JPS63149589A - Fuel aggregate for pressure tube type reactor - Google Patents
Fuel aggregate for pressure tube type reactorInfo
- Publication number
- JPS63149589A JPS63149589A JP61296547A JP29654786A JPS63149589A JP S63149589 A JPS63149589 A JP S63149589A JP 61296547 A JP61296547 A JP 61296547A JP 29654786 A JP29654786 A JP 29654786A JP S63149589 A JPS63149589 A JP S63149589A
- Authority
- JP
- Japan
- Prior art keywords
- fuel
- pressure tube
- fuel assembly
- moderator
- tube type
- 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 40
- XLYOFNOQVPJJNP-ZSJDYOACSA-N Heavy water Chemical compound [2H]O[2H] XLYOFNOQVPJJNP-ZSJDYOACSA-N 0.000 claims description 17
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 10
- 238000002485 combustion reaction Methods 0.000 description 8
- 239000002826 coolant Substances 0.000 description 5
- 230000000694 effects Effects 0.000 description 5
- 230000009257 reactivity Effects 0.000 description 4
- 238000006243 chemical reaction Methods 0.000 description 3
- 230000004992 fission Effects 0.000 description 3
- 239000007787 solid Substances 0.000 description 3
- 238000010521 absorption reaction Methods 0.000 description 2
- 230000008901 benefit Effects 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 230000006866 deterioration Effects 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 239000002574 poison Substances 0.000 description 2
- 231100000614 poison Toxicity 0.000 description 2
- QSGNKXDSTRDWKA-UHFFFAOYSA-N zirconium dihydride Chemical compound [ZrH2] QSGNKXDSTRDWKA-UHFFFAOYSA-N 0.000 description 2
- 229910000568 zirconium hydride Inorganic materials 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- 229910052778 Plutonium Inorganic materials 0.000 description 1
- 229910052770 Uranium Inorganic materials 0.000 description 1
- 229910052790 beryllium Inorganic materials 0.000 description 1
- ATBAMAFKBVZNFJ-UHFFFAOYSA-N beryllium atom Chemical compound [Be] ATBAMAFKBVZNFJ-UHFFFAOYSA-N 0.000 description 1
- 238000009835 boiling Methods 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 229910002804 graphite Inorganic materials 0.000 description 1
- 239000010439 graphite Substances 0.000 description 1
- 238000009413 insulation Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- OYEHPCDNVJXUIW-UHFFFAOYSA-N plutonium atom Chemical compound [Pu] OYEHPCDNVJXUIW-UHFFFAOYSA-N 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 230000005070 ripening Effects 0.000 description 1
- 238000007789 sealing Methods 0.000 description 1
- 125000006850 spacer group Chemical group 0.000 description 1
- 230000003595 spectral effect Effects 0.000 description 1
- 238000001228 spectrum Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- JFALSRSLKYAFGM-UHFFFAOYSA-N uranium(0) Chemical compound [U] JFALSRSLKYAFGM-UHFFFAOYSA-N 0.000 description 1
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E30/00—Energy generation of nuclear origin
- Y02E30/30—Nuclear fission reactors
Landscapes
- Devices And Processes Conducted In The Presence Of Fluids And Solid Particles (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】
〔産業上の利用分野〕
本発明は熱中性子を利用する原子炉、とくに圧力管型重
水原子炉に好適な燃料集合体に関する。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a fuel assembly suitable for a nuclear reactor that utilizes thermal neutrons, particularly a pressure tube type heavy water reactor.
第２図は通常の圧力管型重水原子炉の燃料集合体の１例
を示す水平断面図である。燃料集合体は多数の燃料棒１
と、軽水からなる冷却材２および図示しない上部タイプ
レート、下部タイプレート。FIG. 2 is a horizontal sectional view showing an example of a fuel assembly for a normal pressure tube type heavy water reactor. The fuel assembly consists of many fuel rods 1
, a coolant 2 made of light water, and an upper tie plate and a lower tie plate (not shown).
スペーサ、圧力管３、熟熱層４及びカランドリア管５か
らなっている。この燃料集合体は減速材である重水６の
中に置かれる。It consists of a spacer, a pressure tube 3, a ripening layer 4, and a calandria tube 5. This fuel assembly is placed in heavy water 6, which is a moderator.
中性子は主として重水６で減速されて熱中性子となり、
圧力管３の中の燃料棒１に吸収され、核分裂を起こす。Neutrons are mainly decelerated by heavy water 6 and become thermal neutrons,
It is absorbed by the fuel rod 1 in the pressure tube 3 and undergoes nuclear fission.
ここで、中性子吸収による空間遮蔽効果のため、核分裂
率の分布は燃料集合体内側で低く、外側で高くなる傾向
にある。この出力分布が平坦から余りはずれると、熱的
制限により、出力密度を下げなければならず、運転コス
トの上で不利になる。Here, due to the spatial shielding effect caused by neutron absorption, the distribution of fission rates tends to be low inside the fuel assembly and high outside. If this power distribution deviates too much from flatness, the power density must be reduced due to thermal limitations, which is disadvantageous in terms of operating costs.
この問題を解決して出力分布を平坦化するために、プル
トニウム富化度あるいはウラン濃縮度を内側燃料棒で高
く、外側燃料棒で低くする方法がよく用いられる。ただ
し、富化度あるいは濃縮度の種類を増やすことは燃料製
作コストの増加につながるため、通常は最外層の燃料だ
けを低富化度あるいは低ａ縮度とする。その場合、最内
層の燃料の出力を高めるため、特開昭５２−６１６９７
号公報に記載のように、水封入枠を燃料集合体中心部に
配置する方法が広く用いられている。To solve this problem and flatten the power distribution, a method is often used to increase plutonium or uranium enrichment in the inner fuel rods and lower it in the outer fuel rods. However, since increasing the types of enrichment or enrichment increases fuel production costs, usually only the outermost layer of fuel is made to have low enrichment or low a reduction. In that case, in order to increase the output of the fuel in the innermost layer,
As described in the above publication, a method of arranging a water sealing frame at the center of a fuel assembly is widely used.
水封入棒を装荷する上記従来技術では、減速材である水
封入枠が入ることにより燃料集合体の中性子無限増倍率
が増加する。このため、燃焼初期の余剰反応度が大きく
なり、制御棒あるいは重水中ポイズン濃度などにより制
御する必要がある。In the above-mentioned conventional technology in which a water-filled rod is loaded, the infinite neutron multiplication factor of the fuel assembly is increased by inserting the water-filled frame, which is a moderator. For this reason, the surplus reactivity at the initial stage of combustion becomes large, and it is necessary to control it using control rods or the poison concentration in heavy water.
そのために中性子経済が劣化し、これは燃料の燃焼度を
高める上で不利になる。This degrades the neutron economy, which is a disadvantage in increasing fuel burnup.
本発明の目的は、圧力管型重水原子炉の燃料の燃焼度を
高めることにある。An object of the present invention is to increase the burnup of fuel in a pressure tube type heavy water reactor.
上記目的は、燃料集合体内に配置する水封入枠あるいは
固体減速材の棒を、随時に装荷・取出し可能な構造とす
ることにより達成される。すなわち、燃焼初期には上記
の水封入枠を未装荷のままとし、燃焼が進んだ時点で初
めて装荷する。The above object is achieved by providing a structure in which the water-filled frame or solid moderator rods disposed within the fuel assembly can be loaded and removed at any time. That is, the water-filled frame is left unloaded at the beginning of combustion, and is loaded only after combustion has progressed.
集合体中心部に水封入枠あるいは、固体減速材の棒を未
装荷のまま炉心装荷した場合、燃料集合体中心部での冷
却材が占める体積割合が増加する。When a water-filled frame or a solid moderator rod is loaded into the core without being loaded at the center of the fuel assembly, the volume ratio occupied by the coolant at the center of the fuel assembly increases.
そのため、冷却材沸騰による中性子スペクトル硬化の影
響が集合体中心部で大きくなり、中性子無限増倍率は低
下するが、燃料転換比が良くなる。Therefore, the influence of neutron spectral hardening due to coolant boiling increases in the center of the aggregate, and although the infinite neutron multiplication factor decreases, the fuel conversion ratio improves.
ついで、燃焼が進んで中性子無限増倍率が大きく下った
時点で水封入枠あるいは固体減速材棒を集合体中心部に
装荷すると、そこでの中性子スペクトルは軟化し、核分
裂の割合が増加する。その結果、出力分布は平坦化され
、中性子無限増倍率は増加する。Then, when the combustion progresses and the infinite neutron multiplication factor drops significantly, if a water-filled frame or solid moderator rod is loaded into the center of the aggregate, the neutron spectrum there softens and the rate of nuclear fission increases. As a result, the power distribution is flattened and the neutron infinite multiplication factor increases.
従って、本発明によれば、燃焼初期における余剰反応度
は小さくでき、制御棒や、重水中ポイズンによる中性子
吸収を少なくできる。その結果、燃料転換比が改善され
、運転期間を伸ばすことができる。また、オンパワーの
まま、減速材棒を装荷すれば、中性子無限増倍率が増大
するため、運転期間を一層上げることができる。Therefore, according to the present invention, the surplus reactivity at the initial stage of combustion can be reduced, and neutron absorption by control rods and poisons in heavy water can be reduced. As a result, the fuel conversion ratio is improved and the operating period can be extended. Furthermore, if moderator rods are loaded while the power is on, the infinite neutron multiplication factor increases, so the operating period can be further extended.
以下１本発明の一実施例を第１図により説明する。 An embodiment of the present invention will be described below with reference to FIG.
第１の実施例である燃ｎ朶合体の、炉心装荷直後の水平
断面図を第１（ａ）図に示す、この時点では燃料集合体
中心部に、燃料棒の一部が欠けた箇所があり、冷却材が
代りに流れている。燃焼が進み、中性子無限増倍率が低
下した時点で、第１（ｂ）図に示すように、ジルコニウ
ム・ハイドライドを封入した減速材棒を、燃料棒の欠け
た箇所に装荷する。減速材棒の装荷は、燃料交換のため
の炉停止時に行なうことができる。また、圧力管型原子
炉の利点を生かして、オンパワーのまま行なうこともで
きる。Figure 1(a) shows a horizontal cross-sectional view of the first embodiment of the fuel assembly immediately after loading into the core. At this point, there is a part of the fuel rod missing in the center of the fuel assembly. Yes, coolant is flowing instead. When the combustion progresses and the infinite neutron multiplication factor decreases, a moderator rod containing zirconium hydride is loaded into the chipped part of the fuel rod, as shown in FIG. 1(b). Loading of moderator rods can be done when the reactor is shut down for refueling. Furthermore, taking advantage of the advantages of pressure tube reactors, it is also possible to operate with the power on.
第３図に示すのは、４バツチ燃料交換の場合において、
２年目の燃料交換時に減速材棒を装荷する時の、燃料集
合体の中性子無限増倍率の変化である。図から分るよう
に減速材棒未装荷の時には中性子無限増倍率は小さいが
、燃焼による反応度劣化は小さい。また、減少相棒装荷
により、中性子無限増倍率が上がる分だけ、全体として
の反応度劣化は小さい。Figure 3 shows the case of 4-batch fuel exchange.
This is the change in the infinite neutron multiplication factor of the fuel assembly when moderator rods are loaded during fuel exchange in the second year. As can be seen from the figure, when no moderator rods are loaded, the infinite neutron multiplication factor is small, but the reactivity deterioration due to combustion is small. Furthermore, due to the reduced partner loading, the overall reactivity deterioration is small by the amount that the infinite neutron multiplication factor increases.
第４図に示すのは、減速材棒二装荷前後の集合体内出力
分布の比較である。減速材棒を装荷したことにより、と
くに集合体中心部の出力が増加する結果、出力分布、燃
焼度分布は平坦化される。FIG. 4 shows a comparison of the output distribution within the assembly before and after loading two moderator rods. Loading the moderator rods increases the output, especially at the center of the aggregate, and as a result, the output distribution and burnup distribution are flattened.
なお、ここでは減速材捧としてジルコニウムハイドライ
ドを用いたが、ベリリウム、黒鉛１重水あるいはこれら
の混合物や化合物を使用することができる。また、従来
の水封入枠を用いることもできる。Here, zirconium hydride was used as the moderator, but beryllium, graphite mono-heavy water, or a mixture or compound thereof may also be used. Additionally, a conventional water enclosure can also be used.
さらに、本発明の効果を高めるために、炉心装荷時に物
質を装荷しない空洞の棒を装荷しておき。Furthermore, in order to enhance the effects of the present invention, hollow rods that are not loaded with substances are loaded in the reactor core during loading.
それを減速材棒と交換することも考えられる。It is also conceivable to replace it with a moderator rod.
以上に述べたように本発明によれば、燃焼初期の燃料集
合体の中性子無限増倍率を押えることができ、燃料転換
比を改善できる。その結果、運転期間を押ばし、燃焼度
を高めることができる。また、減速材棒装荷を運転途中
で行なうことにより。As described above, according to the present invention, the infinite neutron multiplication factor of the fuel assembly at the initial stage of combustion can be suppressed, and the fuel conversion ratio can be improved. As a result, the operating period can be extended and the burn-up can be increased. Also, by loading moderator rods during operation.
上記効果を一層高めることができる。The above effects can be further enhanced.
第１図は本発明の一実施例である燃料集合体の水平断面
図、第２図は従来の燃料集合体の水平断面図、第３図は
本発明による燃料集合体の中性子無限増倍率の燃焼に伴
う変化を示す線図、第４図は減速材棒を装荷した時の燃
料集合体内出力分布の変化を示す説明図である。
１・・・燃料棒、２・・・冷却材、３・・・圧力管、４
・・・断熱層、５・・・カランドリア管、６・・・減速
材、７・・・減速材枠。FIG. 1 is a horizontal sectional view of a fuel assembly that is an embodiment of the present invention, FIG. 2 is a horizontal sectional view of a conventional fuel assembly, and FIG. 3 is a horizontal sectional view of a fuel assembly according to the present invention. FIG. 4 is an explanatory diagram showing changes in the output distribution within the fuel assembly when moderator rods are loaded. 1... Fuel rod, 2... Coolant, 3... Pressure pipe, 4
... heat insulation layer, 5 ... calandria tube, 6 ... moderator, 7 ... moderator frame.
Claims (1)
に多数の燃料棒を配置した圧力管型重水原子炉の燃料集
合体において、前記燃料集合体の内部に水封入棒または
その他の減速材棒が随時に装荷、取出し可能なことを特
徴とする圧力管型原子炉用燃料集合体。1. In a fuel assembly for a pressure tube type heavy water reactor in which a pressure tube is arranged in a calandria tube and a large number of fuel rods are arranged in the pressure tube, a water-filled rod or other moderator rod is installed inside the fuel assembly. A fuel assembly for a pressure tube type nuclear reactor, characterized in that it can be loaded and unloaded at any time.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61296547A JPS63149589A (en) | 1986-12-15 | 1986-12-15 | Fuel aggregate for pressure tube type reactor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61296547A JPS63149589A (en) | 1986-12-15 | 1986-12-15 | Fuel aggregate for pressure tube type reactor |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS63149589A true JPS63149589A (en) | 1988-06-22 |
Family
ID=17834943
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP61296547A Pending JPS63149589A (en) | 1986-12-15 | 1986-12-15 | Fuel aggregate for pressure tube type reactor |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS63149589A (en) |
-
1986
- 1986-12-15 JP JP61296547A patent/JPS63149589A/en active Pending
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