Patent Application
20100067645
1. Technology Field
The present invention relates to a reactor system of a fast reactor controlling a reactivity of a reactor core stored in a reactor vessel of the fast reactor filled with a coolant.
2. Background Art
There has been conventionally known a reflector system of a fast reactor controlling a reactivity of a reactor core stored in a reactor vessel of a fast reactor filled with a coolant. The reflector system of the fast reactor comprises a reflector provided so as to be movable in a vertical direction as well as being arranged in an outer side of a peripheral edge of a reactor core, and a reflector drive apparatus coupled to the reflector and moving the reflector in a vertical direction. The reflector has a neutron reflection portion reflecting a neutron radiated from the reactor core, and a cavity portion which is provided above the neutron reflecting portion and having a lower neutron reflecting capacity than the coolant (refer, for example, to Japanese Patent Application Laid-Open No. 2003-35790 and Japanese Patent Application Laid-Open No. 2005-233751).
Among them, the cavity portion of the reflector has a plurality of box-shaped closed vessels, and a gas which is inferior in the neutron reflecting capacity to the coolant is sealed in an inner portion of the closed vessel. Alternatively, the closed vessel is set to a vacuum condition without being filled with the gas. Accordingly, in the case that the cavity portion is arranged so as to be opposed to the reactor core, it is possible to hold down a reactivity of the reactor core in comparison with the case that an outer periphery of the reactor core is covered by the coolant, it is possible to enhance a condensation degree of an atomic fuel and it is possible to elongate a reactivity service life of the reactor core.
However, in the case that the closed vessel of the cavity portion is broken due to a generation of a micro crack by an unexpected matter, the coolant makes an intrusion into the closed vessel little by little. Accordingly, the neutron reflecting capacity of the cavity portion is increased, it becomes hard to control the reactivity of the reflector core, and the reactivity of the reactor core is enhanced so as to cause a reduction of a reactor core service life.
In order to detect the breakage of the cavity portion of the reflector, there is carried out a method of attaching a neutron measuring device to inner and outer sides of a reactor vessel, measuring an amount of neutron in the inner and outer sides of the reactor vessel by the neutron measuring device, evaluating a change-amount of neutron based on the measured data, and detecting presence or absence of the breakage of the cavity portion of the reflector. Further, there is also carried out a method of attaching a temperature measuring device to inner and outer sides of the reactor vessel independently from the neutron measuring device, measuring a temperature in the inner and outer sides of the reactor vessel by the temperature measuring device, calculating a temperature change based on the measured data, and detecting presence or absence of a breakage of the cavity portion of the reflector.
However, a fluctuation of the amount of neutron in the inner and outer sides of the reactor vessel is tiny. Accordingly, it is hard to evaluate the change-amount of neutron so as to detect presence or absence of the breakage of the cavity portion of the reflector. In the same manner, since the change of the temperature in the inner and outer sides of the reactor vessel is tiny, it is also hard to evaluate the change of the temperature so as to detect presence or absence of the breakage of the cavity portion of the reflector. Further, the method of evaluating the amount of neutral or the temperature can be carried out during an operation of the fast reactor, however, cannot be carried out during a shutdown of the fast reactor. Therefore, in the case that the cavity portion of the reflector is broken during the shutdown of the fast reactor, it is difficult to detect the breakage of the cavity portion until the fast reactor starts operating.
In addition, there can be considered a method of filling a tag gas within the closed vessels of the cavity portion of the reflector, providing a detecting portion for detecting the tag gas leaking out of the closed vessel in the case that the closed vessel is broken, and detecting presence or absence of the breakage of the cavity portion. This method has an advantage that it is possible to detect presence or absence of the breakage of the cavity portion even during the shutdown of the fast reactor, however, it is hard to specify the broken closed vessel from a plurality of closed vessels of the cavity portion. Further, in the case of detecting presence or absence of the breakage of the cavity portion by using the tag gas as mentioned above, there is a problem that an equipment of the fast reactor is widely increased and a high cost is necessary.
The present invention has been made in view of the above issue, and an object thereof is to provide a reflector system of a fast reactor which can securely detect presence or absence of a breakage of a cavity portion of a reflector.
The present invention is a reflector system of a fast reactor held to a structure body of the fast reactor and controlling a reactivity of a reactor core stored within a reactor vessel of the fast reactor filled with a coolant, the reflector system comprising: a reflector being provided so as to be movable in a vertical direction as well as being arranged in an outer side of a peripheral edge of a reactor core, the reflector having a neutron reflecting portion reflecting a neutron radiated from the reactor core, and a cavity portion provided above the neutron reflecting portion and having a lower neutron reflecting capacity than the coolant; and a reflector drive apparatus coupled to the reflector and moving the reflector in a vertical direction, wherein the reflector drive apparatus has a driving portion which is coupled to the reflector via a drive shaft as well as being supported to the structure body of the fast reactor, and drives the reflector up and down, and a load sensing portion which is provided between the driving portion and the drive shaft, and senses a load of the reflector, a detecting portion receiving a load signal from the load sensing portion is connected to the load sensing portion of the reflector drive apparatus, and the detecting portion evaluates a change-amount between the load based on the load signal transmitted from the load sensing portion and a predetermined load at a time when the reflector is normal, and determines that the cavity portion of the reflector is broken in the case that the change-amount is increased.
The present invention is the reflector system of a fast reactor, wherein the load sensing portion has a load sensor formed as a ring shape.
The present invention is the reflector system of a fast reactor, wherein the load sensing portion has a plurality of load sensors arranged as a ring shape.
The present invention is the reflector system of a fast reactor, wherein the load sensor is constructed by any one of a tension type load sensor sensing a tensile load, and a shear type load sensor sensing a shearing load.
The present invention is a reflector system of a fast reactor held to a structure body of the fast reactor and controlling a reactivity of a reactor core stored within a reactor vessel of the fast reactor filled with a coolant, the reflector system comprising: a reflector being provided so as to be movable in a vertical direction as well as being arranged in an outer side of a peripheral edge of a reactor core, the reflector having a neutron reflecting portion reflecting a neutron radiated from the reactor core, and a cavity portion provided above the neutron reflecting portion and having a lower neutron reflecting capacity than the coolant; and a reflector drive apparatus coupled to the reflector and moving the reflector in a vertical direction, wherein the reflector drive apparatus has a drive cylinder which is coupled to the reflector via a transmission mechanism as well as being supported to the structure body of the fast reactor, and drives the reflector up and down, and a load sensing portion which is coupled between the transmission mechanism and the drive cylinder, and senses a load of the reflector, a detecting portion receiving a load signal from the load sensing portion is connected to the load sensing portion of the reflector drive apparatus, and the detecting portion evaluates a change-amount between the load based on the load signal transmitted from the load sensing portion and a predetermined load at a time when the reflector is normal, and determines that the cavity portion of the reflector is broken in the case that the change-amount is increased.
The present invention is the reflector system of a fast reactor, wherein the load sensing portion is constructed by any one of a compression type load sensor sensing a compressive load, and a shear type load sensor sensing a shearing load.
The present invention is a reflector system of a fast reactor held to a structure body of the fast reactor and controlling a reactivity of a reactor core stored within a reactor vessel of the fast reactor filled with a coolant, the reflector system comprising: a reflector being provided so as to be movable in a vertical direction as well as being arranged in an outer side of a peripheral edge of a reactor core, the reflector having a neutron reflecting portion reflecting a neutron radiated from the reactor core, and a cavity portion provided above the neutron reflecting portion and having a lower neutron reflecting capacity than the coolant; and a reflector drive apparatus coupled to the reflector and moving the reflector in a vertical direction, wherein the reflector drive apparatus has a driving portion which is coupled to the reflector via a drive shaft as well as being supported to the structure body of the fast reactor, and drives the reflector up and down, a strain gauge sensing a strain is attached to the drive shaft or a coupling member coupled between the driving portion and the drive shaft, a detecting portion receiving the strain signal from the strain gauge is connected to the strain gauge, and the detecting portion calculates a load of the reflector based on the strain signal transmitted from the strain gauge, evaluates a change-amount between the calculated load and a predetermined load at a time when the reflector is normal, and determines that the cavity portion of the reflector is broken in the case that the change-amount is increased.
The present invention is a reflector system of a fast reactor held to a structure body of the fast reactor and controlling a reactivity of a reactor core stored within a reactor vessel of the fast reactor filled with a coolant, the reflector system comprising: a reflector being provided so as to be movable in a vertical direction as well as being arranged in an outer side of a peripheral edge of a reactor core, the reflector having a neutron reflecting portion reflecting a neutron radiated from the reactor core, and a cavity portion provided above the neutron reflecting portion and having a lower neutron reflecting capacity than the coolant; and a reflector drive apparatus coupled to the reflector and moving the reflector in a vertical direction, wherein the reflector drive apparatus has a drive cylinder which is coupled to the reflector via a transmission mechanism as well as being supported to the structure body of the fast reactor, the drive cylinder has an output shaft and drives the reflector up and down, a strain gauge sensing a strain is attached to the output shaft of the drive cylinder, a detecting portion receiving the strain signal transmitted from the strain gauge is connected to the strain gauge, and the detecting portion calculates a load of the reflector based on the strain signal transmitted from the strain gauge, evaluates a change-amount between the calculated load and a predetermined load at a time when the reflector is normal, and determines that the cavity portion of the reflector is broken in the case that the change-amount is increased.
The present invention is a reflector system of a fast reactor held to a structure body of the fast reactor and controlling a reactivity of a reactor core stored within a reactor vessel of the fast reactor filled with a coolant, the reflector system comprising: a reflector being provided so as to be movable in a vertical direction as well as being arranged in an outer side of a peripheral edge of a reactor core, the reflector having a neutron reflecting portion reflecting a neutron radiated from the reactor core, and a cavity portion provided above the neutron reflecting portion and having a lower neutron reflecting capacity than the coolant; and a reflector drive apparatus coupled to the reflector and moving the reflector in a vertical direction, wherein the reflector drive apparatus has a driving portion which is coupled to the reflector via a drive shaft as well as being supported to the structure body of the fast reactor, and drives the reflector up and down, and a torque sensing portion which is provided between the driving portion and the drive shaft and senses a torque of the driving portion, a detecting portion receiving the torque signal from the torque sensing portion is connected to the torque sensing portion of the reflector drive apparatus, and the detecting portion calculates a load of the reflector based on the torque signal transmitted from the torque sensing portion, evaluates a change-amount between the calculated load and a predetermined load at a time when the reflector is normal, and determines that the cavity portion of the reflector is broken in the case that the change-amount is increased.
According to the present invention, it is possible to securely detect presence or absence of the breakage of the cavity portion of the reflector by means of the detecting portion by sensing the load of the reflector by means of the load sensing portion, regardless of an operating state and a shutdown state of the fast reactor. Accordingly, it is possible to further improve a reliability of the fast reactor.
A description will be given below of embodiments according to the present invention with reference to the accompanying drawings.
In this case,
First of all, a description will be given of a whole structure of the fast reactor with reference to
In this case, the fast reactor 1 is a reactor which can be driven continuously for ten and several years to some tens years, for example, about thirty years without exchanging the atomic fuel, and an output thereof is 30 MW to one hundred and some tens MW (ten thousand KW to one hundred and some tens thousand KW in an electric output). Further, a height of a whole of the reactor is between 25 m and 35 m, for example, about 30 m, and a height of a reactor core is, for example, about 2.5 m. A temperature of the coolant may be set to a temperature which is equal to or higher than a temperature at which the liquid sodium is not solidified, and the reactor is operated at 200° C. or higher on the safe side, and preferably at 300° C. to 550° C. Specifically, it comes to 300° C. to 400° C., for example, 350° C., in a coolant flow path within the reactor vessel 3, and comes to 500° C. to 550° C., for example, at 500° C., in the reactor core side.
As shown in
A reflector 30 is provided so as to be arranged in an outer side of a peripheral edge of the reactor core 4 and be movable in a vertical direction, and a reactivity of the reactor core 4 is controlled by regulating a leakage of a neutron discharged from the reactor core 4 by moving the reflector 30 in the vertical direction.
A reactor core barrel 11 covering the reactor core 4 is provided between the reactor core 4 and the reflector 30. Further, a partition wall 12 surrounding the reflector 30 is provided in an outer side of a peripheral edge of the reflector 30, and a coolant flow path of the primary coolant 2 is formed between the partition wall 12 and an inner wall of the reactor vessel 3. Further, a neutron shield 13 shielding the neutron discharged from the reactor core 4 is provided between the partition wall 12 and the inner wall of the reactor vessel 3, and shields the neutron discharged while transmitting or bypassing the reflector 30 from the reactor core 4. Further, a reactor core support plate 15 is provided in a lower portion of the reactor vessel 3 via the reactor core support table 14 fixed to the reactor vessel 3, and the reactor core 4, the reactor core barrel 11, the partition wall 12 and the neutron shield 13 are supported onto the reactor core support plate 15. Further, an entrance module 10 through which the primary coolant 2 flowing into the reactor core 4 passes is provided below the reactor core 4 on the reactor core support plate 15.
An upper support plate 19 supporting the reactor core 4 is provided above the reactor core 4. An annularly formed electromagnetic pump 20 is provided above the neutron shield 13 within the reactor vessel 3, above the upper support plate 19, and the primary coolant 2 is circulated as shown by an arrow shown in
An intermediate heat exchanger 21 carrying out a heat exchange between the primary coolant 2 and a secondary coolant (not shown) is provided above the electromagnetic pump 20. The primary coolant 2 is flowed into a tube (not shown) side of the intermediate heat exchanger 21, the secondary coolant is flowed to a shell (not shown) side, and the primary coolant and the secondary coolant are configured to be heat exchangeable. In this case, the electromagnetic pump 20 and the intermediate heat exchanger 21 can be integrated or integrally constructed, for example. Further, an inlet nozzle 22 introducing the secondary coolant into the reactor vessel 3 is provided above the intermediate heat exchanger 21, and an outlet nozzle 23 introducing the secondary coolant to an outer side of the reactor vessel 3 is provided. The outlet nozzle 23 is coupled to a vapor generator (not shown). In this case, as a material used for the secondary coolant, the liquid sodium can be used in the same manner as the primary coolant 2.
As shown in
As shown in
The neutron reflecting portion 31 of the reflector 30 is constructed by a plurality of laminated metal plates (not shown), and the metal plates have a plurality of coolant flow paths (not shown) through which the primary coolant 2 flows.
The cavity portion 32 of the reflector 30 is constructed by a plurality of closed vessels 33, and an inert gas such as helium (He), argon (Ar) or the like which is inferior in a neutron reflecting capacity to the coolant is filled in each of the closed vessels 33. Alternatively, each of the closed vessels 33 may be kept vacuum without being filled with the inert gas. In this case, the closed vessel 33 of the cavity portion 32 may be formed as an optional shape such as a cylindrical shape, a box shape or the like.
As shown in
As shown in
As shown in
As shown in
As shown in
As shown in
As shown in
As shown in
As shown in
A detecting portion 50 receiving load signals from the first load sensor 46, the second load sensor 47 and the third load sensor 49 is connected to the first load sensor 46 and the second load sensor 47 of the first load sensing portion 45 of the reflector drive apparatus 35, and the third load sensor 49 of the second load sensing portion 48. The detecting portion 50 evaluates change-amounts between each of the loads based on the load signals transmitted from the first load sensor 46, the second load sensor 47 and the third load sensor 49, and the predetermined load at a time when the reflector 30 is normal, and determines that the cavity portion 32 of the reflector 30 is broken in the case that at least one of the change-amounts is increased.
Next, a description will be given of an operation of the present embodiment constructed as mentioned above. First of all, a description will be given of a flow of the coolant in the fast reactor 1 shown in
First of all, as shown by an arrow in
Then, the primary coolant 2 heated within the reactor core 4 moves up in an inner side of the reactor core barrel 11, and reaches the intermediate heat exchanger 21. During this time, as shown in
Next, the primary coolant 2 and the secondary coolant are heat exchanged within the intermediate heat exchanger 21. In this case, the heat of the heated primary coolant 2 moves to the secondary coolant, and the secondary coolant is heated as well as the primary coolant 2 is cooled. Thereafter, the heated secondary coolant is discharged out of the reactor vessel 3 via the outlet nozzle 23, and is supplied to a steam generator (not shown).
After that, the cooled primary coolant 2 flow into the electromagnetic pump 20 provided below the intermediate heat exchanger 21, and circulates within the reactor vessel 3 by the electromagnetic pump 20.
Next, a description will be given of an operation of the reflector system of the fast reactor in the present embodiment.
First of all, a description will be given of the case that the reflector 30 is moved in the vertical direction by the electric motor 37 of the reflector drive apparatus 35, with reference to
Next, a description will be given of the case that the reflector 30 is moved in the vertical direction by the drive cylinder 39 of the reflector drive apparatus 35. In the case that the reflector 30 is moved upward by the drive cylinder 39, the attaching table 38 is moved upward by the drive cylinder 39 of the reflector drive apparatus 35. Accordingly, the electric motor 37 and the reduction gear 41 which are fixed onto the attaching table 38 move upward together with the attaching table 38, and it is possible to move upward the reflector 30 which is coupled to the reduction gear 41 via the ball screw 43, the ball nut 44, and the drive shaft 34 (refer to
On the other hand, in the case that the reflector 30 is moved downward, first of all, the attaching table 38 is moved downward by the drive cylinder 39. Accordingly, the electric motor 37 and the reduction gear 41 which are fixed onto the attaching table 38 move downward together with the attaching table 38, and it is possible to move downward the reflector 30 which is coupled to the reduction gear 41 via the ball screw 43, the ball nut 44 and the drive shaft 34.
Thus, it is possible to hold the reflector 30 at a desired position with respect to the reactor core 4, by moving the reflector 30 in the vertical direction by the electric motor 37 or the drive cylinder 39. In the case that the reflector 30 is moved by the drive cylinder 39, it is possible to make a moving speed of the reflector 30 higher than the case that the reflector 30 is moved by the electric motor 37. Accordingly, in the case of controlling the reactivity of the reactor core 4, the reactor 30 is driven by using the drive cylinder 39, and the reflector 30 can be moved in the vertical direction comparatively rapidly. On the other hand, the drive of the reflector 30 by the electric motor 37 is used in the case of continuously moving up the reflector 30 at an extremely low speed for a long term, for completely burning the atomic fuels of the fuel assembly 4a of the reactor core 4 for a long term.
Incidentally, in the case of enhancing the reactivity of the reactor core 4 in the fast reactor 1, the reflector 30 is moved in the vertical direction by the drive cylinder 39 of the reflector drive apparatus 35 as mentioned above, and the neutron reflecting portion 31 of the reflector 30 is opposed to the fuel assembly 4a in the reactor core 4. In this case, since the neutron reflecting portion 31 has a higher neutron reflecting capacity than the neutron reflecting capacity of the primary coolant 2, the neutron discharged from the reactor core 4 is reflected to the reactor core 4, and it is possible to enhance the reactivity of the reactor core 4.
On the other hand, in the case of lowering the reactivity of the reactor core 4, the reflector 30 is moved in the vertical direction by the drive cylinder 39 of the reflector drive apparatus 35, and the cavity portion 32 of the reflector 30 is opposed to the fuel assembly 4a of the reactor core 4 (refer to
Thus, by moving the reflector 30 in the vertical direction by means of the drive cylinder 39 of the reflector drive apparatus 35, it is possible to regulate the position of the reflector 30 with respect to the reactor core 4 in order to control the reactivity of the reactor core 4.
During this time, as shown in
Next, in the detecting portion 50, the loads based on the load signals which are transmitted respectively from the first load sensor 46, the second load sensor 47 and the third load sensor 49 are stored as the load at the normal time.
Thereafter, after a predetermined time has passed, the load of the reflector 30 is sensed in the first load sensor 46, the second load sensor 47, and the third load sensor 49, and is transmitted as the load signal to the detecting portion 50, and the detecting portion 50 evaluates change-amounts between each of the loads based on the load signals transmitted from the first load sensor 46, the second load sensor 47 and the third load sensor 49, and the previously predetermined and stored load of the reflector 30 mentioned above. In the case that each of the change-amounts is not increased, the cavity portion 32 of the reflector 30 is determined to be normal without being broken.
Incidentally, in the case that the closed vessel 33 is broken due to the micro crack generated by an unexpected matter in the closed vessel 33 of the cavity portion 32 of the reflector 30, the primary coolant 2 makes an intrusion into the closed vessel 33 little by little. In the case that the gas is filled in the closed vessel 33, the gas is going to be discharged according to the intrusion of the primary coolant 2. Accordingly, a buoyancy of the cavity portion 32 is lowered little by little, and the load of the reflector 30 is increased.
In this state, the load sensed by the first load sensor 46 is increased in comparison with the load at a time when the reflector 30 is normal, which is previously evaluated and stored by the detecting portion 50. Accordingly, the change-amount between the load mentioned above and the load at the normal time is increased, and it is determined by the detecting portion 50 that the cavity portion 32 of the reflector 30 is broken. Specifically, the cavity portion 32 is determined to be broken in the case that the change-amount is larger than a predetermined amount. In the same manner, in the case that the change-amount between the load based on the load signal transmitted from the second load sensor 47 and the previously evaluated and stored load at a time when the reflector 30 is normal is increased, the cavity portion 32 of the reflector 30 is determined to be broken. In the case that the change-amount between the load based on the load signal transmitted from the third load sensor 49 and the previously evaluated and stored load at a time when the reflector 30 is normal is increased, the cavity portion 32 of the reflector 30 is determined to be broken. In other words, in the case that the change-amount of the load of the reflector 30 in at least one load sensor of the first load sensor 46, the second load sensor 47 and the third load sensor 49 is increased, the reflector 30 is determined to be broken, by the detecting portion 50.
As mentioned above, according to the present embodiment, it is possible to securely detect presence or absence of the breakage of the cavity portion 32 of the reflector 30 by means of the detecting portion 50, by sensing the load of the reflector 30 by means of the first load sensor 46, the second load sensor 47 and the third load sensor 49, regardless of the operating state or the shutdown state of the fast reactor 1. Accordingly, it is possible to further improve a reliability of the fast reactor 1.
Incidentally, in the present embodiment, the description is given of the example that the loads of the reflector 30 are sensed by the first load sensor 46 provided between the ball nut 44 and the end portion 34b of the drive shaft 34, the second load sensor 47 provided between the bearing portion 41a of the reduction gear 41 and the reduction gear side receiving table 52, and the third load sensor 49 provided between the output shaft 39a of the drive cylinder 39 and the attaching table 38. However, the structure is not limited to this, but at least one load sensor among these load sensors may be provided, and may be configured to sense the load of the reflector 30.
In addition, in the present embodiment, the description is given of the example that the first load sensing portion 45 has the first load sensor 46 formed as the ring. However, the structure is not limited to this, but two load sensors 51 may be arranged as a ring shape (in such a manner as to form a point symmetric with respect to the center of the drive shaft 34) between the ball nut 44 and the end portion 34b of the drive shaft 34, as shown in
In addition, in the present embodiment, the description is given of the example that the second load sensor 47 is provided between the bearing portion 41a of the reduction gear 41 and the reduction gear side receiving table 52. However, the second load sensor 47 is not limited to this, but may be provided between the bearing portion 37a (refer to
Further, in the present embodiment, the description is given of the example that the reflector drive apparatus 35 has the electric motor 37 vertically driving the reflector 30, and the drive cylinder 39 vertically driving the reflector 30 independently form the electric motor 37. However, the reflector drive apparatus 35 is not limited to this, but may be configured to have any one of the electric motor 37 and the drive cylinder 39 so as to vertically drive the reflector 30. In other words, in the case that the mechanism for vertically driving the reflector 30 is constructed only by the electric motor 37, the reflector drive apparatus 35 has only the first load sensing portion 45 without having the second load sensing portion 48. On the other hand, in the case that the mechanism for vertically driving the reflector 30 is constructed by the drive cylinder 39, the reflector drive apparatus 35 has only the second load sensing portion 48 without having the first load sensing portion 45. In this case, the transmission mechanism 57 is constructed by the attaching table 38, and a transmission member (not shown) coupling the attaching table 38 to the drive shaft 34 so as to transmit the driving force of the drive cylinder 39, and is structured such that the reflector 30 is vertically driven by the drive cylinder 39.
Next, a description will be given of a reflector system of a fast reactor in a second embodiment according to the present invention with reference to
In the second embodiment shown in
As shown in
A second strain gauge 55 sensing a strain of an output shaft 39a is attached to the output shaft 39a of a drive cylinder 39 of a reflector drive apparatus 35.
A detecting portion 50 receiving strain signals respectively transmitted from the first strain gauge 54 and the second strain gauge 55 is connected to the first strain gauge 54 and the second strain gauge 55. The detecting portion 50 is configured to calculate a load of the reflector 30 based on the strain signals transmitted from the first strain gauge 54 and the second strain gauge 55, evaluate a change-amount between each of the calculated loads, and each of previously predetermined loads at a time when the reflector 30 is normal, and determine that a cavity portion 32 of the reflector 30 is broken in the case that at least one of the change-amounts is increased.
As mentioned above, according to the present embodiment, it is possible to securely detect presence or absence of the breakage of the cavity portion of the reflector 30 by means of the detecting portion 50, by calculating the load of the reflector 30 by means of the detecting portion 50 based on the strain signals from the first strain gauge 54 and the second strain gauge 55, regardless of the operating state or the shutdown state of the fast reactor 1. Accordingly, it is possible to further improve the reliability of the fast reactor 1.
Incidentally, in the present embodiment, the description is given of the example that the load of the reflector 30 is calculated by the detecting portion 50 based on the strain signals form the first strain gauge 54 attached to the ball nut 44 and the second strain gauge 55 attached to the output shaft 39a of the drive cylinder 39. However, the structure is not limited to this, but it may be configured to calculate the load of the reflector 30 by means of the detecting portion 50 by using only one strain gauge of these strain gauges.
In addition, in the present embodiment, the description is given of the example that the first strain gauge 54 is attached to the ball nut 44. However, the first strain gauge 54 is not limited to this, but may be attached to the drive shaft 34.
Next, a description will be given of a reflector system of a fast reactor in a third embodiment according to the present invention with reference to
In the third embodiment shown in
As shown in
A detecting portion 50 receiving a torque signal transmitted from the strain torque measuring device 56 is connected to the strain torque measuring device 56. The detecting portion 50 is configured to calculate a load of the reflector 30 based on the torque signal transmitted from the torque measuring device 56, evaluate a change-amount between the calculated load and a previously predetermined load at a time when the reflector 30 is normal, and determine that a cavity portion 32 of the reflector 30 is broken in the case that the change-amount is increased.
As mentioned above, according to the present embodiment, it is possible to securely detect presence or absence of the breakage of the cavity portion 32 of the reflector 30 by means of the detecting portion 50, by calculating the load of the reflector 30 by means of the detecting portion 50 based on the torque signal from the strain torque measuring device 56, regardless of the operating state or the shutdown state of the fast reactor 1. Accordingly, it is possible to further improve the reliability of the fast reactor 1.
Incidentally, in the present embodiment, the description is given of the example that the strain torque measuring device 56 is provided between the bearing portion 37 of the electric motor 37 and the electric motor side receiving table 53 in the side of the reduction gear 41 However, the strain torque measuring device is not limited to this, but may be provided between the bearing portion 41a (refer to
| Number | Date | Country | Kind |
|---|---|---|---|
| 2008-239518 | Sep 2008 | JP | national |
