15.1. INTRODUCTION/OBJECTIVES

In connection with design optimisation, comprehensive experimental and theoretical programmes for component and integral design, testing and certification are carried out by vendors. In addition, safety-related projects are performed by major research institutes within various national and international programmes. Many data available for present generation plants are still applicable to evolutionary and advanced future reactors. However, additional data are required for certain physical processes which occupy increased significance in advanced passive systems, e. g. natural circulation, condensation and non-condensable gas-related phenomena. Relevant experimental research for both current and future reactor systems is summarised for some of the major designs under review in this book. In regard to international activities, particular reference is made to the extensive EC research programmes (FISA 2001, 2001; FISA 2003, to be published). The focus in this chapter will be on experimental programmes; theoretical work is covered in the next chapter.

The majority of research to date has been in support of the present generation and evolutionary plant. Many present day plants are coming up towards the end of their original design lives and with the dearth in new build there are strong incentives to consider extension of life. This has, therefore emerged as a key area of research. Severe accident research is being used to develop severe accident plans and support Level 2 PSAs; hence severe accident research is also prominent. Research specific to evolutionary passive designs includes work on natural convection cooling, with and without the presence of water. Many of the evolutionary designs also include improved provision against severe accident loads; research is carried out on passive heat removal from melts within the reactor cavity.

Significant areas of research to support the present generation programme include safety at all stages of the fuel cycle, reactor safety during plant operation, radioactive waste management, radiological protection, and other activities to benefit from ‘lessons learned’ in the past. There are active work programmes in all these areas; for example within the European Union there have been numerous activities funded by the EC Euratom Programme and corresponding counterpart national programmes.

In addition to research projects per se, there are a number of joint and other collaborative projects being co-ordinated under the auspices of the NEA, which primarily collect, make data available and perform analysis on the data. Some of these projects are of a general nature, e. g. the International Common-cause Data Exchange (ICDE) project

collects operating data related to common-cause failures. The Fire Project collects data related to fire events in nuclear environments and the OECD Piping Failure Data Exchange (OPDE) project collects and analyses pipe failure event data. More information is given in NEA Annual Report (2002).

There are a number of technical issues that will need to be addressed in regard to the innovative reactor systems that are envisaged for the future, e. g. the Generation IV concepts. These are covered briefly at the end of this chapter. Many of the concepts will require significant research effort. For some systems, R&D activities are already underway, e. g. in regard to the supercritical and high-temperature gas systems that are expected to be among the first Generation IV systems to become available.

In the first part of this chapter, research primarily relevant to current generation plant is considered.