Method for automatically calibrating nuclear power in power operation stage based on large sodium-cooled fast reactor

Abstract

The invention relates to the field of nuclear reactors, in particular to a nuclear power automatic calibration method based on a large sodium-cooled fast reactor power operation stage. The method comprises the following steps that: a safety-level DCS (Distributed Control System) sends a thermal power calculation value and a manual calibration instruction or an automatic calibration instruction to a nuclear measurement system; the nuclear measurement system carries out automatic calibration judgment; and after entering the automatic calibration state, the nuclear measurement system feeds back to the security-level DCS system-level DAS system. Parameters are corrected in real time, the generating capacity is improved, the misoperation risk of personnel is reduced, and safe, stable and efficient operation of a unit is guaranteed.

Description

Technical Field

[0001] The present invention relates to the field of nuclear reactors, and in particular to an automatic calibration method for nuclear power during the power operation stage of a large sodium-cooled fast reactor. Background Art

[0002] During the power operation stage of a sodium-cooled fast reactor (SFR), high-precision nuclear power monitoring and control are required, and its automatic calibration method needs to comprehensively consider neutron physics, thermal-hydraulics, and core dynamic characteristics.

[0003] During the operation of a sodium-cooled fast reactor, when the true nuclear power of the reactor remains unchanged, due to the effects of burnup, temperature, and refueling during shutdown, the neutron fluence rate at the nuclear measurement detector will change, which in turn causes the output signal of the detector to change. And because there is a linear correspondence between the nuclear power display value and the detector output signal in the nuclear measurement system, the nuclear power display value will also change, forming a deviation from the true nuclear power. As the operation time of the unit increases, the deviation will gradually increase, and it is necessary to periodically correct the linear correspondence between the nuclear power display value and the detector output signal to ensure that the nuclear power display value is consistent with the true nuclear power of the reactor.

[0004] Currently, the modification method is to manually calculate the correspondence parameters between the nuclear power display value and the detector output signal periodically. The operator withdraws the unit state to the manual state, and the instrument control personnel withdraw the nuclear measurement-related protection and then enter the correspondence parameters into different channels of the nuclear measurement system channel by channel. Since the unit state needs to be switched from automatic control to manual control during the parameter modification, it affects the safe operation of the unit. At the same time, it requires the cooperation and confirmation of multiple parties including physics, operation, and instrument control personnel, and the human factor risk is also relatively high. Therefore, there is an urgent need to develop a set of real-time automatic calibration system for nuclear power. Summary of the Invention

[0005] The technical problem to be solved by the present invention is: to provide an automatic calibration method for nuclear power during the power operation stage of a large sodium-cooled fast reactor, which can correct parameters in real time, improve power generation, reduce the risk of human error, and ensure the safe, stable, and efficient operation of the unit.

[0006] The present invention provides an automatic calibration method for nuclear power during the power operation stage of a large sodium-cooled fast reactor, including the following steps:

[0007] Step 1: The safety-class DCS system sends the calculated thermal power value and a manual calibration instruction or an automatic calibration instruction to the nuclear measurement system;

[0008] Step 2: The nuclear measurement system performs an automatic calibration judgment, and the automatic calibration judgment logic includes:

[0009] When the safety-class DCS system sends an automatic calibration instruction and the deviation between the nuclear power and the thermal power is less than ±1.5%, the nuclear measurement system enters the automatic calibration state;

[0010] When the nuclear measurement system is in the automatic calibration state, the nuclear measurement system compares the received thermal power signal with the nuclear power display value, and automatically calculates the correction parameter in real time through PID operation, so that the nuclear power display value is consistent with the thermal power;

[0011] When the nuclear measurement system receives a manual instruction sent by the safety-class DCS system, or there is a deviation between the thermal power and the nuclear power display value greater than ±5%, or the change rate of the correction coefficient K1 is high, or the nuclear power deviation between the channels of the DAS system is large, the nuclear measurement system automatically switches to the manual calibration state;

[0012] Step 3: After the nuclear measurement system enters the automatic calibration state, it feeds back to the safety-class DCS system and the DAS system.

[0013] In a specific embodiment of the present invention, in the step 1, the safety-class DCS system judges the conditions of each channel therein,

[0014] Multiple channels exchange information through network communication, and any channel receives the information feedback of other channels;

[0015] In each channel of the safety-class DCS system, the signal states of all channels are compared. When all channels of the safety-class DCS system receive the allowable automatic input signal fed back by the nuclear measurement system, and all thermal power calculation values and all nuclear measurement signals are normal, an automatic calibration instruction is input to the corresponding channel of the nuclear measurement system;

[0016] If the above conditions are not met, a manual calibration instruction is input to the corresponding channel of the nuclear measurement system.

[0017] In a specific embodiment of the present invention, the information received by any channel of the safety-class DCS system from other channels includes the normal signals of the nuclear power and thermal power of other channels, as well as the allowable automatic calibration instruction.

[0018] In a specific embodiment of the present invention, in the step 2, when the nuclear measurement system is in the automatic calibration state, any channel of the nuclear measurement system compares the received thermal power value with the nuclear power display value, and the comparison result is subjected to PID operation to obtain the correction parameter K1, and the channel nuclear power P is calculated by multiplying with the output current I of the channel detector,

[0019] The calculation formula is: P = K1 × K2 × I + B2

[0020] K2 and B2 are fixed parameters,

[0021] The calculated channel nuclear power P is used as the system negative feedback for the next calculation of the correction parameter K1.

[0022] In a specific embodiment of the present invention, in step 3, the nuclear measurement system feeds back the calculated nuclear power, thermal power value, allowable input automatic signal, and manual and automatic status signals to the safety-class DCS system.

[0023] In a specific embodiment of the present invention, in step 3, the nuclear measurement system sends gear signals, measured micro-current signals, and calibration parameters to the DAS system.

[0024] In a specific embodiment of the present invention, after the DAS system completes the calculation of the nuclear power display value, it feeds back the nuclear power display value and the power deviation judgment of the DAS system to the nuclear measurement system.

[0025] In a specific embodiment of the present invention, the nuclear measurement system sends the calculated nuclear power to the safety-class DCS system in the form of analog hard wiring; the thermal power value, allowable input automatic signal, and manual and automatic status signals are fed back to the safety-class DCS system through digital signal network communication.

[0026] In a specific embodiment of the present invention, when the change rate of the correction coefficient K1 is higher than 1% / h, the nuclear measurement system automatically switches to the manual calibration state.

[0027] In a specific embodiment of the present invention, when the nuclear power deviation between channels A and B of the DAS system is greater than ±5%, the nuclear measurement system automatically switches to the manual calibration state. Compared with the prior art, the nuclear power automatic calibration method based on the power operation stage of a large sodium-cooled fast reactor of the present invention has the following beneficial effects:

[0028] (1) Through the logical signal interaction of the safety-class DCS system, the nuclear measurement system, and the DAS system, it is ensured that the automatic calibration of the nuclear measurement system is implemented under safe conditions;

[0029] (2) The nuclear power is automatically calculated and corrected in real time. It changes from the original regular calibration and correction on a weekly or monthly basis to real-time calculation and correction, and the nuclear power display value is more accurate;

[0030] (3) Since the nuclear power display value is automatically corrected in real time and is consistent with the real nuclear power, the operator can adjust the reactor state to the best, improving the power generation of the unit. It can not only avoid the impact on the reactor core caused by the actual reactor nuclear power exceeding the power when the nuclear power display value is low, but also avoid restricting the power generation of the unit due to the actual reactor nuclear power being low when the nuclear power display value is high;

[0031] (4) The parameters are changed from manual regular modification to automatic real-time modification, eliminating the possible human error risks such as manual calculation errors, wrong intervals, or parameter entry errors; when automatically modifying the parameters, the unit can be in the automatic state without placing the unit in an unsafe position of the manual position, reducing the interference with the normal operation of the unit and comprehensively ensuring the safe and stable operation of the unit.

[0032] (5) Since the nuclear power is realized with real-time automatic calculation and correction, there is no need to regularly carry out the work of manual calculation of thermal power by physical personnel, switching of unit status by operation personnel, and manual modification of parameters by instrument control personnel, saving a large amount of labor costs. Description of the Drawings

[0033] Figure 1 Indicates the signal flow diagram;

[0034] Figure 2 Indicates the automatic calibration judgment logic diagram of the nuclear measurement system;

[0035] Figure 3 Indicates the schematic diagram of the automatic calibration of the nuclear power parameters of the nuclear measurement system. Detailed Implementation Manner

[0036] In order to further understand the present invention, the implementation solutions of the present invention will be described below in conjunction with embodiments. However, it should be understood that these descriptions are only for further explaining the features and advantages of the present invention, rather than limiting the present invention.

[0037] An embodiment of the present invention discloses a method for automatically calibrating nuclear power during the power operation stage of a large sodium-cooled fast reactor, including the following steps:

[0038] Step 1: The safety-class DCS system sends the calculated thermal power value and a manual calibration instruction or an automatic calibration instruction to the nuclear measurement system:

[0039] A plurality of channels are set in the safety-class DCS system, corresponding to the channels of the nuclear measurement system;

[0040] The safety-class DCS system sends the thermal power value calculated based on thermal parameters, as well as a manual calibration instruction or an automatic calibration instruction, to the power range channel of the nuclear measurement system through its internal channels;

[0041] After judging the conditions of its respective channels, the safety-class DCS system sends a manual calibration instruction or an automatic calibration instruction to the nuclear measurement system;

[0042] The plurality of channels in the safety-class DCS system exchange information through a network communication method. Each channel receives the information feedback of other channels, including the normal signals of the nuclear power and thermal power of other channels, and an automatic calibration permission instruction;

[0043] In each channel of the safety-class DCS system, the signal states of all channels are compared. When all channels of the safety-class DCS system receive the automatic calibration permission signal feedback from the nuclear measurement system and all the calculated thermal power values and all the nuclear measurement signals are normal, an automatic calibration instruction is sent to the corresponding channel of the nuclear measurement system.

[0044] Step 2: The nuclear measurement system performs automatic calibration judgment:

[0045] The automatic calibration judgment logic of the nuclear measurement system is as Figure 2 shown and includes:

[0046] When the safety-class DCS system sends an automatic calibration instruction and the deviation between the nuclear power and the thermal power is less than ±1.5%, the nuclear measurement system enters the automatic calibration state;

[0047] When the nuclear measurement system is in the automatic calibration state, the nuclear measurement system compares the received thermal power signal with the nuclear power display value, and automatically calculates the correction parameter in real time through PID operation to make the nuclear power display value consistent with the thermal power;

[0048] As Figure 3 shown, specifically, any channel of the nuclear measurement system compares the received thermal power value with the nuclear power display value, and the comparison result is subjected to PID operation to obtain the correction parameter K1, and the channel nuclear power P is calculated by multiplying with the channel detector output current I. The calculation formula is: P = K1×K2×I + B2

[0049] K2 and B2 are fixed parameters,

[0050] The calculated channel nuclear power P is used as the system negative feedback for the calculation of the next correction parameter K1.

[0051] When the nuclear measurement system receives a manual instruction sent by the safety-class DCS system, or the deviation between the thermal power and the nuclear power display value is greater than ±5%, or the change rate of the correction coefficient K1 is higher than 1% / h, or the deviation between the nuclear powers of channels A and B of the DAS system is greater than ±5%, the nuclear measurement system automatically switches to the manual calibration state.

[0052] Step 3: After the nuclear measurement system enters the automatic calibration state, the nuclear measurement system feeds back the calculated nuclear power, thermal power value, allowable input automatic signal, manual and automatic state signals to the safety-class DCS system; at the same time, it sends the gear signal, measurement micro-current signal and calibration parameter to the DAS system. After the DAS system completes the calculation of the nuclear power display value, it feeds back the nuclear power display value and the nuclear power deviation judgment between channels of the DAS system to the nuclear measurement system;

[0053] The channel of the nuclear measurement system sends the calculated nuclear power to the safety-class DCS system in the form of analog hard wiring, and other signals such as the thermal power value received by the IP channel of the nuclear measurement system, the allowable input manual signal, and the manual / automatic state are fed back to the safety-class DCS system through digital signal network communication.

[0054] To further understand the present invention, the following describes in detail the method for automatically calibrating nuclear power during the power operation stage of a large sodium-cooled fast reactor provided by the present invention in combination with embodiments. The protection scope of the present invention is not limited by the following embodiments.

[0055] Embodiment 1

[0056] As Figure 1 shown, the safety-class DCS system includes 4 channels, namely the safety-class DCS system IP channel, the safety-class DCS system IIP channel, the safety-class DCS system IIIP channel, and the safety-class DCS system IVP channel;

[0057] The nuclear measurement system includes 4 channels in the power range, namely the nuclear measurement system IP channel, the nuclear measurement system IIP channel, the nuclear measurement system IIIP channel, and the nuclear measurement system IVP channel;

[0058] The channels of the safety-class DCS system correspond one-to-one with the channels of the nuclear measurement system, and control the manual or automatic state of their nuclear power calibration;

[0059] The DAS system includes channel A and channel B;

[0060] In the safety-class DCS system, the 4 safety-class DCS channels exchange information through network communication. Each channel receives the information feedback from the other 3 channels, including the normal signals of the nuclear power and thermal power of the other channels, and the signal allowing automatic input. In each channel of the safety-class DCS system, the signal states of the 4 channels are compared. When all 4 channels of the nuclear measurement system feedback the signal allowing automatic input, and all thermal power calculation values and all nuclear measurement signals are normal, this channel can be put into automatic calibration. Otherwise, this channel is automatically switched to the manual state.

[0061] Taking the IP channel as an example, the safety-class DCS system IP channel sends the thermal power calculation value, as well as the manual calibration instruction or the automatic calibration instruction, to the nuclear measurement system IP channel;

[0062] The nuclear measurement system IP channel makes an automatic calibration judgment. The calibration judgment logic, as Figure 2 shown, includes:

[0063] When the safety-class DCS system IP channel sends an automatic calibration instruction to the nuclear measurement system IP channel, and the deviation between the nuclear power and the thermal power is less than ±1.5%, the nuclear measurement system IP channel enters the automatic calibration state;

[0064] When the nuclear measurement system IP channel is in the automatic calibration state, the nuclear measurement system IP channel compares the received thermal power signal with the nuclear power display value, and automatically calculates the correction parameter in real time through PID operation to make the nuclear power display value consistent with the thermal power;

[0065] As shown Figure 3 Specifically, the IP channel of the nuclear measurement system compares the received thermal power value with the nuclear power display value. The comparison result is subjected to PID operation to obtain the correction parameter K1, and the channel nuclear power P is calculated by multiplying the correction parameter K1 with the output current I of the IP channel detector.

[0066] The calculation formula is: P = K1 × K2 × I + B2

[0067] K2 and B2 are fixed parameters.

[0068] The calculated channel nuclear power P is used as the system negative feedback for the calculation of the next correction parameter K1.

[0069] When the IP channel of the nuclear measurement system receives a manual instruction sent by the IP channel of the safety-class DCS system, or the deviation between the thermal power and the nuclear power display value is greater than ±5%, or the change rate of the correction coefficient K1 is higher than 1% / h, or the nuclear power deviation between the A and B channels of the DAS system is greater than ±5%, the IP channel of the nuclear measurement system automatically switches to the manual calibration state;

[0070] Step 3: After the IP channel of the nuclear measurement system enters the automatic calibration state, the IP channel of the nuclear measurement system sends the calculated nuclear power to the IP channel of the safety-class DCS system in the form of analog hard wiring; other signals such as the thermal power value received by the IP channel of the nuclear measurement system, the signal allowing manual input, and the manual / automatic status are fed back to the IP channel of the safety-class DCS system through digital signal network communication.

[0071] At the same time, three gear signals, the measured micro-current signal, and the calibration parameters are sent to the A channel of the DAS system. The nuclear power display value is calculated in the A channel of the DAS system, and the nuclear power display value and the power deviation judgment between the A and B channels of the DAS system are fed back to the IP channel of the nuclear measurement system.

[0072] The description of the above embodiments is only used to help understand the method and its core idea of the present invention. It should be noted that for those of ordinary skill in the art of this technology, without departing from the principle of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

[0073] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the broadest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for automatically calibrating nuclear power during the power operation stage of a large sodium-cooled fast reactor, characterized in that, It includes the following steps: Step 1: The safety-class DCS system sends the calculated thermal power value, as well as a manual calibration instruction or an automatic calibration instruction, to the nuclear measurement system; Step 2: The nuclear measurement system performs an automatic calibration judgment, and the automatic calibration judgment logic includes: When the safety-class DCS system sends an automatic calibration instruction and the deviation between the nuclear power and the thermal power is less than ±1.5%, the nuclear measurement system enters the automatic calibration state; When the nuclear measurement system is in the automatic calibration state, the nuclear measurement system compares the received thermal power signal with the nuclear power display value, and automatically calculates the correction parameter in real time through PID operation to make the nuclear power display value consistent with the thermal power; When the nuclear measurement system receives a manual instruction sent by the safety-class DCS system, or the deviation between the thermal power and the nuclear power display value is greater than ±5%, or the change rate of the correction coefficient K1 is high, or the nuclear power deviation between the channels of the DAS system is large, the nuclear measurement system automatically switches to the manual calibration state; Step 3: After the nuclear measurement system enters the automatic calibration state, it gives feedback to the safety-class DCS system and the DAS system.

2. The nuclear power automatic calibration method based on the power operation stage of a large sodium-cooled fast reactor according to claim 1, wherein In the said Step 1, the safety-class DCS system judges the conditions of each channel therein, Multiple channels exchange information through network communication, and any one channel receives the information feedback of other channels; In each channel of the safety-class DCS system, the signal states of all channels are compared. When all channels of the safety-class DCS system receive the allowed automatic input signal fed back by the nuclear measurement system and all calculated thermal power values and all nuclear measurement signals are normal, an automatic calibration instruction is input to the corresponding channel of the nuclear measurement system; If the above conditions are not met, a manual calibration instruction is input to the corresponding channel of the nuclear measurement system.

3. The nuclear power automatic calibration method based on the power operation stage of a large sodium-cooled fast reactor according to claim 2, characterized in that, Any one channel of the safety-class DCS system receives the information of other channels, including the normal signals of the nuclear power and thermal power of other channels, as well as the allowed automatic calibration instruction.

4. The method for automatically calibrating nuclear power during the power operation stage of a large sodium-cooled fast reactor according to claim 1, wherein In the said Step 2, when the nuclear measurement system is in the automatic calibration state, any one channel of the nuclear measurement system compares the received thermal power value with the nuclear power display value, and the comparison result is subjected to PID operation to obtain the correction parameter K1, and the channel nuclear power P is calculated by multiplying with the output current I of the channel detector, The calculation formula is: P = K1×K2×I + B2 K2 and B2 are fixed parameters, The calculated channel nuclear power P is used as system negative feedback for the next calculation of the correction parameter K1.

5. The automatic nuclear power calibration method for the power operation stage of a large sodium-cooled fast reactor according to claim 1, wherein In the said Step 3, the nuclear measurement system feeds back the calculated nuclear power, thermal power value, allowed input automatic signal, manual and automatic state signals to the safety-class DCS system.

6. The method for automatically calibrating nuclear power during the power operation stage of a large sodium-cooled fast reactor according to claim 1, wherein In the said Step 3, the nuclear measurement system sends a gear signal, a measured micro-current signal and calibration parameters to the DAS system.

7. The method for automatically calibrating nuclear power during the power operation stage of a large sodium-cooled fast reactor according to claim 6, wherein The DAS system completes the calculation of the nuclear power display value and feeds back the nuclear power display value and the DAS system power deviation judgment to the nuclear measurement system.

8. The method for automatically calibrating nuclear power during the power operation stage of a large sodium-cooled fast reactor according to claim 5, wherein The nuclear measurement system sends the calculated nuclear power to the safety-class DCS system in the form of analog hard wiring; the thermal power value, allowed input automatic signal, manual and automatic state signals are fed back to the safety-class DCS system in the form of digital signal network communication.

9. The nuclear power automatic calibration method based on the power operation stage of a large sodium-cooled fast reactor according to claim 1, wherein When the change rate of the correction coefficient K1 is higher than 1% / h, the nuclear measurement system automatically switches to the manual calibration state.

10. The method for automatically calibrating nuclear power during the power operation stage of a large sodium-cooled fast reactor according to claim 1, wherein When the nuclear power deviation between Channel A and Channel B of the DAS system is greater than ±5%, the nuclear measurement system automatically switches to the manual calibration state.

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