KR20010013440A - Digital engineered safety features actuation system - Google Patents

Abstract

An interface between a Plant Protection System and Engineered Safety Features in a nuclear power plant is disclosed for continuously monitoring the plant protection system initiation circuit for each remotely actuated Engineered Safety Feature system to effect remedial action in the event that the Plant Protection System generates a "trip" signal. By using actuation inputs from the Plant Protection System and manual, operator implemented inputs, controls are provided for remote equipment components, such as solenoid valves, motor operated valves, pumps, fans and dampers.

Description

DIGITAL ENGINEERED SAFETY FEATURES ACTUATION SYSTEM}

In nuclear power plants, independent shutdown and safe operating systems are dedicated to monitoring plant operation and evaluating a number of safety-related parameters. In the event that one or more measurement parameters indicate the presence of an unsafe condition, the shutdown system and / or the safe operating system may automatically cause an appropriate maintenance operation. These safety control systems, known as plant protection systems, are absolute to operate reliably and therefore it is essential that various measured and sensed parameters be valid.

In the context of nuclear power plant protection systems, it is not uncommon to measure a number of parameters related to plant operation. These parameters include, for example, temperature, pressure, flow rate, power density, neutron flux, fluid level, and the like. Other functions of this plant protection system include the monitoring of the status of various components including valves, pumps, motors, control units and generators.

In addition, a plant protection system under certain confined conditions can trigger a reactor reactor (RT), or rapid, controlled, safe shutdown of the reactor by operating multiple zone systems and remote operation devices. Can be. In the case of a pressurized light-water reactor, shutdown is often caused by lowering the deceleration control rods into the reactor core to bring the reactor to a critical level.

Co-pending US application serial number 08/848, 556, pointed out above, describes an automatic self-testing system for remote sensors using multiple sensors, multiple monitoring and control circuits by multiple channels. Is disclosed for use in the nuclear industry. The system detects or measures parameters by the process path according to a number of independent and sensor characteristics, each process path being inserted into the process path in order for normal processing or separate from the process path for testing. It is provided to have a plurality of bottom paths in parallel. Each sensor, directly or indirectly, provides a digital value to the comparator that compares the measured value with a predetermined value, and sequentially outputs the comparator's output to the comparator of the other processing paths to provide an output indicating the pass / fail status. A matching logic circuit is provided to evaluate the input. The present invention advantageously provides an automatic self test system for verifying both validity of various logic states and signal path processing functions in a parameter sensing system, in particular a parameter sensing system using multiple multiple processing paths.

In co-pending US Provisional Serial No. 60/048, 922, pointed out above, a nuclear power plant is used to provide a digital plant protection system (DPPS) that uses digital signals and has an average failure time. An invention for use in the is disclosed. The DPPS features a number of cross-connected sensed parameter processing channels, which are digital comparators that test a conditioned digital value against a predetermined value to determine whether the sensed parameter has been exceeded. Provides digitally conditioned digital values. The comparator is associated with each of the plurality of channels and receives individual measurements of the sensed parameters for each channel. If the sensed parameter is determined to be out-of-specification on a two-out-of-four basis, a 'trip' signal is generated to trigger a repair operation.

The subject matter of this application is disclosed in Applicants' co-pending U.S. Provisional Patent Application Nos. 60 / 048,922 and 60 / 048,923, both applications filed June 6, 1997 and all claimed priority.

The subject matter of this provisional application is generally related to the subject matter in pending US application Ser. No. 08 / 848,556, filed April 29, 1997, based on the provisional application filed June 20, 1996, The disclosure of this application is incorporated herein to complete the disclosure. Additionally, the subject matter of this application relates to an application filed by the inventor on the same date and disclosed in the application entitled "Digital Power Plant Protection System" (patent management number ABB-144), the subject matter of which is referred to Is incorporated herein by reference.

1 is a functional block diagram illustrating the correlation between the outputs of a DPPS system in communication with a DESFAS system of the present invention in communication with multiple ESF element control systems.

2 is a front plan view of a digital ESFAS auxiliary relay cabinet for use with the system of the present invention.

3 is a block diagram of a digital ESFAS cabinet control system of the present invention, showing one exemplary train of a two-train system in accordance with the present invention.

4 is a functional block diagram of a typical DESFAS auxiliary cabinet logic diagram in accordance with the present invention.

FIG. 5 illustrates a DESFAS single train block diagram in more detail than FIG. 3. FIG.

5A is a schematic block diagram of an optical modem.

5B is a schematic block diagram of input and output optical cables connected together via optical fiber couplings.

6 is a plan view of a printed circuit board having a relay mounted on the substrate and a voltage drop resistor.

6A is a top view of the printed circuit board of FIG. 6 with connecting jumpers in place of the resistor.

6B is a schematic circuit diagram of a voltage drop resistor in series with the relay coil.

6C is a schematic circuit diagram of jumper wiring in lieu of a voltage drop resistor.

7 is a simplified functional block diagram for a typical DESFAS secondary cabinet test logic arrangement.

8 is a schematic circuit diagram of an optocoupler used to make optical isolation measurements.

9 is a circuit diagram for a dual optically isolated coupler with feedback instructions for use with the present system and other more general systems.

10 is a block diagram of a universally optically selectable selectable system.

10A illustrates an optically isolated selectable system in accordance with the present invention.

FIG. 10B is a circuit diagram illustrating use for the system of FIG. 10A in selectable Type A or Type B, each of which may also be used with another system.

FIG. 11 is a functional block diagram of a dual input optically isolated selectable output relay module for use in the present invention and other systems. FIG.

12 is a functional omission circuit diagram for a dual input optically isolated output driver having a separate output state for optical use with the present invention or other system.

It is an object of the present invention to provide a digital interface between DPPS and engineered safety features (ESF) of a nuclear power plant.

Another object of the present invention is to provide a digitally engineered Safety Features Actuation System (DESFAS) that is digitally processed for use with a pressurized water reactor.

Equivalent to the previously described system of the '556 co-pending application, a digital power plant protection system (DPPS) has been developed as indicated above. In addition, DPPS, the automated self test system described above, and the DESFAS of the present invention jointly constitute a nuclear power plant reactor protection system. DESFAS continuously monitors the DPPS initial circuit for each ESF system. Thus, the present invention provides an interface between the DPPS and the remote operating device that causes a maintenance operation when the DPPS generates a 'trip' signal. In accordance with the present invention, control of remote equipment elements such as solenoid valves, motorized valves, pumps, fans and dampers by using operational inputs from DPPS and inputs performed manually by the operator Is provided.

US Patent No. 5,267,277, assigned to the assignee of the present invention and published on November 30, 1993, describes in detail a conventional control system known under the trade name " NUPLEX 80 +. &Quot; Another general and general purpose of this invention is to retrofit or interface with the nuclear power plant control element control system, including those described in the '277 patent. As such, the disclosure of the '277 patent is incorporated herein.

Thus, a first object of the present invention is to provide a digital interface to an existing or recently developed device control system.

Other objects and features of the present invention will be apparent from the accompanying drawings, which are incorporated by way of description and reference herein.

FIG. 1 shows a functional block diagram for a digitally processed safety feature operating system (DESFAS) that interfaces with a digital power plant protection system (DPPS) described above, generally shown at 20. As indicated above, DPPS is a first multiple (preferably four) cross connected sensing, each represented by channels 21 through 24 (cross connection not shown in FIG. 1). The parameter processing channels (channels A to D). Each channel provides an appropriately conditioned digital value (not shown) to a digital comparator (not shown) that tests the conditioned digital value against a predetermined value to determine whether the sensed parameter has been exceeded. . If the sensed parameter is determined to be out-of-specification on a two-out-of-four channel basis, the 'trip' signal is used to trigger a repair operation. Is generated.

In FIG. 1, each DPPS channel 21-24 generates a second plurality of operational outputs, or initial outputs, for transmission to the same plurality of DESFAS trains. In the preferred configuration shown in FIG. 1, two trains A and B are shown, represented by trains 25 and 26, respectively. Thus, in a preferred configuration, channel 21 generates two operational outputs, initial outputs 27a and 27b, one of which is sent to train 25 and the other to train 26. . Similarly, channels 22 to 24 also produce the same number of operational outputs, i.e., initial outputs.

Each channel 21-24 provides a plurality of operational outputs, i.e., initial outputs, for one of the multiple processed safety characteristic (ESF) systems. The various ESF systems monitored by individual DPPS channels include: safety injection actuation signals (SIAS), containment isolation actuation signals (CIAS) and recirculation actuation signals (RAS). A first system 1 comprising, a containment spray actuation signal (CSAS), a main steam isolation signal (MSIS), and an auxiliary feedwater actuation signal (AFS) A second system 2 comprising AFAS1 and AFAS2. These signals are also output from conventional power plant protection systems.

As indicated above, an operational output, i.e., an initial output, such as 27a and 27b is provided to the pair of inventive trains A and B of the present application. It will be appreciated that the DESFAS auxiliary cabinet, described below, is required for trains A and B and that this specification typically describes only a single train in detail.

Outputs 28 and 29 from trains 25 and 26 are provided to four element control systems 30 to 33 to control elements such as pumps and valves in accordance with the state of the initial signal. The operation of the various ESF systems controlled by 33 is described in more detail below.

Before proceeding to the detailed description of the device comprising the DESFAS of the present invention, the overall functionality of the system will be described to present an operational overview. It is important to note that the DESFAS auxiliary cabinet serves as an interface between the ESFAS portion of the DPPS and the remotely operated device (not shown) as shown in FIG. 1. The DESFAS auxiliary cabinet comprises a solenoid valve, a motor operated valve, a pump, a fan, and a damper upon receiving a DESFAS signal, ie an operating signal, or an initial signal, from the DPPS, in accordance with a confirmed specification. It includes circuitry to interface with the plant control system (PCS) that operates the ESF system. The ESF system is operated independently by a selective two-out-of-four logic as shown in Figures 3 and 4, which are discussed further below. Moreover, simultaneous operation of two manual pushbuttons shown in FIG. 4 as MANUAL ACTUATE signals of a particular ESF system may also cause operation of that system. The DESFAS of the present invention also includes a Maintenance and Test Panel (MTP) interface to test both sides of the functionality of the DESFAS trip logic as well as the DPPS initial input interface.

Once started, the trip logic will be closed and will not reset automatically when the DPPS / DESFAS initial signal is cleared. The trip logic must be reset manually after the DPPS / DESFAS initial signal is cleared. The DESFAS design includes a terminal block to interface with a remote initial reset panel on the main control board (MCB). The closing and reset characteristics are applicable to all ESF systems except the following cycling, i.e. cycling that the selection circuits in the auxiliary feed water operating systems 1 and 2 and the main steam isolation system are not closed and do not require a reset.

DESFAS equipment is arranged to control two groups in which the operating circuits are mechanically separated. One of these groups may include all fans and pumps, while the second group includes other valves and dampers as shown in FIG. 3.

Within each group, smaller subgroups can be performed simultaneously without affecting normal plant operation as described in the co-pending application of '556 shown above with the testing of several devices. Are arranged to be.

As shown in FIG. 3, a test selector switch or keypad on the maintenance and test panel 55 selects the desired subgroup. Manual control is provided to activate the manual trip of the subgroups and close the relay. The DPPS initial input interface can also be tested without the operation of any device (pump or valve).

Before returning to the detailed figure, it should be noted that the DESFAS auxiliary cabinet continuously monitors the DPPS initial circuit output for each ESF system as shown in FIG. Announcements (not shown) are provided for initial circuit operation. The DESFAS auxiliary cabinet upon receiving the selective two-out-of-four initiation inputs from DPPS for each ESF system as discussed above and discussed in the provisional application filed above. The protective action can be started automatically.

Connections between DPPS channels (channels A through D), DESFAS trains (A and B), and CCS channels (channels A through D) are separated from devices such as by fiber optic communication or from separate conducting wire elements such as copper. It will be appreciated that it is a multiple signal to provide a signal that is present. Separation status and test feedback signals are provided from trains A and B to DPPS channels 21 to 24 and between trains 25 and 26 through maintenance and test panel 55 (FIG. 3).

A detailed description of all the features of the DESFAS of the present invention will now be given.

Figure 2 shows a single digital ESFAS auxiliary relay cabinet shown with the front door removed to illustrate the functional deployment of this system. As mentioned above, the DESFAS consists of two completely separate cabinets, one containing trains A and B (numbers 25 and 26 in FIG. 1), respectively. As representatively shown in FIG. 2 with reference numeral 34, one cabinet will operate the train A element and the other cabinet (not shown) will operate the train B element. The two cabinets are practically identical except for the cabinet color plate and the block color coding of the terminals. These cabinets are physically arranged to meet design criteria in the prior art.

The cabinet 34 of FIG. 2 has three positions 35 to 37 for receiving an actuation signal, i.e., an initial signal, from the DPPS channels (channels A to D) shown in FIG. 1 and for accepting these interconnections discussed in the same figure. )

FIG. 3 shows the DESFAS auxiliary cabinet operating logic and circuitry for a single DESFAS cabinet, generally indicated by reference numeral 40 in the form of a functional block diagram. The main purpose of the arrangement 40 of FIG. 3 is to operate the DESFAS element upon receiving the DESFAS channel signal from a typical channel of the DPPS 42.

Within the DESFAS cabinet 40, the logic and I / O of DESFAS are divided into two groups. These groups are involved in pump I / O 44, pump I / O 46, valve I / O 48, and valve I / O 50, each of which is a DPPS channel shown in FIG. It is connected to the DPPS output circuit for a representative one of (channels A to D) and also from the DPPS output circuit. Each group thus has its own programmable logic controller (PLC) and I / O. The functional division of the PLC is as follows. The two PLCs 51 and 52 are shown in FIG. 3 and discussed in connection with FIG. 1 for the safety characteristic system (SIAS, CIAS, RAS, CSAS, AFAS-4 and AFAS-). Operate the pump and fan in 2). Two PLCs 53 and 54 operate the valves and dampers in the previously mentioned safety features system. The device discussed here is housed in an ESFAS cabinet 40.

When the DESFAS secondary cabinet receives the initial signal from the DPPS 42, the DESFAS PLCs 51, 52, 53, and 54 are assigned a DESFAS subgroup on a selective two-out-of-four basis. Activate the relay. Subgroup relays in turn operate the elements needed for complete system operation. Maintenance and test pane (MTP) 55 is provided not only for intercommunication between the first and second systems but also for monitoring the initial testing of each system and the logic within each system. .

Outputs of logic and I / O groups 44, 46, 48, and 50 are optionally provided to system PDAS 56, PCS 57, and PAS 58, where PCS system 57 is block 59 Operate the plant pumps and valves as implied by). The solid line provides a hardwired interface between DPPS operation in bidirectional mode, while the dotted line connecting the MTP provides the data link between the pump and the valve system.

Typical logic for all ESF operations and MSIS except AFAS-1 and AFAS-2 is shown in Figure 4, where the ESFAS initial signal from DPPS is NOT gate, AND gate, time delay circuit and output AND gate 62 and 63. Is provided to the OR gates 60 and 61 which provide an output to a combination of latch circuits that cause the appearance of a logic signal.

In accordance with the logic of FIG. 4, the ESF system is independently operated by a selective two-out-of-four logic. Moreover, the simultaneous operation of two manual pushbuttons of a particular ESF system can make the system work. In FIG. 4, manual pushbuttons are shown as MANUAL ACTUATE inputs 64 and 65. In the preferred logic arrangement, once operation begins, the trip logic will be closed and not automatically reset when the DPPS / DESFAS initial signal is cleared. Instead, the DESFAS design includes a terminal block to interface with remote initial and reset panels (not shown) on the main control board (not shown) for the power plant. Two MANUAL RESETS 66 and 67 Concurrent operation resets the trip logic manually after the initial signal is cleared. The closure and reset characteristics described are preferably applicable to all the ESF systems described above except for the selection circuits in AFAS 1 and AFAS 2 and MSIS that do not close and do not require a reset.

FIG. 5 is a detailed block diagram of a single train A, generally represented by reference numeral 70 to locate columns B1, B2, B3 and B4 and rows R01, R02, R03, and RO4 to provide a plurality of communications and processors. Shows a figure. Each of the four subgroups shown in FIG. 5 may represent the logic and I / O groups of FIG. 3, and each group may further include an extra majority as needed. Many communications and processors are preferably interconnected via fiber optic line 71, substantially reducing the amount of relays, fuses and general wiring achieved with the DESFAS of the present invention. An activation signal, i.e. an initial signal, is transmitted to each subgroup relay via fiber optic cable 72, which also carries ESF system operational information from the DESFAS train A to field elements (not shown). All information is also conveyed to the maintenance and test panel 73 of DESFAS train A and to perform the functions as described above in connection with FIG. 3. Train A and train B are further interconnected with the fiber line 74.

As shown in more detail in FIGS. 5A and 5B, the DESFAS of the present invention is used for overall data communication between trains as well as fiber optic interconnection between various subgroups. As part of a fiber optic system, various electrically powered modems are interposed in a fiber optic circuit. As shown in Fig. 5A, the modem M is provided with an input cable IN and an output cable OUT, both cables being connected to the modem M by a conventional connector ST. In addition, the modem M is provided with a power supply PWR. According to the invention, a conventional fiber optic connector (FOC) is removably attached or otherwise mounted to or associated with modem M. For example, the optical fiber connector FOC may be mounted to the modem M by parentheses (not shown) or connected to the modem M by a stretchable strap. In the event that the modem M causes an internal fault or a power failure, the modem M can be bypassed by disconnecting the input cable IN and the output cable OUT and connecting these cables together through an optical fiber coupler FOC. This can maintain the physical and optical integrity of the fiber path.

Each ESF system also uses an electromechanical relay as part of the operating system. In general, commercially programmable logic controllers (PLCs), depending on the manufacturer, provide a 24 VDC output or a 12 VDC output to allow current to flow into or disconnect current from the coil of the power switching relay. Often, relays that are optimally suited for a particular power switching function are intended to be supplied by 12 VDC and these relays are often coupled to a 24 VDC PLC. The present invention can be used in a 24 VDC or 12 VDC system to provide a measure of installation flexibility for a 12 VDC relay under circumstances where the relay can be driven by either a 12 VDC or a 24 VDC source. Use a relay configuration mounted on a printed circuit board (PCB). As shown in FIG. 6, a printed circuit board PCB is provided with two relays K1 and K2 and two voltage drop resistors R1 and R2. The relays K1 and K2 have a 12 VDC coil and can also be purchased, for example, from the KiloVac Corporation. {Relay K1} As shown in Fig. 6B, the voltage drop resistor R1 is in series with the coil of the relay K1. The resistance value of this resistance drop resistor R1 is selected so that resistor R1 and coil K1 define a voltage divider capable of providing 12 VDC to coil K1 when the supply voltage is 24 VDC. In this way, a 12 VDC relay can be used with a 24 VDC source. When relay K1 is used with a 12 VDC source, the voltage drop resistor R1 is removed and the wiring jumper JP1 is wired or inserted into the circuit in place of the voltage drop resistor R1. It is done. Similarly, the voltage drop resistor R2 is removed and also the wiring jumper JP2 is wired or inserted into the circuit in place of the voltage drop resistor R2. Replacing jumpers instead of voltage drop resistors is shown in FIG. 6A. As shown in the figure of FIG. 6C, a jumper JP1 causes the 12 VDC coil K1 to be directly connected to the 12 VDC source. The circuit for relay K2 is as described for relay K1. In FIG. 6B, the second resistor (not shown) is shown in dashed lines, which resistor R1 is the operating voltage for the coil of relay K1 provided from the intermediate connection between the two resistors. And can be used to define true voltage dividers.

FIG. 7 shows a simplified test logic system in the form of a block diagram for use in the system so described. The ESFAS initial signal from the DPPS is provided to the input OR gate and transmitted via the logic circuit shown to provide a test of the group I and erase status indicator output as shown at 80. In the preferred embodiment via the Train A MTP 73 of FIG. 5, the DESFAS operation is performed from the DPPS input to the selective two-out-of-four logic shown in FIGS. 4 and 7. The initial logic can be tested. Finally, the test logic system of FIG. 7 is also capable of testing to verify that there is no illogical connection between relay groups.

In the design of power plant protection systems, it is important that the circuits be separated from each other so that the over-voltage situation in one circuit does not affect the operation of the other circuits. In general, the digital power plant protection system disclosed herein uses a programmed logic circuit (PLC) to provide a 24 VDC output that is switched on or off under control of the logic array. Since the PLC is critical for system operation, it is important to isolate the PLC from transient voltage situations. According to the invention, system integrity is ensured by using optocouplers at the output of the PLC and in all other voltage switching situations. As shown in Fig. 8, the optocoupler OC comprises a PN light emitting diode, i.e., a pair of D1 and D2, which are connected in parallel (opposite in the direction of conduction) to the input terminals IN1 and IN2. The DC input voltage applied to the input terminals IN1 and IN2 may cause one of the two diodes to emit light (depending on the polarity of the input voltage). The phototransistor PT has a emitter and a base connected between the output terminals OUT1 and OUT2 and undergoes a change in trans-conductance according to a light emitting function by a diode driven by conduction. As a result, the voltage level applied to the terminals IN1 and IN2 will cause a corresponding change in the transconductance of the phototransistor PT. The input to output electrical isolation provided by a typical optocoupler can be in the range of 3 to 5 kilovolts, so that the isolation provided by the optocoupler can ensure system integrity. In the context of a digital plant protection system that requires all devices that must meet IEEE 1E requirements, the use of optocouplers in this context increases the reliability of the system.

In the case of the DESFAS of the present invention, where multiple outputs from the DPPS are provided as inputs to the DESFAS, it is desired to protect the feedback from one input to the DESFAS so as not to affect the other inputs. 9 illustrates a dual optically isolated coupler with feedback instructions for use with the present invention or other inventions. Specifically, the optocoupler requires the control output to come from either input 1 or input 2, including preventing one input supply from being fed back to the other input. Input DC signals 91 and 92 are provided to steering diodes 93 and 94, respectively, to provide an input to the collection of phototransistors in optical isolator 95. A negative input voltage source is shown at 96 while a positive output voltage is shown at 97 connected to the emitter of the coupled transistor in photoisolator 95. Feedback indicator 98 is coupled with a coupled transistor to provide an indication of feedback.

10A and 10B show the optically isolated selectable type A, B type relay outputs for use with the present invention or other inventions, as indicated by reference numeral 100. Input is provided from the PLC output of the circuit of FIG. 3 to input terminals 101 and 102 that are connected to an optical isolator 103 that couples with a phototransistor pair to operate a relay pair, shown generally at 105. A selectable A or B type contact arrangement is shown in more detail in FIG. 10B, where terminal 106 is a common terminal and terminal 107 provides an output of either NC or NO status.

FIG. 11 is another dual input optically isolated selectable output relay module, generally shown at 110 to provide a user with selectable form A or B contact and form C contact formats with additional wiring. The input from the PLC output of FIG. 3 is provided to the input status LEDs 115 and 116 connected to the input and to the inputs 111 and 112 connected to the steering diodes 113 and 114 to show the presence of a signal. . This steered input is provided to an optocoupler 117 that drives relay 118 to A / B selector switch 119 to provide an output as in FIGS. 9 and 10.

FIG. 12 is another sample of such a dual input, optically isolated output driver having a separate output state, generally shown at 120. Individual optically coupled outputs 121 are provided by optically coupling the relay 122 outputs from the optocoupler 123.

DESFAS and its sub-elements described above provide a digital interface between DPPS and any ESF system in a nuclear power plant. The DESFAS of the present invention continuously monitors the DPPS initial circuit that dominates each ESF system. Thus, the present invention provides an interface between the DPPS and the remote operating device that causes a maintenance operation when the DPPS generates a 'trip' signal. In accordance with the present invention, control is provided to remote equipment elements such as solenoid valves, motorized valves, pumps, fans, and dampers by using operational inputs from the DPSS and manually realized inputs by the operator. DESFAS can be easily integrated with the previously described systems of automatic self test systems and digital plant protection systems, both of which are described in the co-pending application identified above. In addition, the DPSS, automatic self test system and DESFAS of the present invention constitute a complete nuclear power plant reactor protection system. Moreover, the DESFAS system of the present invention can be easily interfaced with other nuclear power plant control element control systems.

For the interface between the DPPS and the ESF system, a high energy initial relay interface is provided to operate the safety related Class 1E circuits required by any signal generated by the DESFAS of the system. Moreover, in order to prevent unwanted feedback between the input signal from the DPPS and the output signal of the DESFAS, various optically isolated couplings are described. One such optical coupling can also be used to disconnect power to equipment associated with Class 1E safety.

Fiber optic connections between various system elements are described. Using these fiber optic connections, both input tests and logic defect tests can be performed to verify DESFAS operability without compromising the integrity of DESFAS monitoring. Individual testing of each subgroup relay is also disclosed. Finally, the test logic system allows the test to verify that there are no illogical connections between groups of relays.

Preferred embodiments of the invention are disclosed. However, it will be apparent to one skilled in the art that certain changes and alternative forms may be made within the description of the invention. Therefore, the appended claims should be examined to determine the true scope and content of this invention.

Claims (55)

In a Digital Engineered Safety Features Actuation System, Including a first plurality of initial signal inputs from a plant protection system, The input is received by a second plurality of logic trains, the train converts the input to a predetermined operational output, the output being used to control the engineered Safety Features system components. A digitally processed safety characteristic operating system provided for a fourth plurality of Component Control Systems. The system of claim 1, wherein the power plant protection system provides a digital initial signal input. 3. The safety characteristic actuation system of claim 2, wherein the digital initial signal input is conditionally set. The system of claim 1, wherein the initial signal input is received from a first plurality of power plant protection system channels. The system of claim 1, wherein said second plurality is two. The system of claim 1, wherein said input is received by first and second logic processors and I / O devices. 7. The system of claim 6, wherein said first and second logic processors and I / O devices provide said actuation output to said element control system. 8. The safety feature of claim 7, wherein the first and second logic processors and I / O devices are further coupled to train maintenance and test panels to monitor the first and second logic processors. Working system. 9. The system of claim 8, wherein the maintenance and test panel is capable of initiating a test of the logic within the first and second logic systems. 2. The system of claim 1, wherein the logic train is comprised of a fifth plurality of logic and I / O groups. 11. The system of claim 10, wherein said logic train is digitally processed consisting of four logic and I / O groups. The system of claim 11, wherein the four groups control a first valve and a damper, a first pump, a second valve and a damper, and a second pump, respectively. 13. The system of claim 12, wherein each group further comprises separate I / O modules and separate programmable logic circuits. 14. The digital processing of claim 13, wherein the programmable logic circuit operates an engineered safety feature relays that are processed on a selective two-out-of-four basis. Safety characteristics operating system. 15. The system of claim 14, wherein each group of programmable logic circuits and I / O modules is further processed digitally, further coupled to train maintenance and test panels to monitor the programmable logic circuits and I / O modules. Safety characteristics operating system. 16. The system of claim 15 wherein the maintenance and test panel is further capable of initiating a test of the logic within each of the programmable logic circuits and I / O modules. 17. The system of claim 16, wherein each group of programmable logic circuits and I / O modules are further coupled to train maintenance and test panels by fiber optic data lines. 18. The system of claim 17 wherein the logic train further comprises a MANUAL ACTUATE input to selectively activate the engineered safety features. 19. The system of claim 18, wherein the logic train further comprises a MANUAL RESET input to reset the logic train after the input is deleted. 2. The digitally processed safety of claim 1, wherein the logic train operates an engineered safety features relays that are processed on a selective two-out-of-four basis. Characteristic operating system. 21. The digital system of claim 20, wherein the logic train further comprises a MANUAL ACTUATE input to activate a safety feature that is selectively processed. 22. The system of claim 21, wherein the logic train further comprises a MANUAL RESET input to reset the logic train after deleting the input. 2. The system of claim 1, wherein the input is optically isolated to prevent input feedback. 24. The digitally operated safety characteristic operating system of claim 23, wherein said feedback protection is achieved using dual input, optically isolated output drivers. 25. The system of claim 24, wherein the optically isolated output driver further comprises a selectable output relay module. 27. The digitally processed safety characteristic operating system of claim 25, wherein the optically isolated output driver further comprises separate optically coupled outputs. The system of claim 1, wherein the processed safety characteristic system is operated using a high energy relay that accepts either a 12 VDC or a 24 VDC operating output. The system of claim 1, wherein the train communicates with the power plant auxiliary system using fiber optic data lines. In the safety characteristic operating system processed digitally, Means for receiving a digital input initial signal with a first plurality of conditions set from the plant protection system; Means for converting the input signal into a second plurality of digital output operational signals; Means for converting said output actuation signal into an engineered safety features system actuation. 30. The digitally processed safety feature of claim 29, wherein said means for receiving a first plurality of conditionally set digital input signals further comprises means for manually providing said conditional digital input initial signal. Working system. 31. The system of claim 30, further comprising means for removing the output actuation signal upon deleting the input initial signal. 32. The system of claim 31 wherein the means for canceling the output actuation signal comprises a MANUAL RESET means. In nuclear power plant reactor protection system, The interface between the plant protection system and the engineered safety features treated at the nuclear power plant comprises a first plurality of cross-linked treatment channels, Each of said channels generating a second plurality of initial signal inputs received by a second plurality of logic trains, each logic train having a third plurality of device control systems for controlling operation of one or more of said processed safety features. Further comprising a Component Control System. 34. The interface between a nuclear power plant protection system and a safety feature treated at a nuclear power plant. 35. The nuclear power plant of claim 34, wherein the logic train activates the engineered safety features upon receipt of a selective two-out-of-four of the initial signal input. Interface between plant protection systems and safety features handled in nuclear power plants. 36. The interface of claim 35, wherein the logic train further comprises a MANUAL ACTUATE input to selectively activate the processed safety characteristic. . 37. The interface of claim 36, wherein the logic train further comprises a MANUAL RESET input to reset the logic train after deleting the input. . 38. The interface of claim 37 wherein the logic train is further coupled to train maintenance and a test panel, respectively, to monitor the device control system. 39. The interface between a nuclear power plant protection system and safety features handled at a nuclear power plant according to claim 38, wherein said maintenance and test panel can initiate testing of said logic within said device control system. 40. The interface between a nuclear power plant protection system and a safety feature treated at a nuclear power plant. 41. The nuclear power plant protection system and nuclear power plant of claim 40, wherein the four element control systems control a first valve and a damper, a first pump, a second valve and a damper, and a second pump, respectively. Interface between the safety characteristics being. 42. The interface between a nuclear power plant protection system and safety features handled at a nuclear power plant according to claim 41, wherein each device control system further comprises individual I / O modules and individual programmable logic circuits. 43. An interface between a nuclear power plant protection system and a safety feature treated at a nuclear power plant according to claim 42, wherein said train communicates with said cross-connected processing channel using fiber optic data lines. 43. The interface between a nuclear power plant protection system and a safety feature treated at a nuclear power plant according to claim 42, wherein the logic train communicates with the maintenance and test panel using fiber optic data lines. 45. The interface of claim 44, wherein the initial signal input is optically isolated to prevent input feedback. 46. The interface between a nuclear power plant protection system and a safety feature treated at a nuclear power plant according to claim 45, wherein said feedback prevention is achieved using dual input optically isolated output drivers. 47. The interface between a nuclear power plant protection system and safety features treated at a nuclear power plant according to claim 46, wherein said optically isolated output driver further comprises a selectable output relay module. 48. The interface of claim 47, wherein the optically isolated output driver further comprises individual optically coupled outputs. 49. The safety system of claim 48 wherein the safety characteristic system to be processed is operated using a high energy relay to accommodate a 12 VDC or 24 VDC operational output and a safety to be processed at a nuclear power plant and a high energy system to accommodate a nuclear power plant protective operational output. Interface between the properties. A method for providing an interface between a nuclear power plant protection system and safety features handled at a nuclear power plant, Receiving a digital input initial signal with a first plurality of conditions set from a plant protection system, Converting the input signal into a second plurality of digital output operational signals; Converting the output actuation signal into a processed safety characteristic system operation. 51. The method of claim 50, further comprising removing the output actuation signal upon deleting the input initial signal. 53. The nuclear power plant protection system of claim 51, wherein the output actuation signal activates the processed safety characteristic upon receipt of a selective two-out-of-four of the initial signal inputs. A method for providing an interface between safety features to be addressed. 53. The method of claim 52, further comprising monitoring the input initial signal and the output operational signal via maintenance and test panels. 54. The method of claim 53, further comprising testing the input initial signal and the output operational signal through the maintenance and test panel. 55. The interface of claim 54, further comprising coupling said maintenance and test panel to said input initial signal and said output operational signal with fiber optic data lines. How to.