JPS6134639B2 - - Google Patents
Info
- Publication number
- JPS6134639B2 JPS6134639B2 JP54164501A JP16450179A JPS6134639B2 JP S6134639 B2 JPS6134639 B2 JP S6134639B2 JP 54164501 A JP54164501 A JP 54164501A JP 16450179 A JP16450179 A JP 16450179A JP S6134639 B2 JPS6134639 B2 JP S6134639B2
- Authority
- JP
- Japan
- Prior art keywords
- core
- fuel assemblies
- layer
- burned
- loaded
- 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.)
- Expired
Links
- 239000000446 fuel Substances 0.000 claims description 83
- 230000000712 assembly Effects 0.000 claims description 56
- 238000000429 assembly Methods 0.000 claims description 56
- 230000002093 peripheral effect Effects 0.000 claims description 21
- 231100000614 poison Toxicity 0.000 description 19
- 239000002574 poison Substances 0.000 description 18
- 230000009257 reactivity Effects 0.000 description 16
- 238000002485 combustion reaction Methods 0.000 description 15
- 230000004907 flux Effects 0.000 description 8
- 238000009835 boiling Methods 0.000 description 3
- 238000010586 diagram Methods 0.000 description 3
- 231100000419 toxicity Toxicity 0.000 description 3
- 230000001988 toxicity Effects 0.000 description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 3
- CMIHHWBVHJVIGI-UHFFFAOYSA-N gadolinium(iii) oxide Chemical compound [O-2].[O-2].[O-2].[Gd+3].[Gd+3] CMIHHWBVHJVIGI-UHFFFAOYSA-N 0.000 description 2
- 239000003758 nuclear fuel Substances 0.000 description 2
- 230000000694 effects Effects 0.000 description 1
- 230000004992 fission Effects 0.000 description 1
- 231100000956 nontoxicity Toxicity 0.000 description 1
- 239000003440 toxic substance Substances 0.000 description 1
- JFALSRSLKYAFGM-OIOBTWANSA-N uranium-235 Chemical compound [235U] JFALSRSLKYAFGM-OIOBTWANSA-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
- Monitoring And Testing Of Nuclear Reactors (AREA)
Description
本発明は沸騰水形原子炉等の炉心構造に関す
る。
一般に沸騰水形原子炉は断面十字形の制御棒の
周囲に４体の燃料集合体を配置して単位格子を形
成し、この単位格子を配列して炉心を構成してい
る。そして、この単位格子内には未燃焼の燃料集
合体、１炉心年燃焼して燃料集合体、２炉心年燃
焼した燃料集合体および３炉心年燃焼した燃料集
合体がそれぞれ１体ずつ装荷され、１炉心年毎に
最も燃焼の進んだ燃料集合体を未燃焼の燃料集合
体と交換するように構成されている。ところで、
沸騰水形原子炉の燃料は燃焼期間を長くするため
ウラン235の濃度を高くしてあり、この場合に第
２図に破線で示す如く燃焼初期における、余剰反
応度を制限内に規制するため可燃性毒物が混入さ
れている。そしてこの可燃性毒物は約１炉心年の
燃焼すなわち燃焼度が約8000MWD／Ｄ程度で燃
焼されてその毒性が消失するように構成されてい
る。
この可燃性毒物は燃料の燃焼初期における過大
な反応度を抑制するものであり、所定の期間たと
えば１炉心年燃焼された後はすみやかに消滅し、
燃料の燃焼を妨げないようにすることが好まし
い。しかし従来のものは上述の如く炉心の全域に
わたつて、単位格子内に未燃焼の燃料集合体およ
び１〜３炉心年燃焼して燃料集合体を１体ずつ装
荷した装荷パターンを形成してあるので、炉心周
辺部では可燃性毒物の燃焼が充分に進行せず、毒
性が残り余剰反応度の損失をひきおこす不具合が
あつた。すなわち、一般に炉心の径方向の中性子
束分布は第３図に示す如き特性を示し、炉心周辺
部では中性子束が小さくなつている。したがつて
炉心周辺部に装荷された燃料集合体では可燃性毒
物の燃焼が進行せず、毒性が残るものである。
本発明は以上の事情にもとづいてなされたもの
で、その目的とするところは燃料に混入された可
燃性毒物の燃焼効率がよく、この可燃性毒物の残
留による余剰反応度の損失が少ないとともに炉心
の出力分布を平均化できる原子炉を得ることにあ
る。
以下本発明を第１図に示す一実施例にしたがつ
て説明する。図中１は炉心であつて、この炉心１
には制御棒２…および燃料集合体３…が配置され
ている。上記制御棒２…は断面十字状をなし、そ
の周囲には４体の燃料集合体３…が配置され、単
位格子４…を構成している。そして、これらの単
位格子４…は格子状に配列されて炉心１を構成し
ている。そして、燃料集合体３…中に収容された
核燃料中にはガドリニア等の可燃性毒物が混入さ
れており、燃焼初期における余剰反応度を制限内
に規制するように構成されている。そして、炉心
１の最外層すなわち第１層目に配置されている燃
料集合体３…から炉心１の中心側に向つて第４層
目に配置されている燃料集合体３…までの間を周
辺領域５とし、また第５層目の燃料集合体３…か
ら内側を中央領域６とし、これら周辺領域５と中
央領域６とでは燃料集合体３…の装荷パターンが
異なつている。そして、中央領域６では各単位格
子４…内に新しく装荷された未燃焼の燃料集合体
３…、１炉心年燃焼された燃料集合体３…、２炉
心年燃焼された燃料集合体３…および３炉心年燃
焼された燃料集合体３…がそれぞれ１体ずつ装荷
されている。なお、図中燃料集合体３…の位置に
記された数字はその燃料集合体３…の燃焼期間を
示し、０は未燃焼のもの、１は１炉心年燃焼させ
たもの、２は２炉心年燃焼されたもの、３は３炉
心年燃焼されたもの、４は４炉心年燃焼されたも
のであることを示す。また、周辺領域５では単位
格子４…とは無関係な装荷パターンであり、最外
層すなわち１層目には２炉心年以上燃焼した燃料
集合体３…が装荷され、２層目には１炉心年以上
燃焼した燃料集合体３…が装荷され、第３層目に
は新しく装荷される未燃焼の燃料集合体３…が装
荷され、さらに第４層目には２炉心年以上燃焼し
た燃料集合体３…が装荷されている。そして、上
記燃料集合体３…の装荷パターンは炉心１のＸ方
向およびＹ方向の中心線に対して対称であり、第
１図にはひとつの象限の装荷パターンのみを示
す。なお、回転対称をもたせた装荷パターンの場
合には炉心１の中心に位置する単位格子４には３
炉心年以上燃焼した燃料集合体３…を装荷する。
以上の如く構成された本発明の一実施例は、周
辺領域５と中央領域６とで燃料集合体３…の装荷
パターンを異ならせ、周辺領域５の第３層目に未
燃焼の燃料集合体３…を装荷したので、燃料中に
混入された可燃性毒物が効率よく燃焼され、かつ
炉心１の出力分布が平坦となる。次にその理由を
述べる。炉心１の径方向の中性子束分布φ（γ）
は無限円柱状均一炉心の場合
φ（γ）＝2.3J0（２．４０５／Ｒγ）……(1)
で示される。なおJ0は第１種ベツセル関数、Ｒは
炉心半径である。そして、炉心１ではその中性子
束分布は第３図に示す様な特性を示す。そして、
従来このような炉心の周辺部に装荷された未燃焼
の燃料集合体が１炉心年燃焼されたときの可燃性
毒物の燃焼の割合を調べたところ、第１表に示す
如き結果を得た。
The present invention relates to a core structure of a boiling water nuclear reactor or the like. Generally, in a boiling water reactor, four fuel assemblies are arranged around a control rod having a cross-shaped cross section to form a unit cell, and the unit cells are arranged to form a reactor core. Then, one each of unburned fuel assemblies, fuel assemblies that have been burned for one core year, fuel assemblies that have been burned for two core years, and fuel assemblies that have been burned for three core years are loaded in this unit grid. The fuel assembly is configured to replace the most burnt fuel assembly with an unburned fuel assembly every core year. by the way,
The fuel for boiling water reactors has a high concentration of uranium-235 in order to extend the combustion period, and in this case, as shown by the broken line in Figure 2, flammable Contains toxic substances. This burnable poison is constructed so that its toxicity disappears when it is burned for about one core year, that is, at a burnup of about 8000 MWD/D. This burnable poison suppresses excessive reactivity in the early stage of fuel combustion, and quickly disappears after being burned for a predetermined period of time, for example, one core year.
It is preferable not to interfere with combustion of the fuel. However, as mentioned above, in the conventional system, a loading pattern is formed in which unburned fuel assemblies and fuel assemblies that have been burned for 1 to 3 core years are loaded in the unit grid over the entire area of the reactor core. As a result, combustion of burnable poisons did not proceed sufficiently in the vicinity of the reactor core, resulting in residual toxicity and loss of excess reactivity. That is, the neutron flux distribution in the radial direction of the core generally exhibits characteristics as shown in FIG. 3, with the neutron flux becoming smaller in the periphery of the core. Therefore, combustion of burnable poisons does not proceed in the fuel assemblies loaded around the core, and toxicity remains. The present invention has been made based on the above circumstances, and its objectives are to improve the combustion efficiency of burnable poisons mixed in fuel, reduce the loss of excess reactivity due to the residual burnable poisons, and The objective is to obtain a nuclear reactor that can average out the power distribution of . The present invention will be described below with reference to an embodiment shown in FIG. 1 in the figure is the reactor core, and this core 1
Control rods 2... and fuel assemblies 3... are arranged. The control rods 2 have a cross-shaped cross section, and four fuel assemblies 3 are arranged around the control rods 2 to form a unit grid 4. These unit cells 4 are arranged in a lattice form to constitute the core 1. A burnable poison such as gadolinia is mixed into the nuclear fuel housed in the fuel assembly 3, and the fuel assembly 3 is configured to control excess reactivity within a limit at the initial stage of combustion. Then, the area between the fuel assemblies 3 placed in the outermost layer of the core 1, that is, the first layer, and the fuel assemblies 3 placed in the fourth layer toward the center of the core 1 is covered. The inner side of the fuel assemblies 3 in the fifth layer is defined as a region 5, and the inner side of the fuel assemblies 3 in the fifth layer is defined as a central region 6, and the loading patterns of the fuel assemblies 3 are different between the peripheral region 5 and the central region 6. In the central region 6, unburned fuel assemblies 3 newly loaded in each unit grid 4, fuel assemblies 3 burned in one core year, fuel assemblies 3 burned in two core years, and One fuel assembly 3..., which has been burned for three cores, is loaded. In addition, the numbers written at the positions of fuel assemblies 3 in the figure indicate the combustion period of the fuel assemblies 3, where 0 indicates unburned, 1 indicates 1 core year, and 2 indicates 2 cores. 3 indicates that the core was burned for 3 core years, and 4 indicates that the core was burned for 4 core years. In addition, in the peripheral region 5, the loading pattern is unrelated to the unit grid 4, and the outermost layer, that is, the first layer, is loaded with fuel assemblies 3 that have burned for more than two core years, and the second layer is loaded with fuel assemblies 3 that have burned for more than one core year. The fuel assemblies 3 that have been burned above are loaded, the third layer is loaded with newly loaded unburned fuel assemblies 3, and the fourth layer is loaded with fuel assemblies that have been burned for more than two core years. 3... is loaded. The loading pattern of the fuel assemblies 3 is symmetrical with respect to the center line of the core 1 in the X and Y directions, and only one quadrant of the loading pattern is shown in FIG. In addition, in the case of a loading pattern with rotational symmetry, the unit cell 4 located at the center of the core 1 has 3
Fuel assemblies 3... that have been burned for more than a year are loaded. In one embodiment of the present invention configured as described above, the loading pattern of the fuel assemblies 3 is different between the peripheral region 5 and the central region 6, and unburnt fuel assemblies are placed in the third layer of the peripheral region 5. 3... is loaded, the burnable poison mixed in the fuel is efficiently burned, and the power distribution of the core 1 becomes flat. Next, I will explain the reason. Neutron flux distribution in the radial direction of core 1 φ(γ)
is expressed as φ(γ)=2.3J 0 (2.405/Rγ)...(1) in the case of an infinite cylindrical homogeneous core. Note that J 0 is the Bessel function of the first kind, and R is the core radius. In the core 1, the neutron flux distribution exhibits characteristics as shown in FIG. and,
When we investigated the combustion rate of burnable poisons when unburned fuel assemblies conventionally loaded in the periphery of the core were burned for one core year, we obtained the results shown in Table 1.
【表】
この結果から、第４層より内側の領域であれば、
どのような位置に未燃焼の燃料集合体３…を装荷
しても可燃性毒物は効率よく燃焼し、実質的に余
剰反応度の損失を招くような毒性は残らない。し
たがつて、この領域では出力分布が平坦化され、
かつ燃料の燃焼計画に最も都合の良い従来と同様
の装荷パターンすなわち単位格子４…内に未燃焼
および１〜３炉心年燃焼した燃料集合体３…を１
体ずつ装荷パターンが採用できる。しかし、この
ような装荷パターンは単位格子４…を単位とする
ものであるから第４層目より内側の領域でこの装
荷パターンを採用すると第４層目の燃料集合体３
…が余つてしまうことになる。したがつて、第５
層目から内側を中央領域６とすれば中央領域６に
は整数個の単位格子４…が含まれ、上記の単位格
子４…を単位とする装荷パターンが採用できる。
そして、最外層から第４層目までを周辺領域５と
し、この周辺領域５では未燃焼の燃料集合体３…
の装荷位置によつてその可燃性毒物の燃焼に差が
生じるので、上記中央領域６とは異なる装荷パタ
ーンを採用する。この周辺領域５で可燃性毒物が
完全に燃焼するのへ第４層目であるが、この第４
層目に未燃焼の燃料集合体３…を装荷すると単位
格子４…内に２体の未燃焼の燃料集合体３…が配
置され、１本の制御棒２…の周囲の４体の燃料集
合体３…のうち２体までが未燃焼の燃料集合体３
…となる。そしてこの未燃焼の燃料集合体３…は
第２図に示す如く約１炉心年燃焼されると余剰反
応度が最大となるので、燃焼末期にこの単位格子
４…全体の余剰反応度が過大となり、１本の制御
棒２…の引抜きだけでこの部分が臨界に達してし
まう不具合が生じる。しかし、未燃焼の燃料集合
体３…を第３層目に装荷した場合には、上記と同
様に単位格子４…内に２本の未燃焼の燃料集合体
３…が配置されることになるが、この第３層目で
は相対中性子束分布量が約0.6と比較的低いた
め、上記単位格子４…内に２体の未燃焼の燃料集
合体３…が配置されることによる余剰反応度の過
度の上昇は生じない。したがつて、１本の制御棒
２…の引抜によつてこの部分が臨界に達するよう
なことがなく、また局部的な出力上昇を生じるこ
ともなく炉心１の出力分布が平坦化される。また
未燃焼の燃料集合体３…の可燃性毒物は効率的に
燃焼され、残留した可燃性毒物による余剰反応度
の損失を減少させることができる。さらに１炉心
年燃焼した燃料集合体３…は余剰反応度が最大と
なつているので、これを第４層目に配置すると上
述と同様の不具合を生じるため、この第４層目に
は余剰反応度の低下した２炉心年以上燃焼した燃
料集合体３…を装荷するのが好ましいものであ
る。また、１炉心年燃焼した燃料集合体３…を第
２層目に装荷したので、炉心１の出力分布がより
平坦化される。すなわち、１炉心年燃焼した燃料
集合体３…はその余剰反応度が最も大きいが、こ
れを最外層に配置した場合には相対中性子束分布
量が0.1程度であり、炉心１全体としてこの燃料
集合体３…が余剰反応度に寄与する割合が少な
く、また出力分担の割合が低く、出力分布の平坦
化に寄与する割合が少なくなる。これに対し第２
層目では相対中性子束分布量が比較的大きいた
め、この燃料集合体３…の核分裂の度合が大とな
り、余剰反応度に比較的大きく寄与し、また炉心
１の出力分布をより平坦化するものである。
なお、実際の炉心において8000MWD／Ｔ燃焼
後における従来炉心を本発明炉心の燃焼特性を比
較した結果を第２表に示す。なお、この第２表中
の各欄に複数の数値が記入されている場合には、
その領域に燃焼サイクル数の異なる複数の燃料集
合体が装荷されていることを示し、各数値はそれ
ぞれ各燃焼サイクル数の異なる燃料集合体に対応
するものである。
そして、この第２表から明らかなように、本発
明の炉心は従来の炉心より周辺領域におけるＫ∞
が大きく、よつて炉心全体の出力分布が平坦化さ
れる。また、本発明の炉心はこの周辺部における
残留可燃性毒物の量が減少し、この周辺部におい
て可燃性毒物が効率よく燃焼されていることが示
されている。したがつて、この残留可燃性毒物に
よる反応度の損失が少ないので、この本発明によ
る炉心は燃焼度を8200MWD／Ｔまで延長させる
ことができる。[Table] From this result, if the area is inside the 4th layer,
No matter where the unburned fuel assemblies 3 are loaded, the burnable poison is efficiently burned, and no toxicity remains that would cause a substantial loss of excess reactivity. Therefore, the output distribution is flattened in this region, and
In addition, the loading pattern similar to the conventional one that is most convenient for the fuel combustion plan is used, that is, the unburned fuel assemblies 3... that have been burned for 1 to 3 core years are placed in the unit grid 4...
Loading patterns can be adopted for each body. However, since such a loading pattern is based on the unit grid 4, if this loading pattern is adopted in the area inside the fourth layer, the fuel assembly 3 in the fourth layer
...will be left over. Therefore, the fifth
If the inner side from the layer is defined as the central region 6, the central region 6 includes an integral number of unit lattices 4, and a loading pattern in which the unit lattice 4 is used as a unit can be adopted.
The area from the outermost layer to the fourth layer is defined as a peripheral area 5, and in this peripheral area 5, unburned fuel assemblies 3...
Since the burning of the burnable poison differs depending on the loading position of the central area 6, a loading pattern different from that of the central area 6 is adopted. The burnable poison is completely burned in this peripheral area 5 in the fourth layer.
When unburned fuel assemblies 3 are loaded in the layer, two unburned fuel assemblies 3 are placed in the unit grid 4, and four fuel assemblies are placed around one control rod 2. Fuel assembly 3 of which up to two bodies are unburned
...becomes... As shown in Figure 2, the surplus reactivity of this unburned fuel assembly 3 reaches its maximum after being burned for about one core year, so at the end of combustion, the surplus reactivity of the entire unit cell 4 becomes excessive. , a problem occurs in which this portion reaches criticality just by withdrawing one control rod 2 . However, when unburned fuel assemblies 3... are loaded in the third layer, two unburned fuel assemblies 3... are placed in the unit grid 4... in the same way as above. However, in this third layer, the relative neutron flux distribution is relatively low at about 0.6, so the surplus reactivity due to the two unburned fuel assemblies 3... being placed in the unit cell 4... No excessive increase will occur. Therefore, the power distribution of the core 1 is flattened without causing this portion to reach criticality due to the withdrawal of one control rod 2, and without causing a local increase in power. Furthermore, the burnable poisons in the unburned fuel assemblies 3 are efficiently burned, and the loss of excess reactivity due to the remaining burnable poisons can be reduced. Furthermore, fuel assembly 3... which has been burned for one core year has the maximum surplus reactivity, so if it is placed in the fourth layer, the same problem as mentioned above will occur. It is preferable to load fuel assemblies 3 that have been burned for more than two years and have a reduced core temperature. Moreover, since the fuel assemblies 3 that have been burned for one core year are loaded in the second layer, the power distribution of the core 1 is made even more flat. In other words, the fuel assembly 3 that burns in one core year has the highest surplus reactivity, but when it is placed in the outermost layer, the relative neutron flux distribution is about 0.1, and this fuel assembly as the entire core 1. The proportion of body 3 contributing to surplus reactivity is low, the proportion of output sharing is low, and the proportion of contributing to flattening the output distribution is small. On the other hand, the second
Since the relative neutron flux distribution is relatively large in the layer, the degree of nuclear fission in this fuel assembly 3 is large, contributing to the surplus reactivity relatively largely, and further flattening the power distribution of the core 1. It is. Table 2 shows the results of comparing the combustion characteristics of the conventional core and the core of the present invention after 8000 MWD/T combustion in an actual core. In addition, if multiple numbers are entered in each column in this Table 2,
This indicates that a plurality of fuel assemblies with different numbers of combustion cycles are loaded in that area, and each numerical value corresponds to a fuel assembly with a different number of combustion cycles. As is clear from Table 2, the core of the present invention has a lower K ∞ in the peripheral region than the conventional core.
is large, and the power distribution throughout the core is therefore flattened. Furthermore, it has been shown that in the core of the present invention, the amount of residual burnable poisons in this peripheral area is reduced, and burnable poisons are efficiently burned in this peripheral area. Therefore, since the loss of reactivity due to the residual burnable poison is small, the core according to the present invention can extend the burnup up to 8200 MWD/T.
【表】
なお、本発明は上記の一実施例には限定されな
い。
たとえば周辺領域における燃料集合体の装荷パ
ターンは必らずしも上記の一実施例のものに限定
されず、要は第３層目に未燃焼の燃料集合体を装
荷すればよいものである。
また、中央領域における燃料集合体の装荷パタ
ーンも必らずしも上記一実施例のものに限定され
ない。
上述の如く本発明は炉心の最外層に位置する燃
料集合体から第４層目の燃料集合体までを周辺領
域、第５層目から内側を中央領域とし、周辺領域
では中央領域と異なる燃料集合体の装荷パターン
とし、この周辺領域の第３層目に未燃焼の燃料集
合体を装荷したものである。したがつて、周辺領
域では単位格子内の２体の未燃焼の燃料集合体が
中性子束分布量の適当な第３層目に装荷され、こ
の周辺領域に装荷された未燃焼の燃料集合体の可
燃性毒物が効率的に燃焼され、余剰反応度を損な
うことがないとともに炉心の出力分布も平坦化さ
れ炉心の健全性も向上する等、その効果は大であ
る。[Table] Note that the present invention is not limited to the above embodiment. For example, the loading pattern of fuel assemblies in the peripheral area is not necessarily limited to that of the above-mentioned embodiment, and the point is that unburned fuel assemblies may be loaded in the third layer. Further, the loading pattern of the fuel assembly in the central region is not necessarily limited to that of the above embodiment. As described above, in the present invention, the area from the fuel assembly located at the outermost layer of the core to the fuel assembly in the fourth layer is defined as the peripheral area, and the area from the fifth layer onwards is defined as the central area, and the peripheral area has different fuel assemblies from the central area. This is a loading pattern for the fuel cell, and unburned fuel assemblies are loaded in the third layer of this peripheral area. Therefore, in the peripheral region, the two unburned fuel assemblies in the unit cell are loaded into the third layer appropriate for the neutron flux distribution, and the unburned fuel assemblies loaded in this peripheral region are The burnable poisons are efficiently burned, surplus reactivity is not lost, and the power distribution of the reactor core is flattened, improving the health of the reactor core, which has great effects.
第１図は本発明の一実施例の燃料集合体装荷パ
ターン図、第２図は核燃料の燃焼度と余剰反応度
の特性図、第３図は炉心の相対中性子分布図であ
る。
１……炉心、２……制御棒、３……燃料集合
体、４……単位格子、５……周辺領域、６……中
央領域。
FIG. 1 is a fuel assembly loading pattern diagram of an embodiment of the present invention, FIG. 2 is a characteristic diagram of nuclear fuel burnup and surplus reactivity, and FIG. 3 is a relative neutron distribution diagram of the reactor core. 1... Core, 2... Control rod, 3... Fuel assembly, 4... Unit cell, 5... Peripheral region, 6... Central region.
Claims (1)
に向つて第４層目に位置する燃料集合体までの間
を周辺領域とし、第５層目に位置する燃料集合体
から中心までを中央領域とし、上記周辺領域は上
記中央領域とは異なる燃料装荷パターンとし、第
３層目に未燃焼燃料集合体を装荷したことを特徴
とする原子炉。 ２ 前記周辺領域は第４層目に２炉心年以上燃焼
した燃料集合体が装荷されていることを特徴とす
る前記特許請求の範囲第１項記載の原子炉。 ３ 前記周辺領域は第２層目に１炉心年燃焼した
燃料集合体が装荷され、また最外層には２炉心年
以上燃焼した燃料集合体を装荷されていることを
特徴とする前記特許請求の範囲第１項または第２
項記載の原子炉。[Claims] 1. The area between the fuel assemblies located in the outermost layer of the core and the fuel assemblies located in the fourth layer toward the center is defined as a peripheral region, and the fuel assemblies located in the fifth layer 1. A nuclear reactor characterized in that the area from the center to the center is a central region, the peripheral region has a fuel loading pattern different from that of the central region, and a third layer is loaded with unburned fuel assemblies. 2. The nuclear reactor according to claim 1, wherein a fourth layer of the peripheral area is loaded with fuel assemblies that have been burned for two core years or more. 3. In the peripheral area, the second layer is loaded with fuel assemblies that have been burned for one core year, and the outermost layer is loaded with fuel assemblies that have been burned for two or more core years. Range 1st or 2nd
Nuclear reactor described in section.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP16450179A JPS5687891A (en) | 1979-12-18 | 1979-12-18 | Reactor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP16450179A JPS5687891A (en) | 1979-12-18 | 1979-12-18 | Reactor |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5687891A JPS5687891A (en) | 1981-07-16 |
| JPS6134639B2 true JPS6134639B2 (en) | 1986-08-08 |
Family
ID=15794350
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP16450179A Granted JPS5687891A (en) | 1979-12-18 | 1979-12-18 | Reactor |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5687891A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS61258363A (en) * | 1985-05-10 | 1986-11-15 | Hitachi Ltd | Magnetic head revolving device |
| JPS6314358A (en) * | 1986-07-04 | 1988-01-21 | Mitsubishi Electric Corp | Rotary head assembly for magnetic recording and reproducing device |
Families Citing this family (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS57202675A (en) * | 1981-06-08 | 1982-12-11 | Matsushita Electric Ind Co Ltd | Sheathed heater |
| JPS57202678A (en) * | 1981-06-08 | 1982-12-11 | Matsushita Electric Ind Co Ltd | Sheathed heater |
| JPS58178286A (en) * | 1982-04-12 | 1983-10-19 | 株式会社東芝 | Bwr type reactor |
| JP2915200B2 (en) * | 1991-07-24 | 1999-07-05 | 株式会社日立製作所 | Fuel loading method and reactor core |
| JP2007101398A (en) * | 2005-10-05 | 2007-04-19 | Nuclear Fuel Ind Ltd | Reactor core characterization evaluation tool |
| RU2557563C9 (en) * | 2009-11-06 | 2015-11-20 | ТерраПауэр, ЭлЭлСи | Methods and systems for displacement of fuel elements in nuclear reactor |
| US9799416B2 (en) | 2009-11-06 | 2017-10-24 | Terrapower, Llc | Methods and systems for migrating fuel assemblies in a nuclear fission reactor |
| US9922733B2 (en) | 2009-11-06 | 2018-03-20 | Terrapower, Llc | Methods and systems for migrating fuel assemblies in a nuclear fission reactor |
| US9786392B2 (en) | 2009-11-06 | 2017-10-10 | Terrapower, Llc | Methods and systems for migrating fuel assemblies in a nuclear fission reactor |
| US10008294B2 (en) | 2009-11-06 | 2018-06-26 | Terrapower, Llc | Methods and systems for migrating fuel assemblies in a nuclear fission reactor |
-
1979
- 1979-12-18 JP JP16450179A patent/JPS5687891A/en active Granted
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS61258363A (en) * | 1985-05-10 | 1986-11-15 | Hitachi Ltd | Magnetic head revolving device |
| JPS6314358A (en) * | 1986-07-04 | 1988-01-21 | Mitsubishi Electric Corp | Rotary head assembly for magnetic recording and reproducing device |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5687891A (en) | 1981-07-16 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP2915200B2 (en) | Fuel loading method and reactor core | |
| JPS6244632B2 (en) | ||
| JPS6134639B2 (en) | ||
| JPH0536757B2 (en) | ||
| JP3945719B2 (en) | Initial core | |
| JPH01277798A (en) | Nuclear reactor fuel assembly | |
| JPS6228437B2 (en) | ||
| JP3080663B2 (en) | Operation method of the first loading core | |
| JPS59132389A (en) | Fuel assembly | |
| JP3075749B2 (en) | Boiling water reactor | |
| JPH0636047B2 (en) | Fuel assembly for nuclear reactor | |
| JP2972917B2 (en) | Fuel assembly | |
| JP2852101B2 (en) | Reactor core and fuel loading method | |
| JPS6335440Y2 (en) | ||
| JPH0432355B2 (en) | ||
| JP4653342B2 (en) | Boiling water reactor core | |
| JPS63133086A (en) | Fuel aggregate for boiling water type reactor | |
| JPS6039589A (en) | Fuel aggregate | |
| JPH06347578A (en) | Firstly loaded core of boiling water reactor | |
| JP4044993B2 (en) | Reactor fuel loading method | |
| JPH0331794A (en) | Boiling water reactor | |
| JPH0446396B2 (en) | ||
| JP3274215B2 (en) | Fuel assembly | |
| JPS6158789B2 (en) | ||
| JPS62261988A (en) | Boilint water type reactor |