Improving the safety and extending the lifetime of VVER-440 nuclear reactors
There are several types of nuclear reactors in operation worldwide. VVER-440 is a specific type of pressurised water reactor found predominantly in Eastern Europe. VVER-440 reactors currently provide electricity in several newly admitted Member States, including the Czech Republic, Hungary and Slovakia. As such, Europe has a vested interest in ensuring the safe operation of these reactors. In response, a project entitled VERSAFE was funded by EURATOM through the Fifth Framework Programme. VERSAFE brought together VVER-440 plant owners and managers from these countries in the framework of a thematic network to examine safety issues. Specifically, Severe Accident Management (SAM) and Plant Life Management (PLIM) were analysed. SAM prescribes preventive measures to avoid incidents as well as control and mitigation actions when an accident occurs. PLIM seeks to maximise economic benefit by extending plant life as much as possible without sacrificing performance or safety. The approach of VERSAFE was twofold. Firstly, it was necessary to define a common set of guidelines for SAM and PLIM that could be implemented by all VVER-440 plant operators. The tangible, usable results of VERSAFE are handbooks of best practices guidelines for SAM and PLIM. Plant-specific information adds another level of valuable detail. Baseline research has also been identified necessary for SAM and PLIM. One important outcome of this effort was the realisation that national research organisations from each country must be involved in order to develop home-grown expertise. A detailed list of proposed research topics was generated through VERSAFE. With respect to SAM, prevention and mitigation areas were covered with a special focus on bubble condenser containment issues. Concurrently, the study of the ageing mechanisms of vital systems, structures and components (SSCs) will enable improved PLIM. The thematic network established will encourage continued communication between the stakeholders in this industry. The end result will be safer, operation of VVER-440 nuclear power plants.