため、軸
方向出力分布は第７図の実線２１のように、軸方向の下
部側で出力のピークが出易くなり、燃料経済性、炉心熱
的特性の何れか一方が犠牲とならざるを得ないという問
題があった。However, in the axial direction, as shown in Figure 6,
235 Since the UyA degree of shrinkage and Pu enrichment are uniform, the axial power distribution tends to have a peak in the lower part of the axis, as shown by the solid line 21 in Figure 7, which improves fuel economy and the core. There was a problem in that one of the thermal properties had to be sacrificed.
（発明が解決しようとする問題点）
上記したように従来技術では燃料集合体内の出力分布は
平坦化され、各燃料棒の出力はほぼ均等化されているが
、軸方向の出力分布は平坦化されておらず、ピーク出力
部の出力が高い割には他の部分の出力が低く、燃料経済
性、炉心熱的特性の上から好ましくないものであった。(Problems to be solved by the invention) As described above, in the conventional technology, the power distribution within the fuel assembly is flattened, and the power output of each fuel rod is almost equalized, but the power distribution in the axial direction is flattened. Although the output of the peak output section was high, the output of other sections was low, which was unfavorable from the standpoint of fuel economy and core thermal characteristics.
本発明は上記問題点を解消するためになされたもので、
その目的は、軸方向に適切な反応度弁で［を有しかつ燃
料経済性、炉心熱的特性を改良した・ＭＯＸ燃料集合体
を提供することにある。The present invention was made to solve the above problems, and
The objective is to provide a MOX fuel assembly with adequate axial reactivity valving and improved fuel economy and core thermal properties.
［発明の構成］
（問題点を解決するための手段）
本発明は上記目的を達成するために、ウラン酸化物を装
填した燃料棒とウラン・プルトニウム混合酸化物を装填
した燃料棒を束ねて構成してなる燃料集合体において、
ウラン・プルトニウム混合酸化物を装填した燃料棒の濃
縮度、プルトニウム富化度は軸方向一律とし、ウラン酸
化物を装填した燃料棒のうちその一部の燃料棒は濃縮度
の異な、る複数の軸方向領域に分けられた燃料棒である
ことを特徴とするものである。[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above object, the present invention is constructed by bundling fuel rods loaded with uranium oxide and fuel rods loaded with uranium-plutonium mixed oxide. In the fuel assembly made of
The enrichment and plutonium enrichment of the fuel rods loaded with uranium-plutonium mixed oxide are uniform in the axial direction, and some of the fuel rods loaded with uranium oxide have different enrichment levels. It is characterized by a fuel rod divided into axial regions.
次に、本発明の基本的考え方について説明する。Next, the basic idea of the present invention will be explained.
ＭＯＸ燃料集合体に軸方向反応度分布を付ける方法とし
ては主に次の３通りの方法が挙げられる。There are three main methods for imparting an axial reactivity distribution to a MOX fuel assembly:
（ｉ）２３５Ｕ濃縮度
（ｉｉ）ＰＩＪ富化度
（ｉｉｉ）カドリニア
このうち３番目の方法のガドリアによって軸方向反応度
分布を付ける方法は従来から採用されており実績もある
が、ガドリニアは可燃性毒物と言われるように燃料の燃
焼に伴ってその反応度抑制効果が弱まるため、これのみ
で軸方向に反応度分布を付けるのには限界があり、他の
方法との併用となる。(i) 235U enrichment (ii) PIJ enrichment (iii) Cadolinia The third method, which uses gadolinia to give an axial reactivity distribution, has been used and has a proven track record, but gadolinia is flammable. As the fuel is said to be a poisonous substance, its reactivity suppressing effect weakens as the fuel burns, so there is a limit to the ability to create a reactivity distribution in the axial direction using only this method, so it must be used in combination with other methods.
また、第２番目の方法ではプルトニウムは化学的にも放
射能的にも＠唄な取扱いが必要な物質であり、このため
燃料加工施設では憤重な取扱いが要求される。ＭＯＸｌ
料棒はウラン燃料棒と類似した工程により製造される。In addition, in the second method, plutonium is a substance that requires careful handling both chemically and radioactively, so it must be handled with great care at fuel fabrication facilities. MOXl
Feed rods are manufactured using a process similar to that used for uranium fuel rods.
ウランとプルトニウムの混合酸化物を成型、焼結し、こ
のペレットを被覆管に装填し、溶接することによってＭ
ＯＸ燃料棒が出来上るが、ウラン燃料棒との大きな相違
点はこれらの工程をホット・セルの中で行わなければな
らないことである。従って、１本のＭＯＸ燃料棒に複数
種類のｐｕ富化度の燃料ペレットを使用することは、装
填作業を煩雑化するばかりか、Ｐｕ富化度が替るたびに
行うクリーン・アップの頻度を高めることにもなり、！
！造上のデメリットが大きい。By molding and sintering a mixed oxide of uranium and plutonium, and loading the pellets into a cladding tube and welding, M
OX fuel rods are produced, but the major difference from uranium fuel rods is that these steps must be performed in a hot cell. Therefore, using fuel pellets with multiple types of PU enrichment in one MOX fuel rod not only complicates the loading operation but also increases the frequency of clean-up every time the PU enrichment changes. It also happens!
! There are major structural disadvantages.
そして、第１＠目の方法の２３５Ｕによって軸方向に反
応度分布を付ける方法はウラン燃料でも採用されている
。また、ガドリニアのように燃焼変化は大きくなく、寿
命初期に付けた反応度差が殆どそのまま寿命期間中維持
されるため、ＭＯＸ燃料集合体の軸方向反応度分布を付
ける方法として適している。The first method of providing reactivity distribution in the axial direction using 235U is also used for uranium fuel. In addition, unlike gadolinia, the combustion change is not large, and the reactivity difference established at the beginning of the life is almost maintained throughout the life, so it is suitable as a method for determining the axial reactivity distribution of the MOX fuel assembly.
そこで、本発明では上記のごとき観点から２３５Ｕ濃縮
度によってＭＯＸ燃料集合体の軸方向反応度分布を改善
しようとするものである。Therefore, the present invention attempts to improve the axial reactivity distribution of the MOX fuel assembly by increasing the 235U enrichment from the above viewpoint.
（作 用）
上記したように、本発明のＭＯＸ燃料集合体は” ＩＪ
ｍ縮度によって軸方向反応度分布を平坦化するように
付けられるため、製造費を高めることなく燃料経済性及
び炉心熱的特性の向上を達成することができる。(Function) As described above, the MOX fuel assembly of the present invention
Since the axial reactivity distribution is flattened by the degree of contraction, fuel economy and core thermal characteristics can be improved without increasing manufacturing costs.
（実施例〉 本発明の実施例を図面を参照して説明する。(Example> Embodiments of the present invention will be described with reference to the drawings.
第１図は本発明の一実施例の概略横断面図、第２図は第
１図の燃料棒の縦断面図を示すものである。なお、既に
説明した第５図および第６図と同一部分には同一符号を
付してその詳細な説明は省略するものとする。これらの
図に示すように、ＭＯ×燃料集合体はウラン燃料棒１１
．１２．１３．１４゜Ｇ、ＭＯＸ燃料棒Ｐｔ 、 Ｐ２
及びつ４−タロラドＷを８行８列の正方格子状に配置し
て構成されている。ここで、ウラン燃料棒１２は濃縮度
が３つの領域に分けられており、下から２．６ｗｔ％、
３．８ｗｔ％、 ２．６ｗｔ％となっている。FIG. 1 is a schematic cross-sectional view of one embodiment of the present invention, and FIG. 2 is a longitudinal cross-sectional view of the fuel rod of FIG. 1. Note that the same parts as in FIGS. 5 and 6 already described are given the same reference numerals, and detailed explanation thereof will be omitted. As shown in these figures, the MO x fuel assembly consists of uranium fuel rods 11
．． 12.13.14°G, MOX fuel rod Pt, P2
and 4-talorado W are arranged in a square grid of 8 rows and 8 columns. Here, the uranium fuel rod 12 is divided into three enrichment regions: 2.6 wt% from the bottom,
They are 3.8wt% and 2.6wt%.
第８図は本発明のＭＯＸ燃料集合体の軸方向濃縮度分布
を示すもので、前記の８本のウラン燃料棒１２の寄与に
よって濃縮度分布は中央部が高く、上下端部が低くなっ
ている。そして、第４図に示すように軸方向下部では熱
中性子束が高く、中央部から上部では熱中性子束が低い
ため、本発明による軸方向濃縮度分布は軸方向出力分布
を平坦化するよう作用することになる。第７図の点線２
２は本発明によって平坦化された軸方向出力分布を示し
てものであり、この図からも軸方向の各部が均等に出力
を発生していることが分る。FIG. 8 shows the axial enrichment distribution of the MOX fuel assembly of the present invention. Due to the contribution of the eight uranium fuel rods 12, the enrichment distribution is high in the center and low in the upper and lower ends. There is. As shown in Fig. 4, the thermal neutron flux is high in the lower part of the axis and lower in the upper part from the center, so the axial enrichment distribution according to the present invention acts to flatten the axial power distribution. I will do it. Dotted line 2 in Figure 7
2 shows the axial output distribution flattened by the present invention, and it can be seen from this figure that each part in the axial direction generates output equally.
［発明の効果］
以上説明したように、本発明のＭＯＸ燃利集合体による
と、燃料集合体内の水平方向および軸方向についてら出
力分布が平坦化されており、かつその製造費を高めるこ
となく、ＭＯＸ燃料の燃料経済性及び炉心熱的特性を向
上させることができるという優れた効果を奏する。[Effects of the Invention] As explained above, according to the MOX fuel assembly of the present invention, the power distribution is flattened in the horizontal and axial directions within the fuel assembly, and the power distribution can be flattened without increasing the manufacturing cost. This has the excellent effect of improving the fuel economy and core thermal characteristics of MOX fuel.
第１図は本発明の一実施例の横断面図、第２図は第１図
の燃料棒の縦断面図、第３図は燃料集合体内水平断面に
おける熱中性子束分布を示す図、第４図は軸方向の熱中
性子束分布を示す図、第５図は従来の燃料集合体の横断
面図、第６図は第５図の燃料棒の縦断面図、第７図は本
発明の軸方向濃縮度分布を示す図、第８図は本発明と従
来技術との軸方向の出力分布を示す図である。
１１、１２．１３．１４． Ｇ・・・ウラン燃料棒Ｐ＋
、Ｐ２・・・ＭＯＸ燃料棒
Ｗ・・・ウォータロッド
（８７３３）代理人 弁理士 猪 股 祥 晃（ほか
１名）
第１図
第２図
第３図
第４図
第５図
毫６図
炉・ヒ塙
ヵ掴：
二／７（オ４コブ↑イーｉ）
７図
〉農確度（８対ブｉり
第８図FIG. 1 is a cross-sectional view of an embodiment of the present invention, FIG. 2 is a vertical cross-sectional view of the fuel rod shown in FIG. The figure shows the thermal neutron flux distribution in the axial direction, Figure 5 is a cross-sectional view of a conventional fuel assembly, Figure 6 is a longitudinal cross-sectional view of the fuel rod in Figure 5, and Figure 7 is the axis of the present invention. FIG. 8 is a diagram showing the axial concentration distribution of the present invention and the prior art. 11, 12.13.14. G...Uranium fuel rod P+
, P2...MOX fuel rod W...Water rod (8733) Agent: Patent attorney Yoshiaki Inomata (and others)
1 person) Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 Furnace/Hihanka grab: 2/7 (O4 knob↑Ei) Fig. 7〉Agricultural accuracy (8 vs. Figure 8
Claims (1)
混合酸化物を装填した燃料棒を束ねて構成してなる燃料
集合体において、ウラン・プルトニウム混合酸化物を装
填した燃料棒の濃縮度、プルトニウム富化度は軸方向一
律とし、ウラン酸化物を装填した燃料棒のうちその一部
の燃料棒は濃縮度の異なる複数の軸方向領域に分けられ
た燃料棒であることを特徴とする燃料集合体。In a fuel assembly consisting of a bundle of fuel rods loaded with uranium oxide and fuel rods loaded with uranium/plutonium mixed oxide, the enrichment level and plutonium enrichment of the fuel rods loaded with uranium/plutonium mixed oxide are determined. A fuel assembly characterized in that the concentration is uniform in the axial direction, and some of the fuel rods loaded with uranium oxide are divided into a plurality of axial regions having different enrichment degrees.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61119268A JPS62276492A (en) | 1986-05-26 | 1986-05-26 | Fuel aggregate |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61119268A JPS62276492A (en) | 1986-05-26 | 1986-05-26 | Fuel aggregate |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS62276492A true JPS62276492A (en) | 1987-12-01 |
Family
ID=14757145
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP61119268A Pending JPS62276492A (en) | 1986-05-26 | 1986-05-26 | Fuel aggregate |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS62276492A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5410580A (en) * | 1990-02-26 | 1995-04-25 | Kabushiki Kaisha Toshiba | Fuel assembly for thermal neutron type reactor |
| JP2006300849A (en) * | 2005-04-25 | 2006-11-02 | Toshihisa Shirakawa | Abwr reactor core with high conversion ratio capable of being converted into breeder reactor |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5340181A (en) * | 1976-09-25 | 1978-04-12 | Hitachi Ltd | Core part structure of reactor |
| JPS562589A (en) * | 1979-06-21 | 1981-01-12 | Genshi Nenryo Kogyo | Nuclear fuel assembly |
| JPS60242391A (en) * | 1984-05-16 | 1985-12-02 | 株式会社日立製作所 | Fuel aggregate |
-
1986
- 1986-05-26 JP JP61119268A patent/JPS62276492A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5340181A (en) * | 1976-09-25 | 1978-04-12 | Hitachi Ltd | Core part structure of reactor |
| JPS562589A (en) * | 1979-06-21 | 1981-01-12 | Genshi Nenryo Kogyo | Nuclear fuel assembly |
| JPS60242391A (en) * | 1984-05-16 | 1985-12-02 | 株式会社日立製作所 | Fuel aggregate |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5410580A (en) * | 1990-02-26 | 1995-04-25 | Kabushiki Kaisha Toshiba | Fuel assembly for thermal neutron type reactor |
| JP2006300849A (en) * | 2005-04-25 | 2006-11-02 | Toshihisa Shirakawa | Abwr reactor core with high conversion ratio capable of being converted into breeder reactor |
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