CA1160765A - Absorber member for mounting in the lattice of a boiling water reactor - Google Patents
Absorber member for mounting in the lattice of a boiling water reactorInfo
- Publication number
- CA1160765A CA1160765A CA000385074A CA385074A CA1160765A CA 1160765 A CA1160765 A CA 1160765A CA 000385074 A CA000385074 A CA 000385074A CA 385074 A CA385074 A CA 385074A CA 1160765 A CA1160765 A CA 1160765A
- Authority
- CA
- Canada
- Prior art keywords
- absorber
- sheet
- channels
- sheet element
- ridges
- 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
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
Abstract
ABSTRACT OF THE DISCLOSURE:
An elongated absorber plate, which is stationarily mounted in a gap between two fuel assemblies in a reactor core, comprises a plurality of absorber channels which are filled with a burnable absorber material. The channels are formed by welding to each other two confronting sheet elements of which at least one is corrugated.
An elongated absorber plate, which is stationarily mounted in a gap between two fuel assemblies in a reactor core, comprises a plurality of absorber channels which are filled with a burnable absorber material. The channels are formed by welding to each other two confronting sheet elements of which at least one is corrugated.
Description
The present invention relates to an absorber member arranged in a boiling water reactor (sWR) in a gap between two bunales of vertical fuel rods and comprising at least one absorber plate which contains burnable absorber material.
It is known to make such absorber members in the form of an elongated homogeneous plate which is made of boron steel and formed with a constant, rectangular cross-section along a major part of its length.
In comparison with the known member, an absorber member according to the invention aims at achieving a greater amount of burnable absorber material in relation to carrier material and at achieving as low a final absorption as pos-sible.
According to the present invention there is pro-vided an absorber member stationarily arranged in a boiling water reactor in a gap between two bundles of vertical fuel rods, comprising at least one absorber plate which contains burnable absorber material, each of the two side surfaces of said absorber plate facing a corresponding bundle of fuel rods, said absorber plate containing a first and a second sheet elements, arranged adjacent to each other, each pro-viding one o said side surfaces, at least said first sheet element having a corrugated shape with a plurality of mutually parallel wave ridges, said first and second sheet elements being connected to each other by means of a plural-ity of welded ]oints arranged on said wave ridges, a plural-ity of channels being defined between said first sheet element and said second sheet element, said channels being filled.with said burnable absorber material.
The intention o the present invention is to achieve an absorber member comprising one single or a plu-rality of absorption plates arranged vertically one after the other, which are formed in such a manner that the .
absorption capacity of each plate falls relatively evenly as a function of the time of operation. The absorber member which, when arranged in a gap between two fuel boxes, . _ has a relatively great thickness along a predominant part of its length, for example corresponding to a maximum burnup time of at least half a year, and at the same time permits a sufficient passage of water in the corresponding portion of the gap.
" 1 16076~
In the following the invention will be described with reference to the accompanying schematic drawings.
Figures 1 and 2 show a horizontal view of a first and a second embodiment of an absorber member according to the invention. Fi~ures 1a, 1b, 1c and 1d show sections along a-a, b-b, c-c and d-d of Figure 1, that iB, through each of the four absorber plates, A, B, C, D, which are connected to each other and together form an absorber member. Figures 3 and 4 show partial horizontal sections of two different reactor cores, in which a plurality of absorber memberæ according to the invention are arranged. Figures 5 and 6 show a third and a fourth embodiment of an absorber member according to the invention in cross-section through the channels filled with absorber material.
Figure 7 shows the number of absorbing cores per cm2 in different portions of an absorber channel of triangular cross-section, and Figure B shows the absorption capacity of such a channel as a function of time.
The absorber member 1 shown in Figure 1 is composed of four mutually inter-connected absorber plates A, B, C, D, arranged vertically one after the other. Each of the absorber plates A, ~, C, ~ contains a plane sheet element 2a, 2b, 2c, 2d, respectively, and a wavy sheet element, 3a, 3b, 3c, 3d, respectively, a plurality of wave ridges 4a, 4b, 4c, 4d, respectively, facing the plane sheet element,being welded to said wavy sheet element.
A plurality of absorber channels 5a, 5b, 5c, 5d, respectively of triangular cros~-section are then formed between the two sheet elements. Each of said absorber channels is filled with a burnable absorber material, for example gadolinium oxide. In all embodiments, the sheet elements of the absorber plates are preferably made of a zirconium alloy intended for reactor compo-nents, that is, an alloy with low neutron absorption. The thickness of the sheet is less than 1,0 mm, preferably less than 0.7 mm. Absorber member 1 i8 provided with a lifting eye 6. Absorber plate A has substantially the ~ame vertical dimension as absorber plate D. This dimension is smaller than 50 %
of the vertical dimension of absorber plate C, which ig at most 30 % longer than absorber plate B. The maximum absorption capacity per cm2 of the plate surface is varied by varyinOE the portion of the plate width occupied by absorp-tion channels (100 ~ in C, 75 ~ in B, 50 % in A and D). Varying burnup times have been obtained by making the absorption channels with varying channel heights. ~he channel height iB smallest in plates A and D, larger in plates B and largest in plate C.
It is known to make such absorber members in the form of an elongated homogeneous plate which is made of boron steel and formed with a constant, rectangular cross-section along a major part of its length.
In comparison with the known member, an absorber member according to the invention aims at achieving a greater amount of burnable absorber material in relation to carrier material and at achieving as low a final absorption as pos-sible.
According to the present invention there is pro-vided an absorber member stationarily arranged in a boiling water reactor in a gap between two bundles of vertical fuel rods, comprising at least one absorber plate which contains burnable absorber material, each of the two side surfaces of said absorber plate facing a corresponding bundle of fuel rods, said absorber plate containing a first and a second sheet elements, arranged adjacent to each other, each pro-viding one o said side surfaces, at least said first sheet element having a corrugated shape with a plurality of mutually parallel wave ridges, said first and second sheet elements being connected to each other by means of a plural-ity of welded ]oints arranged on said wave ridges, a plural-ity of channels being defined between said first sheet element and said second sheet element, said channels being filled.with said burnable absorber material.
The intention o the present invention is to achieve an absorber member comprising one single or a plu-rality of absorption plates arranged vertically one after the other, which are formed in such a manner that the .
absorption capacity of each plate falls relatively evenly as a function of the time of operation. The absorber member which, when arranged in a gap between two fuel boxes, . _ has a relatively great thickness along a predominant part of its length, for example corresponding to a maximum burnup time of at least half a year, and at the same time permits a sufficient passage of water in the corresponding portion of the gap.
" 1 16076~
In the following the invention will be described with reference to the accompanying schematic drawings.
Figures 1 and 2 show a horizontal view of a first and a second embodiment of an absorber member according to the invention. Fi~ures 1a, 1b, 1c and 1d show sections along a-a, b-b, c-c and d-d of Figure 1, that iB, through each of the four absorber plates, A, B, C, D, which are connected to each other and together form an absorber member. Figures 3 and 4 show partial horizontal sections of two different reactor cores, in which a plurality of absorber memberæ according to the invention are arranged. Figures 5 and 6 show a third and a fourth embodiment of an absorber member according to the invention in cross-section through the channels filled with absorber material.
Figure 7 shows the number of absorbing cores per cm2 in different portions of an absorber channel of triangular cross-section, and Figure B shows the absorption capacity of such a channel as a function of time.
The absorber member 1 shown in Figure 1 is composed of four mutually inter-connected absorber plates A, B, C, D, arranged vertically one after the other. Each of the absorber plates A, ~, C, ~ contains a plane sheet element 2a, 2b, 2c, 2d, respectively, and a wavy sheet element, 3a, 3b, 3c, 3d, respectively, a plurality of wave ridges 4a, 4b, 4c, 4d, respectively, facing the plane sheet element,being welded to said wavy sheet element.
A plurality of absorber channels 5a, 5b, 5c, 5d, respectively of triangular cros~-section are then formed between the two sheet elements. Each of said absorber channels is filled with a burnable absorber material, for example gadolinium oxide. In all embodiments, the sheet elements of the absorber plates are preferably made of a zirconium alloy intended for reactor compo-nents, that is, an alloy with low neutron absorption. The thickness of the sheet is less than 1,0 mm, preferably less than 0.7 mm. Absorber member 1 i8 provided with a lifting eye 6. Absorber plate A has substantially the ~ame vertical dimension as absorber plate D. This dimension is smaller than 50 %
of the vertical dimension of absorber plate C, which ig at most 30 % longer than absorber plate B. The maximum absorption capacity per cm2 of the plate surface is varied by varyinOE the portion of the plate width occupied by absorp-tion channels (100 ~ in C, 75 ~ in B, 50 % in A and D). Varying burnup times have been obtained by making the absorption channels with varying channel heights. ~he channel height iB smallest in plates A and D, larger in plates B and largest in plate C.
-2-`` 1 160765 The absorber member 8hown in Figure 2 differ~ from that described above in that the wave rid6es 4a', 4b', 4c', 4d' of the absorber plates A', ~', C', D' are running horizontally instead of vertically.
Absorption members of a design similar to those shown in Figures 1 and 2, may also be provided with absorber plates constructed according to Figures 5 and 6. ~he absorber plate 18 shown in Figure 5 differs from those shown in Figures 1 and 2 in that its waved ~heet element 6 ~ubstantially follow~
a sinusoidal curve. A plurality of absorber channels 8 are formed between the sheet element 6 and a plane sheet element 7.
In the absorber plate 19 shown in Figure 6, a plurality of absorber channels 9 are formed with the aid of two waved sheet elements, 10 and 11. The sheet elements 10 and 11 have a plurality of parallelly running wave ridges 12 and 12', respectively, and intermediate, substantially plane sheet portions 13 which are positioned in one and the same plane. The wave ridges 12 of the sheet element 10 are welded to the plane sheet portions 13 of the sheet element 11, and vice versa.
Figure 3 shows part of a reactor core of a oonventional design in which a plurality of ab~orber members 1 are arranged. The core contains a plurality of fuel rod bundles, which are each included in a fuel assembly 14. ~he fuel assemblies 14 are separated from each other by meanæ of intermediate gaps. Some of the gaps are relatively wide and are intended for control rods 15. A plurality of the other gæps are each provided with an absorber member 1.
Figure 4 shows a cross-section through a four-part fuel assembly which is composed of four partial assemblies 16 which are provided with a common bottom portion (not shown). The four-part fuel assembly i8 made with the same external dimensions as the fuel assembly 14, shown in Figure 3, and may replace this. Gaps 17 are provided between the partial assemblies 16 of the fuel aasembly and are each furnished with an absorber member according to the invention, the maximum thickness of said absorber member then consti-tuting at least 75 ~ of the width of the gap. The absorber members are each attached to the upper end of a corresponding partial assembly and may, when the burnable ab~orber material is consumed, be removed without the fuel assemblies or their partial assemblies being lifted out of the core.
An absorber member according to the invention is particularly well adapted 1 16~765 to be positioned in the relatively narrow ~aps between the partial assemblies in a four-part fuel assembly. Even when sdapted to a small gap width, the absorber member oan be constructed with such a large maximum thickness of the absorber bodies located in the channels that the time for complete burnup of the absorber material is sufficiently long, for example more than
Absorption members of a design similar to those shown in Figures 1 and 2, may also be provided with absorber plates constructed according to Figures 5 and 6. ~he absorber plate 18 shown in Figure 5 differs from those shown in Figures 1 and 2 in that its waved ~heet element 6 ~ubstantially follow~
a sinusoidal curve. A plurality of absorber channels 8 are formed between the sheet element 6 and a plane sheet element 7.
In the absorber plate 19 shown in Figure 6, a plurality of absorber channels 9 are formed with the aid of two waved sheet elements, 10 and 11. The sheet elements 10 and 11 have a plurality of parallelly running wave ridges 12 and 12', respectively, and intermediate, substantially plane sheet portions 13 which are positioned in one and the same plane. The wave ridges 12 of the sheet element 10 are welded to the plane sheet portions 13 of the sheet element 11, and vice versa.
Figure 3 shows part of a reactor core of a oonventional design in which a plurality of ab~orber members 1 are arranged. The core contains a plurality of fuel rod bundles, which are each included in a fuel assembly 14. ~he fuel assemblies 14 are separated from each other by meanæ of intermediate gaps. Some of the gaps are relatively wide and are intended for control rods 15. A plurality of the other gæps are each provided with an absorber member 1.
Figure 4 shows a cross-section through a four-part fuel assembly which is composed of four partial assemblies 16 which are provided with a common bottom portion (not shown). The four-part fuel assembly i8 made with the same external dimensions as the fuel assembly 14, shown in Figure 3, and may replace this. Gaps 17 are provided between the partial assemblies 16 of the fuel aasembly and are each furnished with an absorber member according to the invention, the maximum thickness of said absorber member then consti-tuting at least 75 ~ of the width of the gap. The absorber members are each attached to the upper end of a corresponding partial assembly and may, when the burnable ab~orber material is consumed, be removed without the fuel assemblies or their partial assemblies being lifted out of the core.
An absorber member according to the invention is particularly well adapted 1 16~765 to be positioned in the relatively narrow ~aps between the partial assemblies in a four-part fuel assembly. Even when sdapted to a small gap width, the absorber member oan be constructed with such a large maximum thickness of the absorber bodies located in the channels that the time for complete burnup of the absorber material is sufficiently long, for example more than
3/4 year. Thi6 is partly due to the fact that the sheet elements can be made very thin, for example with a thickness of less than 0.5 mm, partly to the fact that the corrugation of each absorber plate results in wave troughs there-in which, even if the intermediate sheet portions pro~ide a tot~l bridging of the gap, prev~nt hydraulic blocking. Instead of the absorber member shown in Figure 4, which is shown in detail in Figure 5, of course any of the other `embodiments shown in the drawings may be used. The embodiment shown in Figure 6 is particularlg advantageous, since the plane sheet portions 13 involve a reduced risk of wearing upon contact with adjacent fuel assemblies. In addition, these portions give a hydraulic damping which counteracts vibrations.
On examining the channel cross-section of the above-described fuel channels, it will be seen that in Figures 1, 2 and 6 said cross-section may be divided into two adjacently positioned right-angled triangles, a small side in each triangle lying in plane with plane limiting surfaces of a plurality of absorber channels. In the embodiment indicated in Figure 7, the channel cross-section consists of one single such triangle. In the channel cross-section shown in Figure 5, two such triangles 8' and 8" may be drawn in such a way that these cover at least 70 % of the channel cross-section.
If an ideal, black absorber is assumed, each of the above-mentioned triangular cross-sectional portions gives a linear burnup cycle. This i8 readily reali~ed by considering Figure 7 and Figure 8. On Figure 7, the hypotenuse in the shown triangle constitutes a curve which depicts the amount of burnable absorber material per cm2 of absorber plate as a function of the distance b from one longitudinal edge of the triangular channel.
It is shown how the channel crosg-section may possibly be divided into a plurality of equally wide portions a, b, c, d, e, f, g, h, i, j. The contents of burnable absorber material in portion a is designated ~N, the corresponding contents in portion b being equal to 1.5~N, in portion c equal to 2.5~N, and 80 on. Then, if we designate the average burnup time for the portion a as ~ t, the average burnup time for portion b is equal to 3~t, for portion c equal to 5~t, and so on.
Since the neutron absorption per cm2 of an absorber plate is substantially independent of the thiokness of the plate, the absorption of the portions a, b, c, and ~o on, has one and the same value, which is designated ~A in Figure 8. ~he absorption capacity of each of the portions a, b, c and 60 on is represented a~ a rectangle with a vertical ~ide of the length ~A and a horizontal side the length of which corresponds to the a~erage burnup time. ~y drawing such re¢tangles, a', b', c' and so on for all portions a, b, ¢ and 80 on and placing them on top Or each other in a system of ooordinates where the ordinate axis relates to the absorption, A, and the abscissa to the time, t, the stepped curve shown in Figure 8 is obtained, which curve approaches a straight line when portions a, b, c and 80 on in Figure 7 are selected with a sufficiently small width.
In practice, the absorber material cannot be considered to constitute an ideal black abæorber, and therefore, also in case of a channel cross-section according to Figure 7, a burnup cycle is obtained which is not quite linear.
However, the absorber channels are still selected with such a shape that the cross-sectional area of each channel is covered at least to 70 c~O by one or more inscribed right-angled triangles, a small side in each triangle then lying on a straight line which touches substantially plane portions of a plurality of absorber channels positioned adjacent to each other. Even if this condition is not fulfilled, the;wavy structure of an absorber member according to the invention results in a burnup cycle which is relatively even and which i8 considerably nearer the linearity than the burnup cycle of an absorber plate of rectangular cross-section, for example the known absorber plate mentioned at the beginning of this description.
In all embodiments of the invention, the absorber channels in an absorber plate are sealed at the ends, unless the ends are connected to corresponding channelæ of adjacent absorber plates.
On examining the channel cross-section of the above-described fuel channels, it will be seen that in Figures 1, 2 and 6 said cross-section may be divided into two adjacently positioned right-angled triangles, a small side in each triangle lying in plane with plane limiting surfaces of a plurality of absorber channels. In the embodiment indicated in Figure 7, the channel cross-section consists of one single such triangle. In the channel cross-section shown in Figure 5, two such triangles 8' and 8" may be drawn in such a way that these cover at least 70 % of the channel cross-section.
If an ideal, black absorber is assumed, each of the above-mentioned triangular cross-sectional portions gives a linear burnup cycle. This i8 readily reali~ed by considering Figure 7 and Figure 8. On Figure 7, the hypotenuse in the shown triangle constitutes a curve which depicts the amount of burnable absorber material per cm2 of absorber plate as a function of the distance b from one longitudinal edge of the triangular channel.
It is shown how the channel crosg-section may possibly be divided into a plurality of equally wide portions a, b, c, d, e, f, g, h, i, j. The contents of burnable absorber material in portion a is designated ~N, the corresponding contents in portion b being equal to 1.5~N, in portion c equal to 2.5~N, and 80 on. Then, if we designate the average burnup time for the portion a as ~ t, the average burnup time for portion b is equal to 3~t, for portion c equal to 5~t, and so on.
Since the neutron absorption per cm2 of an absorber plate is substantially independent of the thiokness of the plate, the absorption of the portions a, b, c, and ~o on, has one and the same value, which is designated ~A in Figure 8. ~he absorption capacity of each of the portions a, b, c and 60 on is represented a~ a rectangle with a vertical ~ide of the length ~A and a horizontal side the length of which corresponds to the a~erage burnup time. ~y drawing such re¢tangles, a', b', c' and so on for all portions a, b, ¢ and 80 on and placing them on top Or each other in a system of ooordinates where the ordinate axis relates to the absorption, A, and the abscissa to the time, t, the stepped curve shown in Figure 8 is obtained, which curve approaches a straight line when portions a, b, c and 80 on in Figure 7 are selected with a sufficiently small width.
In practice, the absorber material cannot be considered to constitute an ideal black abæorber, and therefore, also in case of a channel cross-section according to Figure 7, a burnup cycle is obtained which is not quite linear.
However, the absorber channels are still selected with such a shape that the cross-sectional area of each channel is covered at least to 70 c~O by one or more inscribed right-angled triangles, a small side in each triangle then lying on a straight line which touches substantially plane portions of a plurality of absorber channels positioned adjacent to each other. Even if this condition is not fulfilled, the;wavy structure of an absorber member according to the invention results in a burnup cycle which is relatively even and which i8 considerably nearer the linearity than the burnup cycle of an absorber plate of rectangular cross-section, for example the known absorber plate mentioned at the beginning of this description.
In all embodiments of the invention, the absorber channels in an absorber plate are sealed at the ends, unless the ends are connected to corresponding channelæ of adjacent absorber plates.
Claims (4)
1. An absorber member stationarily arranged in a boiling water reactor in a gap between two bundles of vertical fuel rods, comprising at least one absorber plate which contains burnable absorber material, each of the two side surfaces of said absorber plate facing a corresponding bundle of fuel rods, said absorber plate containing a first and a second sheet elements, arranged adjacent to each other, each providing one of said side surfaces, at least said first sheet element having a corrugated shape with a plurality of mutually parallel wave ridges, said first and second sheet elements being connected to each other by means of a plurality of welded joints arranged on said wave ridges, a plurality of channels being defined between said first sheet element and said second sheet element, said channels being filled with said burnable absorber material.
2. An absorber member as claimed in claim 1, wherein said second sheet element has a corrugated shape with a plurality of ridges which are parallel to the ridges of said first sheet element and, similar to these, mutually connected by means of a plurality of intermediate, substan-tially plane sheet portions lying in one and the same plane, said sheet portions of said second sheet element being each welded to a ridge of said first sheet element and vice versa.
3. An absorber member as claimed in claim 1 or 2, wherein the channel cross-section of each of said channels has such a shape that the cross-sectional area of the channel can be covered to at least 70 % by one or more in-scribed right-angled triangles, a small side in each triangle lying substantially in the same plane as a plurality of sub-stantially plane surface portions belonging to a plurality of mutually adjacent absorber channels.
4. An absorber member as claimed in claim 1, wherein said sheet elements are made of a zirconium alloy intended for nuclear reactors.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000385074A CA1160765A (en) | 1981-09-02 | 1981-09-02 | Absorber member for mounting in the lattice of a boiling water reactor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000385074A CA1160765A (en) | 1981-09-02 | 1981-09-02 | Absorber member for mounting in the lattice of a boiling water reactor |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1160765A true CA1160765A (en) | 1984-01-17 |
Family
ID=4120860
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000385074A Expired CA1160765A (en) | 1981-09-02 | 1981-09-02 | Absorber member for mounting in the lattice of a boiling water reactor |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1160765A (en) |
-
1981
- 1981-09-02 CA CA000385074A patent/CA1160765A/en not_active Expired
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4478786A (en) | Fuel assembly | |
| EP0283836B1 (en) | Thin walled channel | |
| US5666389A (en) | Fuel assembly and spacer for a nuclear reactor | |
| US4576786A (en) | Partial grid for a nuclear reactor fuel assembly | |
| US4544522A (en) | Nuclear fuel assembly spacer | |
| CA1210164A (en) | Fuel assembly for a boiling water reactor | |
| US6421407B1 (en) | Nuclear fuel spacer grid with dipper vanes | |
| US4357298A (en) | Nuclear fuel assembly space arrangement | |
| US6205196B1 (en) | Boiling water type nuclear reactor core and operation method thereof | |
| CA1175959A (en) | Fuel assembly | |
| US2852457A (en) | Nuclear reactors | |
| US4400347A (en) | Absorber member for mounting in the lattice of a boiling water reactor | |
| US4970048A (en) | Mixing grid with fins for nuclear fuel assembly | |
| US4926450A (en) | Fuel assembly | |
| CA1160765A (en) | Absorber member for mounting in the lattice of a boiling water reactor | |
| US5243634A (en) | DNB performing spacer grids | |
| US4888152A (en) | Fuel assembly grid for light water reactor | |
| USRE34246E (en) | Thin walled channel | |
| US5422922A (en) | Fuel assembly and reactor core | |
| EP0514215B1 (en) | Part length rod placement in boiling water reactor fuel assembly for reactivity control | |
| US5174950A (en) | Grid for nuclear fuel assembly | |
| US6332012B1 (en) | Grid strap for a nuclear fuel assembly, and a grid including such straps | |
| JPH11511553A (en) | Spacers and fuel assemblies for fuel assemblies | |
| JPH0713663B2 (en) | Fuel assembly | |
| JPH09166678A (en) | Mox fuel assembly |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |