Small and medium sized reactors SMRs

According to the classification currently in use in the IAEA, small reactors are reactors with the equivalent electric power less than 300 MW, medium sized reactors are reactors with the equivalent electric power between 300 and 700 MW [7, 14]. 

Innovative design is a design that incorporates radical conceptual changes in design approaches or system configuration in comparison with existing practice and would, therefore, require substantial R D, feasibility tests and a prototype or demonstration plant to be implemented . 

According to the definition given in [1], small reactors without on-site refuelling are the reactors designed for infrequent replacement of well-contained fuel cassette(s) in a manner that prohibits clandestine diversion of nuclear fuel material. 

Small reactors without on-site refuelling should have the following essential features [1]  

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A development of small and medium sized reactors (SMRs) is supported by the following major arguments ... 

The Russian Research Centre Kurchatov Institute (RRC KI) develops a project of innovative nuclear energy system with small and medium sized reactors (SMRs). NPPs with SMRs have a number of attractive features, including simplified operation, control and management, high levels of safety and reliability, options for effective management and insurance of risks, flexible design and applications. 

At the time when this report was prepared (in 2005), 146 small and medium sized reactors (SMRs) were operated worldwide, accounting for 61 GW(e) of electricity generation, and 12 more were under construction. These were mostly earlier generation reactors still in operation and a few prototype or tests reactors, intended to support development and deployment of new larger-capacity commercial plants. Their share in worldwide nuclear electricity production was around 16.5%. 

Rowinski, M.K., White, T.J., Zhao, J., 2015. Small and medium sized reactors (SMR), a review of technology. Renewable and Sustainable Energy Reviews 44, 643—656. 

Small and medium size reactor development has many incentives some are economic others are safety related. The motivation for these developments has included the need to enhance public acceptance of nuclear power. The simplification of designs should improve the transparency of their reactor safety. Another incentive to SMR development has been its suitability for the implementation of new design approaches. Innovative and evolutionary designs with novel feamres have been implemented in the SMR range. A passive safety approach has so far been the technology of small and medium reactors. SMRs have particular characteristics which can enable them to be economically viable in spite of losing the advantage of the economics of scale. 

Small and medium size reactor design and development is a very active area. The design work has made maximum use of simplification, modularization and prefabrication. No SMR design has not tried to make use of natural forces. The SMR range has been the main vehicle for innovative designs. 

International Atomic Energy Agency, 2010, Nuclear Power Technology Development Common Technologies and Issues for Small and Medium Sized Reactors, IAEA, http //www.iaea.org/ NuclearPower/SMR/ (current as of September 22,2010). 

To support the preparation of this and the previous report [2], an IAEA technical meeting Innovative small and medium sized reactors design features, safety approaches and R D trends was held on 7-11 June 2004 in Vienna, and its final report was published as IAEA-TECDOC-1451 in May 2005 [1]. That TECDOC presented a variety of innovative water cooled, gas cooled, liquid metal cooled and non-conventional SMR designs developed worldwide and examined the technology and infrastructure development needs that are common to several concepts or lines of such reactors. It also introduced the definition of small reactors without on-site refuelling, which is referred to in this report. Both, the technical meeting and the report [1] provided recommendations on the objectives, structure, scope and content of this report and the report [2]. 

Upon the advice and with the support of its Member States, the IAEA provides a forum for the exchange of information by experts and policy makers from industrialized and developing countries on the technical, economic, environmental, and infrastructure aspects of the SMR development and deployment in the century [1,2]. On 7-11 June 2004 the IAEA convened a Technical Meeting on Innovative Small and Medium Sized Reactors Design Features, Safety Approaches and R D Trends, which had the following main objectives ... 

Small and medium reactor systems provide an attractive option for a wide range of applications worldwide. The design approach and design characteristics of the SMRs with regard to size, economics and safety appear to provide favourable conditions. Specific requirements on these topics will provide a common ground for the suppliers and interested users to further the discussion on specific design requirements such as performance, operability, maintainability, reliability. For successful deployment, overall cost must be competitive with other alternatives, taken into consideration the main objectives. 

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