JPH07234294A - Core of fast breeder reactor - Google Patents
Core of fast breeder reactorInfo
- Publication number
- JPH07234294A JPH07234294A JP6027684A JP2768494A JPH07234294A JP H07234294 A JPH07234294 A JP H07234294A JP 6027684 A JP6027684 A JP 6027684A JP 2768494 A JP2768494 A JP 2768494A JP H07234294 A JPH07234294 A JP H07234294A
- Authority
- JP
- Japan
- Prior art keywords
- neutron
- core
- fuel
- reflector
- coolant
- 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
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
- Structure Of Emergency Protection For Nuclear Reactors (AREA)
- Monitoring And Testing Of Nuclear Reactors (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、液体金属冷却型高速増
殖炉に係り、特に冷却材流量減少時における炉心の反応
度制御性向上に好適な高速増殖炉の炉心に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid metal cooled fast breeder reactor, and more particularly to a fast breeder reactor core suitable for improving the reactivity controllability of the core when the flow rate of the coolant is reduced.
【０００２】[0002]
【従来の技術】本発明に最も近い公知例としては、次の
（１)，(２）が存在している。2. Description of the Related Art The following known examples (1) and (2) exist as the known examples closest to the present invention.
【０００３】（１）１９８６年ＡＮＳ報告書 第５３
巻，Ｐ３１２〜Ｐ３１３ (ANS transaction，Ｖol.５３，Ｐ３１２〜Ｐ３１３(１
９８６)) （２）ティー．ユーブレモーヴィック他，ＡＮＰ '９２
論文集第II巻，Ｐ９.５（１９９２年) (T.Jevremovic et al.,: Proc. ANP'92 International
Conference on Designand Safety of Advanced Nuclear
Power Plants,Tokyo,Japan,October ２５−２９，Ｖo
l.II,Ｐ９.５（１９９２)) 図３に示す従来の高速増殖炉の炉心は、例えば、三木良
平著，「高速増殖炉」（日刊工業新聞社）に記載のよう
に、核燃料物質を被覆管に封入して多数束ねた燃料要素
束をラッパ管で取り囲んだ燃料集合体を複数配置した炉
心燃料領域１の周囲に、主に燃料親物質を被覆管に封入
したブランケット燃料集合体を複数配置したブランケッ
ト領域２を設け、更に、前記ブランケット領域２の周囲
に、中性子吸収物質を封入した中性子遮蔽体を複数配置
した中性子遮蔽領域５を設ける構成をとっている。(1) 1986 ANS Report 53rd
Volume, P312 to P313 (ANS transaction, Vol.53, P312 to P313 (1
986)) (2) Tea. Eubremovic et al., ANP '92
Proceedings II, P9.5 (1992) (T. Jevremovic et al.,: Proc. ANP'92 International
Conference on Designand Safety of Advanced Nuclear
Power Plants, Tokyo, Japan, October 25-29, Vo
l.II, P9.5 (1992)) The core of the conventional fast breeder reactor shown in FIG. 3 has a nuclear fuel material as described in Ryohei Miki, “Fast Breeder Reactor” (Nikkan Kogyo Shimbun). A plurality of blanket fuel assemblies mainly containing a fuel parent substance in a cladding tube are provided around a core fuel region 1 in which a plurality of fuel assemblies each of which is enclosed in a cladding tube and surrounded by a trumpet tube are surrounded by a trumpet tube. The blanket area 2 is arranged, and further, a neutron shielding area 5 is arranged around the blanket area 2 in which a plurality of neutron shields containing neutron absorbing substances are arranged.
【０００４】前記公知例（１）では、小型炉心におい
て、炉心燃料領域の外周に、上部を密閉，下部を冷却材
に開放し、内側に不活性ガスと冷却材とを分離して封入
した中空ダクト構造を持つ中性子反射体を配置する炉心
構成が開示されている。In the above-mentioned known example (1), in a small-sized core, a hollow is formed by sealing the upper part and the lower part to the coolant around the outer periphery of the core fuel region, and separating and sealing the inert gas and the coolant inside. A core configuration for disposing a neutron reflector having a duct structure is disclosed.
【０００５】また、前記公知例（２）では、炉心燃料領
域に隣接する径方向ブランケット集合体の内側に中性子
減速物質である水素化ジルコニウム(ＺｒＨ1.7）の層を
設けた構成が開示されている。Further, the above-mentioned known example (2) discloses a structure in which a layer of zirconium hydride (ZrH 1.7 ) which is a neutron moderating substance is provided inside the radial blanket assembly adjacent to the core fuel region. .
【０００６】[0006]
【発明が解決しようとする課題】一般に、液体ナトリウ
ム冷却型高速増殖炉において、冷却材である液体ナトリ
ウムの温度上昇に伴い炉心の反応度が変化することが、
例えば、前出、「高速増殖炉」において論じられてい
る。Generally, in a liquid sodium-cooled fast breeder reactor, the reactivity of the core changes as the temperature of liquid sodium as a coolant rises.
For example, discussed in "Fast Breeder Reactor", supra.
【０００７】すなわち、高速増殖炉の過渡事象時に液体
ナトリウムの温度が上昇すると、熱膨張によりナトリウ
ムの密度が減少するため、中性子はナトリウム原子に衝
突しにくくなる。That is, when the temperature of liquid sodium rises during a transient event of a fast breeder reactor, the density of sodium decreases due to thermal expansion, so that neutrons are less likely to collide with sodium atoms.
【０００８】その結果、炉心領域の中性子平均エネルギ
ーが高エネルギー側に推移し、炉心内の核分裂反応が増
加するため、炉心の反応度は増大する傾向を示す。この
とき、同時に、炉心からの中性子漏洩量も増大してお
り、公知例（１）に示されている炉心構成を用いると、
この中性子漏洩効果を有効に利用でき、核分裂反応を増
加させる効果よりも中性子漏洩量を増加させる効果の方
を大きくできるので、反応度を低下させることが可能と
なる。As a result, the average neutron energy in the core region shifts to the high energy side, and the fission reaction in the core increases, so that the reactivity of the core tends to increase. At this time, the amount of neutron leakage from the core is also increasing at the same time, and using the core configuration shown in the known example (1),
Since this neutron leakage effect can be effectively used and the effect of increasing the neutron leakage amount can be made larger than the effect of increasing the fission reaction, the reactivity can be lowered.
【０００９】しかし、炉心が大型化するにつれて、中性
子漏洩効果が反応度変化に与える影響が小さくなるの
で、大型炉心では、前述の反応度を低下させる効果が不
十分になる。However, as the core becomes larger, the effect of the neutron leakage effect on the reactivity change becomes smaller, so that the above-described effect of lowering the reactivity becomes insufficient in the large core.
【００１０】また、公知例（２）に示されている炉心構
成を用いると、冷却材の温度上昇等から生じる中性子平
均エネルギーの高エネルギー側への推移を抑制し、炉心
燃料領域における核分裂反応の増加を抑え、ブランケッ
ト領域における中性子吸収反応を増加させるので、前述
の反応度増大を緩和できる。Further, when the core structure shown in the known example (2) is used, the transition of the neutron average energy to the high energy side caused by the temperature rise of the coolant is suppressed, and the fission reaction in the core fuel region is suppressed. Since the increase is suppressed and the neutron absorption reaction in the blanket region is increased, the increase in reactivity described above can be mitigated.
【００１１】水素化ジルコニウムは、ブランケット燃料
集合体中に、燃料棒と同形の被覆管に封入されて装荷さ
れており、炉心燃料領域中の様な高温状態では不安定で
あり、水素原子が解離する可能性がある。Zirconium hydride is loaded in a blanket fuel assembly by being enclosed in a cladding tube having the same shape as the fuel rod, and is unstable in a high temperature state such as in the core fuel region, and hydrogen atoms are dissociated. there's a possibility that.
【００１２】このとき、実際には起こる可能性が非常に
小さいが、被覆管の破損が発生すると、解離した水素原
子により、構造材が腐食される可能性がある。At this time, although the possibility of actually occurring is very small, when the cladding tube is broken, the structural material may be corroded by the dissociated hydrogen atoms.
【００１３】本発明の目的は、冷却材流量減少時に、炉
心からの実効的な中性子漏洩量を増大させる炉心構成，
炉心燃料領域の外周に配置された、比較的温度の低い中
性子反射体と中性子遮蔽体の境界に中性子減速物質を設
置することにより、構造材の腐食を発生させることな
く、大型炉心においても、中性子漏洩による反応度低減
効果を確保できる炉心を提供することにある。It is an object of the present invention to increase the effective amount of neutron leakage from the core when the coolant flow rate decreases,
Located on the outer periphery of the core fuel region, by installing a neutron moderator substance at the boundary between the neutron reflector and the neutron shield having a relatively low temperature, without causing corrosion of structural materials, even in a large core, neutron It is to provide a core capable of ensuring the reactivity reduction effect due to leakage.
【００１４】[0014]
【課題を解決するための手段】上記目的を達成するため
の第１手段は、炉心構成要素として、核分裂性物質と燃
料親物質とを封入した燃料要素束と前記燃料要素束を囲
設したラッパ管からなる燃料集合体、上部を密閉，下部
を冷却材に開放し、内側にガスと冷却材とを分離して封
入した中空ダクト構造を持つ中性子反射体があり、前記
燃料集合体を複数本用いて構成された炉心燃料領域の周
囲に、前記中性子反射体を配置した高速増殖炉の炉心に
おいて、前記中性子反射体全体の反応度低減効果を、炉
心を０％出力から１００％出力にするときに必要となる
反応度、つまり出力補償反応度より大きくしたことを特
徴とした高速増殖炉の炉心とするものである。A first means for achieving the above object is to provide a fuel element bundle containing a fissionable material and a fuel parent material as core constituent elements, and a wrapper surrounding the fuel element bundle. There is a neutron reflector having a hollow duct structure in which a fuel assembly composed of a tube, an upper part is closed, a lower part is opened to a coolant, and a gas and a coolant are separated and enclosed inside, and a plurality of the fuel assemblies are provided. In the core of a fast breeder reactor in which the neutron reflector is arranged around the core fuel region configured by using the effect of reducing the reactivity of the neutron reflector as a whole from 0% output to 100% output It is a core of a fast breeder reactor characterized by having a reactivity higher than that required for the above, that is, a power compensation reactivity.
【００１５】第２手段では、上記第１手段における高速
増殖炉の炉心において、中性子反射体の外側を中性子吸
収物質を封入した中性子遮蔽体とし、中性子反射体と中
性子遮蔽体との境界に、中性子減速物質を配置したこと
を特徴した高速増殖炉の炉心とするものである。In the second means, in the core of the fast breeder reactor in the first means, the outside of the neutron reflector is a neutron shield having a neutron absorbing substance enclosed, and the neutron reflector and the neutron shield are provided with a neutron shield. The core of a fast breeder reactor is characterized in that a moderator material is arranged.
【００１６】第３手段は、上記第２手段における中性子
反射体として、中性子遮蔽体側の内面に中性子減速物質
を設置したことを特徴とした中性子反射体を用いるもの
である。The third means uses, as the neutron reflector in the second means, a neutron reflector characterized in that a neutron moderating substance is installed on the inner surface on the neutron shield side.
【００１７】第４手段は、上記第２手段における中性子
反射体として、中性子遮蔽体側の外面に中性子減速物質
を設置したことを特徴とした中性子反射体を用いるもの
である。The fourth means uses, as the neutron reflector in the second means, a neutron reflector characterized in that a neutron moderating substance is placed on the outer surface of the neutron shield side.
【００１８】第５手段は、上記第２手段における中性子
反射体として、中性子遮蔽体側の構造材に、中性子減速
物質を混入したことを特徴とした高速増殖炉の炉心とす
るものである。The fifth means is the core of a fast breeder reactor characterized in that, as the neutron reflector in the second means, the neutron moderator substance is mixed into the structural material on the neutron shield side.
【００１９】第６手段は、上記第２手段から上記第５手
段までのいずれか１手段における高速増殖炉の炉心にお
いて、中性子遮蔽体の一部を、主に燃料親物質からなる
ブランケット燃料集合体に置き換えたことを特徴とした
高速増殖炉の炉心とするものである。A sixth means is a blanket fuel assembly in which a part of the neutron shield is mainly composed of a fuel parent substance in the core of the fast breeder reactor in any one of the second means to the fifth means. The core of the fast breeder reactor is characterized by being replaced with.
【００２０】[0020]
【作用】本発明に基づく炉心構成を用いた炉心では、炉
心燃料領域の外周に、出力補償反応度よりも大きい負の
反応度を持った中性子反射体を設置している。In the core using the core structure according to the present invention, a neutron reflector having a negative reactivity higher than the power compensating reactivity is installed on the outer periphery of the core fuel region.
【００２１】したがって、冷却材流量減少時に、１次系
循環ポンプの動圧の低下とガスの圧力の不均衡により、
中性子反射体内の冷却材液面レベルが、図２に示した
（ａ）から（ｂ）の様に低下し、反射材として作用して
いた冷却材が炉心外周からなくなる。Therefore, when the flow rate of the coolant is reduced, the dynamic pressure of the primary circulation pump is reduced and the gas pressure is imbalanced.
The liquid level of the coolant in the neutron reflector decreases from (a) to (b) shown in FIG. 2, and the coolant acting as a reflector disappears from the outer periphery of the core.
【００２２】このため、炉心からの中性子漏洩量が大幅
に増大し、炉心に負の反応度が投入される。Therefore, the amount of neutron leakage from the core is significantly increased, and a negative reactivity is injected into the core.
【００２３】この中性子反射体の負の反応度を、出力補
償反応度よりも大きくすることにより、炉心固有の特性
を用いて炉停止が可能となるので、高速増殖炉炉心の安
全性が向上する。By making the negative reactivity of the neutron reflector larger than the power compensation reactivity, the reactor can be shut down by using the characteristics peculiar to the core, so that the safety of the fast breeder reactor core is improved. .
【００２４】また、前記炉心において、中性子反射体の
外側に中性子遮蔽体を配置し、中性子反射体と中性子遮
蔽体の境界に中性子吸収物質を設置した炉心では、冷却
材流量減少時に、中性子反射体内の冷却材液面レベルの
低下により、炉心からの中性子漏洩量が増大する。Further, in the core, in which the neutron shield is arranged outside the neutron reflector and the neutron absorbing material is installed at the boundary between the neutron reflector and the neutron shield, the neutron reflector is The decrease in the coolant liquid level in the core increases the amount of neutron leakage from the core.
【００２５】この漏洩中性子は、前記中性子反射体を通
りぬけ、中性子反射体と中性子吸収物質を封入した中性
子遮蔽体の境界に設置した中性子減速物質によって、そ
の平均エネルギーが低い方向へ移行する。The leaked neutrons pass through the neutron reflector, and the neutron moderating substance placed at the boundary between the neutron shield enclosing the neutron reflector and the neutron absorbing substance moves to a lower average energy direction.
【００２６】その結果、中性子遮蔽体における中性子吸
収効果が増大し、かつ、中性子遮蔽体によって反射され
て炉心に戻っていた中性子量の減少により、炉心の反応
度低下が促進される。As a result, the neutron absorption effect in the neutron shield is increased, and the decrease in the amount of neutrons reflected by the neutron shield and returned to the core accelerates the decrease in the reactivity of the core.
【００２７】また、前記中性子反射体として、中性子遮
蔽体側の内面に、中性子減速物質を設置した炉心では、
前述と同様の作用で炉心の反応度低下を促進させる。Further, as the neutron reflector, in the core in which the neutron moderating substance is installed on the inner surface on the neutron shield side,
The same action as described above promotes the decrease in the reactivity of the core.
【００２８】また、前記中性子反射体として、中性子遮
蔽体側の外面に、中性子減速物質を設置した炉心では、
前述と同様の作用で、炉心の反応度低下を促進させる。Further, as the neutron reflector, in a core in which a neutron moderating substance is installed on the outer surface on the neutron shield side,
By the same action as described above, the decrease in reactivity of the core is promoted.
【００２９】また、前記中性子反射体として、中性子遮
蔽体側の構造材に、中性子減速物質を混入した炉心で
は、上述と同様の作用で、炉心の反応度低下を促進でき
る。Further, as a neutron reflector, in a core in which a neutron moderating substance is mixed in a structural material on the side of the neutron shield, a decrease in reactivity of the core can be promoted by the same action as described above.
【００３０】さらに、前記高速増殖炉の炉心において、
中性子遮蔽体の一部を、主に燃料親物質からなるブラン
ケット燃料集合体に置き換えた炉心では、冷却材流量減
少時に、炉心から前記中性子反射体内に漏洩してきた中
性子が、前記中性子減速物質により、低エネルギー側に
移行される。Further, in the core of the fast breeder reactor,
Part of the neutron shield, the core is replaced with a blanket fuel assembly mainly consisting of the fuel parent material, when the coolant flow rate decreases, neutrons leaking into the neutron reflector from the core, by the neutron moderator material, It is transferred to the low energy side.
【００３１】この結果、ブランケット領域における中性
子吸収量を増大し、かつ、炉心内に反射する中性子の量
を減少させる。この作用により、炉心の反応度低下を促
進させると同時に、ブランケット領域の燃料増殖性を増
大させる。As a result, the amount of neutrons absorbed in the blanket region is increased and the amount of neutrons reflected in the core is reduced. This action promotes a decrease in the reactivity of the core and, at the same time, increases the fuel productivity of the blanket region.
【００３２】したがって、本発明では、十分な負の反応
度効果を持つ中性子反射体を用いた炉心構成とすること
により、冷却材流量減少時に、炉心の反応度低下を促進
することが可能となる。この結果、炉心の安全性をより
確かなものとすることができる。Therefore, in the present invention, by using the neutron reflector having a sufficient negative reactivity effect, it is possible to promote the decrease in the reactivity of the core when the flow rate of the coolant is decreased. . As a result, the safety of the core can be made more reliable.
【００３３】[0033]
【実施例】以下、本発明の第１実施例を、図１と図２を
用いて説明する。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIGS.
【００３４】図１は、液体金属ナトリウムを冷却材とし
て用いる型式の１０００ＭＷｅ級の高速増殖炉の炉心の
垂直断面を示したもので、燃料物質を封入した燃料集合
体を、複数本用いて円柱上に束ねた炉心燃料領域１とブ
ランケット領域２，前記炉心燃料領域とブランケット領
域の周囲に、上部を密閉して下部を冷却材３に開放し、
内側にガス４と冷却材を分離して封入した中空ダクト構
造を持った中性子反射体６を配置し、更に、これらの周
囲に、中性子吸収物質を封入した中性子遮蔽体を複数設
けた中性子遮蔽領域５を配置した構成となっている。FIG. 1 shows a vertical cross section of a core of a 1000 MWe class fast breeder reactor using liquid metal sodium as a coolant, in which a plurality of fuel assemblies containing a fuel substance are used to form a cylinder. The core fuel region 1 and the blanket region 2, which are bundled in the above, around the core fuel region and the blanket region, the upper part is closed and the lower part is opened to the coolant 3.
A neutron shielding region in which a neutron reflector 6 having a hollow duct structure in which a gas 4 and a coolant are separated and enclosed is arranged inside, and a plurality of neutron shields enclosing a neutron absorbing substance are further provided around them. 5 is arranged.
【００３５】前記炉心燃料領域１の直径は３００cmで、
前記中性子反射体６の幅は４０cmである。The core fuel region 1 has a diameter of 300 cm,
The width of the neutron reflector 6 is 40 cm.
【００３６】図１には示していないが、燃料集合体は、
核分裂性物質または燃料親物質からなる燃料物質を、ペ
レット状に焼結して被覆管に封入した燃料棒を複数本束
ね、その間隙を冷却材の流路とし、両端を冷却材の入口
と出口としたラッパ管によって囲まれている。Although not shown in FIG. 1, the fuel assembly is
A fuel material consisting of a fissile material or a fuel parent material is sintered into pellets and bundled into multiple fuel rods enclosed in a cladding tube, with the gaps serving as coolant channels, and both ends serving as coolant inlet and outlet. It is surrounded by a trumpet tube.
【００３７】中性子反射体は、図２に示している様に、
中空ダクト構造としてラッパ管７を用いており、前記ラ
ッパ管の上端を密閉，下端を冷却材流入口８として開放
し、内側にアルゴン（Ａｒ），ヘリウム（Ｈｅ）等のガ
ス４と冷却材３とが分離して封入されている。The neutron reflector, as shown in FIG.
A trumpet tube 7 is used as a hollow duct structure, the upper end of the trumpet tube is closed, the lower end is opened as a coolant inlet 8, and a gas 4 such as argon (Ar) or helium (He) and a coolant 3 are provided inside. And are separated and enclosed.
【００３８】本実施例では、炉心燃料領域の外周に配置
された中性子反射体の持つ負の反応度を、出力補償反応
度よりも大きくしたことを特徴としている。The present embodiment is characterized in that the neutron reflector arranged on the outer periphery of the core fuel region has a negative reactivity higher than the power compensation reactivity.
【００３９】図１において、中性子反射体６の幅を１６
cmとすると、その負の反応度は1.5＄、３２cmとすると
２.４＄ となり、３５cm以上にすると出力補償反応度で
ある２.５＄ を超える。In FIG. 1, the width of the neutron reflector 6 is 16
If it is cm, the negative reactivity is 1.5 $, if it is 32cm, it is 2.4 $, and if it is 35cm or more, it exceeds the output compensation reactivity of 2.5 $.
【００４０】本発明では、図２の（ａ）の状態から
（ｂ）の状態へと、冷却材流量減少による中性子反射体
の冷却材液面レベル低下時に、炉心からの中性子漏洩量
が増大するので、炉心内に負の反応度が投入される。In the present invention, the amount of neutron leakage from the core increases from the state of FIG. 2A to the state of FIG. 2B when the coolant liquid level of the neutron reflector decreases due to the decrease in the coolant flow rate. Therefore, a negative reactivity is injected into the core.
【００４１】この中性子反射体の負の反応度２.８＄
を、出力補償反応度２.５＄よりも大きくすることによ
り、炉心固有の特性を用いて炉停止が可能となるので、
高速増殖炉炉心の安全性が向上する。Negative reactivity of this neutron reflector 2.8 $
Is larger than the power compensation reactivity of 2.5 $, it is possible to stop the reactor by using the characteristics peculiar to the core.
The safety of the fast breeder reactor core is improved.
【００４２】本発明の第２実施例を図４と図５を用いて
説明する。A second embodiment of the present invention will be described with reference to FIGS. 4 and 5.
【００４３】図４は、前述の実施例１の炉心において、
中性子反射体と中性子吸収物質を封入した中性子遮蔽体
の境界に、厚さ５cmの中性子減速物質９を設置したもの
である。FIG. 4 shows the core of Example 1 described above.
A neutron moderator material 9 having a thickness of 5 cm is installed at the boundary between the neutron reflector and the neutron shield in which the neutron absorbing material is enclosed.
【００４４】中性子減速物質には、比較的高温状態でも
安定な水素化カルシウム(ＣａＨ2)を用いている。As the neutron moderating substance, calcium hydride (CaH 2 ) which is stable even at a relatively high temperature is used.
【００４５】また、図５に示したように、中性子反射体
には、水素化カルシウム(ＣａＨ2)を薄肉の被覆管に封
入して、ラッパ管内側表面に設置した中性子反射体１０
を用いている。Also, as shown in FIG. 5, the neutron reflector 10 is a neutron reflector 10 in which calcium hydride (CaH 2 ) is enclosed in a thin-walled cladding tube and installed on the inner surface of the trumpet tube.
Is used.
【００４６】本実施例では、炉心燃料領域の外周に配置
された、中性子反射体と中性子遮蔽体の境界に中性子減
速物質を設けたことを特徴としている。This embodiment is characterized in that a neutron moderating substance is provided at the boundary between the neutron reflector and the neutron shield, which is arranged on the outer periphery of the core fuel region.
【００４７】本発明では、冷却材流量減少による中性子
反射体の冷却材液面レベル低下時に、炉心から漏洩して
くる高速中性子を、中性子減速物質によって低速中性子
とし、中性子遮蔽領域における中性子吸収量を増大させ
ると同時に、炉心内に反射する中性子の量を減少させ
る。In the present invention, when the coolant liquid level of the neutron reflector is lowered due to the decrease of the coolant flow rate, the fast neutrons leaking from the core are made into slow neutrons by the neutron moderating substance, and the neutron absorption amount in the neutron shielding region is At the same time, it increases the amount of neutrons reflected in the core.
【００４８】その結果、前記中性子反射体の負の反応度
を１.３ 倍程度に増大でき、炉心の反応度低下を促進で
きる。As a result, the negative reactivity of the neutron reflector can be increased about 1.3 times, and the decrease in reactivity of the core can be promoted.
【００４９】また、中性子反射体の装荷割合を１／１.
３ 程度に減少しても、従来の中性子反射体と同等の効
果が得られる。Further, the loading ratio of the neutron reflector is 1/1.
Even if it is reduced to about 3, the same effect as the conventional neutron reflector can be obtained.
【００５０】本発明の第３実施例を図６を用いて説明す
る。A third embodiment of the present invention will be described with reference to FIG.
【００５１】本実施例は、前述の実施例２の中性子反射
体において、中性子遮蔽体側内面に中性子減速物質を設
けたものである。In this example, the neutron reflector of Example 2 described above is provided with a neutron moderating substance on the inner surface of the neutron shield side.
【００５２】図６には、燃料棒と同形の被覆管に、水素
化カルシウム(ＣａＨ2）を封入した中性子減速物質入り
棒１１を、前記中性子反射体の下部に設置した冷却材の
流路を設けた支持板１２に固定したことを特徴とした中
性子反射体１０を示している。In FIG. 6, a rod 11 containing a neutron moderator substance, in which calcium hydride (CaH 2 ) is enclosed, is provided in a cladding tube having the same shape as the fuel rod, and the flow path of the coolant is installed below the neutron reflector. 1 shows a neutron reflector 10 characterized by being fixed to a support plate 12 provided.
【００５３】本発明の効果は、前述の第２実施例とほぼ
同様である。The effects of the present invention are almost the same as those of the second embodiment described above.
【００５４】本発明の第４実施例を、図７と図８を用い
て説明する。A fourth embodiment of the present invention will be described with reference to FIGS. 7 and 8.
【００５５】図７は、前述の第１実施例の中性子反射体
において、中性子遮蔽体側外面に中性子減速物質を設置
したものである。FIG. 7 shows the neutron reflector of the above-mentioned first embodiment in which a neutron moderating substance is placed on the outer surface of the neutron shield side.
【００５６】図８には、薄肉の被覆管に水素化カルシウ
ム(ＣａＨ2）を封入し、前記中性子反射体の外面に接す
るように固定したことを特徴とした中性子反射体１３を
示している。FIG. 8 shows a neutron reflector 13 in which calcium hydride (CaH 2 ) is enclosed in a thin-walled covering tube and fixed so as to be in contact with the outer surface of the neutron reflector.
【００５７】本発明の効果は、前述の実施例２とほぼ同
様である。The effects of the present invention are almost the same as those of the second embodiment.
【００５８】本発明の第５実施例を、図９と図１０を用
いて説明する。A fifth embodiment of the present invention will be described with reference to FIGS. 9 and 10.
【００５９】図９は、前述の第２実施例の中性子反射体
において、中性子遮蔽体側の構造材中に中性子減速物質
を混入したものである。FIG. 9 shows the neutron reflector of the above-mentioned second embodiment in which a neutron moderating substance is mixed into the structural material on the neutron shield side.
【００６０】図１０には、６角柱形状をしている中性子
反射体の隣接する２面１５に、中性子減速物質である水
素化カルシウム(ＣａＨ2）を混入したことを特徴とした
中性子反射体１４を示している。FIG. 10 shows a neutron reflector 14 characterized by mixing calcium hydride (CaH 2 ) which is a neutron moderating substance into two adjacent surfaces 15 of a neutron reflector having a hexagonal prism shape. Is shown.
【００６１】本発明の効果は、前述の実施例２とほぼ同
様である。The effects of the present invention are almost the same as those of the above-described second embodiment.
【００６２】本発明の第６実施例を図１１に、第７実施
例を図１２に、第８実施例を図１３に示して以下に説明
する。The sixth embodiment of the present invention is shown in FIG. 11, the seventh embodiment is shown in FIG. 12, and the eighth embodiment is shown in FIG.
【００６３】図１１，図１２，図１３に示した炉心断面
は、それぞれ、前述の実施例２の炉心において、中性子
遮蔽領域を、主に燃料親物質を封入したブランケット燃
料集合体に置き換え、中性子反射領域と中性子減速領域
として、前述の図５，図８，図１０に示した中性子反射
体を用いたものに相当する。The core cross-sections shown in FIGS. 11, 12 and 13 are obtained by replacing the neutron shielding region with a blanket fuel assembly mainly enclosing a fuel parent substance in the core of Example 2 described above. The reflection area and the neutron moderation area correspond to those using the neutron reflector shown in FIGS. 5, 8 and 10 described above.
【００６４】本発明の効果は、前述の実施例２とほぼ同
等であり、更に、中性子吸収領域として中性子遮蔽領域
の替わりにブランケット燃料集合体を用いたことによ
り、前記ブランケット燃料集合体における燃料の増殖性
も増加する。The effect of the present invention is almost the same as that of the above-mentioned second embodiment, and further, by using the blanket fuel assembly instead of the neutron shielding area as the neutron absorption area, the fuel of the blanket fuel assembly is Proliferation is also increased.
【００６５】以上の各実施例においては、中性子減速物
質として水素化カルシウムを想定していたが、これを他
の中性子減速物質、例えば水素化ジルコニウム(ＺｒＨ
1.7)や酸化ベリリウム(ＢｅＯ2）に置き換えても同様の
効果が得られる。In each of the above embodiments, calcium hydride was assumed as the neutron moderating material, but this may be replaced with another neutron moderating material such as zirconium hydride (ZrH).
1.7 ) or beryllium oxide (BeO 2 ) can be used to obtain the same effect.
【００６６】[0066]
【発明の効果】本発明によれば、高速増殖炉において、
冷却材流量減少時に、上部を密閉，下部を冷却材に開放
し、内側にガスと冷却材を分離して封入した中空ダクト
構造を持つ中性子反射体の負の反応度を、出力補償反応
度より大きくしているので、炉心固有の特性により炉停
止が可能となり、炉心のより確かな安全性を実現でき
る。According to the present invention, in a fast breeder reactor,
When the flow rate of the coolant decreases, the negative reactivity of the neutron reflector with a hollow duct structure in which the upper part is closed, the lower part is opened to the coolant, and the gas and coolant are separated and enclosed inside Since it is made large, it is possible to stop the reactor due to the characteristics peculiar to the core, and more reliable safety of the core can be realized.
【図１】本発明の第１実施例による高速増殖炉の炉心の
垂直断面図である。FIG. 1 is a vertical sectional view of a core of a fast breeder reactor according to a first embodiment of the present invention.
【図２】図１の中性子反射体の垂直断面図であり、図中
（ａ）は冷却材液面レベルが上昇している状態を、
（ｂ）は冷却材液面レベルが下降している状態を、それ
ぞれ示している。2 is a vertical cross-sectional view of the neutron reflector of FIG. 1, in which (a) shows a state in which the coolant liquid level is rising,
(B) shows the state where the coolant liquid level is decreasing, respectively.
【図３】従来の高速増殖炉の炉心の垂直断面図である。FIG. 3 is a vertical sectional view of a core of a conventional fast breeder reactor.
【図４】本発明の第２実施例による高速増殖炉の炉心の
垂直断面図である。FIG. 4 is a vertical sectional view of a core of a fast breeder reactor according to a second embodiment of the present invention.
【図５】図４中の中性子反射体の断面図であり、図中
（ａ）は水平断面図を、（ｂ）は垂直断面図を、それぞ
れ表わしている。5A and 5B are sectional views of the neutron reflector in FIG. 4, in which FIG. 5A shows a horizontal sectional view and FIG. 5B shows a vertical sectional view.
【図６】本発明の第３実施例による中性子反射体の断面
図であり、図中（ａ）は水平断面図を、（ｂ）は垂直断
面図を、それぞれ表わしている。FIG. 6 is a sectional view of a neutron reflector according to a third embodiment of the present invention, in which (a) shows a horizontal sectional view and (b) shows a vertical sectional view.
【図７】本発明の第４実施例による高速増殖炉の炉心の
垂直断面図である。FIG. 7 is a vertical sectional view of a core of a fast breeder reactor according to a fourth embodiment of the present invention.
【図８】図７中の中性子反射体の断面図であり、図中
（ａ）は水平断面図を、（ｂ）は垂直断面図を、それぞ
れ表わしている。8 is a cross-sectional view of the neutron reflector in FIG. 7, where (a) shows a horizontal cross-sectional view and (b) shows a vertical cross-sectional view.
【図９】本発明の第５実施例による高速増殖炉の炉心の
垂直断面図である。FIG. 9 is a vertical sectional view of a core of a fast breeder reactor according to a fifth embodiment of the present invention.
【図１０】図９中の中性子反射体の断面図であり、図中
（ａ）は水平断面図を、（ｂ）は垂直断面図を、それぞ
れ表わしている。10 is a cross-sectional view of the neutron reflector in FIG. 9, in which (a) shows a horizontal cross-sectional view and (b) shows a vertical cross-sectional view.
【図１１】本発明の第６実施例による高速増殖炉の炉心
の垂直断面図である。FIG. 11 is a vertical sectional view of a core of a fast breeder reactor according to a sixth embodiment of the present invention.
【図１２】本発明の第７実施例による高速増殖炉の炉心
の垂直断面図である。FIG. 12 is a vertical sectional view of a core of a fast breeder reactor according to a seventh embodiment of the present invention.
【図１３】本発明の第８実施例による高速増殖炉の炉心
の垂直断面図である。FIG. 13 is a vertical sectional view of a core of a fast breeder reactor according to an eighth embodiment of the present invention.
１…炉心燃料領域、２…ブランケット領域、３…冷却
材、４…ガス、５…中性子遮蔽領域、６，１０，１３，
１４…中性子反射体、７…ラッパ管、８…冷却材流入
口、９…中性子減速物質、１１…中性子減速物質入り
棒、１２…支持板、１５…ラッパ管の中性子減速物質を
混入した面。1 ... Core fuel region, 2 ... Blanket region, 3 ... Coolant, 4 ... Gas, 5 ... Neutron shielding region, 6, 10, 13,
14 ... Neutron reflector, 7 ... Trumpet tube, 8 ... Coolant inflow port, 9 ... Neutron moderator substance, 11 ... Rod containing neutron moderator substance, 12 ... Support plate, 15 ... Surface of the trumpet tube mixed with neutron moderator substance.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 村上 朋子 東京都千代田区大手町一丁目６番１号 日 本原子力発電株式会社内 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tomoko Murakami 1-6-1, Otemachi, Chiyoda-ku, Tokyo Nihon Nuclear Power Co., Ltd.
Claims (6)
親物質を封入した燃料要素束と前記燃料要素束を囲設し
たラッパ管からなる燃料集合体と、上部を密閉して下部
を冷却材に開放してあり内側にガスと冷却材とを分離し
て封入した中空ダクト構造を持つ中性子反射体とを備
え、前記燃料集合体を複数束ねた炉心燃料領域の外周に
前記中性子反射体を設置した高速増殖炉の炉心におい
て、前記中性子反射体全体の反応度低減効果を炉心の出
力補償反応度より大きくしたことを特徴とする高速増殖
炉の炉心。1. A fuel assembly comprising, as core components, a fuel element bundle enclosing a fissionable material and a fuel parent material, and a trumpet tube surrounding the fuel element bundle, and an upper portion is hermetically sealed and a lower portion is a coolant. A neutron reflector having a hollow duct structure in which the gas and the coolant are separately sealed and enclosed inside, and the neutron reflector is installed on the outer periphery of a core fuel region in which a plurality of the fuel assemblies are bundled. In the core of the fast breeder reactor, the reactivity reducing effect of the neutron reflector as a whole is made larger than the power compensation reactivity of the core.
中性子吸収物質を封入した中性子遮蔽体とし、中性子反
射体と中性子遮蔽体の境界に中性子減速物質を設置した
ことを特徴とする高速増殖炉の炉心。2. The high-speed breeding system according to claim 1, wherein the neutron reflector is a neutron shield having a neutron absorbing substance enclosed outside, and a neutron moderating substance is installed at a boundary between the neutron reflector and the neutron shield. The core of the furnace.
遮蔽体側の内面に中性子減速物質を設置したことを特徴
とする高速増殖炉の炉心。3. The core of a fast breeder reactor according to claim 2, wherein a neutron moderating substance is installed on the inner surface of the neutron reflector on the neutron shield side.
遮蔽体側の外面に中性子減速物質を設置したことを特徴
とする高速増殖炉の炉心。4. The core of a fast breeder reactor according to claim 2, wherein a neutron moderating substance is installed on the outer surface of the neutron reflector on the neutron shield side.
遮蔽体側の構造材に中性子減速物質を混入したことを特
徴とする高速増殖炉の炉心。5. The core of a fast breeder reactor according to claim 2, wherein a neutron moderator substance is mixed in the structural material on the neutron shield side of the neutron reflector.
において、中性子遮蔽体の一部を、主に燃料親物質から
なるブランケット燃料集合体としたことを特徴とする高
速増殖炉の炉心。6. A fast breeder reactor according to any one of claims 2 to 5, wherein a part of the neutron shield is a blanket fuel assembly mainly composed of a fuel parent substance. Core.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP02768494A JP3346016B2 (en) | 1994-02-25 | 1994-02-25 | Fast breeder reactor core |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP02768494A JP3346016B2 (en) | 1994-02-25 | 1994-02-25 | Fast breeder reactor core |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH07234294A true JPH07234294A (en) | 1995-09-05 |
| JP3346016B2 JP3346016B2 (en) | 2002-11-18 |
Family
ID=12227802
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP02768494A Expired - Fee Related JP3346016B2 (en) | 1994-02-25 | 1994-02-25 | Fast breeder reactor core |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3346016B2 (en) |
-
1994
- 1994-02-25 JP JP02768494A patent/JP3346016B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JP3346016B2 (en) | 2002-11-18 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US5349618A (en) | BWR fuel assembly having oxide and hydride fuel | |
| US7864913B2 (en) | Fast reactor having reflector control system and neutron reflector thereof | |
| US4652427A (en) | Fuel assembly | |
| JPS6186675A (en) | Modelating-material filling rod for fuel aggregate | |
| JP3346016B2 (en) | Fast breeder reactor core | |
| JP6862261B2 (en) | Fast reactor core and fast reactor fuel loading method | |
| JPH09166679A (en) | Fuel assembly, control rod and reactor core for fast reactor | |
| EP0199197B1 (en) | Fuel assembly | |
| JPH11352272A (en) | Reactor core and fuel assembly and fuel element used for the core | |
| JP3155127B2 (en) | Fuel assemblies and fast breeder reactor cores made therefrom | |
| JPH0588439B2 (en) | ||
| JP3039001B2 (en) | Reactor core | |
| US11398315B2 (en) | Fuel element, fuel assembly, and core | |
| JPH07306282A (en) | Assembly for annihilation disposal of long life nuclide and core of reactor | |
| JP2523615B2 (en) | Light water reactor core | |
| JP3054449B2 (en) | Fast breeder reactor | |
| JP3314382B2 (en) | Fuel assembly | |
| JP2911058B2 (en) | Fast reactor core | |
| JP3788170B2 (en) | Fuel assemblies and reactor cores | |
| JP2021135248A (en) | Fast reactor core, and operation method of fast reactor | |
| JPS59133489A (en) | Fuel assembly | |
| JPH06331767A (en) | Fuel assembly and core of nuclear reactor | |
| JPS63172990A (en) | Nuclear-reactor fuel aggregate | |
| JPH09166678A (en) | Mox fuel assembly | |
| JPS63149589A (en) | Fuel aggregate for pressure tube type reactor |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| S111 | Request for change of ownership or part of ownership |
Free format text: JAPANESE INTERMEDIATE CODE: R313114 |
|
| R360 | Written notification for declining of transfer of rights |
Free format text: JAPANESE INTERMEDIATE CODE: R360 |
|
| R371 | Transfer withdrawn |
Free format text: JAPANESE INTERMEDIATE CODE: R371 |
|
| S111 | Request for change of ownership or part of ownership |
Free format text: JAPANESE INTERMEDIATE CODE: R313114 |
|
| R350 | Written notification of registration of transfer |
Free format text: JAPANESE INTERMEDIATE CODE: R350 |
|
| S531 | Written request for registration of change of domicile |
Free format text: JAPANESE INTERMEDIATE CODE: R313531 |
|
| R350 | Written notification of registration of transfer |
Free format text: JAPANESE INTERMEDIATE CODE: R350 |
|
| S111 | Request for change of ownership or part of ownership |
Free format text: JAPANESE INTERMEDIATE CODE: R313115 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20080906 Year of fee payment: 6 |
|
| R350 | Written notification of registration of transfer |
Free format text: JAPANESE INTERMEDIATE CODE: R350 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20080906 Year of fee payment: 6 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20090906 Year of fee payment: 7 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20090906 Year of fee payment: 7 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20100906 Year of fee payment: 8 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20100906 Year of fee payment: 8 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20110906 Year of fee payment: 9 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20120906 Year of fee payment: 10 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20130906 Year of fee payment: 11 |
|
| LAPS | Cancellation because of no payment of annual fees |