Shutdown time sequence interface connection method for out-of-core nuclear measurement system and reactor protection system

Abstract

The invention belongs to the technical field of reactor shutdown time sequences, and particularly relates to a reactor shutdown time sequence interface connection method for an out-of-core nuclear measurement system and a reactor protection system. Threshold triggering signals of a CH1 channel or a CH2 channel of the out-of-pile nuclear measurement system are output to an IP channel, an IIP channel, an IIIP channel and an IVP channel of a reactor protection system through a relay parallel optical coupler isolation connection mode. 'Test or error' signals of a CH1 channel or a CH2 channel of the out-of-pile nuclear testing system are respectively output to an IP channel, an IIP channel, an IIIP channel and an IVP channel of a reactor protection system in a connection mode that relays are connected in series with optocouplers for isolation. According to the method, by establishing a shutdown time sequence signal connection mode between the source range or the middle range of the ex-core nuclear measurement system and the reactor protection system, it is ensured that the shutdown time sequence of the source range or the middle range can be correctly triggered, the problem that the time sequence is random in a traditional connection method is solved, reliability is improved, and cost is reduced. And a combined connection mode with faster response is adopted, so that the response time is better.

Description

Technical Field

[0001] The invention belongs to the technical field of reactor shutdown sequence, and in particular relates to a method for connecting an external nuclear measurement system with a reactor protection system shutdown sequence interface. Background Art

[0002] The main function of the reactor external nuclear measurement system (RPN) is to measure the power of the reactor by monitoring the neutrons leaking from the reactor pressure vessel. According to the different measurement ranges, it is mainly divided into source range, intermediate range and power range. There is a certain overlap between the three ranges. The source range and intermediate range of the reactor external nuclear measurement system are mainly installed in channel one (CH1) and channel two (CH2).

[0003] The main function of the reactor protection system (RPR) of a nuclear power plant is to prevent or reduce damage to the core and coolant system components by shutting down the reactor and / or starting up special safety facilities under abnormal or accident conditions, protect the integrity of the three major nuclear safety barriers of the nuclear power plant, avoid causing a large amount of radioactive substances to escape, and protect the environment around the nuclear power plant from pollution and the safety of personnel. The reactor protection system is divided into four channels (IP or IIP or IIIP or IVP).

[0004] Both the external nuclear measurement system and the reactor protection system are nuclear-grade systems, and both are related to nuclear safety. The abnormal power conditions measured by the external nuclear measurement system are sent to the reactor protection system to trigger the shutdown, and because the response time requirements of the entire reactor protection system channel and the system reliability requirements are relatively high, the traditional connection uses a single relay element interface, which has the problem of random triggering timing, resulting in the signal not being able to be triggered according to the expected timing under certain working conditions. Summary of the invention

[0005] The object of the present invention is to provide a method for connecting the shutdown timing interface of an off-core nuclear measurement system and a reactor protection system. The method establishes a shutdown timing signal connection mode between a source range or an intermediate range of the off-core nuclear measurement system and the reactor protection system to ensure that the source range or the intermediate range shutdown timing can be correctly triggered, thereby solving the problem of random timing in traditional connection methods, improving reliability, and adopting a faster-response combined connection mode with a better response time.

[0006] The technical solution to achieve the purpose of the present invention is:

[0007] A method for connecting an off-core nuclear measurement system with a reactor protection system shutdown timing interface, wherein a "threshold trigger" signal of a CH1 channel or a CH2 channel of the off-core nuclear measurement system is output to an IP channel, an IIP channel, a IIIP channel, and an IVP channel of the reactor protection system respectively through a relay parallel optical coupler isolation connection mode; a "test or error" signal of a CH1 channel or a CH2 channel of the off-core nuclear measurement system is output to an IP channel, an IIP channel, a IIIP channel, and an IVP channel of the reactor protection system respectively through a relay series optical coupler isolation connection mode.

[0008] In the method, the logic operation of triggering a single-channel reactor shutdown signal in the reactor protection system includes: (1) when there is no "test or error" signal, the "2-out-of-1" logic of the "threshold trigger" signal of the CH1 channel and the CH2 channel; (2) the CH1 channel and the CH2 channel trigger the "test or error" signal at the same time; (3) the "threshold trigger" signal appears in the CH1 channel or the CH2 channel, and the "test or error" signal appears in the other channel.

[0009] In the method, the logic operation of the reactor protection system that is triggered to cause the reactor protection system to shut down is: the four channels of IP channel, IIP channel, IIIP channel and IVP channel perform "4 out of 2" logic.

[0010] In the method, each channel in the CH1 channel or CH2 channel of the off-core nuclear measurement system includes a "threshold trigger 1", a "threshold trigger 2" signal and a "test or error 1", a "test or error 2" signal; the "threshold trigger 1" signal is transmitted to the IP channel and the IIP channel of the reactor protection system respectively through a relay in parallel with an optocoupler isolator, the "threshold trigger 2" signal is transmitted to the IIIP channel and the IVP channel of the reactor protection system respectively through a relay in parallel with an optocoupler isolator, the "test or error 1" signal is transmitted to the IP channel and the IIP channel of the reactor protection system respectively through a relay in series with an optocoupler isolator, and the "test or error 2" signal is transmitted to the IIIP channel and the IVP channel of the reactor protection system respectively through a relay in series with an optocoupler isolator.

[0011] In the method, during normal operation, the relays and optocoupler isolators of the "threshold trigger" signal and the "test or error" signal of the off-core nuclear measurement system are both in an energized state, and no reactor shutdown signal is output by logical operation.

[0012] In the method, during an accident condition, the off-core nuclear measurement system automatically triggers a "threshold trigger" signal of CH1 or CH2, and the relay parallel optocoupler isolator operates simultaneously to generate a "threshold trigger" signal, and the "threshold trigger" signal is transmitted to four channels of the reactor protection system, namely, the IP channel, the IIP channel, the IIIP channel, or the IVP channel, and a "2-out-of-1" logic operation is performed inside the four channels to generate IP channel, IIP channel, IIIP channel, and IV channel shutdown signals, respectively, and the four shutdown signals are then subjected to a "4-out-of-2" logic operation to generate a final shutdown signal.

[0013] In the method, when an equipment failure occurs in the off-core nuclear measurement system, when a channel of the off-core nuclear measurement system detects an equipment failure, the channel generates a "test or error" signal, and if a "threshold trigger" signal of the channel occurs at this time, no shutdown signal will be generated; if another channel generates a "threshold trigger" signal, it will be sent to four channels, namely, the IP channel, the IIP channel, the IIIP channel, or the IVP channel of the reactor protection system, respectively, and a 2-out-of-1 logic operation will be performed inside the four channels to generate shutdown signals of the IP channel, the IIP channel, the IIIP channel, and the IV channel, respectively, and a 4-out-of-2 logic operation will be performed on the four shutdown signals to generate a final shutdown signal; when two of the channels of the off-core nuclear measurement system fail, the two channels will simultaneously generate a "test or error" signal, and send it to four channels, namely, the IP channel, the IIP channel, the IIIP channel, or the IVP channel of the reactor protection system, and a logic operation will be performed inside the channels of the reactor protection system to generate a shutdown signal.

[0014] In the method, when the reactor protection system equipment fails, when one of the four channels of the reactor protection system fails, since the four channels have redundancy, when one channel fails and cannot send a shutdown signal, the other three channels 3 take 2 to generate a shutdown signal.

[0015] In the method, when a single channel of the off-core nuclear measurement system loses power, the channel will simultaneously generate a "threshold trigger" and a "test or error". The "test or error" signal will perform a logical "AND" operation with the "threshold trigger" signal, and the "test or error" will lock the "threshold trigger" signal, and no shutdown instruction will be generated in the reactor protection system.

[0016] In the method, when the maintenance of a channel in the off-core nuclear measurement system is completed or the upstream power supply is restored, the "threshold trigger" signal will disappear in the reactor protection system before the "test or error" signal, and the shutdown command will not be erroneously generated during the power supply restoration process.

[0017] The beneficial technical effects of the present invention are:

[0018] 1. In the method for connecting the shutdown timing interface between the off-core nuclear measurement system and the reactor protection system provided by the present invention, the optocoupler-relay combination interface connection method, compared with the original single relay interface connection method, can solve the risk of incorrect shutdown caused by the randomness of the interface response in the power failure and power restoration conditions in the current RPN-RPR design, and can maximize the reliability of the RPN-RPR interface.

[0019] 2. The method for connecting the shutdown timing interface between the off-core nuclear measurement system and the reactor protection system provided by the present invention can be applied to the transformation of the RPN-RPR system using a single relay interface, and can also be applied to the design of other system interfaces that have requirements for interface trigger timing, and has a wide range of applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a connection diagram between the off-core nuclear measurement system and the reactor protection system provided by the present invention.

[0021] In the figure: 1. Optocoupler; 2. Relay. DETAILED DESCRIPTION

[0022] The present invention is further described in detail below with reference to the accompanying drawings and embodiments.

[0023] In a method for connecting an off-core nuclear measurement system and a reactor protection system shutdown timing interface provided by the present invention, the nuclear measurement system (RPN) is divided into one channel (CH1 channel) and two channels (CH2 channel), and the reactor protection system (RPR) on the right is divided into one channel (IP channel), two channels (IIP channel), three channels (IIIP channel), and four channels (IVP channel); wherein the "threshold trigger" signal of the CH1 channel or CH2 channel of the off-core nuclear measurement system is output to the IP channel, IIP channel, IIIP channel, and IVP channel of the reactor protection system respectively through a connection method of relay parallel optical coupling isolation, and the "test or error" signal of the CH1 channel or CH2 channel of the off-core nuclear measurement system is output to the IP channel, IIP channel, IIIP channel, and IVP channel of the reactor protection system respectively through a connection method of relay series optical coupling isolation. The following logic operations in the reactor protection system (IP channel or IIP channel or IIIP channel or IVP channel) will trigger a single-channel reactor shutdown signal: (1) When there is no "test or error" signal, the "2-out-of-1" logic of the "threshold trigger" signal of the CH1 channel and the CH2 channel; (2) The CH1 channel and the CH2 channel trigger the "test or error" signal at the same time; (3) The "threshold trigger" signal appears in the CH1 channel or the CH2 channel, and the "test or error" signal appears in the other channel. The "4-out-of-2" logic triggering of the four channels of the reactor protection system causes the reactor protection system to shut down.

[0024] In order to ensure the high reliability of the entire shutdown system, the implementation methods of the technical solution involved in the present invention under different working conditions are described.

[0025] 1) Normal operation and accident mode

[0026] During normal operation, the relays and optocouplers of the "threshold trigger" signal and "test or error" signal of the external nuclear test system (RPN) are energized. In this state, the "threshold trigger" signal and "test or error" signal are both "0". The reactor protection system (RPR) detects the signal status in real time. Logical operation does not output the reactor shutdown signal.

[0027] In the accident condition, that is, the external nuclear measurement system (RPN) detects an abnormal increase in reactor power, the external nuclear measurement system (RPN) will automatically trigger the "threshold trigger" signal of CH1 or CH2, and the relay parallel optocoupler isolator will act at the same time to generate the "threshold trigger" signal. The signal is transmitted to the IP channel or IIP channel or IIIP channel or IVP channel of the reactor protection system (RPR) respectively, and the "2 out of 1" logic operation is performed inside the four channels to generate the IP channel, IIP channel, IIIP channel, and IV channel shutdown signals respectively. The four shutdown signals are then subjected to the "4 out of 2" logic operation to generate the final shutdown signal.

[0028] Since the reactor protection system (RPR) sets requirements for the response time of the collected signals, the solid-state relay in parallel with the optocoupler isolator is used as the interface for the threshold signal, and the relay in series with the optocoupler isolator is used as the interface for the "test or error" signal. Compared with a single relay interface, the response is faster. Whether in terms of function realization or response time optimization, the interface can be guaranteed to be safe and reliable.

[0029] 2) System equipment failure mode

[0030] a. Failure of the RPN equipment

[0031] When a channel (CH1 channel or CH2 channel) of the external nuclear measurement (RPN) detects a device failure, the channel generates a "test or error" signal. If the "threshold trigger" signal of the channel appears at this time, no shutdown signal will be generated. If another channel generates a "threshold trigger" signal, it will be sent to the IP channel or IIP channel or IIIP channel or IVP channel of the reactor protection system (RPR) respectively. A 2-out-of-1 logic operation is performed inside the four channels to generate shutdown signals for the IP channel, IIP channel, IIIP channel, and IV channel respectively. The four shutdown signals are then subjected to a 4-out-of-2 logic operation to generate the final shutdown signal.

[0032] If two channels (CH1 channel or CH2 channel) of the external nuclear measurement system (RPN) fail, the two channels will generate a "test or error" signal at the same time and send it to the IP channel, IIP channel, IIIP channel or IVP channel of the reactor protection system (RPR). The reactor protection system channels perform logical operations and generate a shutdown signal. At this time, if both RPN channels fail and are unavailable, it is considered that the monitoring of the neutron flux level has been lost. Based on nuclear safety considerations, the reactor needs to be shut down.

[0033] b. Reactor Protection System (RPR) equipment failure

[0034] When a fault occurs in one of the four channels of the reactor protection system (RPR), since the four channels are redundant, if a channel fails and cannot send a shutdown signal, two out of three of the other three channels will generate a shutdown signal.

[0035] Therefore, in the fault mode, the reactor can trigger the reactor shutdown logic normally. Regardless of whether there is a partial failure in the external nuclear measurement system (RPN) or the reactor protection system (RPR), the shutdown logic can be triggered normally to ensure the safety of the reactor. The system design has strong reliability.

[0036] 3) Power failure mode

[0037] a. Single channel power failure of the out-of-core nuclear measurement system

[0038] When a channel (CH1 channel or CH2 channel) in the off-core nuclear measurement system loses power, in order to ensure that when one of the channels loses power and the reactor is in safe mode, to avoid accidental shutdown of the reactor, when one channel loses power, the channel will generate "threshold trigger" and "test or error" at the same time. Considering the processor (CPU) scanning cycle of the reactor protection system, and the interface between the off-core nuclear measurement system and the reactor protection system adopts a fail-safe design of power-off action. Therefore, the connection between the "test or error" signal and the reactor protection system adopts a relay series optocoupler isolation connection method, while the connection between the "threshold trigger" signal and the reactor protection system adopts a relay parallel optocoupler isolation connection method.

[0039] Because the transmission time of the optocoupler is much faster than the time for the relay signal to operate, when a channel (CH1 channel or CH2 channel) in the external nuclear testing system (RPN) loses power, the "test or error" signal connected in series is collected by the reactor protection system (RPR) before the "threshold trigger" signal connected in parallel. The "test or error" signal performs a logical "AND" operation with the "threshold trigger" signal. The "test or error" will block the "threshold trigger" signal and will not generate a shutdown command in the reactor protection system.

[0040] b. Power supply to the out-of-core nuclear testing system channel is restored

[0041] When a channel (CH1 or CH2) in the off-core nuclear test system is overhauled or the upstream power supply is restored, in order to ensure that the power-on process will not trigger the shutdown by mistake, the "threshold trigger" signal in parallel connection will disappear in the reactor protection system (RPR) before the "test or error" signal in series connection. The shutdown command will not be generated by mistake during the power restoration process.

[0042] This design realizes that when a channel in the off-core nuclear test system loses power (upstream power loss or cabinet power loss) or the channel resumes power supply, while the reactor is still in normal working condition, the "test or error" will always lock the "threshold trigger" signal. This avoids the use of a single relay as an interface. Due to the randomness of the relay action, the "threshold trigger" is collected by the reactor protection system (RPR) before the "test or error" and generates a "false shutdown" signal. This ensures the high reliability of the system and the economy of the enterprise.

[0043] 4) Test mode

[0044] According to the relevant requirements of the regulations, the external nuclear testing system (RPN) needs to be tested regularly during the normal power operation of the reactor. The main content of this regular test is to check whether the external nuclear testing system (RPN) channel can normally trigger the reactor shutdown threshold by simulating the change of reactor power. In order to ensure that the reactor will not be shut down by mistake during normal regular testing. There is a "test" rotary switch on the external nuclear testing system. When the "test" rotary switch is triggered, it will generate a "test or error" signal for the channel. The "test or error" signal of the channel will shield the "threshold trigger" signal generated during the test through the logical "and" operation in each channel of the reactor protection.

[0045] This design realizes the regulatory requirements for periodic testing of the off-reactor nuclear measurement system, ensures reactor safety during periodic testing, and prevents accidental shutdown of the reactor due to periodic testing.

[0046] Example

[0047] like Figure 1 As shown, each channel of the external nuclear testing system (RPN) has "threshold trigger 1", "threshold trigger 2" signals and "test or error 1", "test or error 2" signals. The "threshold trigger 1" signal is transmitted to the IP channel and IIP channel of the reactor protection system through a relay in parallel with an optocoupler isolator, and the "threshold trigger 2" signal is transmitted to the IIIP channel and IVP channel of the reactor protection system through a relay in parallel with an optocoupler isolator. The "test or error 1" signal is transmitted to the IP channel and IIP channel of the reactor protection system through a relay in series with an optocoupler isolator, and the "test or error 2" signal is transmitted to the IIIP channel and IVP channel of the reactor protection system through a relay in series with an optocoupler isolator.

[0048] The IP channel of the reactor protection system (RPR) receives the threshold signal (TRIP-CH1-IP) and the "test or error" signal (TF-CH1-IP) transmitted from the CH1 channel of the external nuclear measurement system (RPN), as well as the threshold signal (TRIP-CH2-IP) and the "test or error" signal (TF-CH2-IP) transmitted from the CH2 channel of the external nuclear measurement system (RPN); the IIP channel of the reactor protection system (RPR) receives the threshold signal (TRIP-CH1-IIP) and the "test or error" signal (TF-CH1-IIP) transmitted from the CH1 channel of the external nuclear measurement system (RPN), as well as the threshold signal (TRIP-CH2-IIP) and the "test or error" signal (TF-CH2-IIP) transmitted from the CH2 channel of the external nuclear measurement system (RPN); the IIIP channel of the reactor protection system (RPR) receives the threshold signal (TRIP-CH1-IIIP) and the "test or error" signal (TF-CH1-IIP) transmitted from the CH1 channel of the external nuclear measurement system (RPN) "Signal (TF-CH1-IIIP) and the threshold signal (TRIP-CH2-IIIP) and the "test or error" signal (TF-CH2-IIIP) transmitted from the CH2 channel of the external nuclear measurement system (RPN); The IVP channel of the reactor protection system (RPR) receives the threshold signal (TRIP-CH1-IVP) and the "test or error" signal (TF-CH1-IVP) transmitted from the CH1 channel of the external nuclear measurement system (RPN) and the )The threshold signal (TRIP-CH2-IVP) and the "test or error" signal (TF-CH2-IVP) transmitted from the CH2 channel; in each channel of the reactor protection system, the "test or error" signal is taken "not" and then logically "AND" is performed on the "threshold signal" and the "test or error" signals of the two channels. After the three signals are logically "OR" operated, the shutdown instruction of the channel is generated. After the shutdown instructions of the four channels are subjected to the "4-out-of-2" logic operation, the final shutdown instruction is generated.

[0049] The technical solution involved in this embodiment is implemented in different working conditions as follows:

[0050] 1) Normal operation and accident mode

[0051] During normal operation, the relay and optocoupler isolator of the "threshold trigger" signal of the off-core nuclear measurement system are energized, and the output is "0". The relay and optocoupler isolator of the "test or error" signal are energized, and the output is "0".

[0052] When the reactor power increases abnormally, the two channels (CH1 and CH2) of the external nuclear measurement system (RPN) detect the reactor abnormality and generate a threshold trigger signal, that is, in the IP channel of the reactor protection system, the signals TRIP-CH1-IP and TRIP-CH2-IP are "1", while TF-CH1-IP and TF-CH2-IP are "0" and then take the logical "NOT" to "1", and the logical "AND" is "1" to trigger the IP shutdown signal of the reactor protection system. The same is true for the IIP, IIIP and IVP of the reactor protection systems, which also generate shutdown signals in their respective channels. The shutdown signals of the four channels undergo a logical "4-to-2" operation to generate the final shutdown instruction.

[0053] 2) System equipment failure mode

[0054] Case 1: Single channel failure of the RPN system

[0055] If a fault occurs in the first channel (CH1) of the external nuclear measurement system, then in the IP channel of the reactor protection system, TF-CH1-IP is "1". Regardless of whether TRIP-CH1-IP is "1" or "0", TF-CH1-IP will lock the TRIP-CH1-IP signal, and the shutdown function of CH1 will fail. However, at this time, the second channel (CH2) of the external nuclear measurement system can normally trigger the shutdown signal, that is, in the IP channel of the reactor protection system, the "2 out of 1" shutdown logic becomes "1 out of 1". The signal TRIP-CH2-IP is "1", and TF-CH2-IP is "0". After the logical "not" is taken, it becomes "1", and the logical "and" is "1", which triggers the IP shutdown signal of the reactor protection system. The same is true for the IIP\IIIP\IVP of the reactor protection system, and the shutdown signals in their respective channels are also generated. The shutdown signals of the four channels are subjected to the logical "4 out of 2" operation to generate the final shutdown instruction.

[0056] If only the relay and optocoupler isolator assembly of one of the interfaces of "threshold trigger 1" and "threshold trigger 2" in the second channel of the off-core nuclear measurement system cannot be triggered, because it is not a fault of the upstream processing card of the off-core nuclear measurement system, the "test or fault" signal of the channel will not be generated. Assuming that "threshold trigger 1" cannot be triggered at this time, "threshold trigger 2" can pass the signal to the IIIP and IVP channels of the reactor protection system. In the IIIP channel of the reactor protection system, the signal TRIP-CH2-IIIP is "1", and TF-CH2-IIIP is "0". After the logical "not" is taken, it is "1", and the logical "and" is "1" to trigger the IIIP shutdown signal of the reactor protection system. The situation of the reactor protection system IVP is the same. After satisfying the "4 out of 2" shutdown logic operation, the final shutdown instruction is generated. Assuming that "threshold trigger 2" cannot be triggered at this time, "threshold trigger 1" can pass the signal to the IP or IIP channel of the reactor protection system. After satisfying the "4 out of 2" shutdown logic operation, the final shutdown instruction is generated. The same applies when a fault occurs in the second channel (CH2) of the extra-core nuclear measurement system.

[0057] Case 2: Single channel failure of the reactor protection system (RPR)

[0058] Assume that a channel (IP) of the reactor protection system fails, while IIP or IIIP or IVP works normally, and the shutdown logic of the reactor protection system changes from "4 out of 2" to "3 out of 2". When the reactor power increases abnormally, the external nuclear measurement system detects the reactor abnormality, and the "threshold trigger 1" and "threshold trigger 2" signals in the two channels of the external nuclear measurement system are generated simultaneously, that is, in the IIP channel of the reactor protection system, the signals TRIP-CH1-IIP and TRIP-CH2-IIP are "1", while TF-CH1-IIP and TF-CH2-IIP are "0" and then logically "not" to "1", and the logical "and" is "1" to trigger the IIP shutdown signal of the reactor protection system. The same is true for the IIIP\IVP of the reactor protection system, and the shutdown signals in their respective channels are also generated. The shutdown signals of the three channels are logically "3 out of 2" and the final shutdown instruction is generated. The same is true when IIP or IIIP or IVP fails.

[0059] 3) Power failure mode

[0060] a. Single channel power failure of the out-of-core nuclear testing system

[0061] When a channel in the reactor external nuclear measurement system, assuming that the CH1 channel loses power, when a channel loses power, the channel will generate "threshold trigger" and "test or error" at the same time. However, the "test or error" signal is isolated by a relay in series with an optocoupler isolator, and the response time depends on the optocoupler isolator, while the "threshold trigger" signal is isolated by a relay in parallel with an optocoupler isolator, and its response time depends on the relay. The optocoupler isolator has a faster response time than the relay, so in terms of transmission time, the "test or error" signal will enter the reactor protection system (RPR) before the "threshold trigger", that is, the TF-IP-IP signal in the reactor protection system channel (IP) will lock the TRIP-IP-IP signal (TF-IP-IP is "1" and then "0", TRIP-IP-IP is "1", and the two are "AND" to "0"), so no shutdown signal will be generated in the reactor protection system channel (IP), and the same is true for IIP, IIIP or IVP, so the final shutdown command will not be generated. It will not cause the reactor to be shut down by mistake.

[0062] At this time, the second channel (CH2) of the external nuclear test system is functioning normally. If an abnormal condition occurs at this time, the reactor can be shut down through the CH2 channel. There will be no "refusal to operate" due to power failure of a single channel. The power failure of the second channel (IIP) of the external nuclear test system is the same.

[0063] b. Power supply to the out-of-core nuclear testing system channel is restored

[0064] When a channel in the reactor external nuclear measurement system, assuming that the maintenance of the CH1 channel is completed or the upstream power supply is restored, in order to ensure that the power-on process will not trigger an erroneous shutdown. The "threshold trigger" signal adopts a relay parallel optocoupler isolator connection method, and its response when the power is restored depends on the optocoupler isolator. The "test or error" signal adopts a relay series optocoupler isolator connection method, and its response when the power is restored depends on the relay. Because the optocoupler isolator has a faster response time than the relay, the "threshold trigger" signal will disappear from the reactor protection system (RPR) before the "test or error" signal in terms of transmission time. That is, in the reactor protection system channel (IP), the TRIP-CH1-IP signal will first become "0", at this time TF-CH1-IP is "1" and then "0", and no shutdown signal is output, and then TF-CH1-IP becomes 0, and the non-isolator is "1", and the two are "AND" to "0", so no shutdown signal will be generated in the reactor protection system channel (IP). Similarly, IIP, IIIP or IVP are similar, so the final shutdown command will not be generated. It will not cause an unexpected shutdown of the reactor.

[0065] 4) Test mode

[0066] One channel of the out-of-core nuclear testing system performs regular tests

[0067] When a channel in the reactor external nuclear test system, assuming that the CH1 channel performs periodic tests, the operator first turns the "test rotary switch" to the "test" position, the channel will generate a "test or error" signal, that is, TF-CH1-IP in the reactor protection system channel (IP) is "1" and then negated to "0". During the test execution, TRIP-CH1-IP will forcefully trigger the "1" signal, which will be locked by the TF-CH1-IP "0" signal. Therefore, the shutdown signal will not be mistakenly generated during the test.

[0068] When the first channel (IP) of the external nuclear test system is performing a test, the second channel (IIP) of the external nuclear test system is functioning normally. If an abnormal condition of the reactor occurs at this time, the reactor can be shut down through the IIP channel. There will be no "refusal to operate" due to the test. The same applies to the situation where the second channel (IIP) of the external nuclear test system performs regular tests.

[0069] The present invention is described in detail above with reference to the accompanying drawings and embodiments, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge of ordinary technicians in the field without departing from the purpose of the present invention. The contents not described in detail in the present invention can adopt the existing technology.

Claims

1. A method for connecting an off-core nuclear measurement system with a reactor protection system shutdown timing interface, characterized in that: In the method, the "threshold trigger" signal of the CH1 channel or CH2 channel of the off-core nuclear measurement system is output to the IP channel, IIP channel, IIIP channel, and IVP channel of the reactor protection system respectively through the connection mode of relay parallel optical coupling isolation; the "test or error" signal of the CH1 channel or CH2 channel of the off-core nuclear measurement system is output to the IP channel, IIP channel, IIIP channel, and IVP channel of the reactor protection system respectively through the connection mode of relay series optical coupling isolation.

2. A method for connecting the shutdown timing interface of an off-core nuclear measurement system and a reactor protection system according to claim 1, characterized in that: In the method, the logic operation of triggering a single-channel reactor shutdown signal in the reactor protection system includes: (1) when there is no "test or error" signal, the "2-out-of-1" logic of the "threshold trigger" signals of the CH1 channel and the CH2 channel; (2) the CH1 channel and the CH2 channel trigger the "test or error" signal at the same time; (3) the "threshold trigger" signal appears in the CH1 channel or the CH2 channel, and the "test or error" signal appears in the other channel.

3. A method for connecting the shutdown timing interface of an off-core nuclear measurement system and a reactor protection system according to claim 2, characterized in that: In the method, the logic operation of the reactor protection system that is triggered to cause the reactor protection system to shut down is: the four channels of IP channel, IIP channel, IIIP channel and IVP channel perform "4 out of 2" logic.

4. The method for connecting the shutdown timing interface of the off-core nuclear measurement system and the reactor protection system according to claim 1, characterized in that: In the method, each channel in the CH1 channel or the CH2 channel of the off-core nuclear measurement system includes a "threshold trigger 1", a "threshold trigger 2" signal and a "test or error 1", a "test or error 2" signal; the "threshold trigger 1" signal is transmitted to the IP channel and the IIP channel of the reactor protection system respectively through a relay in parallel with an optical coupler isolator, the "threshold trigger 2" signal is transmitted to the IIIP channel and the IVP channel of the reactor protection system respectively through a relay in parallel with an optical coupler isolator, the "test or error 1" signal is transmitted to the IP channel and the IIP channel of the reactor protection system respectively through a relay in series with an optical coupler isolator, and the "test or error 2" signal is transmitted to the IIIP channel and the IVP channel of the reactor protection system respectively through a relay in series with an optical coupler isolator.

5. The method for connecting the shutdown timing interface of the off-core nuclear measurement system and the reactor protection system according to claim 1, characterized in that: In the method, during normal operation, the relays and optocoupler isolators of the "threshold trigger" signal and the "test or error" signal of the off-core nuclear measurement system are both in an energized state, and no reactor shutdown signal is output by logical operation.

6. The method for connecting the shutdown timing interface of the off-core nuclear measurement system and the reactor protection system according to claim 1, characterized in that: In the method, during an accident condition, the off-core nuclear measurement system automatically triggers a "threshold trigger" signal of CH1 or CH2, and the relay parallel optical coupler isolator operates simultaneously to generate a "threshold trigger" signal, and the "threshold trigger" signal is transmitted to four channels of the reactor protection system, namely, the IP channel, the IIP channel, the IIIP channel, or the IVP channel, and a "2-out-of-1" logic operation is performed inside the four channels to generate IP channel, IIP channel, IIIP channel, and IV channel shutdown signals, respectively, and the four shutdown signals are then subjected to a "4-out-of-2" logic operation to generate a final shutdown signal.

7. The method for connecting the shutdown timing interface of the off-core nuclear measurement system and the reactor protection system according to claim 1, characterized in that: In the method, when an equipment failure occurs in the off-core nuclear measurement system, when a channel of the off-core nuclear measurement system detects an equipment failure, the channel generates a "test or error" signal. If a "threshold trigger" signal of the channel appears at this time, no shutdown signal will be generated. If another channel generates a "threshold trigger" signal, it will be sent to the IP channel or IIP channel or IIIP channel or IVP channel of the reactor protection system respectively, and a 2-out-of-1 logic operation will be performed inside the four channels to generate shutdown signals for the IP channel, IIP channel, IIIP channel and IV channel respectively. The four shutdown signals will then undergo a 4-out-of-2 logic operation to generate the final shutdown signal. When two channels of the off-core nuclear measurement system fail, the two channels will simultaneously generate a "test or error" signal and send it to the IP channel or IIP channel or IIIP channel or IVP channel of the reactor protection system. A logic operation will be performed inside the channels of the reactor protection system to generate a shutdown signal.

8. The method for connecting the shutdown timing interface of the off-core nuclear measurement system and the reactor protection system according to claim 1, characterized in that: In the method, when the reactor protection system equipment fails, when one of the four channels of the reactor protection system fails, since the four channels have redundancy, when one channel fails and cannot send a shutdown signal, the other three channels 3 take 2 to generate a shutdown signal.

9. The method for connecting the shutdown timing interface of the off-core nuclear measurement system and the reactor protection system according to claim 1, characterized in that: In the method, when a single channel of the off-core nuclear measurement system loses power, the channel will simultaneously generate a "threshold trigger" and a "test or error". The "test or error" signal performs a logical "AND" operation with the "threshold trigger" signal. The "test or error" will block the "threshold trigger" signal, and no shutdown instruction will be generated in the reactor protection system.

10. The method for connecting the shutdown timing interface of the off-core nuclear measurement system and the reactor protection system according to claim 1, characterized in that: In the method, when the maintenance of a channel in the off-core nuclear measurement system is completed or the upstream power supply is restored, the "threshold trigger" signal will disappear in the reactor protection system before the "test or error" signal, and the shutdown instruction will not be erroneously generated during the power supply restoration process.

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