JPH07270563A - Fuel assembly for reactor - Google Patents

Fuel assembly for reactor

Info

Publication number
JPH07270563A
JPH07270563A JP6082608A JP8260894A JPH07270563A JP H07270563 A JPH07270563 A JP H07270563A JP 6082608 A JP6082608 A JP 6082608A JP 8260894 A JP8260894 A JP 8260894A JP H07270563 A JPH07270563 A JP H07270563A
Authority
JP
Japan
Prior art keywords
fuel
assembly
cladding tube
thermal neutron
rods
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.)
Withdrawn
Application number
JP6082608A
Other languages
Japanese (ja)
Inventor
Akio Yamamoto
章夫 山本
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Nuclear Fuel Industries Ltd
Original Assignee
Nuclear Fuel Industries Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Nuclear Fuel Industries Ltd filed Critical Nuclear Fuel Industries Ltd
Priority to JP6082608A priority Critical patent/JPH07270563A/en
Publication of JPH07270563A publication Critical patent/JPH07270563A/en
Withdrawn legal-status Critical Current

Links

Classifications

    • YGENERAL 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
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02EREDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E30/00Energy generation of nuclear origin
    • Y02E30/30Nuclear fission reactors

Abstract

PURPOSE:To decrease the output peaking coefficient in a fuel assembly by arranging the fuel rods so that the quantity of thermal neutron in a fuel cladding tube is increased for a fuel rod arranged at a position where thermal neutron flux density is high. CONSTITUTION:A Pu-rich U-Pu mixture fuel is clad with a fuel cladding tube and employed as fuel rods 13, 15 except a neutron measuring tube 11 located at the center of a fuel assembly 10 and a control rod guide tube 12 distributed therein. A fuel rod 15 arranged at the outer peripheral part subjected to high thermal neutron flux density is applied, on the inner surface of the fuel cladding tube thereof, with a coating layer of thermal neutron absorbing substance. The coating layer is not provided for the fuel cladding tube of a fuel rod 13 disposed at the center of the fuel assembly. The output peaking coefficient is decreased by means of two types of fuel rods 13, 15.

Description

【発明の詳細な説明】Detailed Description of the Invention

【0001】[0001]

【産業上の利用分野】本発明は、U−Pu混合酸化物燃
料(以下、MOX燃料)を用いた原子炉燃料集合体に関
するものである。
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a nuclear reactor fuel assembly using a U-Pu mixed oxide fuel (hereinafter referred to as MOX fuel).

【0002】[0002]

【従来の技術】図2は従来のPWR用17×17型MO
X燃料集合体の1/4横断面の構成を示す説明図であ
る。図において、破線で示す部分が燃料集合体の中心線
CLを示し、他の断面は各々の中心線CLに対して対称に配
置されている。
2. Description of the Related Art FIG. 2 shows a conventional 17 × 17 MO for PWR.
It is explanatory drawing which shows the structure of the 1/4 cross section of X fuel assembly. In the figure, the broken line indicates the center line of the fuel assembly.
CL is shown, and other cross sections are arranged symmetrically with respect to each center line CL.

【0003】図に示す通り、軽水炉に用いられるMOX
燃料は、熱中性子群の吸収断面積が大きいため、隣接す
るUO2 燃料より熱中性子が流入する。このため、MO
X燃料においては、燃料集合体外周部のPu富化度を下
げることで、出力ピーキング係数が過大にならない設計
となっている。
As shown in the figure, MOX used in a light water reactor
Since the fuel has a large absorption cross section of thermal neutron group, thermal neutrons flow from the adjacent UO 2 fuel. Therefore, MO
The X fuel is designed so that the output peaking coefficient does not become excessive by lowering the Pu enrichment degree at the outer periphery of the fuel assembly.

【0004】即ち、燃料集合体の中心に1つ存在する中
性子計測管(1) と、燃料集合体に分散して合計24本配
置されている制御棒案内管(2) を除いた燃料棒は、高P
u富化度の燃料棒(3) ,中Pu富化度の燃料棒(4) ,低
Pu富化度の燃料棒(5) の3種類からなる。これら3種
類の燃料棒は、熱中性子束が最も高いコーナー部に低P
u富化度の燃料棒(5) が配置され、次に中Pu富化度の
燃料棒(4) が配置され、熱中性子束が低くなる中心部ほ
ど高Pu富化度の燃料棒(3) が配置されることにより、
出力ピーキング係数を低減させている。
That is, the fuel rods except for the neutron measuring pipe (1) existing in the center of the fuel assembly and the control rod guide pipes (2) arranged in a total of 24 scattered in the fuel assembly are , High P
It consists of three types of fuel rods (3) with u enrichment, fuel rods (4) with medium Pu enrichment, and fuel rods (5) with low Pu enrichment. These three types of fuel rods have low P in the corners where the thermal neutron flux is highest.
The fuel rods (5) with u enrichment are arranged, then the fuel rods (4) with medium Pu enrichment are arranged, and the fuel rods with high Pu enrichment (3 ) Is placed,
The output peaking coefficient is reduced.

【0005】[0005]

【発明が解決しようとする課題】しかしながら、燃料棒
としてPuの富化度を相違させた多種類の燃料棒を作成
し、これを燃料集合体に配する設計では、単種類の燃料
棒を作成するものと比較して、一の燃料棒の製造コスト
が高くなり、また全体として、一燃料集合体当りのPu
装荷量が少なくなるなどの問題がある。
However, in the design in which many kinds of fuel rods having different enrichment levels of Pu are prepared as fuel rods and the fuel rods are arranged in the fuel assembly, a single kind of fuel rod is prepared. The fuel cost of one fuel rod is higher than that of fuel rods, and as a whole, Pu per fuel assembly is
There is a problem that the loading amount becomes small.

【0006】即ち、Pu及びU燃料は、燃料加工のプロ
セスでブレンドされることとなるが、Puの富化度を相
違させた多種類の燃料棒は同時に単一の製造ラインで差
くさいすることは不可能である。従って、Puの富化度
を相違させた多種類の燃料棒の製造コストが高くなる。
That is, the Pu and U fuels are blended in the process of fuel processing, but multiple types of fuel rods having different enrichment levels of Pu must be simultaneously processed in a single production line. Is impossible. Therefore, the manufacturing cost of various types of fuel rods having different Pu enrichment levels becomes high.

【0007】本発明は、Pu富化度を相違させた多種類
の燃料棒とせずに、単一富化度の燃料棒とし、しかも燃
料集合体内の出力ピーキング係数が過大にならないMO
X燃料集合体を得ることを目的とする。
According to the present invention, a fuel rod of a single enrichment is used instead of the various types of fuel rods having different Pu enrichments, and the output peaking coefficient in the fuel assembly does not become excessive.
The purpose is to obtain X fuel assemblies.

【0008】[0008]

【課題を解決するための手段】本請求項1に記載の発明
に係る原子炉燃料集合体では、MOX燃料を含む燃料棒
をバンドル状に束ねて配した原子炉燃料集合体におい
て、前記燃料棒が、燃料被覆管に熱中性子吸収物質を混
入又はコーティングさせてなるものを含み、熱中性子束
が高い位置に配置される燃料棒ほど前記燃料被覆管の熱
中性子吸収物質の量が多い燃料棒が配置されてなるもの
である。
In the reactor fuel assembly according to the present invention as set forth in claim 1, in a reactor fuel assembly in which fuel rods containing MOX fuel are bundled and arranged, Is a fuel clad tube containing a mixture or coating of a thermal neutron absorbing material, the fuel rods having a higher thermal neutron flux the higher the amount of thermal neutron absorbing material in the fuel cladding tube It is arranged.

【0009】本請求項2に記載の発明に係る原子炉燃料
集合体では、請求項1に記載の原子炉燃料集合体におい
て、前記MOX燃料を含む燃料棒のPu富化度を全ての
燃料棒において同一の富化度としたものである。
According to a second aspect of the present invention, there is provided a reactor fuel assembly according to the first aspect, wherein the Pu enrichment of fuel rods containing the MOX fuel is all fuel rods. The same enrichment is used in.

【0010】[0010]

【作用】本発明においては、原子炉燃料集合体でバンド
ル状に束ねて配されたMOX燃料を含む燃料棒が、燃料
被覆管に熱中性子吸収物質を混入又はコーティングさせ
てなるものを含むものであるため、単一富化度の燃料棒
として、しかも燃料集合体内の出力ピーキング係数が過
大にならないMOX燃料集合体を得ることができる。
In the present invention, the fuel rods containing the MOX fuel bundled in a bundle in the reactor fuel assembly and containing MOX fuel include those obtained by mixing or coating the thermal neutron absorbing substance in the fuel cladding tube. It is possible to obtain a MOX fuel assembly as a fuel rod with a single enrichment and in which the output peaking coefficient in the fuel assembly does not become excessive.

【0011】即ち、Puを単一富化した燃料棒をバンド
ル状に束ねたMOX燃料集合体とした場合に、外周部の
高い熱中性子束を、被覆管に混入又はコーティングさせ
た熱中性子吸収物質によって低減させることにより、燃
料集合体内の出力ピーキング係数を低減させることがで
きる。
That is, when a fuel rod enriched with Pu is bundled into a MOX fuel assembly, the thermal neutron flux in the outer periphery is mixed or coated in the cladding tube. The output peaking coefficient in the fuel assembly can be reduced by reducing

【0012】従って、MOX燃料は単一のPu富化度の
燃料棒とすることができ、製造コストが安くなる。即
ち、燃料加工のプロセスでブレンドされるPu及びU燃
料は単一の富化度とすることができ、同時に製造するこ
とができるため、製造コストが安くなる。
Therefore, the MOX fuel can be a single Pu enriched fuel rod, which reduces manufacturing costs. That is, the Pu and U fuels that are blended in the fuel processing process can have a single enrichment and can be manufactured at the same time, so the manufacturing cost is reduced.

【0013】また、全体として、一燃料集合体当りのP
u装荷量も複数種類のPu富化度とした燃料集合体と比
較して多くなる。また、UO2 燃料からMOX燃料に流
入する熱中性子の量は、集合体外周部の位置によって異
なり、集合体のコーナ部で最も流入量が大きい。そのた
め、コーナ部周辺の被覆管のみに対して、中性子吸収物
質量(混入量又はコーティング量)を増加させ、中性子
経済を向上させることが可能である。
Further, as a whole, P per fuel assembly
The u loading amount also becomes larger than that of the fuel assembly having a plurality of types of Pu enrichment. The amount of thermal neutrons flowing from the UO 2 fuel into the MOX fuel differs depending on the position of the outer peripheral portion of the assembly, and the amount of thermal neutrons is largest at the corners of the assembly. Therefore, it is possible to improve the neutron economy by increasing the amount of neutron absorbing substances (mixing amount or coating amount) only for the cladding tube around the corner portion.

【0014】即ち、例えば、熱中性子束が低い中心部に
は、燃料被覆管に熱中性子吸収物質を混入又はコーティ
ングされていない燃料棒を用い、逆に集合体の外周部や
コーナー部には、燃料被覆管に熱中性子吸収物質を混入
又はコーティングされた燃料棒を配置して、中性子経済
を向上させることが可能である。
That is, for example, in the central portion where the thermal neutron flux is low, a fuel rod in which the thermal neutron absorbing material is not mixed or coated in the fuel cladding tube is used, and conversely, in the outer peripheral portion and the corner portion of the assembly, It is possible to improve the neutron economy by arranging fuel rods in which the thermal neutron absorbing material is mixed or coated in the fuel cladding tube.

【0015】尚、得ようとする所望の混入量又はコーテ
ィング量の燃料被覆管の作成は、所望の量の熱中性子吸
収物質を混入又はコーティングすればよく、製造ライン
自体を多数にする必要がなく、得られた所望の混入量又
はコーティング量の燃料被覆管は目印をして保存してお
けば、装着時に取り違え事故も少ない。
The fuel cladding tube having a desired mixing amount or coating amount to be obtained may be prepared by mixing or coating the desired amount of the thermal neutron absorbing substance, and it is not necessary to increase the number of manufacturing lines themselves. If the obtained fuel cladding tube with the desired mixing amount or coating amount is marked and stored, there is little misunderstanding during mounting.

【0016】具体的な熱中性子吸収物質としては、B、
Hf、Cdなど熱中性子に対する吸収断面積が大きいも
のが適切と考えられる。また、熱中性子を吸収する物質
を用いるのは、MOX燃料棒内に流入する熱中性子を遮
断することが目的であるため、燃料被覆管自体に混合さ
せなくても、燃料被覆管の内側もしくは外側にコーティ
ングしても良い。例えば燃料被覆管の内側にコーティン
グを行った場合、冷却水による被覆管の腐食に対しては
特別の考慮を払う必要はない。
Specific thermal neutron absorbing materials include B,
It is considered that a material having a large absorption cross section for thermal neutrons such as Hf and Cd is suitable. Also, the purpose of using a substance that absorbs thermal neutrons is to block the thermal neutrons that flow into the MOX fuel rods, so it is not necessary to mix with the fuel cladding tube itself, but inside or outside the fuel cladding tube. You may coat on. For example, if a coating is applied to the inside of the fuel cladding, no special consideration needs to be given to corrosion of the cladding by cooling water.

【0017】具体的には、燃料被覆管に熱中性子吸収物
質を混入又はコーティングさせてなる燃料棒の配置位置
や熱中性子吸収物質の混入量又はコーティング量は、原
子炉に装荷される燃料集合体の装荷位置等によって相違
するが、原子炉全体として最適な配置位置する。
Specifically, the arrangement position of the fuel rod formed by mixing or coating the thermal neutron absorbing substance in the fuel cladding tube and the mixing amount or coating amount of the thermal neutron absorbing substance are determined by the fuel assembly loaded in the reactor. Although it differs depending on the loading position of the reactor, etc., it is located optimally as a whole reactor.

【0018】また、一般に好ましくは、熱中性子束が高
い位置に配置される燃料棒ほど前記燃料被覆管の熱中性
子吸収物質の混入量又はコーティング量が多くなるよう
に燃料棒を配置し、それにより、原子炉全体として最適
な出力ピーキングが得られる。
Further, it is generally preferable that the fuel rods are arranged such that the higher the thermal neutron flux is, the higher the mixing amount or coating amount of the thermal neutron absorbing substance in the fuel cladding tube becomes. , The optimum power peaking is obtained for the entire reactor.

【0019】更に、MOX燃料を含む燃料棒のPu富化
度を全ての燃料棒において同一の富化度として、燃料被
覆管への熱中性子吸収物質の混入又はコーティングをし
ないものと燃料被覆管への熱中性子吸収物質の混入量又
はコーティング量を徐々に変化させたものとを組み合わ
せて原子炉全体として最適な出力ピーキングを得るよう
に調整してもよい。
Further, the Pu enrichment of fuel rods containing MOX fuel is set to be the same enrichment in all fuel rods, and the fuel neutron absorbing material is not mixed or coated in the fuel cladding tube and the fuel cladding tube is not enriched. The amount of thermal neutron absorbing material or the amount of coating which gradually changes the coating amount may be combined to adjust so as to obtain optimum output peaking for the entire reactor.

【0020】[0020]

【実施例】図1は本発明の原子炉燃料集合体の一実施例
の17×17型MOX燃料集合体の1/4横断面の構成
を示す説明図である。図において、破線で示す部分が燃
料集合体の中心線CLを示し、他の断面は各々の中心線CL
に対して対称に配置されている。
EXAMPLE FIG. 1 is an explanatory view showing the configuration of a 1/4 cross section of a 17 × 17 type MOX fuel assembly which is an example of a nuclear reactor fuel assembly according to the present invention. In the figure, the broken line indicates the center line CL of the fuel assembly, and the other cross sections indicate the center lines CL of the respective fuel assemblies.
They are arranged symmetrically with respect to.

【0021】図に示す通り、燃料集合体(10)の中心に1
つ存在する中性子計測管(11)と、燃料集合体に分散して
合計24本配置されている制御棒案内管(12)を除いた燃
料棒(13)(15)は、全て高Pu富化度のMOX燃料を燃料
被覆管で被覆した燃料棒が用いられている。
At the center of the fuel assembly (10), as shown in FIG.
The fuel rods (13) (15) excluding the existing neutron measuring pipes (11) and the control rod guide pipes (12) distributed in the fuel assembly and having a total of 24 pipes are all enriched with high Pu. A fuel rod is used in which the MOX fuel is coated with a fuel cladding tube.

【0022】この燃料棒において、熱中性子束の高い外
周部に配置された燃料棒(15)の燃料被覆管の内面には、
熱中性子吸収物質からなるコーティング層が形成されて
いる。一方、燃料集合体の中心に配置される燃料棒(13)
の燃料被覆管には熱中性子吸収物質のコーティング層は
ない。
In this fuel rod, the inner surface of the fuel clad tube of the fuel rod (15) arranged at the outer peripheral portion where the thermal neutron flux is high is
A coating layer made of a thermal neutron absorbing material is formed. On the other hand, the fuel rods (13) placed in the center of the fuel assembly
The fuel clad tube has no coating layer of thermal neutron absorbing material.

【0023】この2種類の燃料棒(13)(15)によって、熱
群の吸収断面積が大きいMOX燃料が、隣接するUO2
燃料より熱中性子が流入することで生じる出力ピーキン
グ係数が低減される。
Due to the two types of fuel rods (13) and (15), MOX fuel having a large heat absorption group cross-section is generated by adjoining UO 2
The output peaking coefficient generated by the inflow of thermal neutrons from the fuel is reduced.

【0024】即ち、MOX燃料集合体外周部の燃料棒に
用いる燃料被覆管として、熱中性子を吸収する物質をコ
ーティングさせたものを用いることにより、MOX燃料
集合体外周部の燃料棒内の熱中性子が低下し、従来のよ
うにPu富化度を相違させた多種類の燃料棒を用いなく
ても、過大な出力ピーキングが発生することを避けるこ
とが可能となった。
That is, as the fuel cladding tube used for the fuel rods on the outer peripheral portion of the MOX fuel assembly, the one coated with a substance that absorbs thermal neutrons is used, so that the thermal neutrons inside the fuel rods on the outer peripheral portion of the MOX fuel assembly are used. It became possible to avoid the occurrence of excessive peaking of output without using many kinds of fuel rods having different Pu enrichment levels as in the conventional case.

【0025】尚、前述の実施例では、熱中性子吸収物質
を燃料被覆管内部にコーティングしたものを用いたが、
冷却水による燃料被覆管の腐食に対する耐食処理を施す
ならば、外部にコーティングしてもよいし、燃料被覆管
自体に混入させてもよい。また、前述の実施例では、熱
中性子吸収物質からなるコーティング層が燃料被覆管に
設けられた燃料棒と、設けられていない燃料棒との2種
類を用いたが、コーティング量又は混入量を相違させた
別のコーティング層が燃料被覆管に設けられた燃料棒を
用いてもよい。
In the above-mentioned embodiment, the fuel neutron absorbing material is coated inside the fuel cladding tube.
If the fuel cladding tube is subjected to anticorrosion treatment by cooling water, it may be coated on the outside or mixed into the fuel cladding tube itself. Further, in the above-described embodiment, two types of fuel rods, that is, a fuel rod in which the coating layer made of the thermal neutron absorbing material is provided in the fuel cladding tube and a fuel rod in which the coating layer is not provided, are used, but the coating amount or the mixing amount is different. A fuel rod provided with another coating layer provided on the fuel cladding tube may be used.

【0026】以上のように、燃料集合体外周部に配置さ
れるMOX燃料棒の燃料被覆管に中性子吸収物質を混入
又はコーティングを行うことで、燃料棒内の熱中性子束
の低減を図り、集合体内にPu富化度分布をつけなくて
も集合体内に過大な出力ピーキングを発生しないMOX
燃料集合体が得られる。
As described above, by mixing or coating the neutron absorbing substance on the fuel cladding tube of the MOX fuel rod arranged on the outer periphery of the fuel assembly, the thermal neutron flux in the fuel rod is reduced and the assembly is improved. MOX that does not generate excessive output peaking in the aggregate without the Pu enrichment distribution in the body
A fuel assembly is obtained.

【0027】従って、燃料集合体内Pu富化度分布を単
一にすることが可能であるため、製造コストの低減が可
能である。また、Pu富化度の低いMOX燃料棒を使用
しなくてもよいため、一燃料集合体当りのPuインベン
トリが増大し、Pu消費拡大効果を有する。
Therefore, since the Pu enrichment distribution in the fuel assembly can be made uniform, the manufacturing cost can be reduced. Further, since it is not necessary to use MOX fuel rods having a low Pu enrichment level, the Pu inventory per fuel assembly is increased, which has the effect of increasing Pu consumption.

【0028】[0028]

【発明の効果】本発明は以上説明したとおり、原子炉燃
料集合体でバンドル状に束ねて配されたMOX燃料を含
む燃料棒が、燃料被覆管に熱中性子吸収物質を混入又は
コーティングさせてなるものを含むものであるため、単
一のプルトニウム富化度の燃料棒として、しかも燃料集
合体内の出力ピーキング係数が過大にならないMOX燃
料集合体を得ることができる。
As described above, according to the present invention, a fuel rod containing MOX fuel bundled in a bundle in a reactor fuel assembly and containing MOX fuel is obtained by mixing or coating a thermal neutron absorbing substance in a fuel cladding tube. Since the fuel rods include the fuel rods having a single plutonium enrichment, it is possible to obtain a MOX fuel assembly which does not have an excessive output peaking coefficient in the fuel assembly.

【0029】即ち、Puを単一富化した燃料棒をバンド
ル状に束ねたMOX燃料集合体とした場合に、外周部の
高い熱中性子束を、被覆管に混入又はコーティングさせ
た熱中性子吸収物質によって低減させることにより、燃
料集合体内の出力ピーキング係数を低減させることがで
きる。
That is, when a fuel rod enriched with Pu alone is bundled into a MOX fuel assembly, a high thermal neutron flux in the outer peripheral portion is mixed or coated in the cladding tube. The output peaking coefficient in the fuel assembly can be reduced by reducing

【0030】従って、MOX燃料は単一のPu富化度の
燃料棒とすることができ、製造コストが安くなる。即
ち、燃料加工のプロセスでブレンドされるPu及びU燃
料は単一の富化度とすることができるため、製造コスト
が安くなる。
Therefore, the MOX fuel can be a fuel rod with a single Pu enrichment, which reduces the manufacturing cost. That is, the Pu and U fuels that are blended in the fuel processing process can have a single enrichment, so the manufacturing cost is low.

【0031】また、全体として、一燃料集合体当りのP
u装荷量も複数種類のPu富化度とした燃料集合体と比
較して多くなる。即ち、UO2 燃料からMOX燃料に流
入する熱中性子の量は、集合体外周部の位置によって異
なり、集合体のコーナ部で最も流入量が大きい。そのた
め、コーナ部周辺の被覆管のみに対して、中性子吸収物
質の量(混入量又はコーティング量)を増加させ、出力
ピーキング係数を過大にせず、Puインベントリ量を向
上させることが可能であるという効果がある。
Further, as a whole, P per fuel assembly
The u loading amount also becomes larger than that of the fuel assembly having a plurality of types of Pu enrichment. That is, the amount of thermal neutrons flowing from the UO 2 fuel into the MOX fuel differs depending on the position of the outer peripheral portion of the assembly, and the maximum amount of inflow is at the corners of the assembly. Therefore, it is possible to increase the amount of neutron-absorbing substances (mixed amount or coating amount) only for the cladding tube around the corners, without increasing the output peaking coefficient, and to improve the Pu inventory amount. There is.

【図面の簡単な説明】[Brief description of drawings]

【図1】本発明の原子炉燃料集合体の一実施例の17×
17型MOX燃料集合体の1/4横断面の構成を示す説
明図である。
FIG. 1 is a 17 × embodiment of a reactor fuel assembly of the present invention.
It is explanatory drawing which shows the structure of the 1/4 cross section of a 17 type MOX fuel assembly.

【図2】従来の17×17型MOX燃料集合体の1/4
横断面の構成を示す説明図である。
FIG. 2/4 of a conventional 17 × 17 type MOX fuel assembly
It is explanatory drawing which shows the structure of a cross section.

【符号の説明】[Explanation of symbols]

(10)…燃料集合体、 (11)…中性子計測管、 (12)…制御棒案内管、 (13)…コーティング層が燃料被覆管に設けられていない
燃料棒、 (15)…熱中性子吸収物質からなるコーティング層が燃料
被覆管に設けられた燃料棒
(10) ... Fuel assembly, (11) ... Neutron measuring tube, (12) ... Control rod guide tube, (13) ... Fuel rod where the coating layer is not provided on the fuel cladding tube, (15) ... Thermal neutron absorption Fuel rod with a coating layer of material on the fuel cladding

───────────────────────────────────────────────────── フロントページの続き (51)Int.Cl.6 識別記号 庁内整理番号 FI 技術表示箇所 // G21C 3/06 GDL G21C 3/06 GDL B ─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. 6 Identification code Internal reference number FI technical display location // G21C 3/06 GDL G21C 3/06 GDL B

Claims (2)

【特許請求の範囲】[Claims] 【請求項1】 U−Pu混合酸化物燃料を含む燃料棒を
バンドル状に束ねて配した原子炉燃料集合体において、 前記燃料棒が、燃料被覆管に熱中性子吸収物質を混入又
はコーティングさせてなるものを含み、 熱中性子束が高い位置に配置される燃料棒ほど前記燃料
被覆管の熱中性子吸収物質の量が多い燃料棒が配置され
てなることを特徴とする原子炉燃料集合体。
1. A nuclear reactor fuel assembly in which fuel rods containing a U-Pu mixed oxide fuel are bundled and arranged in a bundle, wherein the fuel rods mix or coat a thermal neutron absorbing substance in a fuel cladding tube. And a fuel rod having a higher amount of thermal neutron absorbing material in the fuel cladding tube, the fuel rod being disposed at a higher thermal neutron flux position.
【請求項2】 請求項1に記載の原子炉燃料集合体にお
いて、 前記U−Pu混合酸化物燃料を含む燃料棒のPu富化度
を全ての燃料棒において同一の富化度としたことを特徴
とする原子炉燃料集合体。
2. The nuclear reactor fuel assembly according to claim 1, wherein the fuel rods containing the U-Pu mixed oxide fuel have the same Pu enrichment ratio in all fuel rods. Characteristic nuclear reactor fuel assembly.
JP6082608A 1994-03-30 1994-03-30 Fuel assembly for reactor Withdrawn JPH07270563A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP6082608A JPH07270563A (en) 1994-03-30 1994-03-30 Fuel assembly for reactor

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP6082608A JPH07270563A (en) 1994-03-30 1994-03-30 Fuel assembly for reactor

Publications (1)

Publication Number Publication Date
JPH07270563A true JPH07270563A (en) 1995-10-20

Family

ID=13779197

Family Applications (1)

Application Number Title Priority Date Filing Date
JP6082608A Withdrawn JPH07270563A (en) 1994-03-30 1994-03-30 Fuel assembly for reactor

Country Status (1)

Country Link
JP (1) JPH07270563A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH1068789A (en) * 1996-08-28 1998-03-10 Hitachi Ltd Mox fuel assembly and reactor core
JP2013007678A (en) * 2011-06-24 2013-01-10 Toshiba Corp Fuel assembly

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH1068789A (en) * 1996-08-28 1998-03-10 Hitachi Ltd Mox fuel assembly and reactor core
JP2013007678A (en) * 2011-06-24 2013-01-10 Toshiba Corp Fuel assembly

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