Western technology used to monitor safety in Russian plants1 January 1998
Sema Group has developed a Safety Parameter Display System (SPDS) prototype to monitor the safety of VVER-1000 reactors, particularly during abnormal conditions, under Tacis contracts. The prototype has been installed and connected to existing systems at Kalinin 2.
Sema Group was awarded two contracts, within the framework of the Tacis programme (see panel), for this project: one for undertaking a feasibility study and the other for the development of the Safety Panel Prototype (SPP) designed for use on VVER-1000 nuclear power plants in Russia.
The purpose of the SPP project was two-fold:
• To study crisis management in case of incident or accident in a nuclear plant.
• To develop a system enabling local teams as well as national centralised teams to monitor the plant process during such an event, and to provide the information needed for taking the appropriate decisions that prevent injury to individuals and damage to property. This system had to be accessible both at the nuclear power plant and remotely from the National Crisis Centre in Moscow.
A CO-OPERATIVE PROJECT
The SPP project has been set up as a co-operative project made up of the following partners:
• Sema Group, main contractor for the project.
• REA (Rosenergoatom), the Russian nuclear power plant operator, which is the beneficiary of the project.
• A Russian company that is a spin-off from Rosenergoatom and Russian institutes.
• Electricité de France (EDF), France’s national electric utility.
Each partner has brought into the project its own expertise.
EDF, which operates some 58 PWR units, took part in the feasibility study and has participated in the prototype validation.
The Russian partners, with their knowledge of VVER-1000 reactors, have been responsible for Safety Panel configuration and its connection to the existing data acquisition systems.
Sema Group has gained wide experience developing supervision and control systems for large industrial processes, in particular for nuclear power plants, for more than 25 years. The company has installed over 300 systems in more than 60 nuclear power plants, which are used for a wide range of functions, including surveillance of safety conditions, vibration monitoring and diagnosis of plant critical equipment (eg turbo-generators, pumps, internal core structures) and for training simulators, computerised control rooms etc.
A TWO-PHASE PROJECT
The SPP project has been split into two phases to ensure that it meets REA’s needs: a feasibility study and development of a prototype.
The first objective of the feasibility study was to analyse the crisis management scheme established in Russia at both local and national levels in cases of accident at a nuclear power plant.
The second objective was to determine the REA requirements for VVER-1000 nuclear power plants that need to be incorporated into the Safety Parameter Display System. This phase included the study of specific features of VVER-1000 nuclear power plants, the connection of a SPDS to existing plant data acquisition systems, and the means of communication between crisis management staff at the site and national staff in Moscow.
The feasibility study culminated with the development of a mock-up.
This first phase enabled the necessary functions of the SPDS to be fully specified and showed how the advantages of modern technology could be adapted to REA needs; it also provided a useful means for initiating a good co-operative relationship between Sema Group and its Russian partners.
Development of a prototype
Taking in the results of the feasibility study, a Safety Panel Prototype has been developed on the basis of the Sema Group ADACS product. It has been installed at the Kalinin 2 nuclear plant and connected to the plant’s existing data systems for use by the station staff. It has also been linked to a process analytical simulator which can run accident scenarios in order to validate the SPP.
The prototype development phase has now been successfully completed.
SAFETY PANEL FUNCTIONS
The SPP provides the following functions:
• Data acquisition.
• Data processing (acquired and derived values).
• Data logging: event and measurement archive.
• Alarm management.
• Data graphical display (operator stations): mimics, logbooks, alarms, trends.
• Data and mimic display generation.
The system also provides a symptom-oriented diagnosis by evaluating the status of six critical safety functions:
• Reactivity control and sub-criticality.
• Reactor core cooling.
• Heat sink.
• Reactor coolant system integrity.
• Containment integrity.
• Water inventory.
For each of these critical safety functions, the system shows how it has established the diagnosis by means of a diagram on which the diagnosis path is highlighted.
The validity and plausibility of all variables involved in the diagnosis are checked. Moreover the system displays the status of the plant’s main safety devices and the discrepancies (if any) from the predicted states related to the safety actions launched.
SPP TECHNOLOGY PLATFORM
As already noted, the SPP has been developed on the basis of ADACS.
ADACS was developed by Sema Group for the new French 1450 MWe nuclear power plants (at Chooz and Civaux) and benefits from a substantial corporate R&D effort. It gives Sema Group the capability to deliver high level solutions, and meet the very severe requirements of the nuclear industry.
A modular and distributed design
ADACS is a software product composed of a set of elementary distributed modules. Each module carries out a well defined function, and uses a software bus to communicate with other modules. This modular design makes it easy to develop architectures adapted to the performance and capacity of each application (processing throughput, number of I/Os, number of variables etc).
The SPP has taken advantage of the flexibility of the ADACS architecture. The configuration is of moderate size (see diagram below). It has been designed to be easy to extend or modify to meet new requirements. For instance, ADACS contains a built-in high availability feature, by which the system may benefit simply by duplicating architectural components of the prototype without having to change the application code.
An open and customisable design
ADACS provides an open interface to data acquisition devices that has enabled the Russian partner to integrate into the system the required specific protocol suitable for the existing data acquisition system.
Another notable feature of Sema’s ADACS is that it organises process data descriptions on the basis of an object type model. This representation is well adapted to the modelling of physical process entities, such as sensors, actuators, hardware devices etc.
For instance, the “analogue sensor” object type encapsulates within a single entity all data and functions of plant devices of the type “analogue sensor” (which measure, for example, level, flow, pressure, temperature etc).
Examples of data encapsulated by the analogue sensor object type are:
• Sensor value.
• Value validity.
• Alarm gravity level.
• Operational state.
Among functions encapsulated within the analogue sensor object type, we may cite:
• Detection and signalisation of threshold under- or over-stepping.
• Archiving of values in the measurement archive.
• Event archiving in the logbook.
• Alarm processing (acknowledgement, shelving, unshelving).
• Display of technical data sheets (generic formats that may be called up by the operator for displaying sensor technical characteristics).
• Management of operating windows for plant control (not used in the SPDS).
• Mimic display (analogue sensor objects may be represented on screen by graphical objects of different types, eg textual form, bargraph or curve).
This object type model ensures that the operator has a clear and well controlled representation that can easily evolve with his process. Moreover, the properties associated with the object concept allow gains in efficiency in the application creation process as well as in the operation and evolution phases throughout the system’s life time.
The SPP project has taken advantage of this ADACS characteristic. Several object types well adapted to the VVER-1000 context have been developed by Sema Group for the purpose of the SPP project; for instance, an object type “redundant analogue sensor” has been added to the system that encapsulates specific redundancy processing performed on the analogue sensors. This enables the SPP application to handle better quality data in a transparent way and thus provide the operator with higher quality information.
This custom-made data representation has enabled the Russian partner to appropriate for himself the product in a very efficient way and consequently to feed the prototype with clean and easy-to-manage plant engineering data.
Early involvement of the Russian partners in the project as well as the complementary skills of the project partners have been important elements in the success of the SPP project. Equally important was Sema Group’s ability to deliver an open product which formed the foundation for a shared development and the excellent co-operation achieved with its Russian partners. Our experience in setting up organisations and developing the methods needed to reach the high level of quality required, while keeping to the project schedule, has also played a key part in its success.
|Tacis – EU’s investment in the newly independent states|
|The Tacis Programme is a European Union initiative to foster the development of economic and political links with the New Independent States and Mongolia as they evolve following the breakup of the Soviet Union. Its aim is to support the partner countries’ own initiatives to develop societies based on political freedom and economic prosperity. Tacis does this mainly by making available substantial grant finance for Western know-how to be used in support of the process of transformation of these countries to market economies and democratic societies. The main priorities for Tacis funding are public administration reform, restructuring of state enterprises and private sector development, transport and telecommunications infrastructures, energy, nuclear safety and environment, building an effective food production, processing and distribution system, developing social services and education. Each country then chooses the priority sectors depending on its needs. In its first six years of operation, 1991-1996, Tacis has committed ECU 2.807 billion to launch more than 2500 projects. About 20% of this fund has been devoted to nuclear safety.|