Automatic and rapid power and flow reduction control method for sodium-cooled fast reactor
By linking and controlling multiple systems of the reactor, the automatic and rapid power reduction and flow matching of the sodium-cooled fast reactor under the operating condition of the condenser half side were realized, which solved the problem of negative reactivity brought in by the falling compensating rods and ensured the safety and controllability of the reactor.
Patent Information
- Application Number
- CN202510986698.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-17
- Publication Date
- 2025-11-18
AI Technical Summary
In existing technologies, when a sodium-cooled fast reactor operates on one side of the condenser, the falling of the compensating rods introduces a large amount of negative reactivity into the reactor, causing the primary and secondary loops to fail to respond quickly, resulting in improper power matching and posing a safety hazard.
The reactor power regulation system, primary loop flow control system, secondary loop flow control system, and rod control and rod position indication system are linked for control. Through a non-drop rod type automatic rapid power and flow reduction method, the reactor power target value is set and the descent action of the compensation rod is adjusted to achieve automatic matching of reactor power and flow.
It enables rapid reduction of nuclear power and primary and secondary loop flow rates to 75% of rated power level under condenser half-side operation conditions, avoiding the introduction of negative reactivity due to excessively rapid fall of compensating rods, and ensuring the safety and controllability of the reactor unit.
Smart Images
Figure CN120977637A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of reactor power flow control, in particular to a sodium-cooled fast reactor automatic rapid power reduction and flow reduction control method. BACKGROUND
[0002] During the full power operation of the reactor unit, if the three-loop circulating water pump needs to be taken out of operation due to some equipment failure or maintenance, a single circulating water pump is not enough to export the heat of the two-loop liquid sodium, that is, the condenser half-side operation condition. At this time, a series of measures need to be taken to quickly reduce the nuclear power and the flow of the primary and secondary loops to ensure the safety of the reactor unit and avoid overheating of the reactor core. This process is called rapid power reduction.
[0003] In the prior art, in the original design of the reactor unit, when the reactor power is higher than 75% of the rated power, and the condenser half-side operation condition occurs, the reactor compensation rod is dropped, and the reactor power regulation system stabilizes the power at 40% of the rated power, and the primary and secondary loop flows are reduced to the corresponding level according to a specific curve. The disadvantage of the current method is that the dropping of the compensation rod brings a large amount of negative reactivity to the reactor core, the reactor power is instantaneously reduced, the primary loop equipment of the reactor cannot respond quickly, and the primary and secondary loop flows of the reactor cannot match the power. SUMMARY
[0004] The present application provides a sodium-cooled fast reactor automatic rapid power reduction and flow reduction control method, which is used to solve the problem that the existing technology adopts the means of dropping the compensation rod to rapidly reduce the power, which brings a large amount of negative reactivity, the primary loop equipment of the reactor cannot respond quickly, and the primary and secondary loop flows of the reactor cannot match the power.
[0005] The technical scheme of the present application is as follows:
[0006] The present application provides a sodium-cooled fast reactor automatic rapid power reduction and flow reduction control method, which is used to solve the problem that the existing technology adopts the means of dropping the compensation rod to rapidly reduce the power, which brings a large amount of negative reactivity, the primary loop equipment of the reactor cannot respond quickly, and the primary and secondary loop flows of the reactor cannot match the power.
[0007] Step one: the sodium-cooled fast reactor starts the rapid power reduction and flow reduction mode, and sets the reactor power target set value when the reactor power is greater than 80% of the rated power;
[0008] Step two: adjust the reactor power regulation system to manual mode, and adjust the primary loop flow control system and the secondary loop flow control system to automatic mode;
[0009] Step three: the rod control and rod position indication system controls the compensation rod to perform the descending action;
[0010] Step four: when the reactor power is less than or equal to 80% of the rated power, the rod control and rod position indication system controls the compensation rod to stop the descending action, and the reactor power regulation system adjusts the reactor power to the power target set value.
[0011] Step five: Manually reset the quick power reduction and flow reduction mode, and the reactor resumes normal operation.
[0012] In some embodiments, the reactor power target setting value is 75% of the rated power.
[0013] In some embodiments, step two specifically includes switching the No. 1 and No. 2 regulation rods of the reactor power regulation system to manual mode, and adjusting the primary loop flow control system and the secondary loop flow control system to automatic mode to adjust the flow following the current real-time reactor power.
[0014] In some embodiments, the compensation rod performs the lowering action in step three specifically includes that during the compensation rod lowering process, the single lowering distance of the compensation rod does not exceed 30 mm, and the single lowering interval time is 1 min.
[0015] In some embodiments, the single lowering of the reactor power by the compensation rod performing the lowering action in step three does not exceed 5% of the rated power.
[0016] In some embodiments, the reactor power regulation system adjusts the reactor power to the power target setting value in step four specifically includes that the reactor power regulation system controls the No. 1 regulation rod to be switched to automatic mode, and the reactor power regulation system controls the No. 1 regulation rod to automatically adjust the reactor power to the power target setting value.
[0017] In some embodiments, the reactor power regulation system adjusts the reactor power to the power target setting value in step four specifically includes that if the reactor power is lower than the power target setting value, the reactor power regulation system controls the No. 1 regulation rod to increase the power to the power target setting value; and if the reactor power is greater than the power target setting value and less than or equal to 80% of the rated power, the reactor power regulation system controls the No. 1 regulation rod to reduce the reactor power to the power target setting value.
[0018] The implementation of the present application has the following beneficial effects:
[0019] The present application provides a sodium-cooled fast reactor automatic quick power reduction and flow reduction control method. Through the linkage control of the reactor power regulation system, the primary loop flow control system, the secondary loop flow control system, and the rod control and rod position indication system, and through the automatic quick power reduction and flow reduction technology without rod falling, the effect of quickly reducing the nuclear power and the flow of the primary loop and the secondary loop to 75% of the rated power level is achieved when the condenser half-side operating condition is realized, the over-fast falling of the compensation rod and the introduction of a large amount of negative reactivity are avoided, the reactor unit enters a larger transient state, and the safety and controllability of the reactor unit are ensured. BRIEF DESCRIPTION OF DRAWINGS
[0020] Figure 1A flow chart of a sodium-cooled fast reactor automatic rapid power reduction and flow reduction control method is provided for an embodiment of the present application. DETAILED DESCRIPTION
[0021] The technical solutions of the present application will be described clearly and completely in combination with the drawings and specific embodiments. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.
[0022] When the sodium-cooled fast reactor needs to be rapidly reduced in power and flow, the rapid power reduction and flow reduction mode needs to be turned on. The related operation systems include the reactor power regulation system, the one-way flow control system, the two-way flow control system, and the rod control and rod position indication system.
[0023] The reactor power regulation system suppresses the power disturbance of the reactor, so that the reactor power is maintained at a given level. The reactor power regulation system controls the reactor power by controlling the regulating rods (including No. 1 regulating rod and No. 2 regulating rod). The control mode of the reactor power regulation system usually includes automatic control and manual control modes. In the automatic control mode, the power regulation system automatically adjusts the regulating rods according to the deviation between the preset power set value and the actual power. In the manual control mode, the operator manually adjusts the position of the regulating rod according to the real-time monitoring data and operating experience to achieve more precise power control. In the present patent, the reactor power regulation system mainly controls the reactor power through No. 1 regulating rod and No. 2 regulating rod.
[0024] The one-way flow control system is mainly responsible for controlling the flow of the reactor coolant (liquid sodium) to maintain the appropriate temperature and pressure of the reactor core. In the automatic mode of the one-way flow control system, the one-way flow control system automatically adjusts the coolant flow according to the reactor power target set value. When the reactor power changes, the system automatically adjusts the flow to maintain the stability of the core temperature and pressure.
[0025] The two-way flow control system is mainly responsible for controlling the flow of the coolant in the steam generator to maintain the stability of the pressure and temperature of the two-way system. In the automatic mode, the two-way flow control system automatically adjusts the coolant flow according to the reactor power target set value. When the reactor power changes, the system automatically adjusts the flow to maintain the stability of the two-way pressure and temperature.
[0026] The rod control and rod position indication system provides timing current for the control rod drive mechanism by receiving operation instructions to realize the lifting, holding or insertion of the control rod, thereby adjusting the power of the reactor and completing the start-up, load operation or shutdown function of the reactor. In a sodium-cooled fast reactor, the control rod is divided into safety rods, compensation rods, regulating rods and passive rods, and the compensation rod is mainly used for burnup reactivity compensation and safe shutdown. In the present patent, the rod control and rod position indication system mainly realizes rapid power reduction by using the compensation rod.
[0027] As shown in Figure 1 The present application provides a sodium-cooled fast reactor automatic rapid power reduction and flow reduction control method, which comprises the following steps:
[0028] Step 1: When the sodium-cooled fast reactor needs to be rapidly reduced in power and flow, the sodium-cooled fast reactor is started in the rapid power reduction and flow reduction mode, and when the reactor power P is greater than 80% of the rated power, the reactor power target setting value is set to 75% of the rated power.
[0029] Step 2: The reactor power regulation system controls No. 1 regulating rod and No. 2 regulating rod to exit the automatic mode and switch to the manual mode; the primary loop flow control system and the secondary loop flow control system remain in the automatic mode, and the primary loop flow control system and the secondary loop flow control system are set to adjust the flow by following the current reactor real-time power instead of the reactor power target setting value.
[0030] Step 3: The rod control and rod position indication system controls No. 1 compensation rod (or any compensation rod) to perform a downward action; wherein during the downward movement of No. 1 compensation rod (or any compensation rod), the single downward distance of No. 1 compensation rod (or any compensation rod) does not exceed 30 mm, the single downward interval time is 1 min, and the single downward reactor power reduction does not exceed 5% of the rated power.
[0031] Step 4: When the reactor power is less than or equal to 80% of the rated power, the rod control and rod position indication system controls No. 1 compensation rod (or any compensation rod) to stop the downward action, the reactor power regulation system controls No. 1 regulating rod to switch to the automatic mode, and the reactor power regulation system controls No. 1 regulating rod to adjust the reactor power to the power target setting value, i.e. 75% of the rated power; if the reactor power is lower than 75% of the rated power at this time, the reactor power regulation system controls No. 1 regulating rod to increase the power to 75% of the rated power; if the reactor power is greater than 75% of the rated power and less than or equal to 80% of the rated power, the reactor power regulation system controls No. 1 regulating rod to reduce the reactor power to 75% of the rated power level.
[0032] Step 5: The operator manually resets the rapid power reduction and flow reduction mode, and the reactor resumes normal operation.
[0033] The application provides a sodium-cooled fast reactor automatic rapid power reduction and flow reduction control method.
[0034] The application realizes the effect of rapidly reducing the nuclear power and the flow of the primary loop and the secondary loop to 75% of the rated power level when the condenser half-side operation condition is realized through the linkage control of the reactor power regulating system, the primary flow control system, the secondary flow control system and the rod control and rod position indication system, avoids the introduction of a large amount of negative reactivity caused by the too fast compensation and rod dropping to make the reactor unit enter a larger transient state, and guarantees the safety and controllability of the reactor unit.
[0035] The above examples only express several embodiments of the application, the description is more specific and detailed, but it cannot be understood as the limitation of the patent scope of the application. It should be pointed out that, for ordinary skilled in the art, without departing from the concept of the application, a number of modifications and improvements can be made, which belong to the protection scope of the application. Therefore, the protection scope of the patent of the application should be subject to the appended claims.
Claims
1. A method for automatic rapid power and flow reduction control in a sodium-cooled fast reactor, characterized in that, The method includes: Step 1: The sodium-cooled fast reactor starts the rapid power reduction and flow reduction mode. When the reactor power is greater than 80% of the rated power, the reactor power target set value is set. Step 2: Set the reactor power regulation system to manual mode and the primary loop flow control system and secondary loop flow control system to automatic mode; Step 3: The rod control and rod position indication system controls the compensating rod to perform the descent action; Step 4: When the reactor power is less than or equal to 80% of the rated power, the rod control and rod position indication system controls the compensating rods to stop descending, and the reactor power regulation system adjusts the reactor power to the target power setting value. Step 5: Manually reset the rapid power reduction and flow reduction mode, and the reactor will return to normal operation.
2. The automatic rapid power and flow reduction control method for a sodium-cooled fast reactor according to claim 1, characterized in that, The reactor power target is set at 75% of rated power.
3. The automatic rapid power and flow reduction control method for a sodium-cooled fast reactor according to claim 2, characterized in that, Step two specifically includes switching the No. 1 and No. 2 regulating rods of the reactor power regulation system to manual mode, and adjusting the primary loop flow control system and the secondary loop flow control system to automatic mode, adjusting the flow according to the current real-time reactor power.
4. The automatic rapid power and flow reduction control method for a sodium-cooled fast reactor according to claim 3, characterized in that, The specific steps of the third step, which involve the compensating rod descending, include: during the descent of the compensating rod, the distance of a single descent does not exceed 30mm, and the interval between single descents is 1min.
5. The automatic rapid power and flow reduction control method for a sodium-cooled fast reactor according to claim 4, characterized in that, In step three, the compensating rods perform a descent action, and the reactor power decreases by no more than 5% of the rated power in a single descent.
6. The automatic rapid power and flow reduction control method for a sodium-cooled fast reactor according to claim 5, characterized in that, In step four, the reactor power regulation system adjusts the reactor power to the target power setting value. Specifically, this includes the reactor power regulation system controlling the No. 1 regulating rod to switch to automatic mode, and the reactor power regulation system controlling the No. 1 regulating rod to automatically adjust the reactor power to the target power setting value.
7. The automatic rapid power and flow reduction control method for a sodium-cooled fast reactor according to claim 6, characterized in that, In step four, the reactor power regulation system adjusts the reactor power to the target power setting value. Specifically, if the reactor power is lower than the target power setting value, the reactor power regulation system controls the No. 1 regulating rod to increase the power to the target power setting value. If the reactor power is greater than the target power setting value but less than or equal to 80% of the rated power, the reactor power regulation system controls the No. 1 regulating rod to reduce the reactor power to the target power setting value level.