Method for testing protection system for multiple reactors

Abstract

The present invention relates to a method for testing a protection system for multiple reactors, wherein the multiple reactors include a first reactor and a second reactor, the protection system receives a state signal of each of the reactors and determines whether to shut down the reactor or whether to operate an engineered safety feature actuation system device, each of the first reactor and the second reactor includes a first operation channel and a second operation channel, each of the operation channels includes a comparison logic processor and a coincidence logic processor, and the method comprises the steps of: indicating an operator to perform a test for the first operation channel of the first reactor; receiving an input of the operator's test performance task performed for the first operation channel of the first reactor; and performing the input operator's test performance task in the same manner for the first operation channel of the second reactor.

Description

Test method for protection systems for multiple reactors

[0001] The present invention relates to a method for testing a protection system for a plurality of nuclear reactors.

[0002] During normal operation, the plant protection system (PPS) monitors plant trip parameters in preparation for accidents and does not take any action. However, its integrity is confirmed through periodic PPS testing.

[0003] Recently, small modular reactors (SMRs) are being developed with the concept of allowing a minimum number of operators to operate multiple units (multi-module: operating multiple power plants from a single control room) from a single main control room, taking into account safety and economic efficiency and applying digital technology.

[0004] In small modular nuclear power plants, testing must be performed on multiple units from a single control room, and each unit has its own protection system. Consequently, the testing burden on the protection system increases, necessitating the development of effective protection system testing methods.

[0005] Accordingly, an object of the present invention is to provide a method for testing a protection system for a plurality of nuclear reactors.

[0006] The above object of the present invention is achieved by a method for testing a protection system for a plurality of nuclear reactors, wherein the plurality of nuclear reactors include a first reactor and a second reactor, the protection system receives a status signal of each of the nuclear reactors and determines whether the reactor is shut down or an engineering safety equipment operating system device is in operation, the first reactor and the second reactor each include a first operation channel and a second operation channel, and each of the operation channels includes a comparison logic processor and a simultaneous logic processor, the method comprising the steps of: instructing an operator to perform a test for the first operation channel of the first reactor; receiving an operator's test performance task performed for the first operation channel of the first reactor; and performing the input operator's test performance task in the same manner for the first operation channel of the second reactor.

[0007] A step of determining whether the first reactor and the second reactor are vulnerable based on the results of the above test; and a step of instructing the operator to test the reactor determined to be vulnerable in the next test cycle may be further included.

[0008] Each of the above reactors includes a device linkage module and an operating device, and the test measures the signal transmission time in the order and reverse order of the comparison logic processor, simultaneous logic processor, the device linkage module, and the operating device of the corresponding channel, and the presence or absence of vulnerability can be determined based on the signal transmission time.

[0009] The above first and second reactors may be small modular reactors.

[0010] The first operation channel of the first reactor and the first operation channel of the second reactor may be the same platform.

[0011] In each of the above channels, the comparison logic processor and the simultaneous logic processor may be integrated.

[0012] The driving channel on which the test is performed is bypassed, and the logic of the comparison processor is changed from N-2 out of N to N-2 out of N-1, where N may be the number of driving channels of the reactor.

[0013] The above N may be 4.

[0014] An additional bypass channel is provided for each of the above reactors, and when testing the operation channel, operation can be performed using the bypass channel.

[0015] The above driving channel and the above bypass channel may be the same platform.

[0016] For each reactor, the above bypass channel may be provided for each platform employed by the above operating channel.

[0017] According to the present invention, a method for testing a protection system for a plurality of nuclear reactors is provided.

[0018] Figure 1 shows the configuration of a nuclear reactor power plant in which a test method of a protection system according to the present invention is performed.

[0019] Figures 2a to 2d illustrate various configurations of a protection system in a nuclear power plant where a test method of a protection system according to the present invention is performed.

[0020] Figure 3 is a flowchart showing a test method of a protection system according to one embodiment of the present invention.

[0021] Figures 4a to 4d are drawings explaining a test method of a protection system according to one embodiment of the present invention.

[0022] Figures 5a to 5d illustrate different configurations of a protection system in a nuclear power plant where a test method for a protection system according to the present invention is performed.

[0023] Hereinafter, various embodiments of the present invention will be described in detail with reference to the attached drawings so that those skilled in the art can easily implement the invention. The present invention may be implemented in various different forms and is not limited to the embodiments described herein.

[0024] In order to clearly explain the present invention, parts that are not related to the description are omitted, and the same reference numerals are used for identical or similar components throughout the specification.

[0025] In addition, the size and thickness of each component shown in the drawing are arbitrarily shown for convenience of explanation, so the present invention is not necessarily limited to what is shown.

[0026] The present invention described below can be implemented by a test system (or test supervisor program) utilizing a computer and communication devices. The communication devices include both wired and wireless communication. The test system may include a driver test instruction module, a driver test performance task input module, a test execution module, and a vulnerability assessment module.

[0027] The reactor of the present invention may be an integral reactor or a small modular reactor (SMR) in which a core and a steam generator are housed within the reactor.

[0028] The reactor protection system receives individual status signals from the reactor and determines the conditions for reactor shutdown or safety device operation, and the nuclear power plant executes reactor shutdown or operation of the engineering safety equipment operation system devices based on this determination.

[0029] The reactor protection system (RPS) has multiple operating channels for input and judgment. Each operating channel includes a comparison logic processor and a concurrent logic processor. The comparison logic processor receives variable inputs and compares them with fixed / variable setpoints. If the setpoints are violated, it generates an initiation signal. These initiation signals are then input to the concurrent logic processor from each operating channel and voted. The specific voting format can be selected according to the multi-design, such as 1 out of 2, 1 out of 3, 2 out of 3, or 2 out of 4.

[0030] In other words, the comparative logic processor processes the results compared with the corresponding setpoints to determine the operation of the plant trip (stop) and the engineering safety equipment (ESFAS) operation system. The concurrent logic processor collects the results calculated on its own channel and those calculated on other channels and generates the final plant trip signal and engineering safety equipment (ESFAS) operation signal based on selection logic such as 2 out of 4.

[0031] Existing large nuclear power plants periodically conduct tests of their protection systems to ensure their integrity. These periodic tests include functional tests of comparison and simultaneous logic, initiation logic, initiation circuits and manual shutdown, response time measurement, and channel calibration.

[0032] To perform periodic testing, features such as maintenance bypass must be used. Operation bypass intentionally lowers the trip variable settings depending on the operating mode to avoid causing a power plant shutdown. Maintenance bypass allows operators or I&C maintenance personnel to intentionally bypass the relevant variables (functions) using a bypass switch to perform tests or perform maintenance (e.g., module replacement) on each channel.

[0033] In the case of small modular reactors (SMRs) with multiple reactors, development is underway to apply the concept of operating multiple units (multi-module: operating multiple power plants from one main control room) with a minimum number of operators by applying digital technology while considering safety and economic efficiency.

[0034] In order to smoothly perform these multi-module operations, it is necessary to conduct power plant protection system tests automatically rather than manually by the operator.

[0035] If a small modular nuclear power plant has to perform three functional tests per month during normal operation, then in the case of four modules, the burden of having to manually perform 12 functional tests while collaborating with the operator and I&C maintenance personnel arises.

[0036] In order to smoothly perform such multi-module operation, it is necessary to perform power plant protection system tests automatically rather than manually by the operator.

[0037] Figure 1 shows the configuration of a nuclear reactor power plant in which a test method for a protection system according to the present invention is performed.

[0038] There are multiple reactors, including the first and second reactors, controlled by a single main control room. The number of reactors operated by a single main control room may range from two to eight, but is not limited thereto.

[0039] Each reactor is connected to an independent protection system, which is connected to equipment interconnection modules and engineering safety equipment operating system devices. Equipment interconnection modules and engineering safety equipment operating system devices include reactor shutdown equipment or safety devices.

[0040] The protection system can take various forms depending on the number of driving channels, the type of platform, and whether the comparative logic processor and the concurrent logic processor are separated.

[0041] Figures 2a to 2d illustrate various forms of the protection system. The number of operating channels in Figures 2a to 2d is four, but the number of operating channels can be selected from two to six.

[0042] In Fig. 2a and Fig. 2b, both driving channels are provided on the same platform. In Fig. 2a, the comparison logic processor and the simultaneous logic processor are separated, and in Fig. 2b, the comparison logic processor and the simultaneous logic processor are provided as an integrated unit.

[0043] The platform may be selected from, but is not limited to, PLC, FPGA, ASIC, DCS and analog electronic cards.

[0044] Figures 2c and 2d illustrate two types of driving channels on a platform to meet diversity requirements. In Figure 2a, the comparison logic processor and the simultaneous logic processor are separated, while in Figure 2b, the comparison logic processor and the simultaneous logic processor are integrated.

[0045] In Figures 2c, 2d, and other drawings, the hatching of processors indicates whether the processors are of the same platform type. That is, processors with hatching and processors without hatching are of different platform types.

[0046] The protection systems of each reactor have the same form. That is, if the protection system of the first reactor is in the form of Fig. 2a, the protection system of the second reactor is also in the form of Fig. 2a.

[0047] Therefore, in the protection systems of each reactor, the first operating channel is the same platform, the second operating channel is the same platform, and the third and fourth operating channels are similarly configured. In other words, the first operating channel in the protection systems of all reactors is identically configured using one of the following: a PLC, FPGA, ASIC, DCS, or analog electronic card.

[0048] Referring to FIGS. 3 and 4a to 4d, a test method of a protection system according to the present invention is described.

[0049] Fig. 4a is a test method for a protection system configuration corresponding to Fig. 2a, and in the same manner, Figs. 4b, 4c and 4d are test methods for a protection system configuration corresponding to Figs. 2b, 2c and 2d, respectively.

[0050] First, the operator's test is instructed for the first operation channel of the first reactor (S10).

[0051] Accordingly, the operator performs a test on the first operation channel of the first reactor.

[0052] Next, the operator's test performance duties for the first operation channel of the first reactor are input (S20).

[0053] The input at this stage can be input by presenting input items and having the driver select and input them, or by automatically identifying the driver's test performance tasks and receiving input.

[0054] Next, the task of performing the test of the input driver is performed in the same manner for the first operation channel of the second reactor (S30).

[0055] This step is performed automatically without operator intervention, reducing the workload on the operator and control room.

[0056] At this time, since the first operation channels of the first reactor and the second reactor are on the same platform, automatic execution of the test is easy.

[0057] In this way, the operating channels of all reactors are tested (S40).

[0058] If there is a third reactor, the first operating channel of the third reactor is tested in the same manner as the first operating channel of the second reactor.

[0059] Next, for the second operation channel of each reactor, the test is performed in the same manner as for the first operation channel.

[0060] The driving channel where the test is performed is bypassed, and the logic of the comparison processor can be changed from N-2 out of N to N-2 out of N-1. As shown in FIGS. 4a to 4d, when N is 4, the logic of the comparison processor is changed from 2 out of 4 to 2 out of 3.

[0061] The test order of the driving channels is not limited to the order of the first driving channel - the second driving channel, and can be performed simultaneously or sequentially.

[0062] The test may be performed by performing at least one of the following: functional test for the comparison processor and concurrent processor, initiation logic functional test, initiation circuit and manual stop functional test, response time measurement test, and channel calibration test.

[0063] Finally, based on the test results, vulnerable reactors are identified and the vulnerable reactors are ordered to be tested by the operator in the next test cycle (S50).

[0064] The test for each driving channel can be performed by measuring the signal transmission time in the sequential and reverse order of the comparison logic processor, the simultaneous logic processor, the device link module, and the operating device of the driving channel.

[0065] The vulnerability of a driving channel or reactor can be determined based on signal transmission time. For example, if signal transmission time exceeds a certain threshold compared to other reactors or the average time for other reactors, it can be determined to be vulnerable.

[0066] Each protection system may additionally include a bypass channel for testing, which is described with reference to FIGS. 5a to 5d.

[0067] Each protection system shown in FIGS. 5a to 5d includes a bypass channel.

[0068] The bypass channel temporarily serves as the driving channel when testing is performed on the driving channel. That is, when the primary driving channel is tested, the bypass channel is used as the driving channel. Therefore, the logic of the concurrent logic processor remains unchanged, for example, 2 out of 4 continues to be maintained. However, during the brief period between the bypass of the primary driving channel and the activation of the bypass channel, the concurrent logic of 2 out of 3 may be used.

[0069] When all driving systems are configured on the same platform, as shown in Figures 5a and 5b, a single bypass channel is configured on the same platform. In this case, when any of the first through fourth driving channels is tested, the bypass channel serves as the driving channel.

[0070] In cases where all driving systems are provided with two types of platforms, as in FIGS. 5c and 5d, the bypass channels are provided with the first bypass channel and the second bypass channel, which are the same as each type of platform.

[0071] In this case, when the first driving channel is tested, the first bypass channel, which is on the same platform as the first driving channel, serves as the driving channel. When the second driving channel is tested, the second bypass channel, which is on the same platform as the second driving channel, serves as the driving channel.

[0072] According to the present invention, testing multiple modules simultaneously can reduce the workload assigned to operators. Furthermore, efficient aging management is possible through comparative assessments of the degree of aging between reactor modules.

[0073] The above-described examples serve as illustrative examples of the present invention and are not intended to limit the scope of the present invention. Those skilled in the art will readily appreciate the potential for various modifications and implementations of the present invention. Therefore, the technical protection scope of the present invention should be defined by the appended claims.

Claims

1. In the test method of the protection system for multiple reactors, The above multiple reactors include a first reactor and a second reactor, and the protection system receives status signals from each of the reactors and determines whether the reactor is shut down or the engineering safety equipment operation system device is in operation. The first reactor and the second reactor each include a first operation channel and a second operation channel, and each operation channel includes a comparison logic processor and a simultaneous logic processor. A step of instructing an operator to perform a test on the first operation channel of the first reactor; A step of receiving input of the operator's test performance duties performed on the first operation channel of the first reactor; and A test method including a step of performing the test performance of the input operator in the same manner for the first operation channel of the second reactor.

2. In paragraph 1, A step of determining whether the first reactor and the second reactor are vulnerable based on the results of the above test; and A test method that further includes a step of directing a test by the operator in the next test cycle for reactors judged to be vulnerable.

3. In paragraph 2, Each of the above reactors includes a device linkage module and an operating device, The above test is, Measure the signal transmission time in the order and reverse order of the comparison logic processor, simultaneous logic processor, the device link module and the operating device of the corresponding channel, A test method for determining the above vulnerability based on the signal transmission time.

4. In paragraph 2, The above first and second reactors are test methods for small modular reactors.

5. In paragraph 4, A test method in which the first operation channel of the first reactor and the first operation channel of the second reactor are on the same platform.

6. In paragraph 5, In each of the above channels, A test method in which the above comparison logic processor and the above simultaneous logic processor are integrated.

7. In paragraph 5, The above driving channel on which the test is performed is bypassed, The logic of the above comparison processor changes from N-2 out of N to N-2 out of N-1, Here, N is the number of operating channels of the reactor. Test method.

8. In paragraph 7, The above N is a 4-person test method.

9. In paragraph 6, An additional bypass channel is provided for each of the above reactors. A test method for performing driving using the bypass channel when testing the above driving channel.

10. In paragraph 9, A test method in which the above driving channel and the above bypass channel are the same platform.

11. In paragraph 10, For each reactor, the above bypass channel is a test method provided for each platform employed by the above operating channel.

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