TACIS Design Safety projects were service or consultancy type projects that were able to address research, design and engineering issues. They were usually implemented in such a way that an EU research, design or engineering organisation worked in close collaboration with Beneficiary country counterpart organisations on a specific technical problem.
The design safety projects therefore achieved a dual purpose of providing the necessary technical resources to solve the issue of concern whilst at the same time transferring know-how and developing capabilities within the Beneficiary country organisations wherever a lack had been identified. This dual purpose also helped to provide the sustainability of the project benefits that was a major objective of the Tacis programme.
The original design of WWER reactors did not include a diagnostic system in order to monitor the potential danger to the integrity of reactor coolant system (RCS) and to provide an early warning of RCS pressure boundary developing defects.
The IAEA issue book (WWER-EBP-03) indentifies a safety issue "Instrumentation and Control 07" which is related to Primary Circuit Diagnostic systems. Without such a diagnostic system the operators had very limited possibilities to recognize e.g. the presence of loose parts in RCS components and of the potential danger of local overheat in the reactor core or of loss of integrity of the RCS pressure boundary.
Owing to above finding, the IAEA recommended installation of diagnostic systems at WWER nuclear plants in order to make it possible to recognize, at an early stage, the anomalies in the operation which could lead later to serious accidents.
In response, the European Commission launched several projects that dealt with an assessment of the original ISI approach used at Soviet designed NPP against EU practices as well as providing recommendations on improvements in ISI methodologies and NDT techniques used for inspection of the reactor coolant system components.
The Project R2.02/97 consisted of two parts; Part A aimed at establishing a normative basis for diagnostic system of VVER rector coolant system components in accordance with EU requirements, and Part B aimed at elaborating Technical Specifications to procure several maintenance tools for VVER reactor coolant system components.
A project ToR required the Consultant to achieve two results, i.e. development of (i) normative basis for diagnostic systems, including design requirements, installation, commissioning, routine use and interactions with the I&C, (ii) normative basis for the collaborative operation of diagnostic systems, and the share of responsibilities between all involved organizations in Russian Federation, and elaboration of the procurement Technical Specifications for purchasing specific maintenance tools.
The service contract was implemented by the EC Consultant Electricité de France (EdF); Rosenergoatom (the utility operating all Russian NPP) was the Beneficiary, and DIAPROM was the local subcontractor, who provided technical and administrative support, and knowledge of Russian regulatory practices.
Project Part A involved several activities that finally resulted in drafting normative basis; these were (i) identification of current normative and regulatory requirements, for design, implementation and operation of diagnostic systems at Russian NPPs, (ii) personnel training including scientific visits at several EDF centers and Divisions (including Chinon NPP), (iii) with the help of local subcontractor drafting general operating conditions and procedures for the diagnostics systems, and (iv) drafting requirements for a national diagnostic center to be established in Rosenergoatom.
A set of documents were elaborated with the aim to help establishing a common diagnostic centre at Rosenergoatom, the role of which would be diagnostic data collection from NPP, and data analysis that would allow for assessing the component health status as well as predicting component deterioration and thus preventing component failure during the plant operation.
The following documents were elaborated:
- Identification of normative requirements,
- Definition of technical and conceptual terms,
- Regulatory documents organization and hierarchy,
- General operating conditions of the diagnostic systems,
- General procedures for processing and analysis of data,
- Operating conditions for National diagnostic Centre,
- Procedures for the treatment of abnormal situations,
- Data treatment procedures at the National diagnostic centre,
- Requirements for communication links.
The EC Consultant organized seminars for Russian experts in France, which was part of the transfer of EU know-how to the Russian specialists. These seminars involved the following facilities and topics:
- Research and development centre in Chatou, Paris; EDF specialists and engineers in monitoring systems presented several monitoring systems in use at French NPP.
- Chinon NPP where the experts visited the unit diagnostics equipment and discussed the corresponding alarm procedures,
- Centre of Diagnostic Operation EDF in Grenoble, data acquisition from the NPP, data analysis and corresponding procedures,
- La Perolliere Center near Lyon for training EDF specialists, and training courses on diagnostics tools for the plant personnel.
During the project implementation, it was observed that a process of diagnostic information collection, exchange and decision making was carried out at each individual plant. The EC Consultant, based on EU experience, helped Rosenergoatom to elaborate requirements for innovative solutions i.e., establishment of a Brach Diagnostic Centre that would collect and evaluate diagnostic information received from the individual NPPs. Besides that the EC Consultant presented the European project PROTEUS (generic platform for e-monitoring) which is directly related to several types of monitoring systems and designed by many different manufacturers. The EC Consultant also elaborated a concept of the National diagnostic centre in Russia. This concept involved several diagnostic systems allowing for monitoring the following NPP parameters:
- vibration of the equipment and pipelines of the primary circuit, including the Reactor pressure internals and fuel assemblies,
- vibration of Reactor Coolant Pumps and Turbine generator,
- acoustic fields, humidity and radioactive nuclides for coolant leakage detection,
- vessel noise for loose parts detection,
- local temperature and expansion stresses in the equipment and pipelines of the primary circuit,
- electrical parameters of the electrically driven valves
Lessons learned from the Project Part A as well as a concept for the national diagnostic centre in Russian Federation were further elaborated in TACIS project R2.01/05 Establishment of a Branch diagnostics system in Concern "Rosenergoatom".
Project Part B aimed to help the Rosenergoatom in addressing safety issues related to the maintenance and operation of VVER-1000 nuclear power plants. As a part of the whole project, the procurement of maintenance tools was aimed to improve maintenance quality, in order to:
- Reduce number and severity of observed issues related to integrity of the primary loop;
- Reduce radioactive doses endured by workers during maintenance operations,
- Allow higher load rate of VVER 1000 NPPs.
The subject of the contract was the design, manufacturing, factory testing, certification, delivery, supervision of commissioning, supervision of on site functional testing, assistance during first maintenance, assistance during warranty of the following goods:
- Maintenance tools for cutting and bevelling pipes;
- Maintenance tools for bolts tightening of Main Circuit pumps;
- Maintenance tools for grinding and lapping of isolation and safety valves;
- Maintenance tools for surfacing of flanges and grooves machining of steam generator collector and cutting sealing surfaces of Main Circuit pumps.
Corresponding Technical Specifications were elaborated and accepted for tendering at the beginning of May 2005.
A supply of maintenance tools was formally included in the TACIS project R2.03/03 Part B, which was tendered in November 2005 (see contracts 76777, 115574 and 114514).