Several recent publications address many advanced SMR design concepts (in most cases still not available for deployment) that are currently being developed in the world [4.1, 4.2]. This report analyses only those reactors that are in advanced stage of development and are designed mainly for electrical production. The followings are therefore not considered in this report:

• purely academic efforts that have not progressed to more advanced design stages;

• design concepts at early design stages announced recently, for which no technical information is currently available;

• design concepts for which development programmes have been stopped, as of 2010;

• design concepts of SMRs intended for the incineration and transmutation of radioactive waste.

Section 4.2 provides the categorisation of advanced SMRs considered in the present report according to the various technologies used and also presents basic characteristics for each of the designs. The technologies are

• pressurised water reactors (PWRs),

• boiling water reactors (BWRs),

• advanced heavy water reactors (AHWRs),

• high temperature gas cooled reactors (HTGRs),

• sodium cooled fast reactors and

• lead-bismuth cooled fast reactors.

Section 4.3 categorises advanced SMRs according to their design status and possible dates of deployment. Section 4.4 provides a categorisation of all SMRs addressed in this report according to the types of energy products.

One of the topical issues is the so-called “mini-reactors” which are, in fact, small modular reactors belonging to various technology lines described in Section 4.2. These “mini-reactors” are analysed in Chapter 5.