1. System Destination

1.1 The integrated diagnostic system is included in the monitoring, control and diagnostic system (MCDS) of WWER-1200 reactor system of Novovoronezh NPP-2 Unit 1 and provides in the mode of normal operating conditions:

• automatic reception of data from the leak monitoring system and ULCS, and periodic automated reception of archived data from LPMS and VMS;
• archiving of diagnostic data received from VMS, LPMS, ULCS and saving data on the external non-volatile data medium;
• comprehensive assessment of equipment integrity based on the data from leak monitoring system, I&C process and radiation monitoring systems (monitoring of pressurization of reactor system equipment detachable connections, temperature and humidity in the bays, controlled leakage volume in the sumps, etc.) in order to localize the leak and specify the leak rate and generate alarm signals about the detected malfunctions in the ULCS equipment for them to be displayed in MCR;
• output of more specific information (leak place and rate) and alarms of the detected malfunctions in the monitored equipment on the basis of the integrated analysis results and generalized data about ULCS inherent malfunctions for them to be displayed in MCR;
• display of data from the systems included in MCDS and power unit process parameters (in the appropriate cases) on the integrated diagnostic system monitor as tables, graphs and protocols;
• an opportunity to interact with the hardware of VMS, LPMS, humidity leak monitoring system, acoustic leak monitoring system.

1.2 The item to be monitored is the reactor system of WWER-1200 reactor, including MCC, emergency core cooling system passive part, pressurizer system.

1.3 The functions of the integrated diagnostic system are subdivided into informational and auxiliary.

1.3.1 The informational functions include:

• Automated data reception from the leak monitoring system and ULCS and periodic automated reception of archived data from VMS and LPMS;
• Archiving of diagnostic data received from VMS, LPMS, ULCS and saving data on the external non-volatile data medium;
• Comprehensive assessment of equipment integrity based on the data from the leak monitoring system, I&C process and radiation monitoring systems (monitoring of pressurization of reactor system equipment detachable connections, temperature and humidity in the bays, controlled leakage volume in the sumps etc.) in order to localize the leak and specify the leak rate and generate alarms about the detected malfunctions in the ULCS equipment for them to be displayed in MCR;
• Comprehensive assessment of equipment integrity based on the data arriving from three secondary circuit coolant leak detection systems , in order to localize the leak and specify the leak rate in the secondary circuit with the accuracy ± 2m, and output of a leak alarm;
• Integrated reactor noise diagnostics based on the data from VMS and in-core noise diagnostics computer;
• Output of more specific data (leak place and rate) as well as an alarm of the detected malfunctions of the monitored equipment based on the integrated analysis results and generalized data of ULCS inherent malfunctions for them to be displayed in MCR;
• Display of data from the systems included in MCDS and of the power unit process parameters (in the appropriate cases) on the integrated diagnostic system monitor as tables, graphs and protocols;
• Interaction with the software-hardware suite of VMS, LPMS, humidity leak monitoring system, acoustic leak monitoring system with the help of remote desktop standard control means (provided by the operating system) with the delimitation of user access privileges.

The auxiliary functions include:

• protection from unauthorized access using the priority system to access the software functions;
• user work accounting;
• maintenance of common time with ULCS;
• diagnostics of own software-hardware suite;
• organization of data exchange with interfacing systems (ULCS, VMS, LPMS, leak monitoring system).

1.3.2 The function of data reception

Integrated diagnostic system ensures data reception from the leak monitoring system, ULCS, VMS and LPMS. The following modes of data reception form MCDS and ULCS subsystems are adopted for the integrated diagnostic system:

• from the leak monitoring system – signal reception with the periodicity of at most 1 sec.;
• from ULCS - signal reception with the periodicity of at most 1 sec;
• from VMS, LPMS – reception of archives in the manual mode (periodicity is not specified).

A malfunction of a data source or of a data transmission channel does not affect data reception at the inputs (interfaces) from other data sources. When a data source malfunction or an error of communication with the data source is detected, a correspondent alarm is triggered in the main format of the integrated diagnostic system.

1.3.3 The function of diagnostic data archiving

The data received from VMS, LPMS, ULCS, are periodically archived in the integrated diagnostic system computer (and, upon the operator’s request, on the external non-volatile medium) to be exposed to subsequent postponed analysis.

1.3.4 The function of comprehensive assessment of the RS equipment integrity

The integrated diagnostic system ensures periodic calculation of updated values providing information about the leak coordinates and rate based on the leak monitoring system readings and on the data received from the process and radiation monitoring systems of I&C over LAN from ULCS.

The integrated diagnostic system ensures periodic calculation of updated values providing information about the secondary loop integrity based on the readings of the secondary circuit coolant leak detection system.

The summary of the data arriving from the integrated diagnostic system, I&C process and radiation monitoring systems is displayed in the special format of the console of integrated diagnostic system (workstation RM-02R) with the update rate of at least once per second.

The information containing the results of the comprehensive assessment of the RS primary and secondary loop integrity is updated once per second. The current status of the variables for the comprehensive assessment of the primary and secondary loop integrity can be checked in the mimic included in the application software.

1.3.5 The functions of the data transmission

The data about the anomalies detected by the integrated diagnostic system are transmitted automatically to ULCS at least once per second. The integrated diagnostic system ensures the transmission of the summarized information about malfunctions of its own software-hardware suite into ULCS.

The summarized diagnostic data are transmitted as codes: 0 – normal value; 1 – anomaly.

The information about the status of its own software-hardware suite is transmitted as codes: 0 – normal value; 1 – a malfunction or opened doors of the hardware cabinet.

1.3.6 The function of the data representation

The information about the anomalies detected by the integrated diagnostic system is automatically displayed to the operator on the workstation RM-02R monitor on an ongoing-basis and is recorded in the appropriate log. The information about the software and hardware of the integrated diagnostic system is also automatically displayed on the monitor.

The integrated diagnostic system ensures the representation of data (upon the personnel’s request) received from the interfacing systems included in MCDS and from ULCS.

Crucial data are highlighted in color or by way of flashing on and off or in some other way complying with the conventional requirements of NPP operating personnel.

The following ways of data representation are envisaged in the integrated diagnostic system:

• mimic formats;
• graphs of variable-time dependence;
• tables;
• formats of signals.

1.3.7 The function of interaction with the software-hardware suite of interfacing systems

The integrated diagnostic system has remote access to the software-hardware suite of the leak monitoring system, VMS, LPMS. The function is based on the standard means of remote desktop control with the delimitation of user access privileges.

1.3.8 The function of diagnostics of own software and hardware

The function ensures:

• diagnostics of network tools condition;
• diagnostics of data reception/transmission;
• equipment monitoring (temperature, cabinet door opening/closing).

The cabinet is supplied with a monitoring device that is equipped with a failure indication light.

The information of software-hardware suite operability is transmitted into ULCS automatically in case of failures.

1.3.9 The function of maintenance of common time

The data support and software of the integrated diagnostic system are operated in the common-timing system. To ensure synchronization, clock signals from ULCS are used. The error of reference to the common time with ULCS is ± 5 msec. The accuracy of assigning time mark at the supply of output data is at most 1 sec.

1.3.10 The function of data access control

The function ensures the control of access of any integrated diagnostic system user to the integrated diagnostic system software. The user work at the workstation RM-02R begins after the authentication data are entered (name and password). The user access to the authorized functions is based these data.

The integrated diagnostic system ensures the control of access to functions. The OS tools enable the capability of user access rights monitoring and control.

1.4 The normal operation of the integrated diagnostic system is made possible if the following conditions are observed:

• smooth functioning of the hardware;
• smooth functioning of the communication links;
• stable protection from the impact of external factors;
• adherence to the operating conditions specified in the technical documentation.

The integrated diagnostic system belongs to safety-related systems of normal operation.

The integrated diagnostic system computer (UV-03R) belongs to safety class 3 (classified designation ZN) according to Nuclear Power Engineering Norms and Standards PNAEG-01-011-97 (General Safety Regulations OPB 88/97) and quality category KZ according to Norms and Rules NP-026-04.

The integrated diagnostic system console (workstation RM-02R) belongs to safety class 3 (classified designation ZN) according to Nuclear Power Engineering Norms and Standards PNAEG-01-011-97 (General Safety Regulations 88/97) and quality category KZ according to Norms and Rules NP-026-04.

1.5 The integrated diagnostic system complies with the requirements of Norms and Rules NP-071-06 «Rules of Compliance Assessment of Equipment, Materials and Semi-Finished Products Supplied to Nuclear Facilities».

2. System Description

2.1 System structure and destination of its constituent parts

The integrated diagnostic system is an automated system not equipped with measuring and indicator channels of its own. The integrated diagnostic system includes:

• computer UV-03R – ensures data reception from ULCS and MCDS subsystems, input data registration, storage, processing and transmission of output data into ULCS;
• console (workstation RM-02R) ensures data input and display;
• cable communication links with MCDS and ULCS LANs (not included in the integrated diagnostic system delivery set).

Basic Technical Characteristics are given in Table 2.1.

The electrical diagram of the integrated diagnostic system is given in Figure 2.1.

Figure 2.1 – Electrical Diagram of the Integrated Diagnostic System

The hardware and software of the integrated diagnostic system are located in the normal operation premises (area 2.2) according to GOST 29075-91.

The level of industrial interference emitted by the hardware components during work as well as at startup/shutdown shall comply with GOST R 51318.22-2006.

The lighting of the room that accommodates the hardware of the integrated diagnostic system shall be fluorescent. The lighting shall comply with the requirements of the Construction Rules and Regulations SNiP 23-05-95 and Sanitary Regulations and Norms 2.2.2/2.4.1340-03. The lighting intensity shall be at least 200 lx. The lighting intensity of the integrated diagnostic system console (RM-02R) keyboard shall be 300 to 500 lx.

2.2 The description of the operating principles of the primary circuit integrity integrated analysis

2.2.1 The basic parameters monitored by the integrated diagnostic system are the readings of the leak monitoring systems (acoustic and humidity) and process parameters of the reactor system (radiation monitoring system readings).

2.2.2 Acoustic leak monitoring system, humidity leak monitoring system and radiation monitoring system are three independent channels of integrated analysis. Based on the principles of "leak before break" concept, the application software of the integrated diagnostic system performs simultaneous analysis of these parameters and their time derivatives.

2.2.3 For each pipeline section monitored by the acoustic and humidity leak monitoring systems, pairs of parameters are supplied to the input of the integrated system, organized as (X,G), where X is the coordinate and G is the flow rate.

The parameter pair (X,G) = (-1,-1) corresponds to the diagnosis "No leak", the parameter pair (X,G) = (0,0) corresponds to the diagnosis "Probability of leak". The parameter pair (X,G) at X > 0 and G > 0 corresponds to the diagnosis "Available leak", with leak coordinates and rate being transmitted.

For radiation monitoring system signals, the calculation of the time derivative and comparison with the threshold value are made.

2.2.4 In order to obtain an integrated diagnosis, Boolean summation of signals from three sources is performed based on the principle "2 out of 3". As a result of the summation for each pipeline section monitored by acoustic and humidity leak monitoring systems, diagnostic data are generated organized as (X,G).

In this case, if the acoustic and humidity leak monitoring system have been actuated, the leak rate on the basis of the integrated analysis results is assumed to be equal to the highest value out of the two systems’ readings and the leak coordinate is assumed to be an average value out of the two systems’ readings.

In case the radiation monitoring system or one of the leak monitoring systems (either acoustic or humidity leak monitoring system) have been actuated, the leak rate and coordinate on the basis of the integrated analysis results are assumed to be equal to those received from acoustic or humidity leak monitoring system.

2.2.5 Diagnostic messages are generated on the basis of the integrated analysis results to be displayed on the monitor of RM-02R. In addition to the diagnostic messages, generalized information about the condition of the equipment monitored is displayed on the RM-02R indicators. The indicator update rate is 2 sec.

The following indicator color legends are adopted:

• green – normal condition;
• orange – probability of leak, leak rate is not specified;
• red – available leak.

Besides, on the basis of the integrated analysis results, the integrated diagnostic system generates a leak alarm and more detailed information about the leak rate and coordinate to be transmitted later on into ULCS.

2.2.6 The application software of the integrated diagnostic system saves an archive of diagnostic messages on the hard drive of UV-03R as text messages to be analyzed later on. Not only a truly detected leak but a probable leak as well is regarded as an anomaly (due to the impossibility to interpret the input data unambiguously), that is why the diagnosis contains categories coded according to 1.1.5.

Diagnostic messages can be accessed in the integrated diagnostic system in two ways. The first way is to view current messages from the integrated diagnostic system console.

The list of the latest diagnostic messages is displayed in the lower part of the screen; each of them is highlighted in the following colors:

• green – normal condition;
• orange – probability of leak, leak rate is not specified;
• red – available leak, leak rate is specified.

The second way is to view the diagnostic messages is to use the menu item "Archive – Diagnostic messages" which will display on screen the window of diagnoses.

2.2.7 In addition to the automatic analysis of readings of acoustic and humidity leak monitoring systems, radiation monitoring systems, the user of the integrated diagnostic system has access to viewing graphs of any input parameters, received from ULCS (with the help of graphic viewing means).

2.2.8 The diagnostic data in the integrated diagnostic system are subdivided into several levels as to the detailed elaboration and hierarchy of data representation:

• A diagnostic message is a short message stating that the leak is available specifying the flow and coordinate of the probable leak.
• A report is the representation of a certain subset of diagnostic messages as texts, graphs and tables grouped to represent the detected anomalies in the primary circuit integrity. Reports incorporate 5-10 sheets of data. The application software of the integrated diagnostic system enables well-structured storage, viewing and comparison of various reports.

2.2.9 The integrated analysis procedure of the primary circuit integrity is automated and does not require operator’s actions.

2.2.10 The integrated analysis procedure of the secondary circuit integrity on the basis of the readings of the secondary circuit leak detection systems functions similarly.