JP2007278814A - Reactor water supply nozzle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve structure soundness of a water supply nozzle by suppressing thermal fatigue, caused by temperature fluctuation to the inside of the water supply nozzle attached to a reactor pressure vessel. <P>SOLUTION: This reactor water supply nozzle is equipped as a basic constitution with the water supply nozzle 1 being provided in the reactor pressure vessel, to which a water supply system is connected; a thermal sleeve 3 provided in the inside; a header tube 35 connected to its end through a T-piece 6; and a water injection nozzle 2 connected to the header tube 35. The width of a circular channel 9, between the water supply nozzle 1 inner surface and the thermal sleeve 3 outer surface, is widened to satisfy the inequality: 0.11<δ/Di≤0.16, in a range of the horizontal distance from a nozzle corner 38 of the water supply nozzle 1 to a safe end 39, wherein Di is the minimum value of the inner diameter of the water supply nozzle, and δ is the width of the circular channel between the minimum value Di of the inner diameter of the water supply nozzle and the maximum value of an outer diameter do of the thermal sleeve. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The technical field of the present invention relates to a reactor water supply nozzle that controls water supply to a reactor pressure vessel.

  FIG. 2 shows the configuration of the reactor pressure vessel employed in the improved boiling water reactor. A core 17 is installed in the shroud 12 in the reactor pressure vessel 11. Water is boiled in the core 17 containing fissile material, and the steam generated by the boiling flows into the steam separator 13 in a mixed state with warm water, and is separated into steam containing droplets and warm water.

  The hot water separated by the steam separator 13 is mixed with the water supplied from the water injection nozzle 2 of the water supply nozzle 1, passes through the downcomer 14 formed between the reactor pressure vessel 11 and the shroud 12, and passes through the reactor pressure vessel. 11 is driven by a recirculation pump 15 provided at the bottom, and is recirculated to the core 17 via the lower plenum 16.

  On the other hand, the steam containing the droplets separated by the steam separator 13 is removed from the steam by the steam dryer 18 disposed above the steam separator 13. It is sent to a high-pressure turbine and a low-pressure turbine via, and electricity is generated by a generator linked to the shafts of the high-pressure turbine and the low-pressure turbine.

  Steam used in each turbine is condensed into water by a condenser, and the temperature of the water is adjusted by each feed water heater as the feed water, the pressure is raised by the feed water pump, and the reactor pressure is passed through the water injection nozzle 2 of the feed water nozzle 1. Water is supplied into the container 11. A plurality of water supply nozzles 1 are provided in the circumferential direction of the reactor pressure vessel 11, and are divided into right and left by T-tubes in the reactor pressure vessel 11. The direction of the water injection nozzle 2 of the water supply nozzle 1 is a horizontal direction toward the center of the reactor pressure vessel 11 so that warm water and cooling water are uniformly mixed in a horizontal section.

  The structure of the feed nozzle of the improved boiling water reactor is shown in FIG. The water supply nozzle 1 is concentric with the water supply nozzle 1 in order to reduce thermal stress and thermal fatigue due to the temperature difference between the high-temperature reactor water 7 descending in the reactor pressure vessel 11 and the water supply 8 having a temperature lower than that of the reactor water. The thermal sleeve 3 is installed in a shape to avoid contact between two fluids having a direct temperature difference.

An annular channel 9 is provided between the inner surface of the water supply nozzle 1 and the outer surface of the thermal sleeve 3. One end of the thermal sleeve 3 is integrated with a portion of the water supply nozzle 1 near the water supply inlet 1a. A T-shaped T-shaped tube 6 is connected to the tip which is the other end of the thermal sleeve 3, and left and right header tubes 35 are connected to the left and right ends of the T-shaped tube 6. A plurality of L-shaped water injection nozzles 2 are connected.

  As shown in FIG. 3, the water injection nozzle 2 is connected to the upper position of the header pipe 35, and the water supply discharge port 36 faces in the horizontal direction toward the center of the reactor pressure vessel 11. Water is discharged from the discharge port 36 of the water injection nozzle 2 in the horizontal direction toward the center of the reactor pressure vessel 11 and supplied into the reactor pressure vessel 11. The central axis 2 a of the water injection nozzle 2 passing through the center of the water supply outlet 36 is disposed above the central axis 3 a common to the thermal sleeve 3 and the water supply nozzle 1. As shown in FIG. 3, a shroud head bolt 4 and a shroud head bolt ring 5 are disposed in the vicinity of the header pipe 35.

  Since the normal operating water level of the reactor water during the rated operation of the nuclear reactor is at the level indicated by the arrows AA in FIG. 2B, the water supply nozzle 1 provided at a position lower than that level. The inside is filled with high-temperature reactor water, and the shroud head bolt ring 5, the water injection nozzle 2, the header tube 35, the T-shaped tube 6 and the thermal sleeve 3 are present in the high-temperature reactor water. Naturally, the high-temperature reactor water 7 is also filled in the annular flow path 9 between the inner surface of the water supply nozzle 1 and the outer surface of the thermal sleeve 3.

  In the design of a normal boiling water reactor, the thermal power of the core is first determined, and the steam flow after the main steam pipe is optimized so that the highest thermal efficiency can be obtained with that thermal output. Specifically, when steam is converted into water by a condenser, 2/3 of the energy is discharged at a normal boiling water reactor pressure (about 7 MPa) from the principle of thermal cycle.

  Therefore, a part of the main steam is extracted and used to heat the feed water in the feed water heater. In this case, since the heat of the extracted steam is recovered, the thermal efficiency of the nuclear reactor is improved. In a boiling water reactor generally equipped with a moisture separator using a recirculation pump and a jet pump, the amount of steam finally sent from the low-pressure turbine outlet to the condenser is about 55 of the main steam. The remaining steam is used to heat the feed water.

  In Japanese Patent Application Laid-Open No. 2005-201696, there is a method for lowering the feed water temperature without increasing the main steam flow rate and the feed water flow rate in order to suppress an increase in load on the feed water pipe, the main steam pipe, and the structure in the reactor. Proposed. At this time, a large temperature difference occurs between the high-temperature reactor water and the low-temperature water supply in the water supply nozzle portion, and there is concern about thermal stress and thermal fatigue in the water supply nozzle portion. Therefore, a water supply system excellent in heat stress and heat fatigue is required.

  Moreover, as a cause of thermal fatigue of the water supply nozzle, both “high cycle thermal fatigue” that occurs during water supply during rated operation and “low cycle thermal fatigue” that occurs when water supply is stopped are considered. During water supply during rated operation, the annular flow path between the inner surface of the water supply nozzle and the outer surface of the thermal sleeve is filled with high-temperature reactor water, but heat is exchanged between the inner and outer surfaces of the thermal sleeve by the low-temperature water supply in the thermal sleeve. A density difference occurs in the reactor water in the annular flow path.

  Therefore, the reactor water in the annular channel is separated into an upper high temperature part and a lower low temperature part, and a high / low temperature water interface is formed in the annular channel. When water is supplied during rated operation, the water discharged from the water injection nozzle of the water supply nozzle bounces back to the reactor internal structure, and the bounced water enters the annular flow path, causing the temperature of the fluid around the nozzle corner to fluctuate. There are concerns about the impact.

  Accordingly, a taper portion is provided on the inner wall of the water supply nozzle body on the nozzle corner side, and a conical concave portion in which the inner diameter of the taper portion expands toward the pressure vessel wall is formed to eliminate thermal fatigue that is a concern with the water supply nozzle. This is described in Japanese Utility Model Publication No. 59-8197. Thereby, the width of the annular flow path of the nozzle corner portion is widened, so that low-temperature rebound water can easily enter the annular flow path, and mixing with the reactor water in the annular flow path is promoted.

  On the other hand, temperature fluctuations due to low-temperature rebound water in the annular flow path may occur not only on the nozzle corner side provided with the tapered part but also on the nozzle corner side to the safe end side where the water supply nozzle and thermal sleeve are connected. It is done. The water supply nozzle portion is a boundary portion with the outside of the pressure vessel as well as the pressure vessel wall, and thermal fatigue needs to be considered in a range from the nozzle corner side to the safe end side.

  However, in the conventional example, the inner wall of the water supply nozzle main body is composed of a tapered portion that forms a conical concave portion that expands toward the pressure vessel wall and a linear portion that forms a cylindrical surface deeper than the tapered portion. Therefore, there is a concern about thermal fatigue due to temperature fluctuations in the reactor water generated in the annular flow path on the safe end side behind the tapered portion.

  In JP-A-55-122196, a collector part and a guide part are installed in an annular flow path between the inner surface of the water supply nozzle and the outer surface of the thermal sleeve, and low-temperature rebound water is actively introduced into the annular flow path. Let them circulate. When the water supply nozzle is assembled, it is desirable that the center axis of the thermal sleeve is the same as the center axis of the water supply nozzle, that is, the width of the annular flow path is uniform in the circumferential direction.

  Therefore, when the guide portion is provided on the outer peripheral surface of the thermal sleeve, it is necessary to improve the manufacturing accuracy of the guide portion and the installation accuracy on the thermal sleeve. In addition, in order to fully utilize the effects of the collector part and guide part, it is necessary to manufacture the collector part and guide part with appropriate dimensions, and to install the collector part and guide part in an appropriate installation location. Confirmation is also required.

  On the other hand, when performing the penetration test of the inner wall of the water supply nozzle, it is desirable that there is no structural material on the inner surface of the water supply nozzle and the outer surface of the thermal sleeve. In the structure of the conventional example, the above test method considering the collector part and the guide part is examined. There is a need.

JP 2005-201696 A Japanese Utility Model Publication No.59-8197 JP-A-55-122196

  FIG. 4 shows the temperature distribution and flow state diagram of the fluid in the water supply nozzle 1 when water is supplied into the reactor pressure vessel. The annular flow path 9 between the inner surface of the water supply nozzle 1 and the outer surface of the thermal sleeve 3 is filled with high-temperature reactor water 7, but since the low-temperature water supply 8 flows in the thermal sleeve 3, the thermal sleeve 3. Heat exchange on the inside and outside of

  At this time, the temperature of the high-temperature reactor water 7 in contact with the outer surface of the thermal sleeve decreases in the annular flow path 9 due to heat exchange, and the low-temperature water 21 whose temperature has decreased has a high density. Since 20 has a low density, it separates to the upper part of the annular flow path 9 due to the density difference, thereby generating a high / low temperature water interface. However, if the high-low-temperature water interface 22 is statically stable, the water supply nozzle 1 and the thermal sleeve 3 become a problem only for static thermal stress generation.

  However, at the time of water supply, the low-temperature water supply 8 discharged from the water injection nozzle 2 toward the center of the reactor pressure vessel 11 rebounds to the water supply nozzle 1 side by the shroud head bolt ring 5 installed in the vicinity of the water injection nozzle 2 outlet, and the annular flow path 9 acts on the high / low temperature water interface 22 in 9 to cause temperature fluctuation.

  As a result, the temperature fluctuation in the annular flow path 9 propagates to the inner surface of the water supply nozzle 1 and the outer surface of the thermal sleeve 3 through heat transfer, and thermal fatigue due to the temperature fluctuation occurs in each material. There is a need to reduce temperature fluctuations. In the nuclear pressure vessel 11, the flow of hot reactor water flowing down from above the water injection nozzle 2 forms a dominant flow, and even when the shroud head bolt ring 5 shown in FIG. There is a concern that it will collide with a stand pipe located at the center of the furnace pressure vessel and bounce back to the water supply nozzle.

  The rebound water 23 discharged from the water injection nozzle 2 of the water supply nozzle 1 rises in temperature when heat is exchanged in the thermal sleeve 3 or discharged into the reactor pressure vessel 11, but forms a high / low temperature water interface 22. It is estimated that the temperature is lower than that of the low-temperature water 21. Therefore, if the rebound water discharged from the water injection nozzle 2 directly acts on the high / low temperature water interface 22, the temperature fluctuation range becomes large, and thermal fatigue is likely to occur in the water supply nozzle 1 and the thermal sleeve 3. Need to be reduced.

  Generally, in boiling water nuclear power generation systems, there is no particular control of the feed water temperature, so there is a change in the thermal balance of the entire plant, specifically, a coolant that condenses steam in a condenser (usually seawater). Due to temperature changes, even the same core and thermal power in the same boiling water nuclear power generation system can change within a range of less than 1 ° C. In order to compensate for the deterioration of the core characteristics when the power is improved, the feed water temperature may be reduced by 1 ° C. or more, which is greater than the fluctuation width of the feed water temperature during normal operation.

  However, the feed water is mixed with water at the saturation temperature in the reactor pressure vessel when entering the reactor pressure vessel. Therefore, a temperature difference is generated between the water supply pipe and the reactor pressure vessel. If the feed water temperature is lowered too much, the temperature difference increases at this part, and there is a concern that the design limit will be exceeded from the viewpoint of thermal fatigue.

  An object of the present invention is to suppress thermal fatigue with a simple configuration in a wide region from a nozzle corner of a water supply nozzle of a reactor pressure vessel to a safe end.

A first means for achieving the object of the present invention includes a water supply nozzle provided in a reactor pressure vessel, a water supply nozzle provided in the water supply nozzle, a safe end connected to the water supply nozzle, and an anti-safe end side In a reactor water nozzle comprising a thermal sleeve communicating with a header pipe and an annular flow path between the inner surface of the water nozzle and the outer surface of the thermal sleeve, Di is the minimum inner diameter of the water nozzle, When δ is the width of the annular flow path between the minimum value Di of the inner diameter of the water supply nozzle and the maximum value of the outer diameter do of the thermal sleeve, the horizontal from the nozzle corner of the water supply nozzle to the safe end Within the distance range, 0.11 <δ /
A reactor water supply nozzle having a width of the annular flow path satisfying a relational expression of Di ≦ 0.16.

  Similarly, in the first means, the second means has, in the horizontal distance range, a step on the outer peripheral surface of the thermal sleeve where the outer diameter of the thermal sleeve is smaller on the nozzle corner side than on the safe end side, The position of the step closest to the nozzle corner is 0.35 <x where L is the horizontal distance from the nozzle corner to the safe end and x is the distance from the nozzle corner to the step closest to the nozzle corner. The reactor water nozzle is arranged at a position satisfying the relational expression / L ≦ 1.

  Similarly, the third means includes a water supply nozzle provided in a reactor pressure vessel, a thermal nozzle provided in the water supply nozzle, a safe end connected to the water supply nozzle, and an anti-safe end side communicating with the header pipe. In the reactor water nozzle comprising a sleeve and an annular flow path between the inner surface of the water nozzle and the outer surface of the thermal sleeve, the water supply as the nozzle corner is approached from the safe end within the horizontal distance range. A reactor water supply nozzle having a tapered shape in which an inner diameter of a nozzle is enlarged.

  Similarly, the fourth means includes a water supply nozzle provided in the reactor pressure vessel, a thermal nozzle provided in the water supply nozzle, the safe end connected to the water supply nozzle, and the anti-safe end side communicating with the header pipe. In a nuclear reactor water supply nozzle comprising a sleeve and an annular flow path between an inner surface of the water supply nozzle and an outer surface of the thermal sleeve, in the range of the horizontal distance, as the nozzle corner approaches the nozzle corner A reactor water supply nozzle having a tapered shape in which an outer diameter of a thermal sleeve is reduced.

  Similarly, in the first means or the second means, the fifth means has a step in which the outer diameter of the thermal sleeve is smaller on the outer peripheral surface of the thermal sleeve on the nozzle corner side than on the safe end side in the horizontal distance range. The reactor water supply nozzle is characterized in that an inner diameter of the water supply nozzle located in a horizontal distance range from the nozzle corner to the position of the step closest to the nozzle corner is made larger than Di.

  Similarly, in the first means, the second means, or the fifth means, the sixth means has an outer diameter of the thermal sleeve on the outer peripheral surface of the thermal sleeve on the nozzle corner side than the safe end side in the horizontal distance range. The inner surface of the water supply nozzle located in a horizontal distance range from the nozzle corner to the position of the step closest to the nozzle corner has a tapered shape in which the inner diameter of the water supply nozzle increases toward the nozzle corner. This is a reactor water nozzle.

  Similarly, the seventh means is any one of the first means to the sixth means, wherein the reactor pressure vessel exceeds a rated heat output of the reactor at the initial stage of construction beyond the initial rated heat output after the construction. A reactor water supply nozzle which is a reactor pressure vessel applied to a reactor whose power is increased and increased.

  Similarly, the eighth means is the seventh means, wherein the nuclear reactor reduces the temperature of water at the inlet of the water supply nozzle by 1 ° C. or more from the temperature at the rated operation at the beginning of construction of the nuclear reactor. A reactor water nozzle is connected to a water supply system that leads toward a reactor pressure vessel.

  According to the invention of this application, it is possible to reduce the thermal stress generated on the inner surface of the water supply nozzle and the outer surface of the thermal sleeve by promoting the mixing of high-temperature reactor water and rebound water in the horizontal distance range from the nozzle corner of the water supply nozzle to the safe end. Therefore, the water supply nozzle excellent in heat fatigue can be realized.

  Means according to each embodiment for achieving the object of the present invention is as follows. That is, the first means is that the water supply nozzle, the thermal sleeve, the T-shaped tube and the water injection nozzle are arranged below the level of the reactor water in the reactor pressure vessel during the rated operation, and are parallel to the central axis of the water supply nozzle. Thus, the width of the annular flow path between the inner surface of the water supply nozzle and the outer surface of the thermal sleeve is widened in the range of the horizontal distance from the nozzle corner of the water supply nozzle to the safe end.

  In the second means, in addition to the first means, the thermal sleeve is arranged on the outer peripheral surface of the thermal sleeve toward the nozzle corner in the range of the horizontal distance from the nozzle corner of the water supply nozzle to the safe end in parallel with the central axis of the water supply nozzle. There is a step with a smaller outer diameter, and the position of the step closest to the nozzle corner is moved to the safe end side.

  The third means is that the inner surface of the water supply nozzle has a tapered shape that expands from the safe end toward the nozzle corner in the range of the horizontal distance from the safe end to the nozzle corner in parallel with the central axis of the water supply nozzle.

  The fourth means is that the outer peripheral surface of the thermal sleeve is tapered such that the outer peripheral surface of the thermal sleeve is reduced from the safe end toward the nozzle corner in the range of the horizontal distance from the safe end to the nozzle corner in parallel with the central axis of the water supply nozzle. .

  The fifth means includes, in addition to the first, second and fourth means, a horizontal line from the nozzle corner of the water supply nozzle to the step closest to the nozzle corner provided on the outer peripheral surface of the thermal sleeve in parallel with the central axis of the water supply nozzle. The inner diameter of the water supply nozzle corresponding to the distance range is increased.

  In addition to the first, second, fourth and fifth means, the sixth means is a step closest to the nozzle corner provided on the outer peripheral surface of the thermal sleeve from the nozzle corner of the water supply nozzle in parallel with the central axis of the water supply nozzle. The inner surface of the water supply nozzle corresponding to the range of the horizontal distance up to the taper shape that expands toward the nozzle corner.

  The seventh means is to adopt the reactor water supply nozzles shown in the first to sixth means in the existing, new and improved nuclear power plants.

  Hereinafter, each embodiment in which the present invention is applied to a nuclear power plant reactor facility will be specifically described with reference to the drawings. The water supply nozzle of the present invention is employed in the reactor pressure vessel 11 shown in FIG. The flow of the high-temperature reactor water 7 in the reactor pressure vessel 11 and the low-temperature feed water 8 from the feed water nozzle 1 will be described.

  From the BB cross section of FIG. 1, high-temperature reactor water 7 (for example, 280 ° C.) separated from steam by the steam separator 13 in the nuclear pressure vessel 11 shown in FIG. Flowing from above 2. Thereafter, the high temperature reactor water 7 is mixed with the low temperature feed water 8 discharged from the water injection nozzle 2, passes through the downcomer 14, is driven by the recirculation pump 15, and is recirculated to the core 17 via the lower plenum 16. The

  The low-temperature water supply 8 passes through the thermal sleeve 3 in the water supply nozzle 1 from the water supply pipe 37, is divided in two directions by the T-shaped pipe 6, passes through the header pipe 35 in the two directions, and enters each water injection nozzle 2. Then, the water is discharged from the discharge port 36 of each water injection nozzle 2 into the reactor pressure vessel 11.

  Since the direction of the discharge port 36 of the water injection nozzle 2 of the water supply nozzle 1 is a horizontal direction toward the center of the reactor pressure vessel 11, the low-temperature water supply 8 discharged into the reactor pressure vessel 11 is the reactor pressure. Mixing with the high-temperature reactor water 7 while moving and diffusing horizontally toward the center of the vessel 11.

  On the other hand, the annular flow passage 9 between the inner surface of the water supply nozzle 1 and the outer surface of the thermal sleeve 3 is filled with high-temperature reactor water 7, but since the low-temperature water supply 8 flows in the thermal sleeve 3, Heat exchange is performed on the inner and outer surfaces of the sleeve 3. At this time, the temperature of the high-temperature reactor water 7 in contact with the outer surface of the thermal sleeve decreases in the annular flow path 9 due to heat exchange, and the low-temperature water 21 whose temperature has decreased has a high density. Since 20 has a low density, it is separated to the upper part of the annular flow path 9 due to the density difference, and a high / low temperature water interface 22 is generated.

  A part of the discharged low-temperature water supply 8 rebounds to the water supply nozzle 1 side by the shroud head bolt 4, the shroud head bolt ring 5 and the reactor internal structure in the reactor pressure vessel 11, and the high and low temperature water in the annular channel 9. It acts on the interface 22 to cause temperature fluctuation. As a result, there is a concern that temperature fluctuations in the annular flow path 9 propagate to the inner surface of the water supply nozzle 1 and the outer surface of the thermal sleeve 3 through heat transfer, and thermal fatigue due to temperature fluctuations occurs in each material. The

The structural soundness of the water supply nozzle can be evaluated by thermal stress using the relationship shown in FIG. 5 and equations (1) and (2). In order to reduce the thermal stress generated on the wall surface of the water supply nozzle, it is necessary to reduce the temperature fluctuation width ΔT _f and the heat transfer coefficient h of the fluid in the annular flow path 9 between the inner surface of the water supply nozzle 1 and the outer surface of the thermal sleeve 3. There is.

ΔT _w ∝ f (ΔT _f , h) (1)
σ _alt ｆ f (ΔT _w ) (2)
Where ΔT _w is the temperature fluctuation width of the wall surface of the water supply nozzle, ΔT _f is the temperature fluctuation width of the fluid in the annular flow path between the inner surface of the water supply nozzle and the outer surface of the thermal sleeve, h is the heat transfer coefficient in the annular flow path, σ _alt is a thermal stress generated on the wall surface of the water supply nozzle.

As a final evaluation, if the thermal stress σ _alt generated on the wall surface of the water supply nozzle is lower than the fatigue limit σ _{cr of the} material, it is considered that there is no problem of thermal fatigue of the water supply nozzle. However, in practice, the water supply nozzle needs to be designed and manufactured in consideration of safety margin, although it is naturally lower than the fatigue limit.

Next, an outline of the results obtained by the reduced model test will be described. In the reduction model test, a test was performed in which the width of the annular flow path 9 between the inner surface of the water supply nozzle 1 and the outer surface of the thermal sleeve 3 was changed. FIG. 6 shows the temperature fluctuation range βmax with respect to the dimensionless axial distance x / L of the water supply nozzle. The horizontal axis indicates the dimensionless axial distance x / L. x represents a distance from the nozzle corner as shown in FIG. L indicates a horizontal distance (not shown) from the nozzle corner 38 to the safe end 39 parallel to the central axis of the water supply nozzle 1. The vertical axis indicates βmax that maximizes the temperature fluctuation width ΔT _{f of} the fluid slightly away from the outer peripheral surface of the water supply nozzle (circumferential angle is 0 to 180 °) at an arbitrary position.

  In the figure, ◯ indicates conventional example 1 (δ / Di≈0.11), Δ indicates conventional example 2 (δ / Di <0.11), and □ indicates the present invention (δ / Di> 0.11). Show. Di represents the minimum value of the inner diameter of the water supply nozzle, and δ represents the width of the annular flow path between the minimum value Di of the inner diameter of the water supply nozzle and the maximum value of the outer diameter do of the thermal sleeve. The temperature fluctuation range βmax of the fluid with respect to the dimensionless axial distance x / L increases on the nozzle corner 38 side and decreases and decreases on the safe end 39 side.

  Further, when the width of the annular flow path 9 is increased, the maximum temperature fluctuation range βmax of the fluid is decreased. In the structure in which the width of the annular channel 9 is widened, the maximum temperature fluctuation range of the fluid in the structure of the present invention is about Reduced by 10%.

  FIG. 7 shows the heat transfer coefficient with respect to the dimensionless axial distance of the water supply nozzle. The abscissa indicates the dimensionless axial distance x / L, and the ordinate indicates hmax that maximizes the heat transfer coefficient h on the outer peripheral surface (circumferential angle is 0 to 180 °) of the water supply nozzle at an arbitrary position. In the figure, three representative points are plotted in the axial direction of the water supply nozzle. As in FIG. 6, the heat transfer coefficient increases on the nozzle corner 38 side, and the heat transfer coefficient decreases on the safe end 39 side.

As for the influence of the width of the annular flow path 9, when compared with the dimensionless axial distance at which the heat transfer coefficient hmax is maximized, the heat transfer coefficient is increased by about 5% when the width is narrower than that of the conventional example 1. On the other hand, in the conventional examples 1 and 2, the heat transfer coefficient is almost the same as the conventional one. The results of FIG. 6 and FIG.
From (2), it is estimated that the thermal stress for the dimensionless axial distance x / L increases on the nozzle corner 38 side and decreases on the safe end 39 side.

  Next, FIG. 8 shows the temperature fluctuation width with respect to the width of the annular flow path. The horizontal axis represents the dimensionless annular flow path width δ / Di obtained by dividing the width δ of the annular flow path 9 by the inner diameter Di of the water supply nozzle, and the vertical axis represents the temperature fluctuation width βmax of Conventional Example 1 compared to Conventional Example 2 or The ratio βc of the temperature fluctuation range of the present invention is shown. Note that the temperature fluctuation range when βc is derived is the maximum value of the temperature fluctuation range shown in FIG. It can be seen that when the width of the annular flow path 9 is narrower than that of the conventional example 1, the temperature fluctuation width βc becomes smaller.

  FIG. 9 shows the heat transfer coefficient with respect to the width of the annular flow path. The horizontal axis represents the dimensionless annular flow path width δ / Di obtained by dividing the width δ of the annular flow path 9 by the inner diameter Di of the water supply nozzle, and the vertical axis represents the heat transfer coefficient hmax of Conventional Example 1, The heat transfer rate hc of the present invention is shown. The heat transfer coefficient when hc is derived is the maximum value of the heat transfer coefficient in FIG. It can be seen that the heat transfer coefficient is substantially the same and the heat transfer coefficient is low in the range where the width of the annular flow path 9 is narrower than in the conventional example 1.

  Therefore, the heat transfer coefficient of Conventional Example 1 and the present invention is considered as the lower limit value, and the lower limit value of δ / Di is set to the conventional δ / Di = 0.11. On the other hand, if the width of the annular flow path 9 is excessively widened, the pressure loss when the low-temperature water supply 8 flows in the thermal sleeve 3 increases, and the specifications of the water supply pump must be changed.

  Therefore, by reducing the inner diameter of the thermal sleeve 3, the increase in pressure loss due to the increase in the flow rate of the water supply in the thermal sleeve 3 is suppressed to, for example, 10% or less. Assuming that only the outer diameter of the thermal sleeve and the inner diameter of the water supply nozzle are changed without changing the specification, the upper limit value of δ / Di is δ / Di = 0.16.

  Therefore, the range of δ / Di in which the effect of the present invention is obtained is 0.11 <x / L ≦ 0.16 (δ / Di = 0.11 of Conventional Example 1 is not included). In addition, it is possible to implement | achieve a present Example by calculating (delta) / Di from the manufacture drawing of the reactor water nozzle with a dimension display.

  Another embodiment of the reactor water nozzle of the present invention is shown in FIG. The feature of this embodiment is that the thermal sleeve 3 extends toward the nozzle corner 38 on the outer peripheral surface of the thermal sleeve 3 in the range of the horizontal distance from the nozzle corner 38 of the water supply nozzle 1 to the safe end 39 in parallel with the central axis 3a of the water supply nozzle 1. This is to move the position of the step 40 closest to the nozzle corner 38 on the outer peripheral surface of the thermal sleeve 3 toward the safe end 39 side.

  In the case of the present embodiment, in addition to the embodiment of FIG. 1, the space space of the annular flow path 9 of the nozzle corner 38 is further widened, so that the high-temperature reactor water 7 can easily flow into the annular flow path 9. Mixing of the reactor water 7 and the low-temperature feed water 8 is promoted, and temperature fluctuation can be reliably reduced. The effect obtained by moving the position of the step to the safe end 39 side and widening the annular flow path 9 and the annular shape from the nozzle corner 38 of the water supply nozzle 1 to the safe end 39 as in the embodiment of FIG. The effect obtained by widening the width of the flow path 9 is considered to be the same.

The range of x / L is derived from the axial distance shown in FIG. As in the embodiment of FIG. 1, the lower limit value of x / L is assumed to be conventional x / L = 0.35. The upper limit value is set to x / L = 1 where the step matches the safe end 39 of the water supply nozzle 1. Therefore, the range of x / L in which the effect of the present invention is obtained is 0.35 <x / L ≦ 1 (not including δ / Di = 0.35 in Conventional Example 1). In addition, it is possible to implement | achieve a present Example by calculating x / L from the manufacture drawing of the reactor water nozzle with a dimension display.

Another embodiment of the reactor water nozzle of the present invention is shown in FIG. The feature of this embodiment is that the thermal sleeve 3 extends toward the nozzle corner 38 on the outer peripheral surface of the thermal sleeve 3 in the range of the horizontal distance from the nozzle corner 38 of the water supply nozzle 1 to the safe end 39 in parallel with the central axis 3a of the water supply nozzle 1. The position of the step closest to the nozzle corner 38 where the outer diameter of the nozzle becomes smaller is made to coincide with the safe end 39 and no step is provided on the outer peripheral surface of the thermal sleeve 3.

  In the present embodiment, not only the nozzle corner 38 at the inlet of the annular channel 9 but also the width of the annular channel 9 in the range of the horizontal distance from the nozzle corner 38 to the safe end 39, the water injection nozzle of the water supply nozzle 1 The water supply discharged from 2 rebounds to the reactor internal structure, and the rebound water easily enters the annular flow path 9, and the mixing of the low-temperature water supply 8 and the furnace water in the annular flow path 9 is promoted. 9 can reduce the temperature fluctuation of the reactor water, and the thermal stress can be reduced accordingly. Further, since the step on the outer peripheral surface of the thermal sleeve 3 can be eliminated, the amount and cost for manufacturing the step can be reduced, and the manufacturing of the thermal sleeve 3 is facilitated and the economy is improved.

  Another embodiment of the reactor water nozzle of the present invention is shown in FIG. The feature of this embodiment is that the inner surface of the water supply nozzle 1 is directed from the safe end 39 toward the nozzle corner 38 within a horizontal distance from the safe end 39 of the water supply nozzle 1 to the nozzle corner 38 in parallel with the central axis 3a of the water supply nozzle 1. The taper shape is enlarged.

  In this embodiment, in addition to the embodiments of FIGS. 1, 10 and 11, the width of the annular passage 9 close to the nozzle corner 38 where the temperature fluctuation of the reactor water in the annular passage 9 is estimated to be large is widened. Therefore, the high-temperature reactor water and the low-temperature rebound water in the annular flow path 9 can be easily mixed, and the temperature fluctuation is reduced. Accordingly, the thermal stress generated on the inner wall of the water supply nozzle 1 can also be reduced. Furthermore, the width of the annular flow path 9 on the safe end 39 side is preferably in the range of 0.11 <δ / Di ≦ 0.16 as shown in the embodiment of FIG.

  Another embodiment of the reactor water nozzle of the present invention is shown in FIG. The feature of this embodiment is that the outer peripheral surface of the thermal sleeve 3 is reduced from the safe end 39 toward the nozzle corner 38 within a horizontal distance from the safe end 39 to the nozzle corner 38 in parallel with the central axis 3a of the water supply nozzle 1. It is to make a shape.

  In the present embodiment, as in FIG. 12, the width of the annular channel 9 close to the nozzle corner 38 where the temperature fluctuation of the reactor water in the annular channel 9 is estimated to be large can be increased. The high-temperature reactor water 7 in 9 and the low-temperature rebound water are easy to mix, and the temperature fluctuation becomes small. It should be noted that there is no problem even if the embodiments of FIGS. 1 and 12 are combined.

  Another embodiment of the reactor water nozzle of the present invention is shown in FIG. The feature of the present embodiment corresponds to the range of the horizontal distance z from the nozzle corner 38 of the water supply nozzle 1 to the step closest to the nozzle corner 38 provided on the outer peripheral surface of the thermal sleeve 3 in parallel with the central axis 3a of the water supply nozzle 1. This is to make the inner diameter of the water supply nozzle 1 larger than Di. Di indicates the minimum value of the inner diameter of the water supply nozzle.

  In this embodiment, in addition to the embodiment of FIG. 1, temperature fluctuation can be reduced in the range from the nozzle corner 38 to the safe end 39 of the water supply nozzle 1. Furthermore, since the width of the annular flow path 9 close to the nozzle corner 38, where the temperature fluctuation of the reactor water in the annular flow path 9 is estimated to be large, can be widened. The rebound water becomes easy to mix and the temperature fluctuation becomes small. Furthermore, the width of the annular flow path 9 on the safe end 39 side is preferably in the range of 0.11 <δ / Di ≦ 0.16 as shown in the embodiment of FIG.

  Another embodiment of the reactor water nozzle of the present invention is shown in FIG. The inner surface of the water supply nozzle 1 corresponding to the range of the horizontal distance z from the nozzle corner 38 of the water supply nozzle 1 in parallel to the central axis 3a of the water supply nozzle 1 to the step closest to the nozzle corner 38 provided on the outer peripheral surface of the thermal sleeve 3 is used as the nozzle corner. It is to make it into the taper shape which expands toward.

  In the present embodiment, as in the embodiment of FIG. 14, temperature fluctuations can be reduced in the range from the nozzle corner 38 to the safe end 39 of the water supply nozzle 1. Further, by providing the nozzle corner 38 with a tapered portion, it becomes easier for the high-temperature reactor water 7 to enter the annular flow path 9, and the mixing of the high-temperature reactor water 7 and the feed water in the annular flow path 9 is promoted, resulting in temperature fluctuations. Can be reduced.

  FIG. 16 shows an embodiment of a nuclear power generation system using the reactor water supply nozzle of the present invention. The feature of the present embodiment is a reactor whose power output has been improved by increasing the heat output from the rated heat output at the time of reactor construction, and the feed water nozzle inlet temperature at the rated operation after the power improvement is the same as that at the time of reactor construction. The operation is performed by lowering the feed water nozzle inlet temperature during rated operation by 1 ° C. or more.

  As shown in FIG. 16, a nuclear power plant nuclear reactor includes a main steam system and a water supply system connected to the reactor pressure vessel 11. The main steam system is a system that supplies steam from the reactor pressure vessel 11 to the high-pressure turbine 26 and the low-pressure turbine 28. That is, the high-temperature and high-pressure steam generated in the reactor pressure vessel 11 is supplied to the high-pressure turbine 26 through the main steam pipe 19 and used to rotate the high-pressure turbine 26.

  The steam used in the high-pressure turbine 26 is supplied to the moisture separator 27 to reduce the moisture. The steam with reduced moisture is supplied to the low-pressure turbine 28 and used to rotate the low-pressure turbine 28. Thus, the steam used in each turbine of the main steam system is supplied to the condenser 29, where the steam is condensed into low-temperature water.

  When the high-pressure turbine 26 and the low-pressure turbine 28 are rotationally driven, the generator connected to each turbine is driven by the rotational driving force of each turbine to exert a power generation action, and the generated power is output to the outside of the nuclear power plant with a cable. It is configured to transmit power.

  After the steam used in each turbine is returned to low-temperature water by the condenser 29, the water is handled as water supply in the water supply system. The water supply system is as follows. That is, in the water supply system, water generated from the steam by the condenser 29 is passed as water supply through the water supply pipe 37, and the water supply is supplied into the reactor pressure vessel 11 by the water supply pump 31.

  In the middle of the water supply pipe 37, a low-pressure feed water heater 30 and a high-pressure feed water heater 32 are equipped in series to heat the feed water passing through the feed water system. Steam is extracted and supplied from the intermediate stage of the moisture separator 27 and the low-pressure turbine 28 to the low-pressure feed water heater 30 of the feed water system as a fluid subject to heat exchange with the feed water. Similarly, steam is extracted and supplied from the intermediate stage and the final stage of the high-pressure turbine 26 to the high-pressure feed water heater 32 of the feed water system as a fluid subject to heat exchange with the feed water.

In the middle of the pipe for supplying the steam extracted from the final stage of the high-pressure turbine 26 to the high-pressure feed water heater 32, an extraction flow rate adjustment valve 33 is provided so that the amount of steam supplied to the high-pressure feed water heater 32 is extracted. It can be adjusted by adjusting the opening of 33. Further, the water supply system includes a water supply bypass pipe 34 that bypasses the high-pressure feed water heater 32, a pipe that supplies steam, which is a heat source in the high-pressure feed water heater 32, to the low-pressure feed water heater 30, and a low-pressure feed water heater. A pipe or the like for supplying a fluid such as steam as a heat source 30 to the condenser 29 is attached.

  The water supply system can guide the temperature of the feed water at the inlet of the feed water nozzle into the reactor pressure vessel 11 by lowering the temperature by 1 ° C. or more from the temperature at the rated operation at the beginning of the construction of the reactor. Further, the flow rate of supplying steam (heat source) in the high-pressure turbine 26 to the high-pressure feed water heater 32 is reduced by performing an operation of narrowing (closing direction) the extraction flow rate adjusting valve 33 from the rated operation at the beginning of construction. Alternatively, the feed water from the feed water pump 31 is not supplied to the high-pressure feed water heater 32, but is fed directly to the reactor pressure vessel 11 through the feed water bypass pipe 34. The operating condition is to improve the output by reducing it by 1 ° C. or more from the water supply temperature at the inlet of the water supply nozzle during the initial rated operation.

  The water supply bypass pipe 34 is provided with a flow rate adjustment valve, the opening of the flow rate adjustment valve is adjusted to adjust the flow distribution of the water supply to the water supply bypass pipe 34 and the high pressure feed water heater 32, and at the inlet of the water supply nozzle. The operation condition for improving the output may be set by lowering the feed water temperature by 1 ° C. or more than the feed water temperature at the inlet of the feed water nozzle at the rated operation at the beginning of construction.

  In this embodiment, a method is adopted in which the output is improved by lowering the feed water temperature without increasing the main steam flow rate and the feed water flow rate. That is, since the temperature difference between the reactor water in the reactor pressure vessel and the temperature of the feed water becomes large, there is a concern about thermal fatigue of the feed nozzle portion. However, by providing the reactor feed nozzle in the embodiment of FIG. The occurrence of thermal stress and thermal fatigue can be prevented, and the structural integrity of the water supply nozzle can be improved.

  Thus, the feed water temperature may be lowered by 1 ° C. or more, which is equal to or greater than the fluctuation width of the feed water temperature during normal operation. However, since the feed water is mixed with water at the saturation temperature in the reactor pressure vessel 11 when entering the reactor pressure vessel 11, a temperature difference occurs in the feed water nozzle portion. If the water supply temperature is lowered too much, the temperature difference will increase at this part, and it may exceed the design limit from the viewpoint of thermal fatigue, so set the reduction range considering the balance with the design limit so that there is no concern .

In FIG. 16, Q represents the percentage of heat output generated in the reactor pressure vessel, G represents the mass flow percentage in the system of FIG. 16, and H represents enthalpy (kJ / kg). In FIG. 16, Q =
“105” means that the power output percentage Q of the rated heat output at the beginning of the reactor construction was 100%, and the power was improved to 105% after the construction.

  As described above, if the existing boiling water reactor water supply system is replaced with the water supply system according to any of the embodiments of the present invention and the operation is performed with improved output, the water supply temperature will be lower than the conventional one. However, it is possible to maintain sufficiently high reliability, and an effective nuclear power generation system capable of increasing the electric output as compared with the current plant operation.

  According to the embodiment of the present invention, the width of the annular flow path between the inner surface of the water supply nozzle and the outer surface of the thermal sleeve is widened in the range of the horizontal distance from the nozzle corner of the water supply nozzle to the safe end in parallel with the central axis of the water supply nozzle. As a result, mixing of high-temperature reactor water and rebound water can be promoted, temperature fluctuations can be reduced, and thermal stress generated on the inner surface of the water supply nozzle and the outer surface of the thermal sleeve can be reduced accordingly. realizable.

  Also, if there is a step on the outer peripheral surface of the thermal sleeve in the horizontal distance from the nozzle corner of the water supply nozzle to the safe end parallel to the central axis of the water supply nozzle, the outer diameter of the thermal sleeve decreases toward the nozzle corner. By moving the position of the step closest to the nozzle corner on the outer peripheral surface of the sleeve to the safe end side, the width of the annular channel on the nozzle corner side in the water supply nozzle can be expanded, and mixing of hot reactor water and rebound water The temperature fluctuation can be reduced. Moreover, the water supply nozzle which improved the structural soundness which can suppress a thermal stress and thermal fatigue much more reliably is realizable.

  In addition, by forming the inner surface of the water supply nozzle in a horizontal distance range from the nozzle corner of the water supply nozzle to the safe end in parallel with the central axis of the water supply nozzle, the nozzle corner portion has an annular shape. The width of the flow path can be widened, and the mixing of reactor water and feed water can be further promoted.

  In addition, the outer peripheral surface of the thermal sleeve has a taper shape that decreases in the horizontal direction from the nozzle corner to the safe end in parallel with the central axis of the water supply nozzle, and further decreases in the annular flow path from the safe end to the nozzle corner. This leads to the promotion of mixing of high-temperature reactor water and low-temperature feed water from the water injection nozzle.

  Further, by increasing the inner diameter of the water supply nozzle corresponding to the horizontal distance range from the nozzle corner of the water supply nozzle to the step closest to the nozzle corner provided on the outer peripheral surface of the thermal sleeve in parallel with the central axis of the water supply nozzle, Since the width of the annular channel can be widened, and the temperature fluctuation of the reactor water in the annular channel of the nozzle corner, which is particularly concerned about thermal fatigue, can be reduced, so that a water supply nozzle excellent in heat fatigue can be realized.

  Also, the taper shape that expands the inner surface of the water supply nozzle toward the nozzle corner corresponding to the horizontal distance from the nozzle corner of the water supply nozzle to the step closest to the nozzle corner provided on the outer peripheral surface of the thermal sleeve in parallel with the central axis of the water supply nozzle By doing so, the width of the annular channel of the nozzle corner can be widened, and a water supply nozzle excellent in heat fatigue can be realized.

  Moreover, even if the reactor water supply nozzle of the present invention is provided in the reactor whose power output is increased by increasing the heat output from the rated heat output at the time of reactor construction, the structural integrity of the water supply nozzle can be improved.

  Further, the reactor water nozzle shown in claims 1 to 6 is used for the reactor whose power output has been increased by increasing the heat output from the rated heat output at the time of reactor construction. Even if the inlet temperature is provided in a nuclear power generation system that performs an output improvement operation in which the inlet temperature is lowered by 1 ° C. or more than the inlet temperature of the feed water nozzle during rated operation at the time of reactor construction, the structural soundness of the feed water nozzle can be improved.

  The present invention has a field of application to a water supply nozzle attached to a reactor pressure vessel.

FIG. 1 is a view showing a reactor water supply nozzle which is a preferred embodiment of the present invention. FIG. 1 (a) is a view of the front surface of the water supply nozzle together with surrounding structures from the inside of the reactor pressure vessel, and FIG. (A) It is BB arrow sectional drawing of a figure. It is a figure which shows a reactor pressure vessel, (a) A figure is AA arrow sectional drawing of the (b) figure, (b) figure is the schematic of the longitudinal cross-section of a reactor pressure vessel. It is a figure which shows the conventional nuclear reactor water supply nozzle, (a) figure is the figure which looked at the front of the water supply nozzle with the surrounding structure from the reactor pressure vessel inner side, (b) figure is B- of figure (a). It is B arrow sectional drawing. It is a figure which shows the temperature distribution of the conventional water supply nozzle part of FIG. It is explanatory drawing of the evaluation parameter | index regarding the thermal fatigue evaluation of the conventional water supply nozzle part of FIG. It is a graph of the relationship between the axial direction distance of a nuclear reactor water supply nozzle part, and a temperature fluctuation range. It is a relationship graph of the axial direction distance of a nuclear reactor water supply nozzle part, and a heat transfer rate. It is a graph of the relationship between the width | variety of the annular flow path of a nuclear reactor water supply nozzle part, and a temperature fluctuation range. It is a graph of the relationship between the width | variety of the annular flow path of a nuclear reactor water supply nozzle part, and a heat transfer rate. It is a figure which shows the reactor water nozzle which is another Example of this invention, (a) A figure is the figure which looked at the front of the water nozzle with the surrounding structure from the reactor pressure vessel inner side, (b) Figure (A) It is BB arrow sectional drawing of a figure. It is a figure which shows the reactor water nozzle which is another Example of this invention, (a) A figure is the figure which looked at the front of the water nozzle with the surrounding structure from the reactor pressure vessel inner side, (b) Figure (A) It is BB arrow sectional drawing of a figure. It is a figure which shows the reactor water nozzle which is another Example of this invention, (a) A figure is the figure which looked at the front of the water nozzle with the surrounding structure from the reactor pressure vessel inner side, (b) Figure (A) It is BB arrow sectional drawing of a figure. It is a figure which shows the reactor water nozzle which is another Example of this invention, (a) A figure is the figure which looked at the front of the water nozzle with the surrounding structure from the reactor pressure vessel inner side, (b) Figure (A) It is BB arrow sectional drawing of a figure. It is a figure which shows the reactor water nozzle which is another Example of this invention, (a) A figure is the figure which looked at the front of the water nozzle with the surrounding structure from the reactor pressure vessel inner side, (b) Figure (A) It is BB arrow sectional drawing of a figure. It is a figure which shows the reactor water nozzle which is another Example of this invention, (a) A figure is the figure which looked at the front of the water nozzle with the surrounding structure from the reactor pressure vessel inner side, (b) Figure (A) It is BB arrow sectional drawing of a figure. It is a main steam and water supply system diagram of a nuclear power plant using a reactor water supply nozzle which is an embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Water supply nozzle, 2 ... Water injection nozzle, 3 ... Thermal sleeve, 3a ... Center axis, 4 ... Shroud head bolt, 5 ... Shroud head bolt ring, 6 ... T-tube, 7 ... High temperature reactor water, 8 ... Low temperature Feed water, 9 ... annular flow path, 11 ... reactor pressure vessel, 12 ... shroud, 13 ... steam separator, 14 ... downcomer, 15 ... recirculation pump, 16 ... lower plenum, 17 ... core,
DESCRIPTION OF SYMBOLS 18 ... Steam dryer, 19 ... Main steam piping, 20 ... High temperature water, 21 ... Low temperature water, 22 ... High / low temperature water interface, 23 ... Rebound water, 24 ... Communication pipe, 25, 35 ... Header pipe, 26 ... High pressure turbine, 27 ... Moisture separator, 28 ... Low pressure turbine, 29 ... Condenser, 30 ... Low pressure feed water heater, 31 ... Feed water pump, 32 ... High pressure feed water heater, 33 ... Extraction flow rate adjustment valve, 34 ... Feed water bypass pipe,
36, 36a, 36b ... discharge port, 37 ... water supply pipe, 38 ... nozzle corner, 39 ... safe end, 40 ... step.

Claims (8)

A water supply nozzle installed in the reactor pressure vessel;
A thermal sleeve that is installed in the water supply nozzle, has a safe end connected to the water supply nozzle, and is connected to the header pipe on the anti-safe end side;
An annular flow path between the inner surface of the water supply nozzle and the outer surface of the thermal sleeve;
In the reactor water nozzle with
When Di is the minimum value of the inner diameter of the water supply nozzle and δ is the width of the annular flow path between the minimum value Di of the inner diameter of the water supply nozzle and the maximum value of the outer diameter do of the thermal sleeve,
Reactor feed water characterized by having a width of the annular flow passage satisfying a relational expression of 0.11 <δ / Di ≦ 0.16 in a horizontal distance range from a nozzle corner of the water supply nozzle to the safe end nozzle.   2. The step according to claim 1, wherein the outer peripheral surface of the thermal sleeve has a step in which the outer diameter of the thermal sleeve is smaller on the nozzle corner side than the safe end side in the range of the horizontal distance, and is closest to the nozzle corner. Where L is the horizontal distance from the nozzle corner to the safe end, and x is the distance from the nozzle corner to the step closest to the nozzle corner, 0.35 <x / L ≦ 1 The reactor water nozzle is arranged at a position satisfying the above. A water supply nozzle installed in the reactor pressure vessel;
A thermal sleeve that is installed in the water supply nozzle, has a safe end connected to the water supply nozzle, and is connected to the header pipe on the anti-safe end side;
An annular flow path between the inner surface of the water supply nozzle and the outer surface of the thermal sleeve;
In the reactor water nozzle with
A reactor water supply nozzle having a taper shape in which an inner diameter of the water supply nozzle expands as the nozzle corner is approached from the safe end within the range of the horizontal distance. A water supply nozzle installed in the reactor pressure vessel;
A thermal sleeve that is installed in the water supply nozzle, has a safe end connected to the water supply nozzle, and is connected to the header pipe on the anti-safe end side;
An annular flow path between the inner surface of the water supply nozzle and the outer surface of the thermal sleeve;
In the reactor water nozzle with
A reactor water supply nozzle having a taper shape in which an outer diameter of the thermal sleeve is reduced as the nozzle corner is approached from the safe end within the range of the horizontal distance.   In Claim 1 or Claim 2, it has a level | step difference in which the outer diameter of the said thermal sleeve becomes smaller on the outer peripheral surface of the said thermal sleeve than the said safe end side on the outer peripheral surface of the said thermal distance in the range of the said horizontal distance, From the said nozzle corner A reactor water supply nozzle, wherein an inner diameter of the water supply nozzle located in a horizontal distance range to a position of a step closest to the nozzle corner is made larger than Di.   6. The step according to claim 1, wherein the outer diameter of the thermal sleeve is smaller on the outer peripheral surface of the thermal sleeve on the nozzle corner side than on the safe end side in the horizontal distance range. The inner surface of the water supply nozzle located in the range of the horizontal distance from the nozzle corner to the position of the step closest to the nozzle corner has a tapered shape in which the inner diameter of the water supply nozzle increases toward the nozzle corner. Reactor water nozzle.   7. The reactor pressure vessel according to claim 1, wherein the reactor pressure vessel increases the rated heat output of the reactor at the beginning of the construction beyond the original rated heat output after the construction. A reactor water supply nozzle, which is a reactor pressure vessel applied to a later reactor. 8. The reactor according to claim 7, wherein the temperature of the water at the inlet of the water supply nozzle is decreased by 1 ° C. or more from the temperature at the rated operation at the beginning of the construction of the reactor, and directed into the reactor pressure vessel. Reactor water nozzle characterized by being connected to the water supply system.

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