JPS61292590A - Nuclear reactor - Google Patents
Nuclear reactorInfo
- Publication number
- JPS61292590A JPS61292590A JP60134122A JP13412285A JPS61292590A JP S61292590 A JPS61292590 A JP S61292590A JP 60134122 A JP60134122 A JP 60134122A JP 13412285 A JP13412285 A JP 13412285A JP S61292590 A JPS61292590 A JP S61292590A
- Authority
- JP
- Japan
- Prior art keywords
- fuel
- core
- heavy water
- reactor
- light water
- 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
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
- Analysing Materials By The Use Of Radiation (AREA)
- Treatment Of Water By Oxidation Or Reduction (AREA)
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】
〔発明の利用分野〕
本発明は1重水および軽水を中性子減速材とする原子炉
に係り、とくに従来よりも燃料経済性を向上した原子炉
に関する。DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a nuclear reactor using heavy water and light water as neutron moderators, and particularly to a nuclear reactor with improved fuel economy compared to conventional reactors.
[発明の背景〕
中性子とウラン、プルトニウム等の原子核との核***反
応から発生する熱を利用して発電する原子炉は、核***
性性物質を含有する燃料、熱を除去するための冷却材、
中性子を減速する減速材及び原子炉を構成する構造材で
成り立っている。減速材あるいは冷却材として使用され
るのは、軽水。[Background of the Invention] A nuclear reactor that generates electricity using the heat generated from the nuclear fission reaction between neutrons and atomic nuclei such as uranium and plutonium requires fuel containing fissile material, a coolant for removing heat,
It consists of a moderator that slows down neutrons and structural materials that make up the reactor. Light water is used as a moderator or coolant.
重水、ガス、ナトリウムなどであり、それぞれ、軽水炉
2重水炉、ガス炉、液体金属冷却炉などと呼ばれている
。軽水炉および重水炉は、いずれも中性子減速能の強い
軽水および重水を使用しているので、核***により高速
エネルギーを持って生まれた中性子は減速材原子核との
衝突によりエネルギーを失なって低エネルギーになった
状態、いわゆる熱中性子として炉心内に存在する。した
が力で、JI子炉内の減速材対燃料の比が炉心特性に大
きな影響を及ぼすことになる。また、軽水あるいは重水
のいづれを減速材として用いるかで炉心特性は大きく異
なってくる。These include heavy water, gas, and sodium, and are respectively called light water reactors, double heavy water reactors, gas reactors, and liquid metal cooled reactors. Light water reactors and heavy water reactors both use light water and heavy water, which have strong neutron moderating abilities, so neutrons produced with high-speed energy through nuclear fission lose energy through collision with moderator nuclei and become low-energy. They exist in the reactor core in the form of thermal neutrons. However, the moderator-to-fuel ratio in the JI subreactor has a significant impact on core characteristics. Additionally, core characteristics vary greatly depending on whether light water or heavy water is used as a moderator.
第2図に、減速材/燃料を横軸に、無限増倍率および燃
料転換比(生成した核***性性物質/削減した核***性
性物質)の変化を、軽水および重水を減速材とする原子
炉について示した。軽水炉では、無限増倍率が重水炉よ
り大きく、減速材対燃料比が大きくなるにつれ増大する
傾向を持っている。Figure 2 shows changes in the infinite multiplication factor and fuel conversion ratio (fissile material produced/fissile material reduced), with moderator/fuel on the horizontal axis, for nuclear reactors with light water and heavy water as moderators. The following was shown. In light water reactors, the infinite multiplication factor is larger than in heavy water reactors, and tends to increase as the moderator-to-fuel ratio increases.
しかし、転換比は逆に重水炉よりも小さく、減速材対燃
料の比が大きくなると減少してゆく。軽水炉であるBW
RやPWRでは、軽水対燃料の比は2前後であり1重水
炉であるATRでは、重水対燃料の比は8前後である。However, the conversion ratio is conversely smaller than in heavy water reactors and decreases as the moderator-to-fuel ratio increases. BW, a light water reactor
In R and PWR, the ratio of light water to fuel is around 2, and in ATR, which is a single heavy water reactor, the ratio of heavy water to fuel is around 8.
第2図から分るように、軽水炉の特徴に、無限増倍率が
大きく、軽水対燃料の比も小さいため、一定の出力を発
生するのに必要な燃料が少なく、炉心も小型比できるこ
とが長所である。しかし、燃料転換比が小さいため、燃
料経済性が悪く、多量のウラン資源を必要とすることが
欠点である。As can be seen from Figure 2, light water reactors have the advantage of having a large infinite multiplication factor and a small ratio of light water to fuel, so less fuel is required to generate a certain amount of output, and the reactor core can be smaller. It is. However, due to the low fuel conversion ratio, fuel economy is poor and a large amount of uranium resources are required.
また、運転を長期化するためには高濃縮燃料が不可欠と
なり燃料コストが増大すると共に、運転初期の余剰反応
度が増大するためガドリニアなどの可燃性毒物を添加す
る必要性が生じ、炉心運用の信頼度が低下し燃料経済性
が劣化するなどの課題が生じる。PWRの燃料装荷パタ
ーンの1例を第3図に示したが(「核燃料管理の方法と
解析」HoW・グレイブス著)、複雑な燃料シャフリン
グ行わないと出力分布が平坦化されず、炉心管理の繁雑
さをまねき、原子炉の稼動率が低下する6重水炉におい
ては、燃料転換比が高く燃料経済性が軽水炉より優れて
いるのは利点であるが、無限増倍率が小さく、重水対燃
料の比が大きいため一定出力を発生するのに必要な燃料
の量が増大すると共に炉心サイズも増大し、プラントコ
ストが上昇する。In addition, in order to prolong operation, highly enriched fuel is indispensable, which increases fuel costs. At the same time, excess reactivity increases at the beginning of operation, making it necessary to add burnable poisons such as gadolinia, which reduces core operation. Problems arise such as reduced reliability and fuel economy. An example of a PWR fuel loading pattern is shown in Figure 3 (``Methods and Analysis of Nuclear Fuel Management'' by HoW Graves), but unless complex fuel shuffling is performed, the power distribution will not be flattened, making it difficult to improve core management. Heavy water reactors have the advantage of having a high fuel conversion ratio and better fuel economy than light water reactors, but they have a small infinite multiplication factor and the ratio of heavy water to fuel is low. The large ratio increases the amount of fuel required to produce a given power output, increases the core size, and increases plant costs.
以上述べたように、軽水炉及び重水炉ともに、特徴をも
った原子炉であるが、軽水および重水のそれぞれの長所
を十分に活用した炉心特性が実現しているとは言いがた
いのが現状である。As mentioned above, both light water reactors and heavy water reactors have their own characteristics, but at present it is difficult to say that core characteristics that fully utilize the strengths of light water and heavy water have been achieved. be.
本発明の目的は、燃料転換比が高く、小型で長期サイク
ル運転ができ、プラントコストが低く燃料経済性に優れ
た原子炉を提供することにある。An object of the present invention is to provide a nuclear reactor that has a high fuel conversion ratio, is small in size, can be operated in a long cycle, has low plant cost, and is excellent in fuel economy.
本発明の基本的考え方は、原子炉の冷却材である軽水お
よび重水のそれぞれの長所を有効に活用することにより
上記の目的を達成しようとするものである。即ち1重水
減速材の高転換比特性と軽水減速材の高反応度特性とを
利用するものである。The basic idea of the present invention is to achieve the above object by effectively utilizing the respective advantages of light water and heavy water, which are coolants for nuclear reactors. That is, it utilizes the high conversion ratio characteristics of a single heavy water moderator and the high reactivity characteristics of a light water moderator.
原子炉の炉心を径方向に二分割し、内側および外側領域
の減速材を、それぞれ重水および軽水とする。本発明で
は、まず炉心滞在期間の前半は燃料集合体を転換比の高
い内側領域に装荷して燃焼により発熱させると共にプル
トニウムの蓄積を図る。そして、炉心滞在期間の後半に
は・燃焼により反応度の低下した燃料集合体を外側の高
反応度領域に移し、蓄積されているプルトニウムを有効
に発熱させる。このように、本発明では、原子燃料の有
している転換性という特性を最大限活用して燃料の利用
効率を高めるものである。The core of a nuclear reactor is divided into two in the radial direction, and the moderators in the inner and outer regions are heavy water and light water, respectively. In the present invention, first, during the first half of the stay in the reactor core, fuel assemblies are loaded into the inner region where the conversion ratio is high to generate heat through combustion and to accumulate plutonium. Then, in the latter half of the stay in the core, the fuel assemblies whose reactivity has decreased due to combustion are moved to the outer high reactivity area, and the accumulated plutonium is effectively heated. In this manner, the present invention makes full use of the convertibility characteristic of nuclear fuel to increase fuel utilization efficiency.
また、本発明によれば、中性子もれの寄与が大きくて出
力分布が下がる炉心周辺部に高反応度領域を設けるので
出力分布平坦化も同時に実現できる。Further, according to the present invention, since a high reactivity region is provided in the periphery of the reactor core where the contribution of neutron leakage is large and the power distribution decreases, it is possible to simultaneously achieve flattening of the power distribution.
本発明を、実施例に基づいて詳細に説明する。 The present invention will be explained in detail based on examples.
第1図に、本発明の一実施例を示す。この図は、原子炉
の燃料装荷パターンを示すものであるが。FIG. 1 shows an embodiment of the present invention. This figure shows the fuel loading pattern for a nuclear reactor.
重水を減速材1とする内側領域と軽水を減速材2とする
外側領域とに分れており、内側領域には1〜3年滞在の
燃料が装荷され、外側領域には4年目滞在の燃料が装荷
されている。即ち、本実施例は、4バツチ装荷炉心(全
炉心の1/4の燃料を取替える)に対するものである。It is divided into an inner region with heavy water as moderator 1 and an outer region with light water as moderator 2. The inner region is loaded with fuel for 1 to 3 years of stay, and the outer region is loaded with fuel for 4 years of stay. Fuel is loaded. That is, this embodiment is for a core loaded in four batches (one quarter of the fuel in the entire core is replaced).
燃料集合体の無限増倍率の燃焼に伴なう変化を第4図に
示した。従来炉心の燃料集合体の特性を破線で示したが
、炉心装荷時の新燃料は無限増倍率が高いが、燃焼と共
に単調に減少してゆき4年目の末期で炉心から取出され
る。この図に示した本発明の燃料集合体は運転期間を従
来炉心と合せるために、平均濃縮度を従来例よりも下げ
である。Figure 4 shows the change in the infinite multiplication factor of the fuel assembly due to combustion. The characteristics of the fuel assembly in the conventional core are shown by the broken line.The new fuel when loaded into the core has a high infinite multiplication factor, but it monotonically decreases as it burns and is removed from the core at the end of the fourth year. The fuel assembly of the present invention shown in this figure has an average enrichment lower than that of the conventional example in order to match the operating period with that of the conventional reactor core.
本発明の無限増倍率は、1〜3年滞在燃料に対しては、
平均濃縮度が下がったことと低反応度の重水領域(内側
領域)に装荷されたために、従来炉心より低い値となる
。しかし、燃焼に伴なう無限増倍率の減少割合は小さく
、高転換比領域にあるためプルトニウムが従来炉心より
多量に蓄積していることが分かる。そして、4年目には
高反応度領域(外側領域)に装荷されるので、図に示す
ように、無限増倍率は大きく増加する。この無限増倍率
の増加には、上記のプルトニウムの蓄積効果も寄与して
いる。このように、外側領域の4年目燃料が炉心反応度
の大部分を分担するために、燃料濃縮度を下げても従来
炉心と同じサイクル長さの運転を実現できる。また、外
側炉心の無限増倍率が高くなるため径方向出力分布が平
坦化され、従来の軽水炉にような燃料シャフリングある
いは出力分布平坦化のための制御棒挿入は不要となり、
従来の重水炉のように外側領域のために濃縮度の高い燃
料を別に製造する必要もなくなる。The infinite multiplication factor of the present invention is for fuel that stays for 1 to 3 years,
This value is lower than in conventional cores due to the lower average enrichment and the loading of heavy water into the low-reactivity region (inner region). However, the rate of decrease in the infinite multiplication factor due to combustion is small, and because the reactor is in a high conversion ratio region, it can be seen that more plutonium is accumulated than in conventional cores. Then, in the fourth year, it is loaded into the high reactivity region (outer region), so the infinite multiplication factor increases greatly, as shown in the figure. The above-mentioned plutonium accumulation effect also contributes to this increase in the infinite multiplication factor. In this way, since the fourth-year fuel in the outer region shares most of the core reactivity, operation with the same cycle length as the conventional core can be achieved even if the fuel enrichment is lowered. In addition, since the infinite multiplication factor of the outer core is increased, the radial power distribution is flattened, eliminating the need for fuel shuffling or control rod insertion to flatten the power distribution as in conventional light water reactors.
There is no need to separately produce highly enriched fuel for the outer regions, as in conventional heavy water reactors.
以上のように1本発明によれば、従来炉心と同じサイク
ル長さの運転をする場合、燃料濃縮度を下げることによ
り燃料コストの低減、省ウラン資源が実現できると共に
、燃料シャフリング不要による稼働率の向上、挿入制御
本数低減による炉心運用の簡素化等が実現できる。As described above, according to the present invention, when operating the same cycle length as a conventional core, it is possible to reduce fuel costs and save uranium resources by lowering the fuel enrichment, and to operate without fuel shuffling. It is possible to improve the efficiency and simplify core operation by reducing the number of insertion controls.
第5図には、燃料濃縮度を下げないで、従来炉心と同じ
濃縮度を用いて本発明の効果を運転サイクル長期化に適
用した場合の無限増倍率の燃焼に伴なう変化が示しであ
る。上記と同じ原理により。Figure 5 shows the change associated with combustion of the infinite multiplication factor when the effect of the present invention is applied to lengthen the operating cycle by using the same enrichment as the conventional core without lowering the fuel enrichment. be. By the same principle as above.
サイクル長期化が実現できる。A longer cycle can be achieved.
この場合も、本発明の効果は前記と同じである。In this case as well, the effects of the present invention are the same as described above.
なお、以上の説明では、内側領域には重水を用いるとし
たが、この領域の反応度を高める必要が年じた場合には
、重水と軽水との混合液を減速材として使用することも
できる。この場合、内側領域の転換比が少し劣化するの
で、燃料コスト低減省ウラン資源などの効果は小さくな
るが、出力分布平坦化、炉心運用簡素化などの効果は実
現できる。In the above explanation, heavy water is used in the inner region, but if it becomes necessary to increase the reactivity in this region, a mixture of heavy water and light water can also be used as a moderator. . In this case, the conversion ratio in the inner region deteriorates a little, so the effects of reducing fuel costs and saving uranium resources are reduced, but effects such as flattening the power distribution and simplifying core operation can be achieved.
第6図には、本発明を3バツチ装荷炉心に適用した場合
を、第7図には、5バツチ装荷炉心に適用した場合の燃
料装荷パターンを示す。これらの例から分かるように、
本発明は、バッチ数の大小にかかわらず適用可能である
。FIG. 6 shows a fuel loading pattern when the present invention is applied to a 3-batch loaded core, and FIG. 7 shows a fuel loading pattern when the present invention is applied to a 5-batch loaded core. As you can see from these examples,
The present invention is applicable regardless of the number of batches.
本発明によれば、燃料濃縮度の低減あるいは運転期間の
長期化による燃料コストの低減及び省ウラン資源が実現
できる。また、出力分布平坦化が実現できるために燃料
シャフリングが不要となって稼働率が向上し、制御棒挿
入本数を低減できて炉心運用が簡素化される。According to the present invention, it is possible to reduce fuel costs and save uranium resources by reducing fuel enrichment or prolonging the operating period. Furthermore, since the power distribution can be flattened, fuel shuffling is no longer necessary, improving operating efficiency, reducing the number of control rods inserted, and simplifying core operation.
【図面の簡単な説明】
第1図は、本発明の一実施例を示す燃料装荷パターン図
、第2図は、減速材対燃料比を変えた場合の軽水炉およ
び重水炉の核特性線図、第3図は、従来のPWHの燃料
装荷パターン図、第4図、第5図は、本発明の燃料の燃
焼特性線図、第6図。
第7図は4本発明の他の実施例を示すパターン図である
。
1・・・重水減速材、2・・・軽水減速材。[Brief Description of the Drawings] Fig. 1 is a fuel loading pattern diagram showing one embodiment of the present invention, Fig. 2 is a nuclear characteristic diagram of a light water reactor and a heavy water reactor when the moderator to fuel ratio is changed, FIG. 3 is a fuel loading pattern diagram of a conventional PWH, FIGS. 4 and 5 are combustion characteristic diagrams of the fuel of the present invention, and FIG. 6 is a diagram. FIG. 7 is a pattern diagram showing another embodiment of the present invention. 1... Heavy water moderator, 2... Light water moderator.
Claims (1)
熱を除去する冷却材が燃料間を流れる構成の原子炉にお
いて、原子炉の炉心領域を径方向に二領域に分割し、内
側領域に重水を充填し、外側領域に軽水を充填し、炉心
滞在期間前半の燃料を内側領域に装荷し、滞在期間の後
半に外側領域に装荷することを特徴とする原子炉。1. In a nuclear reactor configured such that fuel containing fissile material and a coolant that removes heat generated by the fuel flow between the fuel, the core region of the reactor is divided into two regions in the radial direction, and an inner region is divided into two regions. A nuclear reactor is characterized in that the core is filled with heavy water, the outer region is filled with light water, fuel for the first half of the stay period is loaded into the inner region, and fuel is loaded into the outer region during the second half of the stay period.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP60134122A JPS61292590A (en) | 1985-06-21 | 1985-06-21 | Nuclear reactor |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP60134122A JPS61292590A (en) | 1985-06-21 | 1985-06-21 | Nuclear reactor |
Publications (1)
Publication Number | Publication Date |
---|---|
JPS61292590A true JPS61292590A (en) | 1986-12-23 |
Family
ID=15120978
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP60134122A Pending JPS61292590A (en) | 1985-06-21 | 1985-06-21 | Nuclear reactor |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPS61292590A (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS63208790A (en) * | 1987-02-25 | 1988-08-30 | 株式会社日立製作所 | Pressure tube type reactor and operating method of said reactor |
-
1985
- 1985-06-21 JP JP60134122A patent/JPS61292590A/en active Pending
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS63208790A (en) * | 1987-02-25 | 1988-08-30 | 株式会社日立製作所 | Pressure tube type reactor and operating method of said reactor |
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